WorldWideScience

Sample records for parkway north nearby

  1. 78 FR 32442 - Record of Decision for the General Management Plan, Blue Ridge Parkway, Virginia and North Carolina

    Science.gov (United States)

    2013-05-30

    ... constraints with the traditional parkway concept developed from 1935 to 1955. As a result, the selected action... economy, while enhancing parkway visitor services. The selected action will provide a comprehensive...

  2. Rock slope stability analysis along the North Carolina section of the Blue Ridge Parkway: Using a geographic information system (GIS) to integrate site data and digital geologic maps

    Science.gov (United States)

    Latham, R.S.; Wooten, R.M.; Cattanach, B.L.; Merschat, C.E.; Bozdog, G.N.

    2009-01-01

    In 2008, the North Carolina Geological Survey (NCGS) completed a five-year geologic and geohazards inventory of the 406-km long North Carolina segment of the Blue Ridge Parkway (BRP). The ArcGIS??? format deliverables for rock slopes include a slope movement and slope movement deposit database and maps and site-specific rock slope stability assessments at 158 locations. Database entries for known and potential rock slope failures include: location data, failure modes and dimensions, activity dates and levels, structural and lithologic data, the occurrence of sulfide minerals and acid-producing potential test results. Rock slope stability assessments include photographs of the rock cuts and show locations and orientations of rock data, seepage zones, and kinematic stability analyses. Assigned preliminary geologic hazard ratings of low, moderate and high indicate the generalized relative probability of rock fall and/or rock slide activity at a given location. Statistics compiled based on the database indicate some general patterns within the data. This information provides the National Park Service with tools that can aid in emergency preparedness, and in budgeting mitigation, maintenance and repair measures. Copyright 2009 ARMA, American Rock Mechanics Association.

  3. Geology along the Blue Ridge Parkway in Virginia

    Science.gov (United States)

    Carter, Mark W.; Southworth, C. Scott; Tollo, Richard P.; Merschat, Arthur J.; Wagner, Sara; Lazor, Ava; Aleinikoff, John N.

    2017-01-01

    Back Formations. These rocks are bound by numerous faults, including the Rock Castle Creek fault that separates Ashe Formation rocks from Alligator Back Formation rocks in the core of the Ararat River synclinorium. The lack of unequivocal paleontologic or geochronologic ages for any of these rock sequences, combined with fundamental and conflicting differences in tectonogenetic models, compound the problem of regional correlation with Blue Ridge cover rocks to the north.The geologic transition from the central to southern Appalachians is also marked by a profound change in landscape and surficial deposits. In central Virginia, the Blue Ridge consists of narrow ridges that are held up by resistant but contrasting basement and cover lithologies. These ridges have shed eroded material from their crests to the base of the mountain fronts in the form of talus slopes, debris flows, and alluvial-colluvial fans for perhaps 10 m.y. South of Roanoke, however, ridges transition into a broad hilly plateau, flanked on the east by the Blue Ridge escarpment and the eastern Continental Divide. Here, deposits of rounded pebbles, cobbles, and boulders preserve remnants of ancestral west-flowing drainage systems.Both bedrock and surficial geologic processes provide an array of economic deposits along the length of the Blue Ridge Parkway corridor in Virginia, including base and precious metals and industrial minerals. However, common stone was the most important commodity for creating the Blue Ridge Parkway, which yielded building stone for overlooks and tunnels, or crushed stone for road base and pavement.

  4. Antibiotic residues in liquid manure from swine feedlot and their effects on nearby groundwater in regions of North China.

    Science.gov (United States)

    Li, Xiaohua; Liu, Chong; Chen, Yongxing; Huang, Hongkun; Ren, Tianzhi

    2018-04-01

    A survey was conducted in regions of North China to better understand the effect of antibiotic residue pollution from swine feedlots to nearby groundwater environment. A total of nine experimental sites located in the regions of Beijing, Hebei, and Tianjin were selected to analyze the presence of residues of 11 most commonly used antibiotics, including tetracyclines (TCs), fluoroquinolones (FQNs), sulfonamides (SAs), macrolides, and fenicols, by using liquid chromatography spectrometry. The three most common antibiotics were TCs, FQNs, and SAs, with mean concentrations of 416.4, 228.8, and 442.4 μg L -1 in wastewater samples; 19.9, 11.8, and 0.3 μg L -1 in groundwater samples from swine feedlots; and 29.7, 14.0, and 0 μg L -1 in groundwater samples from villages. Ordination analysis revealed that the composition and distribution of antibiotics and antibiotic resistance genes (AGRs) were similar in groundwater samples from swine feedlots and villages. FQNs and TCs occurred along the path from wastewater to groundwater at high concentrations and showed correlations with ARGs, with a strong correlation between FQN resistance gene (qnrA) copy number. FQN concentration was also found (P swine feedlots through wastewater could disseminate into surrounding groundwater environments together with ARG occurrence (i.e., qnrA, sulI, sulII, tetG, tetM, and tetO). Overall, this study suggests that the spread of veterinary antibiotics from swine feedlots to groundwater environments should be highly attended and controlled by restricting excess antibiotic usage or improving the technology of manure management.

  5. Foothills Parkway Section 8B Final Environmental Report, Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Blasing, T.J.; Cada, G.F.; Carer, M.; Chin, S.M.; Dickerman, J.A.; Etnier, D.A.; Gibson, R.; Harvey, M.; Hatcher, B.; Lietzske, D.; Mann, L.K.; Mulholland, P.J.; Petrich, C.H.; Pounds, L.; Ranney, J.; Reed, R.M.; Ryan, P.F.; Schweitzer, M.; Smith, D.; Thomason, P.; Wade, M.C.

    1999-07-01

    In 1994, Oak Ridge National Laboratory (ORNL) was tasked by the National Park Service (NPS) to prepare an Environmental Report (ER) for Section 8B of the Foothills Parkway in the Great Smoky Mountains National Park (GSMNP). Section 8B represents 27.7 km (14.2 miles) of a total of 115 km (72 miles) of the planned Foothills Parkway and would connect the Cosby community on the east to the incorporated town of Pittman Center to the west.

  6. The MEarth-North and MEarth-South Transit Surveys: Searching for Habitable Super-Earth Exoplanets Around Nearby M-dwarfs

    Science.gov (United States)

    Irwin, Jonathan M.; Berta-Thompson, Zachory K.; Charbonneau, David; Dittmann, Jason; Falco, Emilio E.; Newton, Elisabeth R.; Nutzman, Philip

    2015-01-01

    Detection and characterization of potentially habitable Earth-size extrasolar planets is one of the major goals of contemporary astronomy. By applying the transit method to very low-mass M-dwarfs , it is possible to find these planets from the ground with present-day instrumentation and observational techniques. The MEarth project is one such survey with stations in both hemispheres: MEarth-North at the Fred Lawrence Whipple Observatory, Mount Hopkins, Arizona, and MEarth-South at Cerro Tololo Inter-American Observatory, Chile. We present an update on recent results of this survey, for planet occurrence rates, and interesting stellar astrophysics, for which our sample of 3000 nearby mid-to-late M-dwarfs has been very fruitful. All light curves gathered during the survey are made publicly available after one year, and we describe how to access and use these data.

  7. 76 FR 35909 - Temporary Concession Contract for Blue Ridge Parkway

    Science.gov (United States)

    2011-06-20

    ... accommodations, food and beverage, retail sales, boat rentals, and other services at Crabtree Falls, Price Lake... DEPARTMENT OF THE INTERIOR National Park Service [NPS-WASO-CONC-0511-7182; 2410-OYC] Temporary Concession Contract for Blue Ridge Parkway AGENCY: National Park Service, Interior. ACTION: Notice of...

  8. Garden State Parkway Corridor : ITS early deployment planning study : strategic deployment plan

    Science.gov (United States)

    1997-12-01

    This Strategic Deployment Plan describes ways of improving travel within the Garden : State Parkway Corridor using intelligent transportation systems (ITS) and without : constructing additional roadway lanes. Travel improvements will be possible with...

  9. Seismic evaluation and ranking of embankments for bridges on and over the parkways in Western Kentucky.

    Science.gov (United States)

    2008-06-01

    This study represents one of the Seismic Evaluation of Bridges on and over the Parkways in Western Kentucky investigative series. The effort is focused on the seismic vulnerability of bridge embankments against slope instability and liquefaction pote...

  10. Preliminary seismic evaluation and ranking of bridges on and over the parkways in Western Kentucky.

    Science.gov (United States)

    2008-06-01

    Five parkways in Western Kentucky are located in the region that is greatly influenced by the New Madrid and Wabash Valley Seismic Zones. This report executes a preliminary screening process, known also as the Seismic Rating System, for bridges on an...

  11. The nearby supernova factory

    International Nuclear Information System (INIS)

    Wood-Vasey, W.M.; Aldering, G.; Lee, B.C.; Loken, S.; Nugent, P.; Perlmutter, S.; Siegrist, J.; Wang, L.; Antilogus, P.; Astier, P.; Hardin, D.; Pain, R.; Copin, Y.; Smadja, G.; Gangler, E.; Castera, A.; Adam, G.; Bacon, R.; Lemonnier, J.-P.; Pecontal, A.; Pecontal, E.; Kessler, R.

    2004-01-01

    The Nearby Supernova Factory (SNfactory) is an ambitious project to find and study in detail approximately 300 nearby Type Ia supernovae (SNe Ia) at redshifts 0.03 < z < 0.08. This program will provide an exceptional data set of well-studied SNe in the nearby smooth Hubble flow that can be used as calibration for the current and future programs designed to use SNe to measure the cosmological parameters. The first key ingredient for this program is a reliable supply of Hubble-flow SNe systematically discovered in unprecedented numbers using the same techniques as those used in distant SNe searches. In 2002, 35 SNe were found using our test-bed pipeline for automated SN search and discovery. The pipeline uses images from the asteroid search conducted by the Near Earth Asteroid Tracking group at JPL. Improvements in our subtraction techniques and analysis have allowed us to increase our effective SN discovery rate to ∼12 SNe/month in 2003

  12. Disturbance Ecology from nearby Supernovae

    OpenAIRE

    Hartmann, D. H.; Kretschmer, K.; Diehl, R.

    2002-01-01

    Monte Carlo simulations of Galactic Supernovae are carried out to study the rate of nearby events, which may have a direct effect on Earth's ecology though ionizing radiation and cosmic ray bombardment. A nearby supernova may have left a radioactive imprint (60Fe) in recent galactic history.

  13. Hydride Molecules towards Nearby Galaxies

    Science.gov (United States)

    Monje, Raquel R.; La, Ngoc; Goldsmith, Paul

    2018-06-01

    Observations carried out by the Herschel Space Observatory revealed strong spectroscopic signatures from light hydride molecules within the Milky Way and nearby active galaxies. To better understand the chemical and physical conditions of the interstellar medium, we conducted the first comprehensive survey of hydrogen fluoride (HF) and water molecular lines observed through the SPIRE Fourier Transform Spectrometer. By collecting and analyzing the sub-millimeter spectra of over two hundred sources, we found that the HF J = 1 - 0 rotational transition which occurs at approximately 1232 GHz was detected in a total of 39 nearby galaxies both in absorption and emission. The analysis will determine the main excitation mechanism of HF in nearby galaxies and provide steady templates of the chemistry and physical conditions of the ISM to be used in the early universe, where observations of hydrides are more scarce.

  14. Foothills Parkway Section 8B Final Environmental Report, Volume 2, Appendices A-C

    Energy Technology Data Exchange (ETDEWEB)

    Blasing, T.J.; Cada, G.F.; Carer, M.; Chin, S.M.; Dickerman, J.A.; Etnier, D.A.; Gibson, R.; Harvey, M.; Hatcher, B.; Lietzske, D.; Mann, L.K.; Mulholland, P.J.; Petrich, C.H.; Pounds, L.; Ranney, J.; Reed, R.M.; Ryan, P.F.; Schweitzer, M.; Smith, D.; Thomason, P.; Wade, M.C.

    1999-07-01

    In 1994, Oak Ridge National Laboratory (ORNL) was tasked by the National Park Service (NPS) to prepare an Environmental Report (ER) for Section 8B of the Foothills Parkway in the Great Smoky Mountains National Park (GSMNP). Section 8B represents 27.7 km (14.2 miles) of a total of 115 km (72 miles) of the planned Foothills Parkway and would connect the Cosby community on the east to the incorporated town of Pittman Center to the west. The major deliverables for the project are listed. From August 1995 through October 1996, NW, GSMNP, and ORNL staff interacted with Federal Highway Administration staff to develop a conceptual design plan for Section 8B with the intent of protecting critical resources identified during the ER process to the extent possible. In addition, ORNL arranged for bioengineering experts to discuss techniques that might be employed on Section 8B with NPS, GSMNP, and ORNL staff during September 1996. For the purposes of this EN there are two basic alternatives under consideration: (1) a build alternative and (2) a no-build alternative. Within the build alternative are a number of options including constructing Section 8B with no interchanges, constricting Section 8B with an interchange at SR 416 or U.S. 321, constructing Section 8B with a spur road on Webb Mountain, and considering operation of Section 8B both before and after the operation of Section 8C. The no-build alternative is considered the no-action alternative and is not to construct Section 8B. This volume of the ER, which consists of Appendices A, B, and C, assesses the potential geologic impacts of the proposed Section 8B construction, presents the results of the Section 8B soil survey, and describes the water quality studies and analyses performed for the ER. The following summary sections provide information for geology, soils, and water quality.

  15. Planetesimals around nearby millisecond pulsars

    International Nuclear Information System (INIS)

    Chakrabarti, S.K.

    1992-05-01

    We predict that it is possible to observe line emissions of OH, CN and C 2 from the planetesimals around some of the nearby millisecond pulsars, such as PSR1257+12. Observation of these lines will provide an independent test of either an existing planetary system or one which is in the process of formation. (author). 11 refs, 1 tab

  16. Foothills Parkway Section 8B Final Environmental Report, Volume 6, Appendix N

    Energy Technology Data Exchange (ETDEWEB)

    Blasing, T.J.; Cada, G.F.; Carer, M.; Chin, S.M.; Dickerman, J.A.; Etnier, D.A.; Gibson, R.; Harvey, M.; Hatcher, B.; Lietzske, D.; Mann, L.K.; Mulholland, P.J.; Petrich, C.H.; Pounds, L.; Ranney, J.; Reed, R.M.; Ryan, P.F.; Schweitzer, M.; Smith, D.; Thomason, P.; Wade, M.C.

    1999-07-01

    In 1994, Oak Ridge National Laboratory (ORNL) was tasked by the National Park Service (NPS) to prepare an Environmental Report (ER) for Section 8B of the Foothills Parkway in the Great Smoky Mountains National Park (GSMNP). Section 8B represents 27.7 km (14.2 miles) of a total of 115 km (72 miles) of the planned Foothills Parkway and would connect the Cosby community on the east to the incorporated town of Pittman Center to the west. The major deliverables for the project are listed. From August 1995 through October 1996, NPS, GSMNP, and ORNL staff interacted with Federal Highway Administration staff to develop a conceptual design plan for Section 8B with the intent of protecting critical resources identified during the ER process to the extent possible. In addition, ORNL arranged for bioengineering experts to discuss techniques that might be employed on Section 8B with NPS, GSMNP, and ORNL staff during September 1996. For the purposes of this ER, there are two basic alternatives under consideration: (1) a build alternative and (2) a no-build alternative. Within the build alternative are a number of options including constructing Section 8B with no interchanges, constructing Section 8B with an interchange at SR 416 or U.S. 321, constructing Section 8B with a spur road on Webb Mountain, and considering operation of Section 8B both before and after the operation of Section 8C. The no-build alternative is considered the no-action alternative and is not to construct Section 8B. This volume of the ER documents the results of the architectural, historical, and cultural resources assessment for the entire Section 8B ROW that was completed in May 1995 to document the architectural, historical, and cultural resources located within the project area. The assessment included evaluation of the potential for cultural (i.e., rural historic) landscapes in the area of the ROW. The assessment showed that one National Register-listed property is located 0.3 mile south of the ROW

  17. Foothills Parkway Section 8B Final Environmental Report, Volume 3, Appendix D

    Energy Technology Data Exchange (ETDEWEB)

    Blasing, T.J.; Cada, G.F.; Carer, M.; Chin, S.M.; Dickerman, J.A.; Etnier, D.A.; Gibson, R.; Harvey, M.; Hatcher, B.; Lietzske, D.; Mann, L.K.; Mulholland, P.J.; Petrich, C.H.; Pounds, L.; Ranney, J.; Reed, R.M.; Ryan, P.F.; Schweitzer, M.; Smith, D.; Thomason, P.; Wade, M.C.

    1999-07-01

    In 1994, Oak Ridge National Laboratory (ORNL) was tasked by the National Park Service (NPS) to prepare an Environmental Report (ER) for Section 8B of the Foothills Parkway in the Great Smoky Mountains National Park (GSMNP). Section 8B represents 27.7 km (14.2 miles) of a total of 115 km (72 miles) of the planned Foothills Parkway and would connect the Cosby community on the east to the incorporated town of Pittman Center to the west. The major deliverables for the project are listed. From August 1995 through October 1996, NPS, GSMNP, and ORNL staff interacted with Federal Highway Administration staff to develop a conceptual design plan for Section 8B with the intent of protecting critical resources identified during the ER process to the extent possible. In addition, ORNL arranged for bioengineering experts to discuss techniques that might be employed on Section 8B with NPS, GSMNP, and ORNL staff during September 1996. For the purposes of this ER, there are two basic alternatives under consideration: (1) a build alternative and (2) a no-build alternative. Within the build alternative are a number of options including constructing Section 8B with no interchanges, constructing Section 8B with an interchange at SR416 or U.S. 321, constructing Section 8B with a spur road on Webb Mountain, and considering operation of Section 8B both before and after the operation of Section 8C. The no-build alternative is considered the no-action alternative and is not to construct Section 8B. This volume of the ER inventories the fishes and benthic macroinvertebrates inhabiting the aquatic ecosystems potentially affected by the proposed construction of Section 8B. Stream biological surveys were completed at 31 stream sites during the Fall of 1994. The sampling strategy for both invertebrates and fish was to survey the different taxa from all available habitats. For benthic invertebrates, a standardized qualitative manual collection technique was employed for all 31 stations. For fish

  18. Foothills Parkway Section 8B Final Environmental Report, Volume 4, Appendices E-I

    Energy Technology Data Exchange (ETDEWEB)

    Blasing, T.J.; Cada, G.F.; Carer, M.; Chin, S.M.; Dickerman, J.A.; Etnier, D.A.; Gibson, R.; Harvey, M.; Hatcher, B.; Lietzske, D.; Mann, L.K.; Mulholland, P.J.; Petrich, C.H.; Pounds, L.; Ranney, J.; Reed, R.M.; Ryan, P.F.; Schweitzer, M.; Smith, D.; Thomason, P.; Wade, M.C.

    1999-07-01

    In 1994, Oak Ridge National Laboratory (ORNL) was tasked by the National Park Service (NPS) to prepare an Environmental Report (ER) for Section 8B of the Foothills Parkway in the Great Smoky Mountains National Park (GSMNP). Section 8B represents 27.7 km (14.2 miles) of a total of 115 km (72 miles) of the planned Foothills Parkway and would connect the Cosby community on the east to the incorporated town of Pittman Center to the west. The major deliverables for the project are listed. From August 1995 through October 1996, NPS, GSMNP, and ORNL staff interacted with Federal Highway Administration staff to develop a conceptual design plan for Section 8B with the intent of protecting critical, resources identified during the ER process to the extent possible. In addition, ORNL arranged for bioengineering experts to discuss techniques that might be employed on Section 8B with NPS, GSMNP, and ORNL staff during September 1996. For the purposes of this ER, there are two basic alternatives under consideration: (1) a build alternative and (2) a no-build alternative. Within the build alternative are a number of options including constructing Section 8B with no interchanges, constructing Section 8B with an interchange at SR 416 or U.S. 321, constructing Section 8B with a spur road on Webb Mountain, and considering operation of Section 8B both before and after the operation of Section 8C. The no-build alternative is considered the no-action alternative and is not to construct Section 8B. This volume of the ER consists of Appendices E through I (all ecological survey reports), which are summarized individually in the sections that follow. The following conclusions result from the completion of these surveys and the ER impact analysis: (1) Forest clearing should be limited as much as possible; (2) Disturbed areas should be replanted with native trees; (3) Drainages should be bridged rather than leveled with cut and fill; (4) For areas of steep slopes and potential erosion

  19. The Long Term Features of Tropical Cyclones Nearby Taiwan

    Science.gov (United States)

    Wu, Yueh-Shyuan; Lee, Cheng-Shang

    2017-04-01

    Tropical cyclone (TC) activity is affected by several factors. The variability of TC activity over the western North Pacific (WNP) has been examined in the past decade. Previous studies showed that TC activity (such as TC number, intensity and tracks) has multiscale variation or affected by natural oscillation of different scales. However, most of these studies focused mainly on the entire WNP. Very few studies examined the variability of annual TC track or the variability of TC number in the area nearby Taiwan, which caused severe economic loss and life damage to Taiwan in the typhoon season. The main purpose of this study is to analyze the variation of TC activity nearby Taiwan to address its long term features, and also the possible relationship with the associated flow patterns. Preliminary results of wavelet analysis showed that the TC number nearby Taiwan during 1970-2014 had multiscale variations. The following analysis focused on the scale about 4- and 11-year signals, in the targeted area of 118o-125oE, 20o-27oN. The positive phases of both scale 4 and scale 11 showed a tendency of TC tracks toward Taiwan area, while the negative phases showed a lower tendency toward Taiwan. An empirical orthogonal function (EOF) analysis was applied on the 4-yr and the 11-yr filtered 500-hPa wind fields and geopotential heights. Results showed that the 4-yr signal was mostly dominated by the 500-hPa U- and V-wind fields, suggesting that the TC track patterns were affected mainly by the midlevel steering flow. On the other hand, the 11-yr signal was mostly dominated by the 500-hPa U-wind field and geopotential anomalies, indicating that the main cause of the difference in TC occurrence nearby Taiwan was the location of TC formation.

  20. Redshift differences of galaxies in nearby groups

    Science.gov (United States)

    Harrison, E. R.

    1975-01-01

    It is reported that galaxies in nearby groups exhibit anomalous nonvelocity redshifts. In this discussion, (1) four classes of nearby groups of galacies are analyzed, and no significant nonvelocity redshift effect is found; and (2) it is pointed out that transverse velocities (i.e., velocities transverse to the line of sight of the main galaxy, or center of mass) contribute components to the redshift measurements of companion galaxies. The redshifts of galaxies in nearby groups of appreciable angular size are considerably affected by these velocity projection effects. The transverse velocity contributions average out in rich, isotropic groups, and also in large samples of irregular groups of low membership, as in the four classes referred to in (1), but can introduce apparent discrepancies in small samples (as studied by Arp) of nearby groups of low membership.

  1. The AGN Population in Nearby Galaxies

    International Nuclear Information System (INIS)

    Filho, Mercedes; Barthel, Peter; Ho, Luis

    2006-01-01

    In order to determine the incidence of black hole accretion-driven nuclear activity in nearby galaxies, we have compiled radio data for the LINERs, composite LINER,/Hn and Seyfert galaxies from a complete magnitude-limited sample of bright nearby galaxies (Palomar sample). Our results show an overall radio detection rate of 54% (22% of all bright nearby galaxies) and we estimate that at least ∼50% (∼20% of all bright nearby galaxies) are true AGN. By comparing the radio luminosity function of the LINERs, composite LINER/Hll and Seyferts galaxies in the Palomar sample with those of selected moderate-redshift AGN, we fhd that our sources naturally extend the radio luminosity function of powerful AGN down to powers of about 10 times that of Sgr A*

  2. Spectrophotometry of nearby field galaxies : The data

    NARCIS (Netherlands)

    Jansen, RA; Fabricant, D; Franx, M; Caldwell, N

    We have obtained integrated and nuclear spectra as well as U, B, R surface photometry for a representative sample of 196 nearby galaxies. These galaxies span the entire Hubble sequence in morphological type, as well as a wide range of luminosities (M(B) = -14 to -22). Here we present the

  3. The ISM in nearby galaxies: NGC1365

    NARCIS (Netherlands)

    Baan, Willem; Loenen, Edo; Spaans, Marco

    We propose a sensitive spectral survey of the nuclear region of the nearby Luminous Infrared Galaxy NGC1365. These observations are to confirm a similar program carried out in 2007, which suffers from severe bandpass issues. The previous observations have resulted in 76+ tentative detections,

  4. Nobeyama CO Atlas of Nearby Spiral Galaxies

    Science.gov (United States)

    Kuno, N.; Nakai, N.; Sorai, K.; Sato, N..; Yamauchi, A.; Tosaki, T.; Shioya, Y.; Vila-Vilaró, B.; Nishiyama, K.; Ishihara, Y.; Cepa, J.

    BEARS is a 25-beam focal plane array receiver mounted on the Nobeyama 45-m telescope. The combination of the large dish size of the telescope with the excellent performance of this receiver makes it an ideal tool for mapping observations of extended regions of the sky. We present here one of its current applications in a CO mapping survey of nearby spiral galaxies.

  5. Identifying New Members of Nearby Moving Groups

    Science.gov (United States)

    Holmbeck, Erika; Vican, Laura

    2014-06-01

    Our group has assembled a sample of 14,000 stars of spectral types B9-M9 with measured UVW Galactic space velocities and lying within 125 pc of Earth. We have identified candidate members of three nearby young (less than 100 Myr) moving groups. For stars of spectral types G5 and later, we have used the Kast spectrometer on the Shane 3m telescope at Lick Observatory to measure lithium abundance in order to determine stellar ages. With the data we have obtained from this run, we will be able to establish whether our candidates are bona fide members of the moving groups in question. I will be presenting the preliminary results from this survey, including spectra of the ~50 stars observed thus far. These nearby young stars will make excellent targets for direct imaging followup surveys, since any giant planets around young stars will still be warm, and will therefore be bright enough to detect with instruments like GPI.

  6. Star Formation Histories of Nearby Dwarf Galaxies

    OpenAIRE

    Grebel, Eva K.

    2000-01-01

    Properties of nearby dwarf galaxies are briefly discussed. Dwarf galaxies vary widely in their star formation histories, the ages of their subpopulations, and in their enrichment history. Furthermore, many dwarf galaxies show evidence for spatial variations in their star formation history; often in the form of very extended old populations and radial gradients in age and metallicity. Determining factors in dwarf galaxy evolution appear to be both galaxy mass and environment. We may be observi...

  7. Stellar Death in the Nearby Universe

    Science.gov (United States)

    Holoien, Thomas Warren-Son

    The night sky is replete with transient and variable events that help shape our universe. The violent, explosive deaths of stars represent some of the most energetic of these events, as a single star is able to outshine billions during its final moments. Aside from imparting significant energy into their host environments, stellar deaths are also responsible for seeding heavy elements into the universe, regulating star formation in their host galaxies, and affecting the evolution of supermassive black holes at the centers of their host galaxies. The large amount of energy output during these events allows them to be seen from billions of lightyears away, making them useful observational probes of physical processes important to many fields of astronomy. In this dissertation I present a series of observational studies of two classes of transients associated with the deaths of stars in the nearby universe: tidal disruption events (TDEs) and supernovae (SNe). Discovered by the All-Sky Automated Survey for Supernovae (ASAS-SN), the objects I discuss were all bright and nearby, and were subject to extensive follow-up observational campaigns. In the first three studies, I present observational data and theoretical models of ASASSN-14ae, ASASSN-14li, and ASASSN-15oi, three TDEs discovered by ASAS-SN and three of the most well-studied TDEs ever discovered. Next I present the discovery of ASASSN-13co, an SN that does not conform to the traditional model of Type II SNe. Finally, I discuss the full sample of bright SNe discovered from 2014 May 1 through 2016 December 31, which is significantly less biased than previous nearby SN samples due to the ASAS-SN survey approach, and perform statistical analyses on this population that will be used for future studies of nearby SNe and their hosts.

  8. Sunspot Light Walls Suppressed by Nearby Brightenings

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Shuhong; Zhang, Jun; Hou, Yijun; Li, Xiaohong [CAS Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China); Erdélyi, Robertus [Solar Physics and Space Plasma Research Centre, School of Mathematics and Statistics, University of Sheffield, Hicks Building, Hounsfield Road, Sheffield S3 7RH (United Kingdom); Yan, Limei, E-mail: shuhongyang@nao.cas.cn [Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029 (China)

    2017-07-01

    Light walls, as ensembles of oscillating bright structures rooted in sunspot light bridges, have not been well studied, although they are important for understanding sunspot properties. Using the Interface Region Imaging Spectrograph and Solar Dynamics Observatory observations, here we study the evolution of two oscillating light walls each within its own active region (AR). The emission of each light wall decays greatly after the appearance of adjacent brightenings. For the first light wall, rooted within AR 12565, the average height, amplitude, and oscillation period significantly decrease from 3.5 Mm, 1.7 Mm, and 8.5 minutes to 1.6 Mm, 0.4 Mm, and 3.0 minutes, respectively. For the second light wall, rooted within AR 12597, the mean height, amplitude, and oscillation period of the light wall decrease from 2.1 Mm, 0.5 Mm, and 3.0 minutes to 1.5 Mm, 0.2 Mm, and 2.1 minutes, respectively. Particularly, a part of the second light wall even becomes invisible after the influence of a nearby brightening. These results reveal that the light walls are suppressed by nearby brightenings. Considering the complex magnetic topology in light bridges, we conjecture that the fading of light walls may be caused by a drop in the magnetic pressure, where the flux is canceled by magnetic reconnection at the site of the nearby brightening. Another hypothesis is that the wall fading is due to the suppression of driver source ( p -mode oscillation), resulting from the nearby avalanche of downward particles along reconnected brightening loops.

  9. Suites of dwarfs around Nearby giant galaxies

    International Nuclear Information System (INIS)

    Karachentsev, Igor D.; Kaisina, Elena I.; Makarov, Dmitry I.

    2014-01-01

    The Updated Nearby Galaxy Catalog (UNGC) contains the most comprehensive summary of distances, radial velocities, and luminosities for 800 galaxies located within 11 Mpc from us. The high density of observables in the UNGC makes this sample indispensable for checking results of N-body simulations of cosmic structures on a ∼1 Mpc scale. The environment of each galaxy in the UNGC was characterized by a tidal index Θ 1 , depending on the separation and mass of the galaxy's main disturber (MD). We grouped UNGC galaxies with a common MD in suites, and ranked suite members according to their Θ 1 . All suite members with positive Θ 1 are assumed to be physical companions of the MD. About 58% of the sample are members of physical groups. The distribution of suites by the number of members, n, follows a relation N(n) ∼ n –2 . The 20 most populated suites contain 468 galaxies, i.e., 59% of the UNGC sample. The fraction of MDs among the brightest galaxies is almost 100% and drops to 50% at M B = –18 m . We discuss various properties of MDs, as well as galaxies belonging to their suites. The suite abundance practically does not depend on the morphological type, linear diameter, or hydrogen mass of the MD, the tightest correlation being with the MD dynamical mass. Dwarf galaxies around MDs exhibit well-known segregation effects: the population of the outskirts has later morphological types, richer H I contents, and higher rates of star formation activity. Nevertheless, there are some intriguing cases where dwarf spheroidal galaxies occur at the far periphery of the suites, as well as some late-type dwarfs residing close to MDs. Comparing simulation results with galaxy groups, most studies assume the Local Group is fairly typical. However, we recognize that the nearby groups significantly differ from each other and there is considerable variation in their properties. The suites of companions around the Milky Way and M31, consisting of the Local Group, do not

  10. Demographics of Starbursts in Nearby Seyfert Galaxies

    Science.gov (United States)

    Schinnerer, E.; Colbert, E.; Armus, L.; Scoville, N. Z.; Heckman, T.

    2002-12-01

    We investigate the frequency of circumnuclear starbursts in Seyfert galaxies using medium-resolution H and K band spectroscopy. An unbiased sample of ~20 nearby Seyfert galaxies was observed at the KeckII telescope with an average seeing of ~0.7''. Preliminary analysis shows strong stellar absorption lines for most galaxies in our sample. Comparison of stellar equivalent widths in the H and K band will allow us to determine the average age of the dominating stellar population. Evidence for an age trend with Seyfert type would provide a strong hint toward a starburst/AGN connection.

  11. Seasonal variations of ambient air mercury species nearby an airport

    Science.gov (United States)

    Fang, Guor-Cheng; Tsai, Kai-Hsiang; Huang, Chao-Yang; Yang, Kuang-Pu Ou; Xiao, You-Fu; Huang, Wen-Chuan; Zhuang, Yuan-Jie

    2018-04-01

    This study focuses on the collection of ambient air mercury species (total gaseous mercury (TGM), reactive gaseous mercury (RGM), gaseous element mercury (GEM) and particulate bound mercury (PBM) pollutants at airport nearby sampling site during the year of Apr. 2016 to Mar. 2017 by using Four-stage gold amalgamation and denuder. The results indicated that the average TGM, RGM and GEM concentrations were 5.04 ± 2.43 ng/m3, 29.58 ± 80.54 pg/m3, 4.70 ± 2.63 ng/m3, respectively during the year of Apr. 2016 to Mar. 2017 (n = 49) period at this airport sampling site nearby. In addition, the results also indicated that the average PBM concentrations in TSP and PM2.5 were 0.35 ± 0.08 ng/m3 and 0.09 ± 0.03 ng/m3, respectively. And the average PBM in TSP concentrations order follows as summer > autumn > spring > winter, while the average PBM in PM2.5 concentrations order follows as spring > summer > winter > autumn. Moreover, the average TGM, RGM and GEM concentrations order follow as spring > summer > autumn > winter. Finally, the Asian continent has the highest average mercury species concentrations (TGM, RGM, GEM and PBM) when compared with the American and European continents, and the average mercury species concentrations (TGM, RGM, GEM and PBM) displayed declined trends for North America (United States and Canada) and Europe (Spain, Sweden and Southern Baltic) during the years of 2004-2014. Also noteworthy is that the average mercury species concentrations (TGM, RGM, GEM) displayed increasing trends in China and Taiwan during the years of 2008-2016. Japan and Korea are the only two exceptions. Those above two countries mercury species concentrations displayed decreasing trends during years of 2008-2015.

  12. THE ACS NEARBY GALAXY SURVEY TREASURY

    International Nuclear Information System (INIS)

    Dalcanton, Julianne J.; Williams, Benjamin F.; Rosema, Keith; Gogarten, Stephanie M.; Christensen, Charlotte; Gilbert, Karoline; Hodge, Paul; Seth, Anil C.; Dolphin, Andrew; Holtzman, Jon; Skillman, Evan D.; Weisz, Daniel; Cole, Andrew; Girardi, Leo; Karachentsev, Igor D.; Olsen, Knut; Freeman, Ken; Gallart, Carme; Harris, Jason; De Jong, Roelof S.

    2009-01-01

    The ACS Nearby Galaxy Survey Treasury (ANGST) is a systematic survey to establish a legacy of uniform multi-color photometry of resolved stars for a volume-limited sample of nearby galaxies (D 4 in luminosity and star formation rate. The survey data consist of images taken with the Advanced Camera for Surveys (ACS) on the Hubble Space Telescope (HST), supplemented with archival data and new Wide Field Planetary Camera 2 (WFPC2) imaging taken after the failure of ACS. Survey images include wide field tilings covering the full radial extent of each galaxy, and single deep pointings in uncrowded regions of the most massive galaxies in the volume. The new wide field imaging in ANGST reaches median 50% completenesses of m F475W = 28.0 mag, m F606W = 27.3 mag, and m F814W = 27.3 mag, several magnitudes below the tip of the red giant branch (TRGB). The deep fields reach magnitudes sufficient to fully resolve the structure in the red clump. The resulting photometric catalogs are publicly accessible and contain over 34 million photometric measurements of >14 million stars. In this paper we present the details of the sample selection, imaging, data reduction, and the resulting photometric catalogs, along with an analysis of the photometric uncertainties (systematic and random), for both ACS and WFPC2 imaging. We also present uniformly derived relative distances measured from the apparent magnitude of the TRGB.

  13. The Glory of a Nearby Star

    Science.gov (United States)

    2001-08-01

    -west (the 4 o'clock direction). The motion is clearly visible on these two images obtained with the UK Schmidt telescope and reproduced from the Second Digized Sky Survey (DSS-2); the blue image (left) was taken several years before the red one (right). Moreover, the red colour of the star is obvious; the red image is clearly brighter than the blue one. The field measures 5 x 5 arcmin 2 ; North is up and East is left. These DSS-2 images are copyright by the UK SERC/PPARC (Particle Physics and Astronomy Research Council, formerly Science and Engineering Research Council), the Anglo-Australian Telescope Board and the Association of Universities for Research in Astronomy (AURA). In order to increase the chances of success, Jürgen Schmitt and his colleagues decided to focus on optically faint, red dwarf stars . Such stars may have the same X-ray output (or even larger) than the Sun, and hence presumably possess pronounced coronae, yet their disks emit over one thousand times less visible light than does that of the Sun. They first turned their attention towards an optically faint (visual magnitude 14) and nearby (distance 8 light-years) red dwarf star (of type M5.5) known as CN Leonis , cf. PR Photo 24b/01 . It is located slightly north of the celestial equator in the constellation Leo (the Lion) and the two-letter name indicates that it is a variable star. It has been found to undergo sudden brightenings (it is a 'flare star' ), and exhibits strong magnetic activity. It is also a source of strong X-rays which the German astronomers had previously studied with the ROSAT satellite observatory and they therefore considered this star as an excellent first choice for a coronal study with the VLT. UVES detects a coronal line in the visible spectral region ESO PR Photo 24c/01 ESO PR Photo 24c/01 [Preview - JPEG: 400 x 471 pix - 31k] [Normal - JPEG: 800 x 942 pix - 81k] [Hi-Res - JPEG: 2549 x 3000 pix - 496k] ESO PR Photo 24d/01 ESO PR Photo 24d/01 [Preview - JPEG: 400 x 489 pix - 43

  14. Parks not Parkways

    DEFF Research Database (Denmark)

    Conley, Jim; Jensen, Ole B.

    2016-01-01

    This case study of a dispute over a project to construct a road through green space in a small Canadian city brings together two hitherto separate theoretical approaches to mobility disputes: “culture stories” and “regimes of engagement”. The stories opponents tell, in interviews and documents, c...

  15. WINGS: WFIRST Infrared Nearby Galaxy Survey

    Science.gov (United States)

    Williams, Benjamin

    WFIRST's combination of wide field and high resolution will revolutionize the study of nearby galaxies. We propose to produce and analyze simulated WFIRST data of nearby galaxies and their halos to maximize the scientific yield in the limited observing time available, ensuring the legacy value of WFIRST's eventual archive. We will model both halo structure and resolved stellar populations to optimize WFIRST's constraints on both dark matter and galaxy formation models in the local universe. WFIRST can map galaxy structure down to ~35 mag/square arcsecond using individual stars. The resulting maps of stellar halos and accreting dwarf companions will provide stringent tests of galaxy formation and dark matter models on galactic (and even sub-galactic) scales, which is where the most theoretical tension exists with the Lambda-CDM model. With a careful, coordinated plan, WFIRST can be expected to improve current sample sizes by 2 orders of magnitude, down to surface brightness limits comparable to those currently reached only in the Local Group, and that are >4 magnitudes fainter than achievable from the ground due to limitations in star-galaxy separation. WFIRST's maps of galaxy halos will simultaneously produce photometry for billions of stars in the main bodies of galaxies within 10 Mpc. These data will transform studies of star formation histories that track stellar mass growth as a function of time and position within a galaxy. They also will constrain critical stellar evolution models of the near-infrared bright, rapidly evolving stars that can contribute significantly to the integrated light of galaxies in the near-infrared. Thus, with WFIRST we can derive the detailed evolution of individual galaxies, reconstruct the complete history of star formation in the nearby universe, and put crucial constraints on the theoretical models used to interpret near-infrared extragalactic observations. We propose a three-component work plan that will ensure these gains by

  16. Nearby outdoor environments and seniors physical activities

    Directory of Open Access Journals (Sweden)

    Zhe Wang

    2014-09-01

    Full Text Available More than 60% of older Americans have sedentary lifestyles1 1 According to DHHS (1996. and are recommended more physical activities for health benefit. Nearby outdoor environments on residential sites may impact older inhabitants׳ physical activities there (defined as walking, gardening, yard work, and other outdoor physical activities on residential sites. This study surveyed 110 assisted-living residents in Houston, Texas, regarding their previous residential sites before moving to a retirement community and physical activities there. Twelve environmental features were studied under four categories (typology, motivators, function, and safety. Based on data availability, a subset of 57 sample sites was analyzed in Geographic Information Systems. Hierarchical linear modeling was applied to estimate physical activities as a function of the environments. Higher levels of physical activity were found to be positively related with four environmental features (transitional-areas, connecting-paths, walk-ability, and less paving.

  17. Three Temperate Neptunes Orbiting Nearby Stars

    Science.gov (United States)

    Fulton, Benjamin J.; Howard, Andrew W.; Weiss, Lauren M.; Sinukoff, Evan; Petigura, Erik A.; Isaacson, Howard; Hirsch, Lea; Marcy, Geoffrey W.; Henry, Gregory W.; Grunblatt, Samuel K.; Huber, Daniel; von Braun, Kaspar; Boyajian, Tabetha S.; Kane, Stephen R.; Wittrock, Justin; Horch, Elliott P.; Ciardi, David R.; Howell, Steve B.; Wright, Jason T.; Ford, Eric B.

    2016-10-01

    We present the discovery of three modestly irradiated, roughly Neptune-mass planets orbiting three nearby Solar-type stars. HD 42618 b has a minimum mass of 15.4 ± 2.4 {M}\\oplus , a semimajor axis of 0.55 au, an equilibrium temperature of 337 K, and is the first planet discovered to orbit the solar analogue host star, HD 42618. We also discover new planets orbiting the known exoplanet host stars HD 164922 and HD 143761 (ρ CrB). The new planet orbiting HD 164922 has a minimum mass of 12.9 ± 1.6 {M}\\oplus and orbits interior to the previously known Jovian mass planet orbiting at 2.1 au. HD 164922 c has a semimajor axis of 0.34 au and an equilibrium temperature of 418 K. HD 143761 c orbits with a semimajor axis of 0.44 au, has a minimum mass of 25 ± 2 {M}\\oplus , and is the warmest of the three new planets with an equilibrium temperature of 445 K. It orbits exterior to the previously known warm Jupiter in the system. A transit search using space-based CoRoT data and ground-based photometry from the Automated Photometric Telescopes (APTs) at Fairborn Observatory failed to detect any transits, but the precise, high-cadence APT photometry helped to disentangle planetary-reflex motion from stellar activity. These planets were discovered as part of an ongoing radial velocity survey of bright, nearby, chromospherically inactive stars using the Automated Planet Finder (APF) telescope at Lick Observatory. The high-cadence APF data combined with nearly two decades of radial velocity data from Keck Observatory and gives unprecedented sensitivity to both short-period low-mass, and long-period intermediate-mass planets. Based on observations obtained at the W. M. Keck Observatory, which is operated jointly by the University of California and the California Institute of Technology. Keck time was granted for this project by the University of Hawai‘I, the University of California, and NASA.

  18. Discovery of a New Nearby Star

    Science.gov (United States)

    Teegarden, B. J.; Pravdo, S. H.; Covey, K.; Frazier, O.; Hawley, S. L.; Hicks, M.; Lawrence, K.; McGlynn, T.; Reid, I. N.; Shaklan, S. B.

    2003-01-01

    We report the discovery of a nearby star with a very large proper motion of 5.06 +/- 0.03 arcsec/yr. The star is called SO025300.5+165258 and referred to herein as HPMS (high proper motion star). The discovery came as a result of a search of the SkyMorph database, a sensitive and persistent survey that is well suited for finding stars with high proper motions. There are currently only 7 known stars with proper motions greater than 5 arcsec/yr. We have determined a preliminary value for the parallax of pi = 0.43 +/- 0.13 arcsec. If this value holds our new star ranks behind only the Alpha Centauri system (including Proxima Centauri) and Barnard's star in the list of our nearest stellar neighbours. The spectrum and measured tangential velocity indicate that HPMS is a main-sequence star with spectral type M6.5. However, if our distance measurement is correct, the HPMS is underluminous by 1.2 +/- 0.7 mag.

  19. Morphology and Structures of Nearby Dwarf Galaxies

    Science.gov (United States)

    Seo, Mira; Ann, HongBae

    2015-08-01

    We performed an analysis of the structure of nearby dwarf galaxies based on a 2-dimensional decomposition of galaxy images using GALFIT. The present sample consists of ~1,100 dwarf galaxies with redshift less than z = 0.01, which is is derived from the morphology catalog of the Visually classified galaxies in the local universe (Ann, Seo, and Ha 2015). In this catalog, dwarf galaxies are divided into 5 subtypes: dS0, dE, dSph, dEbc, dEblue with distinction of the presence of nucleation in dE, dSph, and dS0. We found that dSph and dEblue galaxies are fainter than other subtypes of dwarf galaxies. In most cases, single component, represented by the Sersic profile with n=1~1.5, well describes the luminosity distribution of dwarf galaxies in the present sample. However, a significant fraction of dS0, dEbc, and dEbue galaxies show sub-structures such as spiral arms and rings. We will discuss the morphology dependent evolutionary history of the local dwarf galaxies.

  20. Young star clusters in nearby molecular clouds

    Science.gov (United States)

    Getman, K. V.; Kuhn, M. A.; Feigelson, E. D.; Broos, P. S.; Bate, M. R.; Garmire, G. P.

    2018-06-01

    The SFiNCs (Star Formation in Nearby Clouds) project is an X-ray/infrared study of the young stellar populations in 22 star-forming regions with distances ≲ 1 kpc designed to extend our earlier MYStIX (Massive Young Star-Forming Complex Study in Infrared and X-ray) survey of more distant clusters. Our central goal is to give empirical constraints on cluster formation mechanisms. Using parametric mixture models applied homogeneously to the catalogue of SFiNCs young stars, we identify 52 SFiNCs clusters and 19 unclustered stellar structures. The procedure gives cluster properties including location, population, morphology, association with molecular clouds, absorption, age (AgeJX), and infrared spectral energy distribution (SED) slope. Absorption, SED slope, and AgeJX are age indicators. SFiNCs clusters are examined individually, and collectively with MYStIX clusters, to give the following results. (1) SFiNCs is dominated by smaller, younger, and more heavily obscured clusters than MYStIX. (2) SFiNCs cloud-associated clusters have the high ellipticities aligned with their host molecular filaments indicating morphology inherited from their parental clouds. (3) The effect of cluster expansion is evident from the radius-age, radius-absorption, and radius-SED correlations. Core radii increase dramatically from ˜0.08 to ˜0.9 pc over the age range 1-3.5 Myr. Inferred gas removal time-scales are longer than 1 Myr. (4) Rich, spatially distributed stellar populations are present in SFiNCs clouds representing early generations of star formation. An appendix compares the performance of the mixture models and non-parametric minimum spanning tree to identify clusters. This work is a foundation for future SFiNCs/MYStIX studies including disc longevity, age gradients, and dynamical modelling.

  1. Overview of the nearby supernova factory

    International Nuclear Information System (INIS)

    Aldering, Greg; Adam, Gilles; Antilogus, Pierre; Astier, Pierre; Bacon, Roland; Bongard, S.; Bonnaud, C.; Copin, Yannick; Hardin, D.; Howell, D. Andy; Lemmonnier, Jean-Pierre; Levy, J.-M.; Loken, S.; Nugent, Peter; Pain, Reynald; Pecontal, Arlette; Pecontal, Emmanuel; Perlmutter, Saul; Quimby, Robert; Schahmaneche, Kyan; Smadja, Gerard; Wood-Vasey, W. Michael

    2002-01-01

    The Nearby Supernova Factory (SNfactory) is an international experiment designed to lay the foundation for the next generation of cosmology experiments (such as CFHTLS, wP, SNAP and LSST) which will measure the expansion history of the Universe using Type Ia supernovae. The SNfactory will discover and obtain frequent lightcurve spectrophotometry covering 3200-10000 (angstrom) for roughly 300 Type Ia supernovae at the loW--redshift end of the smooth Hubble flow. The quantity, quality, breadth of galactic environments, and homogeneous nature of the SNfactory dataset will make it the premier source of calibration for the Type Ia supernova width-brightness relation and the intrinsic supernova colors used for K-correction and correction for extinction by host-galaxy dust. This dataset will also allow an extensive investigation of additional parameters which possibly influence the quality of Type Ia supernovae as cosmological probes. The SNfactory search capabilities and folloW--up instrumentation include wide-field CCD imagers on two 1.2-m telescopes (via collaboration with the Near Earth Asteroid Tracking team at JPL and the QUEST team at Yale), and a two-channel integral-field-unit optical spectrograph/imager being fabricated for the University of Hawaii 2.2-m telescope. In addition to ground-based folloW--up, UV spectra for a subsample of these supernovae will be obtained with HST. The pipeline to obtain, transfer via wireless and standard internet, and automatically process the search images is in operation. Software and hardware development is now underway to enable the execution of folloW--up spectroscopy of supernova candidates at the Hawaii 2.2-m telescope via automated remote control of the telescope and the IFU spectrograph/imager

  2. Proper motion survey for solar nearby stars

    International Nuclear Information System (INIS)

    Goldman, Bertrand

    2001-01-01

    For its microlensing observations EROS 2 built one of the largest CCD mosaic opera ting since 1996. This instrument allowed us to survey a large area of the sky, to look for faint, cool compact objects in the Solar neighborhood that may contribute to the Dark Matter revealed by flat rotation curves of spiral galaxies and the Milky Way. We imaged over 400 square degrees, at least three times over four years, with a single, stable instrument. The aim of this work is the reduction, the analysis and the detection of high proper motion objects that would look like those expected in a dark halo. We selected and analyzed thousands of images taken in two bands, visible and near-infrared, and obtained a catalogue of several thousand stars with proper motion typically higher than 80 milli-arc-seconds per year. None of these candidates displays the expected properties of the halo objects: very high proper motion and faintness. The second part of our work was to put constraints on the contributions of white dwarfs and brown dwarfs ta the halo. To do that, we simulated our data set and estimated our sensitivity to halo objects. We compared our results about moderately high proper motion stars with existing Galactic models, and confirmed the robustness of these models. We deduced a upper limit ta the contribution of M_v = 17.5 white dwarfs to the standard halo of 10% (at the 95% confidence level), or 5% of a 14 Gyr old halo, and to the contribution of brown dwarfs of 7% (95% C.L.). Finally, among our candidates, several interesting objects, that do not belong to the halo but are among the coolest and faintest known, have been discovered. Systematic search for faint, nearby objects thus lead us to study disk L dwarfs, as well as old white dwarfs of the disk. (author) [fr

  3. Symposium “Mapping the Galaxy and Nearby Galaxies”

    CERN Document Server

    Wada, Keiichi; ASTROPHYSICS AND SPACE SCIENCE PROCEEDINGS

    2008-01-01

    This is a proceedings book of the symposium "Mapping the Galaxy and Nearby Galaxies" held on Ishigaki Island, Okinawa, Japan, on June 25 – 30, 2006. The symposium focused on mapping the interstellar media and other components in galaxies. Latest results of the following main topics are presented in the volume: Our Galaxy -- mass distribution, local ISM, supermassive black holes and their environments Central part of nearby galaxies -- ISM around starbursts, fueling mechanisms Nearby Galaxies -- molecular gas and star formation, gas dynamics Galactic environment and evolution -- formation of our Galaxy, origin of supermassive black holes The nature of the Dark Matter component -- effects on the internal structures of galaxies

  4. Discovery of path nearby clusters in spatial networks

    KAUST Repository

    Shang, Shuo; Zheng, Kai; Jensen, Christian S.; Yang, Bin; Kalnis, Panos; Li, Guohe; Wen, Ji Rong

    2015-01-01

    The discovery of regions of interest in large cities is an important challenge. We propose and investigate a novel query called the path nearby cluster (PNC) query that finds regions of potential interest (e.g., sightseeing places and commercial

  5. MaNGA: Mapping Nearby Galaxies at Apache Point Observatory

    Science.gov (United States)

    Weijmans, A.-M.; MaNGA Team

    2016-10-01

    MaNGA (Mapping Nearby Galaxies at APO) is a galaxy integral-field spectroscopic survey within the fourth generation Sloan Digital Sky Survey (SDSS-IV). It will be mapping the composition and kinematics of gas and stars in 10,000 nearby galaxies, using 17 differently sized fiber bundles. MaNGA's goal is to provide new insights in galaxy formation and evolution, and to deliver a local benchmark for current and future high-redshift studies.

  6. Initial Hubble Diagram Results from the Nearby Supernova Factory

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, S. [Lab. Nuclear and High-Energy Physics (LPNHE), Paris (France); Aldering, G. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Antilogus, P. [Lab. Nuclear and High-Energy Physics (LPNHE), Paris (France); Aragon, C. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Baltay, C. [Yale Univ., New Haven, CT (United States); Bongard, S. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Buton, C [Inst. of Nuclear Physics of Lyon (France); Childress, M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Copin, Y. [Inst. of Nuclear Physics of Lyon (France); Gangler, E. [Inst. of Nuclear Physics of Lyon (France); Loken, S. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Nugent, P. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Pain, R. [Lab. Nuclear and High-Energy Physics (LPNHE), Paris (France); Pecontal, E. [Center of Research Astrophysics of Lyon (CRAL) (France); Pereira, R. [Lab. Nuclear and High-Energy Physics (LPNHE), Paris (France); Perlmutter, S. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Rabinowitz, D. [Yale Univ., New Haven, CT (United States); Rigaudier, G. [Center of Research Astrophysics of Lyon (CRAL) (France); Ripoche, P. [Lab. Nuclear and High-Energy Physics (LPNHE), Paris (France); Runge, K. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Scalzo, R. [Yale Univ., New Haven, CT (United States); Smadja, G. [Inst. of Nuclear Physics of Lyon (France); Tao, C. [Inst. of Nuclear Physics of Lyon (France); Thomas, R. C. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Wu, C. [Lab. Nuclear and High-Energy Physics (LPNHE), Paris (France)

    2017-07-06

    The use of Type Ia supernovae as distance indicators led to the discovery of the accelerating expansion of the universe a decade ago. Now that large second generation surveys have significantly increased the size and quality of the high-redshift sample, the cosmological constraints are limited by the currently available sample of ~50 cosmologically useful nearby supernovae. The Nearby Supernova Factory addresses this problem by discovering nearby supernovae and observing their spectrophotometric time development. Our data sample includes over 2400 spectra from spectral timeseries of 185 supernovae. This talk presents results from a portion of this sample including a Hubble diagram (relative distance vs. redshift) and a description of some analyses using this rich dataset.

  7. Temporal Variation of Tectonic Tremor Activity Associated with Nearby Earthquakes

    Science.gov (United States)

    Chao, K.; Van der Lee, S.; Hsu, Y. J.; Pu, H. C.

    2017-12-01

    Tectonic tremor and slow slip events, located downdip from the seismogenic zone, hold the key to recurring patterns of typical earthquakes. Several findings of slow aseismic slip during the prenucletion processes of nearby earthquakes have provided new insight into the study of stress transform of slow earthquakes in fault zones prior to megathrust earthquakes. However, how tectonic tremor is associated with the occurrence of nearby earthquakes remains unclear. To enhance our understanding of the stress interaction between tremor and earthquakes, we developed an algorithm for the automatic detection and location of tectonic tremor in the collisional tectonic environment in Taiwan. Our analysis of a three-year data set indicates a short-term increase in the tremor rate starting at 19 days before the 2010 ML6.4 Jiashian main shock (Chao et al., JGR, 2017). Around the time when the tremor rate began to rise, one GPS station recorded a flip in its direction of motion. We hypothesize that tremor is driven by a slow-slip event that preceded the occurrence of the shallower nearby main shock, even though the inferred slip is too small to be observed by all GPS stations. To better quantify what the necessary condition for tremor to response to nearby earthquakes is, we obtained a 13-year ambient tremor catalog from 2004 to 2016 in the same region. We examine the spatiotemporal relationship between tremor and 37 ML>=5.0 (seven events with ML>=6.0) nearby earthquakes located within 0.5 degrees to the active tremor sources. The findings from this study can enhance our understanding of the interaction among tremor, slow slip, and nearby earthquakes in the high seismic hazard regions.

  8. Evidence of nearby supernovae affecting life on Earth

    DEFF Research Database (Denmark)

    Svensmark, Henrik

    2012-01-01

    . A statistical analysis indicates that the Solar system has experienced many large short-term increases in the flux of Galactic cosmic rays (GCR) from nearby SNe. The hypothesis that a high GCR flux should coincide with cold conditions on the Earth is borne out by comparing the general geological record...

  9. Monitoring variable X-ray sources in nearby galaxies

    Science.gov (United States)

    Kong, A. K. H.

    2010-12-01

    In the last decade, it has been possible to monitor variable X-ray sources in nearby galaxies. In particular, since the launch of Chandra, M31 has been regularly observed. It is perhaps the only nearby galaxy which is observed by an X-ray telescope regularly throughout operation. With 10 years of observations, the center of M31 has been observed with Chandra for nearly 1 Msec and the X-ray skies of M31 consist of many transients and variables. Furthermore, the X-ray Telescope of Swift has been monitoring several ultraluminous X-ray sources in nearby galaxies regularly. Not only can we detect long-term X-ray variability, we can also find spectral variation as well as possible orbital period. In this talk, I will review some of the important Chandra and Swift monitoring observations of nearby galaxies in the past 10 years. I will also present a "high-definition" movie of M31 and discuss the possibility of detecting luminous transients in M31 with MAXI.

  10. Prospects for SODART observations of nearby clusters of galaxies

    DEFF Research Database (Denmark)

    Pedersen, Kenneth; Westergaard, Niels Jørgen Stenfeldt

    1998-01-01

    Using the current best understanding of the SODART mirror system, the Bragg panel and of the LEPC/HEPC responses [1] we have studied the feasibility and prospects for SODART studies of nearby clusters of galaxies. From simulated HEPC data of the cluster Abell 2256, we demonstrate that SODART...

  11. AN UPDATED ULTRAVIOLET CATALOG OF GALEX NEARBY GALAXIES

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Yu; Zou, Hu; Liu, JiFeng; Wang, Song, E-mail: ybai@nao.cas.cn, E-mail: zouhu@nao.cas.cn, E-mail: jfliu@nao.cas.cn, E-mail: songw@nao.cas.cn [Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Chaoyang Distict, 100012 Beijing (China)

    2015-09-15

    The ultraviolet (UV) catalog of nearby galaxies compiled by Gil de Paz et al. presents the integrated photometry and surface brightness profiles for 1034 nearby galaxies observed by GALEX. We provide an updated catalog of 4138 nearby galaxies based on the latest Genral Release (GR6/GR7) of GALEX. These galaxies are selected from HyperLeda with apparent diameters larger than 1′. From the surface brightness profiles accurately measured using the deep NUV and FUV images, we have calculated the asymptotic magnitudes, aperture (D25) magnitudes, colors, structural parameters (effective radii and concentration indices), luminosities, and effective surface brightness for these galaxies. Archival optical and infrared photometry from HyperLeda, 2MASS, and IRAS are also integrated into the catalog. Our parameter measurements and some analyses are consistent with those of Paz et al. The (FUV − K) color provides a good criterion to distinguish between early- and late-type galaxies, which can be improved further using the concentration indices. The IRX–β relation is reformulated with our UV-selected nearby galaxies.

  12. Safety aspects of nuclear power plants nearby urban areas

    International Nuclear Information System (INIS)

    Kroeger, W.

    1986-01-01

    According to the Environmental Experts Council smaller reactors would correspond best to the heat demand of the Federal Republic of Germany. The study discusses and investigates into the present safety concepts and site selection criteria, trends towards power plant sites nearby urban areas, site-dependent parameters and their influence on the extent of damage, protective aims, compatibility of the protective aims proposed, and the protective measures required. (DG) [de

  13. CCD photometry of Cepheid sequences in four nearby galaxies

    International Nuclear Information System (INIS)

    Metcalfe, N.; Shanks, T.

    1991-01-01

    We present Isaac Newton Telescope B and V CCD observations of deep photometric sequences in the vicinity of Cepheid variable stars in three nearby galaxies - M31, M33 and NGC 2403. We have also checked the photometry of the brightest stars in M81 and its dwarf companion, Holmberg IX. We use our data, combined with other recent results, to re-analyse the Cepheid distances to these galaxies. (author)

  14. Nearby Galaxies: Templates for Galaxies Across Cosmic Time

    OpenAIRE

    Lockman, F. J.; Ott, J.

    2009-01-01

    Studies of nearby galaxies including the Milky Way have provided fundamental information on the evolution of structure in the Universe, the existence and nature of dark matter, the origin and evolution of galaxies, and the global features of star formation. Yet despite decades of work, many of the most basic aspects of galaxies and their environments remain a mystery. In this paper we describe some outstanding problems in this area and the ways in which large radio facilities will contribute ...

  15. A search for thermal extreme ultraviolet radiation from nearby pulsars

    International Nuclear Information System (INIS)

    Greenstein, G.; Margon, B.

    1977-01-01

    We present the first extreme ultraviolet (100-1000 A) observations of radio pulsars. Using an EUV telescope carried aboard the Apollo-Soyuz mission, data were acquired on the nearby pulsars PSR 1133 + 16, 1451 - 68 and 1929 + 10. The data are interpreted to set limits on the effective temperatures of the neutron stars, yielding T 5 K in the best cases, and the limits compared with theoretical predictions. (orig./BJ) [de

  16. Doses of Nearby Nature Simultaneously Associated with Multiple Health Benefits

    Directory of Open Access Journals (Sweden)

    Daniel T. C. Cox

    2017-02-01

    Full Text Available Exposure to nature provides a wide range of health benefits. A significant proportion of these are delivered close to home, because this offers an immediate and easily accessible opportunity for people to experience nature. However, there is limited information to guide recommendations on its management and appropriate use. We apply a nature dose-response framework to quantify the simultaneous association between exposure to nearby nature and multiple health benefits. We surveyed ca. 1000 respondents in Southern England, UK, to determine relationships between (a nature dose type, that is the frequency and duration (time spent in private green space and intensity (quantity of neighbourhood vegetation cover of nature exposure and (b health outcomes, including mental, physical and social health, physical behaviour and nature orientation. We then modelled dose-response relationships between dose type and self-reported depression. We demonstrate positive relationships between nature dose and mental and social health, increased physical activity and nature orientation. Dose-response analysis showed that lower levels of depression were associated with minimum thresholds of weekly nature dose. Nearby nature is associated with quantifiable health benefits, with potential for lowering the human and financial costs of ill health. Dose-response analysis has the potential to guide minimum and optimum recommendations on the management and use of nearby nature for preventative healthcare.

  17. Nearby Red Dwarfs are Sexy for Planets and Life

    Science.gov (United States)

    Henry, T. J.; Jao, W.-C.; Subasavage, J. P.; RECONS Team

    2005-12-01

    The RECONS group continues to discover many nearby red dwarfs in the southern sky through a combination of proper motion surveys, literature review, and ultimately, our parallax program CTIOPI. Already, we have measured the first accurate parallaxes for 11 of the nearest 100 stellar systems, including four within 5 parsecs of the Sun. These nearby red dwarfs are prime candidates for NASA's Space Interferometry Mission (SIM) because the astrometric perturbations are largest for planets orbiting stars of low mass that are nearby. In addition, new multiple red dwarf systems can be targeted for mass determinations, thereby providing points on a comprehensive mass-luminosity relation for the most populous members of the Galaxy. Recent atmospheric modeling of planets orbiting red dwarfs indicates that even if the planets are tidally locked, heat distribution is highly effective in keeping the worlds balmy over the entire surface. Red dwarfs are therefore "back on the table" as viable hosts of life-bearing planets. Given their ubiquity, red dwarfs are being seriously considered as prime SETI targets, and will allow us to answer not only the question "Are We Alone?" but "Just How Alone Are We?" This work has been supported by the National Science Foundation, NASA's Space Interferometry Mission, and Georgia State University.

  18. The Mitchell Spectrograph: Studying Nearby Galaxies with the VIRUS Prototype

    Directory of Open Access Journals (Sweden)

    Guillermo A. Blanc

    2013-01-01

    Full Text Available The Mitchell Spectrograph (a.k.a. VIRUS-P on the 2.7 m Harlan J. Smith telescope at McDonald Observatory is currently the largest field of view (FOV integral field unit (IFU spectrograph in the world (1.7′×1.7′. It was designed as a prototype for the highly replicable VIRUS spectrograph which consists of a mosaic of IFUs spread over a 16′ diameter FOV feeding 150 spectrographs similar to the Mitchell. VIRUS will be deployed on the 9.2 meter Hobby-Eberly Telescope (HET and will be used to conduct the HET Dark Energy Experiment (HETDEX. Since seeing first light in 2007 the Mitchell Spectrograph has been widely used, among other things, to study nearby galaxies in the local universe where their internal structure and the spatial distribution of different physical parameters can be studied in great detail. These observations have provided important insight into many aspects of the physics behind the formation and evolution of galaxies and have boosted the scientific impact of the 2.7 meter telescope enormously. Here I review the contributions of the Mitchell Spectrograph to the study of nearby galaxies, from the investigation the spatial distribution of dark matter and the properties of supermassive black holes, to the studies of the process of star formation and the chemical composition of stars and gas in the ISM, which provide important information regarding the formation and evolution of these systems. I highlight the fact that wide field integral field spectrographs on small and medium size telescopes can be powerful cost effective tools to study the astrophysics of galaxies. Finally I briefly discuss the potential of HETDEX for conducting studies on nearby galaxies. The survey parameters make it complimentary and competitive to ongoing and future surveys like SAMI and MANGA.

  19. Planck early results. XVI. The Planck view of nearby galaxies

    DEFF Research Database (Denmark)

    Lähteenmäki, A.; Poutanen, T.; Natoli, P.

    2011-01-01

    they have been observed. We here present the first results on the properties of nearby galaxies using these data. We match the ERCSC catalogue to IRAS-detected galaxies in the Imperial IRAS Faint Source Redshift Catalogue (IIFSCz), so that we can measure the spectral energy distributions (SEDs......) of these objects from 60 to 850μm. This produces a list of 1717 galaxies with reliable associations between Planck and IRAS, from which we select a subset of 468 for SED studies, namely those with strong detections in the three highest frequency Planck bands and no evidence of cirrus contamination. The SEDs...

  20. SPECKLE INTERFEROMETRY OF SECONDARY COMPONENTS IN NEARBY VISUAL BINARIES

    International Nuclear Information System (INIS)

    Tokovinin, Andrei; Horch, Elliott P.

    2016-01-01

    Statistical characterization of secondary subsystems in binaries helps to distinguish between various scenarios of multiple-star formation. The Differential Speckle Survey Instrument was used at the Gemini-N telescope for several hours in 2015 July to probe the binarity of 25 secondary components in nearby solar-type binaries. Six new subsystems were resolved, with meaningful detection limits for the remaining targets. The large incidence of secondary subsystems agrees with other similar studies. The newly resolved subsystem HIP 115417 Ba,Bb causes deviations in the observed motion of the outer binary from which an astrometric orbit of Ba,Bb with a period of 117 years is deduced.

  1. Spectral differential imaging detection of planets about nearby stars

    International Nuclear Information System (INIS)

    Smith, W.H.

    1987-01-01

    Direct ground-based optical imaging of planets in orbit about nearby stars may be accomplished by spectral differential imaging using multiple passband acoustooptic filters with a CCD. This technique provides two essential results. First, it provides a means to modulate the stellar flux reflected from a planet while leaving the flux from the star and other sources in the same field of view unmodulated. Second, spectral differential imaging enables the CCD detector to achieve a sufficiently high dynamic range to locate planets near a star in spite of an integrated brightness differential of 5 x 10 8 . Spectral differential imaging at nearby diffraction limited imaging conditions with telescope apodization can reduce the time to conduct a sensitive planetary search to a few hours in some cases. The feasibility of this idea is discussed here and shown to provide, in principle, the discrimination and sensitivity to detect a Jovian-class planet about stars at distances of about 10 parsecs. The detection of brown dwarfs is shown to be feasible as well. 31 references

  2. Modelling the star formation histories of nearby elliptical galaxies

    Science.gov (United States)

    Bird, Katy

    Since Lick indices were introduced in 1994, they have been used as a source of observational data against which computer models of galaxy evolution have been compared. However, as this thesis demonstrates, observed Lick indices lead to mathematical ill-conditioning: small variations in observations can lead to very large differences in population synthesis models attempting to recreate the observed values. As such, limited reliance should be placed on any results currently or historically in the literature purporting to give the star formation history of a galaxy, or group of galaxies, where this is deduced from Lick observations taken from a single instrument, without separate verification from at least one other source. Within these limitations, this thesis also constrains the star formation histories of 21 nearby elliptical galaxies, finding that they formed 13.26 +0.09 -0.06 Gyrs ago, that all mergers are dry, and that galactic winds are formed from AGN activity (rather than being supernovae-driven). This thesis also finds evidence to support the established galaxy-formation theory of "downsizing". An existing galactic model from the literature is examined and evaluated, and the reasons for it being unable to establish star formation histories of individual galaxies are ascertained. A brand-new model is designed, developed, tested and used with two separate data sets, corroborated for 10 galaxies by data from a third source, and compared to results from a Single Stellar Population model from the literature, to model the star formation histories of nearby elliptical galaxies.

  3. Geological isotope anomalies as signatures of nearby supernovae

    CERN Document Server

    Ellis, Jonathan Richard; Schramm, David N; Ellis, John; Fields, Brian D; Schramm, David N

    1996-01-01

    Nearby supernova explosions may cause geological isotope anomalies via the direct deposition of debris or by cosmic-ray spallation in the earth's atmosphere. We estimate the mass of material deposited terrestrially by these two mechanisms, showing the dependence on the supernova distance. A number of radioactive isotopes are identified as possible diagnostic tools, such as Be-10, Al-26, Cl-36, Mn-53, Fe-60, and Ni-59, as well as the longer-lived I-129, Sm-146, and Pu-244. We discuss whether the 35 and 60 kyr-old Be-10 anomalies observed in the Vostok antarctic ice cores could be due to supernova explosions. Combining our estimates for matter deposition with results of recent nucleosynthesis yields, we calculate the expected signal from nearby supernovae using ice cores back to \\sim 300 kyr ago, and we discuss using deep ocean sediments back to several hundred Myr. In particular, we examine the prospects for identifying isotope anomalies due to the Geminga supernova explosion, and signatures of the possibility...

  4. A Predicted Astrometric Microlensing Event by a Nearby White Dwarf

    Science.gov (United States)

    McGill, Peter; Smith, Leigh C.; Wyn Evans, N.; Belokurov, Vasily; Smart, R. L.

    2018-04-01

    We used the Tycho-Gaia Astrometric Solution catalogue, part of Gaia Data Release 1, to search for candidate astrometric microlensing events expected to occur within the remaining lifetime of the Gaia satellite. Our search yielded one promising candidate. We predict that the nearby DQ type white dwarf LAWD 37 (WD 1142-645) will lens a background star and will reach closest approach on November 11th 2019 (± 4 days) with impact parameter 380 ± 10 mas. This will produce an apparent maximum deviation of the source position of 2.8 ± 0.1 mas. In the most propitious circumstance, Gaia will be able to determine the mass of LAWD 37 to ˜3%. This mass determination will provide an independent check on atmospheric models of white dwarfs with helium rich atmospheres, as well as tests of white dwarf mass radius relationships and evolutionary theory.

  5. Gravitational interaction of a black hole with nearby matter

    International Nuclear Information System (INIS)

    Price, R.H.; Thorne, K.S.; Redmount, I.H.

    1986-01-01

    The interaction of a black hole with nearby matter is examined with a membrane paradigm which includes a 3+1 formalism that splits spacetime coordinates into a family of three-dimensional spacelike hypersurfaces and one-dimensional time. Emphasis is placed on the influence of matter and its gravity on the shape and evolution of the hole horizon and the effects of the hole on the matter. Universal time coordinates and fiduciary observers are defined outside a dynamically perturbed black hole and tidal gravitational fields are assumed to carry information on the disturbances. The exterior of the hole is examined in terms of the perturbed tidal fields and the material energy, momentum and stress which produce the perturbations. Finally, a membrane model is derived for the interaction of matter and its tidal fields with the stretched null horizon

  6. PROBING EXTRAGALACTIC DUST THROUGH NEARBY GAMMA-RAY BURST AFTERGLOWS

    International Nuclear Information System (INIS)

    Liang, S. L.; Li Aigen

    2010-01-01

    The quantities and wavelength dependencies of the dust extinction along the lines of sight toward 33 nearby gamma-ray bursts (GRBs) with redshifts z V derived from the Drude approach is generally larger by a factor of ∼2-5 than that inferred by assuming a SMC-type template extinction law. Consistent with previous studies, the extinction-to-gas ratio is mostly smaller than that of the MW, and does not seem to correlate with the shape of the extinction curve. It is shown that the standard silicate-graphite interstellar grain model closely reproduces the extinction curves of all 33 GRBs host galaxies. For these 33 bursts at z < 2, we find no evidence for the evolution of the dust extinction, dust sizes, and relative abundances of silicate to graphite on redshifts.

  7. Fast and flexible: argentine ants recruit from nearby trails.

    Directory of Open Access Journals (Sweden)

    Tatiana P Flanagan

    Full Text Available Argentine ants (Linepithema humile live in groups of nests connected by trails to each other and to stable food sources. In a field study, we investigated whether some ants recruit directly from established, persistent trails to food sources, thus accelerating food collection. Our results indicate that Argentine ants recruit nestmates to food directly from persistent trails, and that the exponential increase in the arrival rate of ants at baits is faster than would be possible if recruited ants traveled from distant nests. Once ants find a new food source, they walk back and forth between the bait and sometimes share food by trophallaxis with nestmates on the trail. Recruiting ants from nearby persistent trails creates a dynamic circuit, like those found in other distributed systems, which facilitates a quick response to changes in available resources.

  8. COMPANIONS TO NEARBY STARS WITH ASTROMETRIC ACCELERATION. II

    International Nuclear Information System (INIS)

    Tokovinin, Andrei; Hartung, Markus; Hayward, Thomas L.

    2013-01-01

    Hipparcos astrometric binaries were observed with the NICI adaptive optics system at Gemini-S, completing the work of Paper I. Among the 65 F, G, and K dwarfs within 67 pc of the Sun studied here, we resolve 18 new subarcsecond companions, remeasure 7 known astrometric pairs, and establish the physical nature of yet another 3 wider companions. The 107 astrometric binaries targeted at Gemini so far have 38 resolved companions with separations under 3''. Modeling shows that bright enough companions with separations on the order of an arcsecond can perturb the Hipparcos astrometry when they are not accounted for in the data reduction. However, the resulting bias of parallax and proper motion is generally below formal errors and such companions cannot produce fake acceleration. This work contributes to the multiplicity statistics of nearby dwarfs by bridging the gap between spectroscopic and visual binaries and by providing estimates of periods and mass ratios for many astrometric binaries.

  9. Resolving the Milky Way and Nearby Galaxies with WFIRST

    Science.gov (United States)

    Kalirai, Jasonjot

    High-resolution studies of nearby stellar populations have served as a foundation for our quest to understand the nature of galaxies. Today, studies of resolved stellar populations constrain fundamental relations -- such as the initial mass function of stars, the time scales of stellar evolution, the timing of mass loss and amount of energetic feedback, the color-magnitude relation and its dependency on age and metallicity, the stellar-dark matter connection in galaxy halos, and the build up of stellar populations over cosmic time -- that represent key ingredients in our prescription to interpret light from the Universe and to measure the physical state of galaxies. More than in any other area of astrophysics, WFIRST will yield a transformative impact in measuring and characterizing resolved stellar populations in the Milky Way and nearby galaxies. The proximity and level of detail that such populations need to be studied at directly map to all three pillars of WFIRST capabilities - sensitivity from a 2.4 meter space based telescope, resolution from 0.1" pixels, and large 0.3 degree field of view from multiple detectors. Our WFIRST GO Science Investigation Team (F) will develop three WFIRST (notional) GO programs related to resolved stellar populations to fully stress WFIRST's Wide Field Instrument. The programs will include a Survey of the Milky Way, a Survey of Nearby Galaxy Halos, and a Survey of Star-Forming Galaxies. Specific science goals for each program will be validated through a wide range of observational data sets, simulations, and new algorithms. As an output of this study, our team will deliver optimized strategies and tools to maximize stellar population science with WFIRST. This will include: new grids of IR-optimized stellar evolution and synthetic spectroscopic models; pipelines and algorithms for optimal data reduction at the WFIRST sensitivity and pixel scale; wide field simulations of MW environments and galaxy halos; cosmological simulations

  10. Radioactive Iron Rain: Evidence of a Nearby Supernova Explosion

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    A very close supernova explosion could have caused a mass extinction of life in Earth. In 1996, Brian Fields, the late Dave Schramm and the speaker proposed looking for unstable isotopes such as Iron 60 that could have been deposited by a recent nearby supernova explosion. A group from the Technical University of Munich has discovered Iron 60 in deep-ocean sediments and ferromanganese crusts due to one or more supernovae that exploded O(100) parsecs away about 2.5 million years ago. These results have recently been confirmed by a group from the Australian National University, and the Munich group has also discovered supernova Iron 60 in lunar rock samples. This talk will discuss the interpretation of these results in terms of supernova models, and the possible implications for life on Earth.

  11. Fast and flexible: argentine ants recruit from nearby trails.

    Science.gov (United States)

    Flanagan, Tatiana P; Pinter-Wollman, Noa M; Moses, Melanie E; Gordon, Deborah M

    2013-01-01

    Argentine ants (Linepithema humile) live in groups of nests connected by trails to each other and to stable food sources. In a field study, we investigated whether some ants recruit directly from established, persistent trails to food sources, thus accelerating food collection. Our results indicate that Argentine ants recruit nestmates to food directly from persistent trails, and that the exponential increase in the arrival rate of ants at baits is faster than would be possible if recruited ants traveled from distant nests. Once ants find a new food source, they walk back and forth between the bait and sometimes share food by trophallaxis with nestmates on the trail. Recruiting ants from nearby persistent trails creates a dynamic circuit, like those found in other distributed systems, which facilitates a quick response to changes in available resources.

  12. Smooth H I Low Column Density Outskirts in Nearby Galaxies

    Science.gov (United States)

    Ianjamasimanana, R.; Walter, Fabian; de Blok, W. J. G.; Heald, George H.; Brinks, Elias

    2018-06-01

    The low column density gas at the outskirts of galaxies as traced by the 21 cm hydrogen line emission (H I) represents the interface between galaxies and the intergalactic medium, i.e., where galaxies are believed to get their supply of gas to fuel future episodes of star formation. Photoionization models predict a break in the radial profiles of H I at a column density of ∼5 × 1019 cm‑2 due to the lack of self-shielding against extragalactic ionizing photons. To investigate the prevalence of such breaks in galactic disks and to characterize what determines the potential edge of the H I disks, we study the azimuthally averaged H I column density profiles of 17 nearby galaxies from the H I Nearby Galaxy Survey and supplemented in two cases with published Hydrogen Accretion in LOcal GAlaxieS data. To detect potential faint H I emission that would otherwise be undetected using conventional moment map analysis, we line up individual profiles to the same reference velocity and average them azimuthally to derive stacked radial profiles. To do so, we use model velocity fields created from a simple extrapolation of the rotation curves to align the profiles in velocity at radii beyond the extent probed with the sensitivity of traditional integrated H I maps. With this method, we improve our sensitivity to outer-disk H I emission by up to an order of magnitude. Except for a few disturbed galaxies, none show evidence of a sudden change in the slope of the H I radial profiles: the alleged signature of ionization by the extragalactic background.

  13. Local ISM 3D Distribution and Soft X-ray Background Inferences for Nearby Hot Gas

    Science.gov (United States)

    Puspitarini, L.; Lallement, R.; Snowden, Steven L.; Vergely, J.-L.; Snowden, S.

    2014-01-01

    Three-dimensional (3D) interstellar medium (ISM) maps can be used to locate not only interstellar (IS) clouds, but also IS bubbles between the clouds that are blown by stellar winds and supernovae, and are filled by hot gas. To demonstrate this, and to derive a clearer picture of the local ISM, we compare our recent 3D IS dust distribution maps to the ROSAT diffuse Xray background maps after removal of heliospheric emission. In the Galactic plane, there is a good correspondence between the locations and extents of the mapped nearby cavities and the soft (0.25 keV) background emission distribution, showing that most of these nearby cavities contribute to this soft X-ray emission. Assuming a constant dust to gas ratio and homogeneous 106 K hot gas filling the cavities, we modeled in a simple way the 0.25 keV surface brightness along the Galactic plane as seen from the Sun, taking into account the absorption by the mapped clouds. The data-model comparison favors the existence of hot gas in the solar neighborhood, the so-called Local Bubble (LB). The inferred mean pressure in the local cavities is found to be approx.9,400/cu cm K, in agreement with previous studies, providing a validation test for the method. On the other hand, the model overestimates the emission from the huge cavities located in the third quadrant. Using CaII absorption data, we show that the dust to CaII ratio is very small in those regions, implying the presence of a large quantity of lower temperature (non-X-ray emitting) ionized gas and as a consequence a reduction of the volume filled by hot gas, explaining at least part of the discrepancy. In the meridian plane, the two main brightness enhancements coincide well with the LB's most elongated parts and chimneys connecting the LB to the halo, but no particular nearby cavity is found towards the enhancement in the direction of the bright North Polar Spur (NPS) at high latitude. We searched in the 3D maps for the source regions of the higher energy

  14. Models of bedrock surface and overburden thickness over Olkiluoto island and nearby sea area

    International Nuclear Information System (INIS)

    Moenkkoenen, H.

    2012-04-01

    In this report, a model of bedrock surface and a model of overburden thickness over the Olkiluoto Island and the nearby sea area are presented. Also in purpose to produce material for biosphere and radionuclide transport modelling, stratigraphy models of different sediment layers were created at two priority areas north and south of the Olkiluoto Island. The work concentrated on the collection and description of available data of bedrock surface and overburden thickness. Because the information on the bedrock surface and overburden is collected from different sources and is based on a number of types of data the quality and applicability of data sets varies. Consequently also the reliability in different parts of the models varies. Input data for the bedrock surface and overburden thickness models include 2928 single points and additional outcrops observations (611 polygons) in the modelled area. In addition, the input data include 173 seismic refraction lines (6534 points) and acousticseismic sounding lines (26655 points from which 13721 points are located in model area) in the Olkiluoto offshore area. The average elevation of bedrock surface in area is 2.1 metres above the sea level. The average thickness of overburden is 2.5 metres varying typically between 2 - 4 metres. Thickest overburden covers (approximately 16 metres) of terrestrial area are located at the western end of the Olkiluoto Island and in sea basin south of the island. (orig.)

  15. Models of bedrock surface and overburden thickness over Olkiluoto island and nearby sea area

    Energy Technology Data Exchange (ETDEWEB)

    Moenkkoenen, H. [WSP Finland Oy, Helsinki (Finland)

    2012-04-15

    In this report, a model of bedrock surface and a model of overburden thickness over the Olkiluoto Island and the nearby sea area are presented. Also in purpose to produce material for biosphere and radionuclide transport modelling, stratigraphy models of different sediment layers were created at two priority areas north and south of the Olkiluoto Island. The work concentrated on the collection and description of available data of bedrock surface and overburden thickness. Because the information on the bedrock surface and overburden is collected from different sources and is based on a number of types of data the quality and applicability of data sets varies. Consequently also the reliability in different parts of the models varies. Input data for the bedrock surface and overburden thickness models include 2928 single points and additional outcrops observations (611 polygons) in the modelled area. In addition, the input data include 173 seismic refraction lines (6534 points) and acousticseismic sounding lines (26655 points from which 13721 points are located in model area) in the Olkiluoto offshore area. The average elevation of bedrock surface in area is 2.1 metres above the sea level. The average thickness of overburden is 2.5 metres varying typically between 2 - 4 metres. Thickest overburden covers (approximately 16 metres) of terrestrial area are located at the western end of the Olkiluoto Island and in sea basin south of the island. (orig.)

  16. UVES Abundances of Stars in Nearby Dwarf Spheroidal Galaxies

    Science.gov (United States)

    Tolstoy, Eline; Venn, Kim; Shetrone, Matt; Primas, Francesca; Hill, Vanessa; Kaufer, Andreas; Szeifert, Thomas

    2002-07-01

    It is a truth universally acknowledged, that a galaxy in possession of a good quantity of gas must want to form stars. It is the details of how and why that baffle us all. The simplest theories either would have this process a carefully self-regulated affair, or one that goes completely out of control and is capable of wrecking the galaxy which hosts it. Of course the majority of galaxies seem to amble along somewhere between these two extremes, and the mean properties tend to favour a quiescent self-regulated evolutionary scenario. But there area variety of observations which require us to invoke transitory ‘bursts’ of star-formation at one time or another in most galaxy types. Several nearby dwarf spheroidal galaxies have clearly determined star-formation histories with apparent periods of zero star formation followed by periods of fairly active star formation. If we are able to understand what separated these bursts we would understand several important phenomena in galaxy evolution. Were these galaxies able to clear out their gas reservoir in a burst of star formation? How did this gas return? or did it? Have these galaxies receieved gas from the IGM instead? Could stars from these types of galaxy contribute significantly to the halo population in our Galaxy? To answer these questions we need to combine accurate stellar photometry and Colour-Magnitude Diagram interpretation with detailed metal abundances to combine a star-formation rate versus time with a range of element abundances with time. Different elements trace different evolutionary process (e.g., relative contributions of type I and II supernovae). We often aren't even sure of the abundance spread in these galaxies. We have collected detailed high resolution UVES spectra of four nearby dwarf spheroidal galaxies (Sculptor, Fornax, Leo I & Carina) to begin to answer these questions. This is a precursor study to a more complete study with FLAMES. We presented at this meeting the initial results for

  17. On the nature of absorption features toward nearby stars

    Science.gov (United States)

    Kohl, S.; Czesla, S.; Schmitt, J. H. M. M.

    2016-06-01

    Context. Diffuse interstellar absorption bands (DIBs) of largely unknown chemical origin are regularly observed primarily in distant early-type stars. More recently, detections in nearby late-type stars have also been claimed. These stars' spectra are dominated by stellar absorption lines. Specifically, strong interstellar atomic and DIB absorption has been reported in τ Boo. Aims: We test these claims by studying the strength of interstellar absorption in high-resolution TIGRE spectra of the nearby stars τ Boo, HD 33608, and α CrB. Methods: We focus our analysis on a strong DIB located at 5780.61 Å and on the absorption of interstellar Na. First, we carry out a differential analysis by comparing the spectra of the highly similar F-stars, τ Boo and HD 33608, whose light, however, samples different lines of sight. To obtain absolute values for the DIB absorption, we compare the observed spectra of τ Boo, HD 33608, and α CrB to PHOENIX models and carry out basic spectral modeling based on Voigt line profiles. Results: The intercomparison between τ Boo and HD 33608 reveals that the difference in the line depth is 6.85 ± 1.48 mÅ at the DIB location which is, however, unlikely to be caused by DIB absorption. The comparison between PHOENIX models and observed spectra yields an upper limit of 34.0 ± 0.3 mÅ for any additional interstellar absorption in τ Boo; similar results are obtained for HD 33608 and α CrB. For all objects we derive unrealistically large values for the radial velocity of any presumed interstellar clouds. In τ Boo we find Na D absorption with an equivalent width of 0.65 ± 0.07 mÅ and 2.3 ± 0.1 mÅ in the D2 and D1 lines. For the other Na, absorption of the same magnitude could only be detected in the D2 line. Our comparisons between model and data show that the interstellar absorption toward τ Boo is not abnormally high. Conclusions: We find no significant DIB absorption in any of our target stars. Any differences between modeled and

  18. A systematic search for brown dwarfs orbiting nearby stars

    International Nuclear Information System (INIS)

    Henry, T.J.; Mccarthy, D.W. Jr.

    1990-01-01

    Survey data for brown dwarf and stellar companions relative to known M dwarf stars within 5 pc north of -30 deg are analyzed. A region 0.2 to 5 arcsec in radius around 27 stars at the IR H and K bands are examined using IR speckle interferometry. The frequency of binary versus single M dwarfs in the solar neighborhood is examined. The IR mass-magnitude relations and mass-luminosity-age relation are studied. The data reveal that there are 19 single M dwarfs, 8 M dwarf binaries, 1 M dwarf triple system, and 1 M dwarf in a triple system for M dwarfs within 5 pc north of -30 deg. Also of the 27 M dwarfs studied none was found to have a brown dwarf companion. 64 refs

  19. EVIDENCE FOR ACCRETION IN A NEARBY, YOUNG BROWN DWARF

    International Nuclear Information System (INIS)

    Reiners, Ansgar

    2009-01-01

    We report on the discovery of the young, nearby, brown dwarf 2MASS J0041353-562112. The object has a spectral type of M7.5; it shows Li absorption and signatures of accretion, which implies that it still has a disk and suggests an age below 10 Myr. The space motion vector and position on the sky indicate that the brown dwarf is probably a member of the ∼20 Myr old Tuc-Hor association, or that it may be an ejected member of the ∼12 Myr old β Pic association; both would imply that 2MASS J0041353-562112 may in fact be older than 10 Myr. No accreting star or brown dwarf was previously known in these associations. Assuming an age of 10 Myr, the brown dwarf has a mass of about 30 M Jup and is located at 35 pc distance. The newly discovered object is the closest accreting brown dwarf known. Its membership to an association older than 10 Myr implies that either disks in brown dwarfs can survive as long as in more massive stars, perhaps even longer, or that star formation in Tuc-Hor or β Pic occurred more recently than previously thought. The history and evolution of this object can provide new fundamental insight into the formation process of stars, brown dwarfs, and planets.

  20. The POKEMON Speckle Survey of Nearby M-Dwarfs

    Science.gov (United States)

    van Belle, Gerard; von Braun, Kaspar; Horch, Elliott; Clark, Catherine; DSSI Speckle Team

    2018-01-01

    The POKEMON (Pervasive Overview of Kompanions of Every M-dwarf in Our Neighborhood) survey of nearby M-dwarfs intends to inspect, at diffraction-limited resolution, every low-mass star out to 15pc, along with selected additional objects to 25pc. The primary emphasis of the survey is detection of low-mass companions to these M-dwarfs for refinement of the low-mass star multiplicity rate. The resultant catalog of M-dwarf companions will also guide immediate refinement of transit planet detection results from surveys such as TESS. POKEMON is using Lowell Observatory's 4.3-m Discovery Channel Telescope (DCT) with the Differential Speckle Survey Instrument (DSSI) speckle camera, along with the NN-Explore Exoplanet Stellar Speckle Imager (NESSI) speckle imager on 3.5-m WIYN; the survey takes advantage of the extremely rapid observing cadence rates possible with WIYN and (especially) DCT. The current status and preliminary results from the first 20+ nights of observing will be presented. Gotta observe them all!

  1. Do landfills affect the environmental quality of nearby streams?

    Directory of Open Access Journals (Sweden)

    Leandro Schlemmer Brasil

    2017-12-01

    Full Text Available When inappropriately disposed, solid waste may contaminate the soil, water and air, leading to severe negative impacts on biodiversity. The Brazilian National Policy for Solid Waste (PNRS requires municipalities to ensure the environmental quality of landfills. Accordingly, our objective was to evaluate the community of aquatic insects in a stream with stretches downstream and upstream of a sanitary landfill. Our hypothesis was that there will be no differences in insect community between the stretches (downstream and upstream on the basis of the premise that landfills abiding by the PNRS do not cause environmental damage to nearby areas. There was no change in any aspect of the composition of the macroinvertebrate community as a result of the landfill. The only changes observed in the macroinvertebrate communities occurred between the dry and rainy seasons, which were related to the seasonality and consequent changes in the environmental conditions of the water over the year. Our study, although limited, showed primary and pioneering evidence that the PNRS can contribute positively to the conservation of the biotic quality of aquatic environments, further reinforcing the need for immediate implementation of the PNRS throughout the country.

  2. DUSTY WINDS: EXTRAPLANAR POLYCYCLIC AROMATIC HYDROCARBON FEATURES OF NEARBY GALAXIES

    Energy Technology Data Exchange (ETDEWEB)

    McCormick, Alexander; Veilleux, Sylvain [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Rupke, David S. N., E-mail: alexm@astro.umd.edu, E-mail: veilleux@astro.umd.edu, E-mail: rupked@rhodes.edu [Rhodes College, 2000 North Parkway, Memphis, TN 38112 (United States)

    2013-09-10

    Recent observations have shown the presence of dust and molecular material in galactic winds, but relatively little is known about the distribution of these outflow components. To shed some light on this issue, we have used IRAC images from the Spitzer Space Telescope archive to investigate polycyclic aromatic hydrocarbon (PAH) emission from a sample of 16 local galaxies with known winds. Our focus on nearby sources (median distance 8.6 Mpc) has revealed detailed PAH structure in the winds and allowed us to measure extraplanar PAH emission. We have identified extraplanar PAH features on scales of {approx}0.8-6.0 kpc. We find a nearly linear correlation between the amount of extraplanar PAH emission and the total infrared flux, a proxy for star formation activity in the disk. Our results also indicate a correlation between the height of extraplanar PAH emission and star formation rate surface density, which supports the idea of a surface density threshold on the energy or momentum injection rate for producing detectable extraplanar wind material.

  3. Scaling Relations between Gas and Star Formation in Nearby Galaxies

    Science.gov (United States)

    Bigiel, Frank; Leroy, Adam; Walter, Fabian

    2011-04-01

    High resolution, multi-wavelength maps of a sizeable set of nearby galaxies have made it possible to study how the surface densities of H i, H2 and star formation rate (ΣHI, ΣH2, ΣSFR) relate on scales of a few hundred parsecs. At these scales, individual galaxy disks are comfortably resolved, making it possible to assess gas-SFR relations with respect to environment within galaxies. ΣH2, traced by CO intensity, shows a strong correlation with ΣSFR and the ratio between these two quantities, the molecular gas depletion time, appears to be constant at about 2 Gyr in large spiral galaxies. Within the star-forming disks of galaxies, ΣSFR shows almost no correlation with ΣHI. In the outer parts of galaxies, however, ΣSFR does scale with ΣHI, though with large scatter. Combining data from these different environments yields a distribution with multiple regimes in Σgas - ΣSFR space. If the underlying assumptions to convert observables to physical quantities are matched, even combined datasets based on different SFR tracers, methodologies and spatial scales occupy a well define locus in Σgas - ΣSFR space.

  4. Radiation-Induced Correlation between Molecules Nearby Metallic Antenna Array

    Directory of Open Access Journals (Sweden)

    Yoshiki Osaka

    2015-01-01

    Full Text Available We theoretically investigate optical absorption of molecules embedded nearby metallic antennas by using discrete dipole approximation method. It is found that the spectral peak of the absorption is shifted due to the radiation-induced correlation between the molecules. The most distinguishing feature of our work is to show that the shift is largely enhanced even when the individual molecules couple with localized surface plasmons near the different antennas. Specifically, we first consider the case that two sets of dimeric gold blocks with a spacing of a few nanometers are arranged and reveal that the intensity and spectral peak of the optical absorption strongly depend on the position of the molecules. In addition, when the dimeric blocks and the molecules are periodically arranged, the peak shift is found to increase up to ~1.2 meV (300 GHz. Because the radiation-induced correlation is essential for collective photon emission, our result implies the possibility of plasmon-assisted superfluorescence in designed antenna-molecule complex systems.

  5. Multicolor photometry of the nearby galaxy cluster A119

    International Nuclear Information System (INIS)

    Tian Jintao; Zhou Xu; Jiang Zhaoji; Ma Jun; Wu Zhenyu; Fan Zhou; Zhang Tianmeng; Zou Hu; Yuan Qirong; Wu Jianghua

    2012-01-01

    This paper presents multicolor optical photometry of the nearby galaxy cluster Abell 119 (z = 0.0442) with the Beijing-Arizona-Taiwan-Connecticut system of 15 intermediate bands. Within the BATC field of view of 58' × 58', there are 368 galaxies with known spectroscopic redshifts, including 238 member galaxies (called sample I). Based on the spectral energy distributions of 1376 galaxies brighter than i BATC = 19.5, the photometric redshift technique and the color-magnitude relation of early-type galaxies are applied to select faint member galaxies. As a result, 117 faint galaxies were selected as new member galaxies. Combined with sample I, an enlarged sample (called sample II) of 355 member galaxies is obtained. Spatial distribution and localized velocity structure for two samples demonstrate that A119 is a dynamically complex cluster with at least three prominent substructures in the central region within 1 Mpc. A large velocity dispersion for the central clump indicates a merging along the line of sight. No significant evidence for morphology or luminosity segregations is found in either sample. With the PEGASE evolutionary synthesis model, the environmental effect on the properties of star formation is confirmed. Faint galaxies in the low-density region tend to have longer time scales of star formation, smaller mean stellar ages, and lower metallicities in their interstellar medium, which is in agreement with the context of the hierarchical cosmological scenario. (research papers)

  6. Could a nearby supernova explosion have caused a mass extinction?

    International Nuclear Information System (INIS)

    Ellis, J.; Schramm, D.N.

    1995-01-01

    We examine the possibility that a nearby supernova explosion could have caused one or more of the mass extinctions identified by paleontologists. We discuss the possible rate of such events in the light of the recent suggested identification of Geminga as a supernova remnant less than 100 parsec (pc) away and the discovery of a millisecond pulsar about 150 pc away and observations of SN 1987A. The fluxes of γ-radiation and charged cosmic rays on the Earth are estimated, and their effects on the Earth's ozone layer are discussed. A supernova explosion of the order of 10 pc away could be expected as often as every few hundred million years and could destroy the ozone layer for hundreds of years, letting in potentially lethal solar ultraviolet radiation. In addition to effects on land ecology, this could entail mass destruction of plankton and reef communities, with disastrous consequences for marine life as well. A supernova extinction should be distinguishable from a meteorite impact such as the one that presumably killed the dinosaurs at the open-quotes KT boundary.close quotes The recent argument that the KT event was exceedingly large and thus quite rare supports the need for other catastrophic events. 24 refs

  7. Could a nearby supernova explosion have caused a mass extinction?

    CERN Document Server

    Ellis, Jonathan Richard

    1995-01-01

    We examine the possibility that a nearby supernova explosion could have caused one or more of the mass extinctions identified by palaeontologists. We discuss the likely rate of such events in the light of the recent identification of Geminga as a supernova remnant less than 100 pc away and the discovery of a millisecond pulsar about 150 pc away, and observations of SN 1987A. The fluxes of $\\gamma$ radiation and charged cosmic rays on the Earth are estimated, and their effects on the Earth's ozone layer discussed. A supernova explosion of the order of 10 pc away could be expected every few hundred million years, and could destroy the ozone layer for hundreds of years, letting in potentially lethal solar ultraviolet radiation. In addition to effects on land ecology, this could entail mass destruction of plankton and reef communities, with disastrous consequences for marine life as well. A supernova extinction should be distinguishable from a meteorite impact such as the one that presumably killed the dinosaurs.

  8. LOW-MASS VISUAL COMPANIONS TO NEARBY G-DWARFS

    International Nuclear Information System (INIS)

    Tokovinin, Andrei

    2011-01-01

    A complete census of wide visual companions to nearby G-dwarf stars can be achieved by selecting candidates from the Two Micron All Sky Survey (2MASS) Point-Source Catalog and checking their status by second-epoch imaging. Such data are obtained for 124 candidates with separations up to 20'', 47 of which are shown to be new physical low-mass stellar companions. A list of visual binaries with G-dwarf primaries is produced by combining newly found companions with historical data. Maximum likelihood analysis leads to a companion frequency of 0.13 ± 0.015 per decade of separation. The mass ratio is distributed almost uniformly, with a power-law index between -0.4 and 0. The remaining uncertainty in the index is related to modeling of the companion detection threshold in 2MASS. These findings are confirmed by an alternative analysis of wider companions in 2MASS, removing the contamination by background stars statistically. Extension of this work will lead to a complete detection of visual companions-a necessary step toward reaching unbiased multiplicity statistics over the full range of orbital periods and, eventually, understanding the origin of multiple systems.

  9. [Nearby nature as a moderator of stress during childhood].

    Science.gov (United States)

    Corraliza, José Antonio; Collado, Silvia

    2011-04-01

    The aim of this investigation is to study the relation between the amount of nature existing in children's daily environments and the way children deal with stressful events. Every day, children are exposed to situations that cause stress. Taking into account previous studies, it is thought that the greener the place where children spend their time, the better they cope with adversities. Thus, when comparing the stress level of children who are exposed to the same amount of adverse situations, the children who have more frequent daily contact with nature will show less stress than those who do not spend time in nature. This effect from nearby nature is called a buffering effect. The present study provides empirical evidence of the buffering effect caused by the existence of Nature in the residential and the school environment. Therefore, our results show that children who have more access to nature increase their resilience, showing a lower stress level than children whose contact with nature is less frequent.

  10. Could a nearby supernova explosion have caused a mass extinction?

    Science.gov (United States)

    Ellis, J; Schramm, D N

    1995-01-03

    We examine the possibility that a nearby supernova explosion could have caused one or more of the mass extinctions identified by paleontologists. We discuss the possible rate of such events in the light of the recent suggested identification of Geminga as a supernova remnant less than 100 parsec (pc) away and the discovery of a millisecond pulsar about 150 pc away and observations of SN 1987A. The fluxes of gamma-radiation and charged cosmic rays on the Earth are estimated, and their effects on the Earth's ozone layer are discussed. A supernova explosion of the order of 10 pc away could be expected as often as every few hundred million years and could destroy the ozone layer for hundreds of years, letting in potentially lethal solar ultraviolet radiation. In addition to effects on land ecology, this could entail mass destruction of plankton and reef communities, with disastrous consequences for marine life as well. A supernova extinction should be distinguishable from a meteorite impact such as the one that presumably killed the dinosaurs at the "KT boundary." The recent argument that the KT event was exceedingly large and thus quite rare supports the need for other catastrophic events.

  11. Ultrahigh energy cosmic rays from nearby starburst galaxies

    Science.gov (United States)

    Attallah, Reda; Bouchachi, Dallel

    2018-04-01

    Ultrahigh energy cosmic rays are the most energetic of any subatomic particles ever observed in nature. The quest for their mysterious origin is currently a major scientific challenge. Here we explore the possibility that these particles originate from nearby starburst galaxies, a scenario that matches the recent observation by the Telescope Array experiment of a cosmic-ray hotspot above 57 EeV not far from the direction of the starburst galaxy M82. Specifically, we study the stochastic propagation in space of ultrahigh energy cosmic rays through the state-of-the-art simulation framework CRPropa 3, taking into account all relevant particle interactions as well as deflections by the intervening magnetic fields. To ensure a comprehensive understanding of this model, we consider the energy spectrum, the cosmogenic neutrinos and gamma rays, and the distribution of arrival directions. The starburst galaxy scenario reproduces well observations from both the Telescope Array and Pierre Auger Observatories, making it very attractive for explaining the origin of cosmic rays at the highest energies.

  12. THE GREEN BANK TELESCOPE MAPS THE DENSE, STAR-FORMING GAS IN THE NEARBY STARBURST GALAXY M82

    International Nuclear Information System (INIS)

    Kepley, Amanda A.; Frayer, David; Leroy, Adam K.; Usero, Antonio; Marvil, Josh; Walter, Fabian

    2014-01-01

    Observations of the Milky Way and nearby galaxies show that dense molecular gas correlates with recent star formation, suggesting that the formation of this gas phase may help regulate star formation. A key test of this idea requires wide-area, high-resolution maps of dense molecular gas in galaxies to explore how local physical conditions drive dense gas formation, but these observations have been limited because of the faintness of dense gas tracers like HCN and HCO + . Here we demonstrate the power of the Robert C. Byrd Green Bank Telescope (GBT)—the largest single-dish millimeter radio telescope—for mapping dense gas in galaxies by presenting the most sensitive maps yet of HCN and HCO + in the starburst galaxy M82. The HCN and HCO + in the disk of this galaxy correlates with both recent star formation and more diffuse molecular gas and shows kinematics consistent with a rotating torus. The HCO + emission extending to the north and south of the disk is coincident with the outflow previously identified in CO and traces the eastern edge of the hot outflowing gas. The central starburst region has a higher ratio of star formation to dense gas than the outer regions, pointing to the starburst as a key driver of this relationship. These results establish that the GBT can efficiently map the dense molecular gas at 90 GHz in nearby galaxies, a capability that will increase further with the 16 element feed array under construction

  13. The Keck/OSIRIS Nearby AGN Survey (KONA). I. The Nuclear K-band Properties of Nearby AGN

    Science.gov (United States)

    Müller-Sánchez, F.; Hicks, E. K. S.; Malkan, M.; Davies, R.; Yu, P. C.; Shaver, S.; Davis, B.

    2018-05-01

    We introduce the Keck OSIRIS Nearby AGN survey (KONA), a new adaptive optics-assisted integral-field spectroscopic survey of Seyfert galaxies. KONA permits at ∼0.″1 resolution a detailed study of the nuclear kinematic structure of gas and stars in a representative sample of 40 local bona fide active galactic nucleus (AGN). KONA seeks to characterize the physical processes responsible for the coevolution of supermassive black holes and galaxies, principally inflows and outflows. With these IFU data of the nuclear regions of 40 Seyfert galaxies, the KONA survey will be able to study, for the first time, a number of key topics with meaningful statistics. In this paper we study the nuclear K-band properties of nearby AGN. We find that the K-band (2.1 μm) luminosities of the compact Seyfert 1 nuclei are correlated with the hard X-ray luminosities, implying a non-stellar origin for the majority of the continuum emission. The best-fit correlation is log L K = 0.9log L 2–10 keV + 4 over three orders of magnitude in both K-band and X-ray luminosities. We find no strong correlation between 2.1 μm luminosity and hard X-ray luminosity for the Seyfert 2 galaxies. The spatial extent and spectral slope of the Seyfert 2 galaxies indicate the presence of nuclear star formation and attenuating material (gas and dust), which in some cases is compact and in some galaxies extended. We detect coronal-line emission in 36 galaxies and for the first time in 5 galaxies. Finally, we find 4/20 galaxies that are usually classified as Seyfert 2 based on their optical spectra exhibit a broad component of Brγ emission, and one galaxy (NGC 7465) shows evidence of a double nucleus. Based on observations at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The observatory was made possible by the generous financial support of the W. M

  14. A Metagenomic Survey of Serpentinites and Nearby Soils in Taiwan

    Science.gov (United States)

    Li, K. Y.; Hsu, Y. W.; Chen, Y. W.; Huang, T. Y.; Shih, Y. J.; Chen, J. S.; Hsu, B. M.

    2016-12-01

    The serpentinite of Taiwan is originated from the subduction zone of the Eurasian plate and the Philippine Sea plate. Many small bodies of serpentinite are scattered around the lands of the East Rift Valley, which are also one of the major agricultural areas in Taiwan. Since microbial communities play a role both on weathering process and soil recovery, uncovering the microbial compositions in serpentinites and surrounding soils may help people to understand the roles of microorganisms on serpentinites during the nature weathering process. In this study, microorganisms growing on the surface of serpentinites, in the surrounding soil, and agriculture soils that are miles of horizontal distance away from serpentinite were collected. Next generation sequencing (NGS) was carried out to examine the metagenomics of uncultured microbial community in these samples. The metagenomics were further clustered into operational taxonomic units (OTUs) to analyze relative abundance, heatmap of OTUs, and principal coordinates analysis (PCoA). Our data revealed the different types of geographic material had their own distinct structures of microbial community. In serpentinites, the heatmaps based on the phylogenetic pattern showed that the OTUs distributions were similar in phyla of Bacteroidetes, Cyanobacteria, Proteobacteria, Verrucomicrobia, and WPS-1/WPS-2. On the other hand, the heatmaps of phylogenetic pattern of agriculture soils showed that the OTUs distributions in phyla of Chloroflexi, Acidobacteria, Actinobacteria, WPS-1/WPS-2, and Proteobacteria were similar. In soil nearby the serpentinite, some clusters of OTUs in phyla of Bacteroidetes, Cyanobacteria, and WPS-1/WPS-2 have disappeared. Our data provided evidence regarding kinetic evolutions of microbial communities in different geographic materials.

  15. Nearby stars of the Galactic disc and halo - IV

    Science.gov (United States)

    Fuhrmann, Klaus

    2008-02-01

    The Milky Way Galaxy has an age of about 13 billion years. Solar-type stars evolve all the long way to the realm of degenerate objects on essentially this time-scale. This, as well as the particular advantage that the Sun offers through reliable differential spectroscopic analyses, render these stars the ideal tracers for the fossil record of our parent spiral. Astrophysics is a science that is known to be notoriously plagued by selection effects. The present work - with a major focus in this fourth contribution on model atmosphere analyses of spectroscopic binaries and multiple star systems - aims at a volume-complete sample of about 300 nearby F-, G-, and K-type stars that particularly avoids any kinematical or chemical pre-selection from the outset. It thereby provides an unbiased record of the local stellar populations - the ancient thick disc and the much younger thin disc. On this base, the detailed individual scrutiny of the long-lived stars of both populations unveils the thick disc as a single-burst component with a local normalization of no less than 20 per cent. This enormous fraction, combined with its much larger scaleheight, implies a mass for the thick disc that is comparable to that of the thin disc. On account of its completely different mass-to-light ratio the thick disc thereby becomes the dark side of the Milky Way, an ideal major source for baryonic dark matter. This massive, ancient population consequently challenges any gradual build-up scenario for our parent spiral. Even more, on the supposition that the Galaxy is not unusual, the thick disc - as it emerges from this unbiased spectroscopic work - particularly challenges the hierarchical cold-dark-matter-dominated formation picture for spiral galaxies in general.

  16. STAR FORMATION AND SUPERCLUSTER ENVIRONMENT OF 107 NEARBY GALAXY CLUSTERS

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, Seth A.; Hickox, Ryan C.; Wegner, Gary A. [Department of Physics and Astronomy, Dartmouth College, 6127 Wilder Laboratory, Hanover, NH 03755 (United States); Einasto, Maret; Vennik, Jaan [Tartu Observatory, 61602 Tõravere (Estonia)

    2017-01-20

    We analyze the relationship between star formation (SF), substructure, and supercluster environment in a sample of 107 nearby galaxy clusters using data from the Sloan Digital Sky Survey. Previous works have investigated the relationships between SF and cluster substructure, and cluster substructure and supercluster environment, but definitive conclusions relating all three of these variables has remained elusive. We find an inverse relationship between cluster SF fraction ( f {sub SF}) and supercluster environment density, calculated using the Galaxy luminosity density field at a smoothing length of 8 h {sup −1} Mpc (D8). The slope of f {sub SF} versus D8 is −0.008 ± 0.002. The f {sub SF} of clusters located in low-density large-scale environments, 0.244 ± 0.011, is higher than for clusters located in high-density supercluster cores, 0.202 ± 0.014. We also divide superclusters, according to their morphology, into filament- and spider-type systems. The inverse relationship between cluster f {sub SF} and large-scale density is dominated by filament- rather than spider-type superclusters. In high-density cores of superclusters, we find a higher f {sub SF} in spider-type superclusters, 0.229 ± 0.016, than in filament-type superclusters, 0.166 ± 0.019. Using principal component analysis, we confirm these results and the direct correlation between cluster substructure and SF. These results indicate that cluster SF is affected by both the dynamical age of the cluster (younger systems exhibit higher amounts of SF); the large-scale density of the supercluster environment (high-density core regions exhibit lower amounts of SF); and supercluster morphology (spider-type superclusters exhibit higher amounts of SF at high densities).

  17. Marine exotic isopods from the Iberian Peninsula and nearby waters.

    Science.gov (United States)

    Martínez-Laiz, Gemma; Ros, Macarena; Guerra-García, José M

    2018-01-01

    Effective management of marine bioinvasions starts with prevention, communication among the scientific community and comprehensive updated data on the distribution ranges of exotic species. Despite being a hotspot for introduction due to numerous shipping routes converging at the Strait of Gibraltar, knowledge of marine exotics in the Iberian Peninsula is scarce, especially of abundant but small-sized and taxonomically challenging taxa such as the Order Isopoda. To fill this gap, we conducted several sampling surveys in 44 marinas and provide the first comprehensive study of marine exotic isopods from the Iberian Peninsula, the southern side of the Strait of Gibraltar (northern Africa) and the Balearic Islands. Exotic species included Ianiropsis serricaudis (first record for the Iberian Peninsula and Lusitanian marine province), Paracerceis sculpta (first record for the Alboran Sea ecoregion), Paradella dianae , Paranthura japonica (earliest record for the Iberian Peninsula) and Sphaeroma walkeri . Photographs with morphological details for identification for non-taxonomic experts are provided, their worldwide distribution is updated and patterns of invasion are discussed. We report an expansion in the distribution range of all species, especially at the Strait of Gibraltar and nearby areas. Ianiropsis serricaudis and Paranthura japonica are polyvectic, with shellfish trade and recreational boating being most probable vectors for their introduction and secondary spread. The subsequent finding of the studied species in additional marinas over the years points at recreational boating as a vector and indicates a future spread. We call for attention to reduce lags in the detection and reporting of small-size exotics, which usually remain overlooked or underestimated until the invasion process is at an advanced stage.

  18. Discovery of path nearby clusters in spatial networks

    KAUST Repository

    Shang, Shuo

    2015-06-01

    The discovery of regions of interest in large cities is an important challenge. We propose and investigate a novel query called the path nearby cluster (PNC) query that finds regions of potential interest (e.g., sightseeing places and commercial districts) with respect to a user-specified travel route. Given a set of spatial objects O (e.g., POIs, geo-tagged photos, or geo-tagged tweets) and a query route q , if a cluster c has high spatial-object density and is spatially close to q , it is returned by the query (a cluster is a circular region defined by a center and a radius). This query aims to bring important benefits to users in popular applications such as trip planning and location recommendation. Efficient computation of the PNC query faces two challenges: how to prune the search space during query processing, and how to identify clusters with high density effectively. To address these challenges, a novel collective search algorithm is developed. Conceptually, the search process is conducted in the spatial and density domains concurrently. In the spatial domain, network expansion is adopted, and a set of vertices are selected from the query route as expansion centers. In the density domain, clusters are sorted according to their density distributions and they are scanned from the maximum to the minimum. A pair of upper and lower bounds are defined to prune the search space in the two domains globally. The performance of the PNC query is studied in extensive experiments based on real and synthetic spatial data. © 2014 IEEE.

  19. Biomonitoring a human population inhabiting nearby a deactivated uranium mine

    International Nuclear Information System (INIS)

    Lourenço, J.; Pereira, R.; Pinto, F.; Caetano, T.; Silva, A.; Carvalheiro, T.

    2013-01-01

    Highlights: ► Human population environmentally exposed to uranium mining wastes. ► Significantly higher levels of manganese and uranium in peripheral blood samples. ► Significant DNA damages detected by the comet assay. ► Significant decrease of NK and T lymphocytes counts in exposed individuals. ► Concerns on the risks of human populations living nearby uranium mining areas. - Abstract: Environmental exposure to uranium and its daughter radionuclides, has been linked to several negative effects such as those related with important physiological processes, like hematopoiesis, and may also be associated with genotoxicity effects. Herein, genotoxic effects, immunotoxicity, trace elements and C reactive protein (CRP) analyses, were performed in peripheral blood samples collected from individuals of a population living near a deactivated uranium mine. C reactive protein analysis was performed to exclude candidates with active inflammatory processes from further evaluations. DNA damage and immunotoxicity (immunophenotyping and immune cell counts) were evaluated by comet assay and flow cytometry, respectively. Significant DNA damage was observed in the peripheral blood samples from volunteers living in the Cunha Baixa village. A significant decrease of NK and T lymphocytes counts were observed in the individuals from the Cunha Baixa village, when compared with individuals from the reference site. Uranium and manganese levels were significantly higher in the Cunha Baixa village inhabitants. On the other hand, zinc levels were significantly lower in those individuals when compared with the volunteers from the control village. Results suggest that inhabitants from Cunha Baixa have a higher risk of suffering from serious diseases such as cancer, since high DNA damages were observed in peripheral blood leukocytes and also decreased levels of NK and T cells, which play an essential role in the defense against tumor growth

  20. THE NUCLEAR ACTIVITIES OF NEARBY S0 GALAXIES

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Meng-Yuan; Gu, Qiu-Sheng; Chen, Yan-Mei; Zhou, Luwenjia, E-mail: qsgu@nju.edu.cn [School of Astronomy and Space Science, Nanjing University, Nanjing 210093, P. R. China (China)

    2016-11-01

    We present a study of nuclear activities in nearby S0 galaxies. After cross-matching the Sloan Digital Sky Survey Data Release 7 with the Third Reference Catalog of Bright Galaxies (RC3) and visually checking the SDSS images, we derive a sample of 583 S0 galaxies with the central spectrophotometric information. In order to separate nebular emission lines from the underlying stellar contribution, we fit the stellar population model to the SDSS spectra of these S0 galaxies. According to the BPT diagram, we find that 8% of S0 galaxies show central star-forming activity, while the fractions of Seyfert, Composite, and low-ionization nuclear emission-line regions (LINERs) are 2%, 8%, and 21.4%, respectively. We also find that star-forming S0s have the lowest stellar masses, over one magnitude lower than the others, and that the active S0s are mainly located in the sparse environment, while the normal S0s are located in the dense environment, which might suggest that the environment plays an important role in quenching star formation and/or AGN activity in S0 galaxies. By performing bulge-disk decomposition of 45 star-forming S0s in g - and r -bands with the 2D fitting software Galfit, as well as exploiting the catalog of 2D photometric decompositions of Meert et al., we find that the bulges of approximately one-third of star-forming S0 galaxies (16/45) are bluer than their disks, while for other types of S0s the bulge and disk components show similar color distributions. Besides, the Sérsic index of most star-forming S0s bulges is less than two, while for normal S0s, it is between two and six.

  1. A COMPREHENSIVE CENSUS OF NEARBY INFRARED EXCESS STARS

    Energy Technology Data Exchange (ETDEWEB)

    Cotten, Tara H.; Song, Inseok, E-mail: tara@physast.uga.edu, E-mail: song@physast.uga.edu [Department of Physics and Astronomy, University of Georgia, Athens, GA 30602 (United States)

    2016-07-01

    The conclusion of the Wide-Field Infrared Survey Explorer ( WISE ) mission presents an opportune time to summarize the history of using excess emission in the infrared as a tracer of circumstellar material and exploit all available data for future missions such as the James Webb Space Telescope . We have compiled a catalog of infrared excess stars from peer-reviewed articles and perform an extensive search for new infrared excess stars by cross-correlating the Tycho-2 and all-sky WISE (AllWISE) catalogs. We define a significance of excess in four spectral type divisions and select stars showing greater than either 3 σ or 5 σ significance of excess in the mid- and far-infrared. Through procedures including spectral energy distribution fitting and various image analyses, each potential excess source was rigorously vetted to eliminate false positives. The infrared excess stars from the literature and the new stars found through the Tycho-2 and AllWISE cross-correlation produced nearly 500 “Prime” infrared excess stars, of which 74 are new sources of excess, and >1200 are “Reserved” stars, of which 950 are new sources of excess. The main catalog of infrared excess stars are nearby, bright, and either demonstrate excess in more than one passband or have infrared spectroscopy confirming the infrared excess. This study identifies stars that display a spectral energy distribution suggestive of a secondary or post-protoplanetary generation of dust, and they are ideal targets for future optical and infrared imaging observations. The final catalogs of stars summarize the past work using infrared excess to detect dust disks, and with the most extensive compilation of infrared excess stars (∼1750) to date, we investigate various relationships among stellar and disk parameters.

  2. Search for bright nearby M dwarfs with virtual observatory tools

    Energy Technology Data Exchange (ETDEWEB)

    Aberasturi, M.; Caballero, J. A.; Montesinos, B.; Gálvez-Ortiz, M. C.; Solano, E.; Martín, E. L. [Centro de Astrobiología (CSIC-INTA), Departamento de Astrofísica, P.O. Box 78, E-28691 Villanueva de la Cañada, Madrid (Spain)

    2014-08-01

    Using Virtual Observatory tools, we cross-matched the Carlsberg Meridian 14 and the 2MASS Point Source catalogs to select candidate nearby bright M dwarfs distributed over ∼25,000 deg{sup 2}. Here, we present reconnaissance low-resolution optical spectra for 27 candidates that were observed with the Intermediate Dispersion Spectrograph at the 2.5 m Isaac Newton Telescope (R≈ 1600). We derived spectral types from a new spectral index, R, which measures the ratio of fluxes at 7485-7015 Å and 7120-7150 Å. We also used VOSA, a Virtual Observatory tool for spectral energy distribution fitting, to derive effective temperatures and surface gravities for each candidate. The resulting 27 targets were M dwarfs brighter than J = 10.5 mag, 16 of which were completely new in the Northern hemisphere and 7 of which were located at less than 15 pc. For all of them, we also measured Hα and Na I pseudo-equivalent widths, determined photometric distances, and identified the most active stars. The targets with the weakest sodium absorption, namely, J0422+2439 (with X-ray and strong Hα emissions), J0435+2523, and J0439+2333, are new members in the young Taurus-Auriga star-forming region based on proper motion, spatial distribution, and location in the color-magnitude diagram, which reopens the discussion on the deficit of M2-4 Taurus stars. Finally, based on proper motion diagrams, we report on a new wide M dwarf binary system in the field, LSPM J0326+3929EW.

  3. Health effects on nearby residents of a wood treatment plant

    International Nuclear Information System (INIS)

    Dahlgren, James; Warshaw, Raphael; Thornton, John; Anderson-Mahoney, P.M.; Takhar, Harpreet

    2003-01-01

    Objectives: The aim of the study was to evaluate the health status of nearby residents of a wood treatment plant who had sustained prolonged low-level environmental exposure to wood processing waste chemicals. Methods: A population of 1269 exposed residents who were plaintiffs or potential plaintiffs in a lawsuit against the wood treatment plant were evaluated by questionnaire for a health history and symptoms. A representative sample of 214 exposed subjects was included in the analysis. One hundred thirty-nine controls were selected from 479 unexposed volunteers and matched to the exposed subjects as closely as possible by gender and age. Subjects and controls completed additional questionnaires and were evaluated by a physician for medical history and physical examination, blood and urine testing, neurophysiological and neuropsychological studies, and respiratory testing. Environmental sampling for wood processing waste chemicals was carried out on soil and drainage ditch sediment in the exposed neighborhood. Results: The exposed subjects had significantly more cancer, respiratory, skin, and neurological health problems than the controls. The subjective responses on questionnaires and by physician histories revealed that the residents had a significantly greater prevalence of mucous membrane irritation, and skin and neurological symptoms, as well as cancer. (Exposed versus unexposed, cancer 10.0% versus 2.08%, bronchitis 17.8% versus 5.8%, and asthma by history 40.5% versus 11.0%) There were significantly more neurophysiologic abnormalities in adults of reaction time, trails A and B, and visual field defects. Conclusions: Adverse health effects were significantly more prevalent in long-term residents near a wood treatment plant than in controls. The results of this study suggest that plant emissions from wood treatment facilities should be reduced

  4. The circumnuclear environment of nearby non-interacting Seyfert galaxies

    International Nuclear Information System (INIS)

    Pogge, R.W.

    1988-01-01

    An investigation into the physical conditions prevailing in the regions immediately surrounding the active nuclei in 20 nearby, non-interacting Seyfert galaxies is reported. CCD interference-band images isolating the bright emission lines of Hα + [N II] λλ6548, 6583 and [O III] λ5007 have been obtained to search for spatially extended circumnuclear emission regions. Long-slit, low resolution spectrophotometry of interesting cases was used to probe the ionization state of the extended emission regions. For comparison, a CCD Hα + [N II] interference-band imaging survey of a statistically significant sample of 91 bright non-Seyfert spiral galaxies meeting the same non-interaction criteria has been carried out. Only three out of nine Seyfert 1s have spatially extended ionized gas regions compared with eight out of eleven Seyfert 2s. Enhanced circumnuclear star formation is uncommon to both Seyfert 1s and 2s. Extended emission in Seyfert 1s has essentially the same morphology in both Hα + [N II] and [O III] emission. In the Seyfert 2s, the Hα + [N II] and [O III] images show different extended emission morphologies. The [O III] emission regions appear as either one- or two-sided structures, four of which are resolved into two distinct cones of high-ionization gas emanating from the active nucleus. The morphology and ionization of these regions suggest collimation of the nuclear ionizing radiation field. The 91 non-interacting non-Seyfert spiral galaxies exhibit a rich variety of nuclear and circumnuclear emission-line structures ranging from no emission detected to bright stellar nuclei with complicated circumnuclear emission regions extending for many kiloparsecs

  5. NEW DEBRIS DISKS IN NEARBY YOUNG MOVING GROUPS

    Energy Technology Data Exchange (ETDEWEB)

    Moór, A.; Kóspál, Á.; Ábrahám, P.; Kiss, Cs. [Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, Hungarian Academy of Sciences, P.O. Box 67, H-1525 Budapest (Hungary); Balog, Z.; Henning, Th. [Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany); Csengeri, T. [Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany); Juhász, A., E-mail: moor@konkoly.hu [Institute of Astronomy, Madingley Road, Cambridge CB3, OHA (United Kingdom)

    2016-08-01

    A significant fraction of nearby young moving group members harbor circumstellar debris dust disks. Due to their proximity and youth, these disks are attractive targets for studying the early evolution of debris dust and planetesimal belts. Here we present 70 and 160 μ m observations of 31 systems in the β Pic moving group, and in the Tucana–Horologium, Columba, Carina, and Argus associations, using the Herschel Space Observatory . None of these stars were observed at far-infrared wavelengths before. Our Herschel measurements were complemented by photometry from the WISE satellite for the whole sample, and by submillimeter/millimeter continuum data for one source, HD 48370. We identified six stars with infrared excess, four of them are new discoveries. By combining our new findings with results from the literature, we examined the incidence and general characteristics of debris disks around Sun-like members of the selected groups. With their dust temperatures of <45 K the newly identified disks around HD 38397, HD 48370, HD 160305, and BD-20 951 represent the coldest population within this sample. For HD 38397 and HD 48370, the emission is resolved in the 70 μ m Photodetector Array Camera and Spectrograph images, the estimated radius of these disks is ∼90 au. Together with the well-known disk around HD 61005, these three systems represent the highest mass end of the known debris disk population around young G-type members of the selected groups. In terms of dust content, they resemble the hypothesized debris disk of the ancient solar system.

  6. STAR FORMATION AND SUPERCLUSTER ENVIRONMENT OF 107 NEARBY GALAXY CLUSTERS

    International Nuclear Information System (INIS)

    Cohen, Seth A.; Hickox, Ryan C.; Wegner, Gary A.; Einasto, Maret; Vennik, Jaan

    2017-01-01

    We analyze the relationship between star formation (SF), substructure, and supercluster environment in a sample of 107 nearby galaxy clusters using data from the Sloan Digital Sky Survey. Previous works have investigated the relationships between SF and cluster substructure, and cluster substructure and supercluster environment, but definitive conclusions relating all three of these variables has remained elusive. We find an inverse relationship between cluster SF fraction ( f SF ) and supercluster environment density, calculated using the Galaxy luminosity density field at a smoothing length of 8 h −1 Mpc (D8). The slope of f SF versus D8 is −0.008 ± 0.002. The f SF of clusters located in low-density large-scale environments, 0.244 ± 0.011, is higher than for clusters located in high-density supercluster cores, 0.202 ± 0.014. We also divide superclusters, according to their morphology, into filament- and spider-type systems. The inverse relationship between cluster f SF and large-scale density is dominated by filament- rather than spider-type superclusters. In high-density cores of superclusters, we find a higher f SF in spider-type superclusters, 0.229 ± 0.016, than in filament-type superclusters, 0.166 ± 0.019. Using principal component analysis, we confirm these results and the direct correlation between cluster substructure and SF. These results indicate that cluster SF is affected by both the dynamical age of the cluster (younger systems exhibit higher amounts of SF); the large-scale density of the supercluster environment (high-density core regions exhibit lower amounts of SF); and supercluster morphology (spider-type superclusters exhibit higher amounts of SF at high densities).

  7. Nearby Hot Stars May Change Our View of Distant Sources

    Science.gov (United States)

    Kohler, Susanna

    2017-07-01

    As if it werent enough that quasars distant and bright nuclei of galaxies twinkle of their own accord due to internal processes, nature also provides another complication: these distant radio sources can also appear to twinkle because of intervening material between them and us. A new study has identified a possible source for the material getting in the way.Unexplained VariabilityA Spitzer infrared view of the Helix nebula, which contains ionized streamers of gas extending radially outward from the central star. [NASA/JPL-Caltech/Univ. of Ariz.]Distant quasars occasionally display extreme scintillation, twinkling with variability timescales shorter than a day. This intra-day variability is much greater than we can account for with standard models of the interstellar medium lying between the quasar and us. So what could cause this extreme scattering instead?The first clue to this mystery came from the discovery of strong variability in the radio source PKS 1322110. In setting up follow-up observations of this object, Mark Walker (Manly Astrophysics, Australia) and collaborators noticed that, in the plane of the sky, PKS 1322110 lies very near the bright star Spica. Could this be coincidence, or might this bright foreground star have something to do with the extreme scattering observed?Diagram explaining the source of the intra-day radio source variability as intervening filaments surrounding a hot star. [M. Walker/CSIRO/Manly Astrophysics]Swarms of ClumpsWalker and collaborators put forward a hypothesis: perhaps the ultraviolet photons of nearby hot stars ionize plasma around them, which in turn causes the extreme scattering of the distant background sources.As a model, the authors consider the Helix Nebula, in which a hot, evolved star is surrounded by cool globules of molecular hydrogen gas. The radiation from the star hits these molecular clumps, dragging them into long radial streamers and ionizing their outer skins.Though the molecular clumps in the Helix

  8. An Unbiased Survey of 500 Nearby Stars for Debris Disks: A JCMT Legacy Program

    NARCIS (Netherlands)

    Matthews, B.C.; Greaves, J.S.; Holland, W.S.; Wyatt, M.C.; Barlow, M.J.; Bastien, P.; Beichman, C.A.; Biggs, A.; Butner, H.M.; Dent, W.R.F.; Francesco, J. Di; Dominik, C.; Fissel, L.; Friberg, P.; Gibb, A.G.; Halpern, M.; Ivison, R.J.; Jayawardhana, R.; Jenness, T.; Johnstone, D.; Kavelaars, J.J.; Marshall, J.L.; Phillips, N.; Schieven, G.; Snellen, I.A.G.; Walker, H.J.; Ward-Thompson, D.; Weferling, B.; White, G.J.; Yates, J.; Zhu, M.; Craigon, A.

    2007-01-01

    We present the scientific motivation and observing plan for an upcoming detection survey for debris disks using the James Clerk Maxwell Telescope. The SCUBA-2 Unbiased Nearby Stars (SUNS) survey will observe 500 nearby main-sequence and subgiant stars (100 of each of the A, F, G, K, and M spectral

  9. [North] Korea.

    Science.gov (United States)

    1986-05-01

    In 1985, the population of the Democratic People's Republic of Korea (North Korea) stood at 20 million, with an annual growth rate of 2.3%. The infant mortality rate was 30/1000 live births and life expectancy was 66 years. The gross national product (GNP) was US$23 billion in 1984, with a per capita GNP of $1175. Both North Korea's labor force and natural resources have been concentrated in recent years on an effort to achieve rapid economic development. During the early 1970s, a large-scale modernization program involving the importation of Western technology, primarily in the heavy industiral sectors of the economy, was attempted and resulted in a massive foreign debt. North Korea has a strongly centralized government under the control of the communist Korean Workers' Party. Literacy in the country is at the 99% level. Medical treatment is free. There is 1 physician/600 population and 1 hospital bed/350 inhabitants.

  10. MOLECULAR GAS AND STAR FORMATION IN NEARBY DISK GALAXIES

    International Nuclear Information System (INIS)

    Leroy, Adam K.; Munoz-Mateos, Juan-Carlos; Walter, Fabian; Sandstrom, Karin; Meidt, Sharon; Rix, Hans-Walter; Schinnerer, Eva; Schruba, Andreas; Bigiel, Frank; Bolatto, Alberto; Brinks, Elias; De Blok, W. J. G.; Rosolowsky, Erik; Schuster, Karl-Friedrich; Usero, Antonio

    2013-01-01

    We compare molecular gas traced by 12 CO (2-1) maps from the HERACLES survey, with tracers of the recent star formation rate (SFR) across 30 nearby disk galaxies. We demonstrate a first-order linear correspondence between Σ mol and Σ SFR but also find important second-order systematic variations in the apparent molecular gas depletion time, τ dep mol =Σ mol /Σ SFR . At the 1 kpc common resolution of HERACLES, CO emission correlates closely with many tracers of the recent SFR. Weighting each line of sight equally, using a fixed α CO equivalent to the Milky Way value, our data yield a molecular gas depletion time, τ dep mol =Σ mol /Σ SFR ∼2.2 Gyr with 0.3 dex 1σ scatter, in very good agreement with recent literature data. We apply a forward-modeling approach to constrain the power-law index, N, that relates the SFR surface density and the molecular gas surface density, Σ SFR ∝Σ mol N . We find N = 1 ± 0.15 for our full data set with some scatter from galaxy to galaxy. This also agrees with recent work, but we caution that a power-law treatment oversimplifies the topic given that we observe correlations between τ dep mol and other local and global quantities. The strongest of these are a decreased τ dep mol in low-mass, low-metallicity galaxies and a correlation of the kpc-scale τ dep mol with dust-to-gas ratio, D/G. These correlations can be explained by a CO-to-H 2 conversion factor (α CO ) that depends on dust shielding, and thus D/G, in the theoretically expected way. This is not a unique interpretation, but external evidence of conversion factor variations makes this the most conservative explanation of the strongest observed τ dep mol trends. After applying a D/G-dependent α CO , some weak correlations between τ dep mol and local conditions persist. In particular, we observe lower τ dep mol and enhanced CO excitation associated with nuclear gas concentrations in a subset of our targets. These appear to reflect real enhancements in the

  11. Backyard Worlds: Finding Nearby Brown Dwarfs Through Citizen Science

    Science.gov (United States)

    Kuchner, Marc

    Recent discoveries of cool brown dwarfs in the solar neighborhood and microlensing surveys both point to an undiscovered population of brown dwarfs and rogue planets in the solar neighborhood. We propose to develop and sustain a novel website that enables a unique and powerful citizen-science based search for these and other high-proper-motion objects at 3.5 and 4.6 microns. Through this search, we have an opportunity to discover new ultracool Y dwarfs, crucial links between star formation and planet formation, and also the Sun's nearest neighbors-potentially a system closer than Proxima Centauri. NASA's Wide-field Infrared Survey Explorer mission (WISE) is nominally sensitive enough to detect a 250 K brown dwarf to > 6 pc and even a Jupiter analog to > 0.6 pc. However, high proper motion objects like these can easily be confused with variable stars, electronic noise, latent images, optical ghosts, cosmic ray hits, and so on in the WISE archive. Computer-based searches for high-proper motion objects falter in dense star fields, necessitating visual inspection all candidates. Our citizen science project, called "Backyard Worlds: Planet 9", remedies this problem by engaging volunteers to visually inspect WISE and NEOWISE images. Roughly 104,000 participants have already begun using a preliminary version of the site to examine time-resolved co-adds of unWISE-processed images, four epochs spanning 2010 to 2014. They have already performed more than 3.6 million classifications of these images since the site's launch on February 15, 2017. Besides seeking new brown dwarfs and nearby stars, this site is also the most sensitive all-sky WISE-based search for a planet orbiting the Sun beyond Pluto (sometimes called Planet Nine). Preliminary analysis data from the site has resulted in the discovery of 13 brown dwarf candidates including 6 T dwarfs. We obtained a spectrum of one of these candidates and published it in Astrophysical Journal Letters, with four citizen scientists

  12. X-ray Emission Line Spectroscopy of Nearby Galaxies

    Science.gov (United States)

    Wang, Daniel

    What are the origins of the diffuse soft X-ray emission from non-AGN galaxies? Preliminary analysis of XMM-Newton RGS spectra shows that a substantial fraction of the emission cannot arise from optically-thin thermal plasma, as commonly assumed, and may originate in charge exchange at the interface with neutral gas. We request the support for a comprehensive observing, data analysis, and modeling program to spectroscopically determine the origins of the emission. First, we will use our scheduled XMM-Newton AO-10 368 ks observations of the nearest compact elliptical galaxy M32 to obtain the first spectroscopic calibration of the cumulative soft X-ray emission from the old stellar population and will develop a spectral model for the charge exchange, as well as analysis tools to measure the spatial and kinematic properties of the X-ray line- emitting plasma. Second, we will characterize the truly diffuse emission from the hot plasma and/or its interplay with the neutral gas in a sample of galactic spheroids and active star forming/starburst regions in nearby galaxies observed by XMM-Newton. In particular, we will map out the spatial distributions of key emission lines and measure (or tightly constrain) the kinematics of hot plasma outflows for a few X-ray-emitting regions with high-quality RGS data. For galaxies with insufficient counting statistics in individual emission lines, we will conduct a spectral stacking analysis to constrain the average properties of the X-ray-emitting plasma. We will use the results of these X-ray spectroscopic analyses, together with complementary X-ray CCD imaging/spectral data and observations in other wavelength bands, to test the models of the emission. In addition to the charge exchange, alternative scenarios such as resonance scattering and relic AGN photo-ionization will also be examined for suitable regions. These studies are important to the understanding of the relationship between the diffuse soft X-ray emission and various

  13. H α IMAGING OF NEARBY SEYFERT HOST GALAXIES

    Energy Technology Data Exchange (ETDEWEB)

    Theios, Rachel L.; Malkan, Matthew A. [Department of Physics and Astronomy, University of California, Los Angeles, 430 Portola Plaza, Los Angeles, CA 90095 (United States); Ross, Nathaniel R., E-mail: rtheios@astro.caltech.edu [Raytheon Space and Airborne Systems, 2000 E El Segundo Boulevard, El Segundo, CA 90245 (United States)

    2016-05-01

    We used narrowband (Δ λ = 70 Å) interference filters with the CCD imaging camera on the Nickel 1.0 m telescope at Lick Observatory to observe 31 nearby ( z < 0.03) Seyfert galaxies in the 12 μ m active galaxy sample. We obtained pure emission-line images of each galaxy, which reach down to a flux limit of 7.3 × 10{sup −15} erg cm{sup −2} s{sup −1} arcsec{sup −2}, and corrected these images for [N ii] emission and extinction. We separated the H α emission line of the “nucleus” (central 100–1000 pc) from that of the host galaxy. The extended H α emission is expected to be powered by newly formed hot stars, and indeed correlates well with other indicators of current star formation rates (SFRs) in these galaxies: extended 7.7 μ m polycyclic aromatic hydrocarbon, total far-infrared, and radio luminosity. Relative to what would be expected from recent star formation, there is a 0.8 dex excess of radio emission in our Seyfert galaxies. The H α luminosity we measured in the centers of our galaxies is dominated by the active galactic nucleus (AGN), and is linearly correlated with the hard X-ray luminosity. There is, however, an upward offset of 1 dex in this correlation for the Seyfert 1s, because their nuclear H α emission includes a strong additional contribution from the broad-line region. We found a correlation between SFR and AGN luminosity. In spite of selection effects, we concluded that the absence of bright Seyfert nuclei in galaxies with low SFRs is real, albeit only weakly significant. Finally, we used our measured spatial distributions of H α emission to determine what these Seyfert galaxies would look like when observed through fixed apertures (e.g., a spectroscopic fiber) at high redshifts. We found that although all of these Seyfert galaxies would be detectable emission-line galaxies at any redshift, most of them would appear to be dominated by (>67%) their H ii region emission. Only the most luminous AGNs (log( L {sub Hα}/erg s

  14. Black holes at the centers of nearby dwarf galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Moran, Edward C.; Shahinyan, Karlen; Sugarman, Hannah R.; Vélez, Darik O. [Astronomy Department, Wesleyan University, Middletown, CT 06459 (United States); Eracleous, Michael [Department of Astronomy and Astrophysics, and Institute for Gravitation and the Cosmos, The Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States)

    2014-12-01

    Using a distance-limited portion of the Sloan Digital Sky Survey (SDSS) Data Release 7, we have identified 28 active galactic nuclei (AGNs) in nearby (d⩽80 Mpc) low-mass, low-luminosity dwarf galaxies. The accreting objects at the galaxy centers are expected to be intermediate-mass black holes (IMBHs) with M{sub BH}⩽10{sup 6} M{sub ⊙}. The AGNs were selected using several optical emission-line diagnostics after careful modeling of the continuum present in the spectra. We have limited our survey to objects with spectral characteristics similar to those of Seyfert nuclei, excluding emission-line galaxies with ambiguous spectra that could be powered by stellar processes. Thus, as a set, the host galaxies in our sample are the least massive objects in the very local universe certain to contain central black holes. Our sample is dominated by narrow-line (type 2) AGNs, and it appears to have a much lower fraction of broad-line objects than that observed for luminous, optically selected Seyfert galaxies. Given our focus on the nearest objects included in the SDSS, our survey is more sensitive to low-luminosity emission than previous optical searches for AGNs in low-mass galaxies. The [O iii] λ5007 luminosities of the Seyfert nuclei in our sample have a median value of L{sub 5007}=2×10{sup 5} L{sub ⊙} and extend down to ∼10{sup 4} L{sub ⊙}. Using published data for broad-line IMBH candidates, we have derived an [O iii] bolometric correction of log(L{sub bol}/L{sub 5007})=3.0±0.3, which is significantly lower than values obtained for high-luminosity AGNs. Applying this correction to our sample, we obtain minimum black hole mass estimates that fall mainly in the 10{sup 3} M{sub ⊙}–10{sup 4} M{sub ⊙} range, which is roughly where the predicted mass functions for different black hole seed formation scenarios overlap the most. In the stellar mass range that includes the bulk of the AGN host galaxies in our sample, we derive a lower limit on the AGN fraction

  15. The Nature of Accreting Black Holes in Nearby Galaxy Nuclei

    Science.gov (United States)

    Colbert, E. J. M.; Mushotzky, R. F.

    1999-05-01

    We have found compact X-ray sources in the center of 21 (54%) of 39 nearby face-on spiral and elliptical galaxies with available ROSAT HRI data. ROSAT X-ray luminosities (0.2 - 2.4 keV) of these compact X-ray sources are ~ 10(37) -10(40) erg s(-1) (with a mean of 3 x 10(39) erg s(-1) ). The mean displacement between the location of the compact X-ray source and the optical photometric center of the galaxy is ~ 390 pc. The fact that compact nuclear sources were found in nearly all (five of six) galaxies with previous evidence for a black hole or an AGN indicates that at least some of the X-ray sources are accreting supermassive black holes. ASCA spectra of six of the 21 galaxies show the presence of a hard component with relatively steep (Gamma ~ 2.5) spectral slope. A multicolor disk blackbody model fits the data from the spiral galaxies well, suggesting that the X-ray object in these galaxies may be similar to a Black Hole Candidate in its soft (high) state. ASCA data from the elliptical galaxies indicate that hot (kT ~ 0.7 keV) gas dominates the emission. The fact that (for both spiral and elliptical galaxies) the spectral slope is steeper than in normal type 1 AGNs and that relatively low absorbing columns (N_H ~ 10(21) cm(-2) ) were found to the power-law component indicates that these objects are somehow geometrically and/or physically different from AGNs in normal active galaxies. The X-ray sources in the spiral and elliptical galaxies may be black hole X-ray binaries, low-luminosity AGNs, or possibly young X-ray luminous supernovae. Assuming the sources in the spiral galaxies are accreting black holes in their soft state, we estimate black hole masses ~ 10(2) -10(4) M_sun.

  16. Motions in Nearby Galaxy Cluster Reveal Presence of Hidden Superstructure

    Science.gov (United States)

    2004-09-01

    A nearby galaxy cluster is facing an intergalactic headwind as it is pulled by an underlying superstructure of dark matter, according to new evidence from NASA's Chandra X-ray Observatory. Astronomers think that most of the matter in the universe is concentrated in long large filaments of dark matter and that galaxy clusters are formed where these filaments intersect. A Chandra survey of the Fornax galaxy cluster revealed a vast, swept-back cloud of hot gas near the center of the cluster. This geometry indicates that the hot gas cloud, which is several hundred thousand light years in length, is moving rapidly through a larger, less dense cloud of gas. The motion of the core gas cloud, together with optical observations of a group of galaxies racing inward on a collision course with it, suggests that an unseen, large structure is collapsing and drawing everything toward a common center of gravity. X-ray Image of Fornax with labels X-ray Image of Fornax with labels "At a relatively nearby distance of about 60 million light years, the Fornax cluster represents a crucial laboratory for studying the interplay of galaxies, hot gas and dark matter as the cluster evolves." said Caleb Scharf of Columbia University in New York, NY, lead author of a paper describing the Chandra survey that was presented at an American Astronomical Society meeting in New Orleans, LA. "What we are seeing could be associated directly with the intergalactic gas surrounding a very large scale structure that stretches over millions of light years." The infalling galaxy group, whose motion was detected by Michael Drinkwater of the University of Melbourne in Australia, and colleagues, is about 3 million light years from the cluster core, so a collision with the core will not occur for a few billion years. Insight as to how this collision will look is provided by the elliptical galaxy NGC 1404 that is plunging into the core of the cluster for the first time. As discussed by Scharf and another group

  17. MOLECULAR GAS AND STAR FORMATION IN NEARBY DISK GALAXIES

    Energy Technology Data Exchange (ETDEWEB)

    Leroy, Adam K.; Munoz-Mateos, Juan-Carlos [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States); Walter, Fabian; Sandstrom, Karin; Meidt, Sharon; Rix, Hans-Walter; Schinnerer, Eva [Max Planck Institute fuer Astronomie, Koenigstuhl 17, D-69117 Heidelberg (Germany); Schruba, Andreas [California Institute for Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Bigiel, Frank [Theoretische Astrophysik, Albert-Ueberle-Str. 2, D-69120 Heidelberg (Germany); Bolatto, Alberto [Department of Astronomy, University of Maryland, College Park, MD (United States); Brinks, Elias [Centre for Astrophysics Research, University of Hertfordshire, Hatfield AL10 9AB (United Kingdom); De Blok, W. J. G. [Astrophysics, Cosmology and Gravity Centre, Department of Astronomy, University of Cape Town, Private Bag X3, Rondebosch 7701 (South Africa); Rosolowsky, Erik [University of British Columbia, Okanagan Campus, Kelowna, BC (Canada); Schuster, Karl-Friedrich [IRAM, 300 rue de la Piscine, F-38406 St. Martin d' Heres (France); Usero, Antonio [Observatorio Astronomico Nacional, C/ Alfonso XII, 3, E-28014 Madrid (Spain)

    2013-08-01

    We compare molecular gas traced by {sup 12}CO (2-1) maps from the HERACLES survey, with tracers of the recent star formation rate (SFR) across 30 nearby disk galaxies. We demonstrate a first-order linear correspondence between {Sigma}{sub mol} and {Sigma}{sub SFR} but also find important second-order systematic variations in the apparent molecular gas depletion time, {tau}{sub dep}{sup mol}={Sigma}{sub mol}/{Sigma}{sub SFR}. At the 1 kpc common resolution of HERACLES, CO emission correlates closely with many tracers of the recent SFR. Weighting each line of sight equally, using a fixed {alpha}{sub CO} equivalent to the Milky Way value, our data yield a molecular gas depletion time, {tau}{sub dep}{sup mol}={Sigma}{sub mol}/{Sigma}{sub SFR}{approx}2.2 Gyr with 0.3 dex 1{sigma} scatter, in very good agreement with recent literature data. We apply a forward-modeling approach to constrain the power-law index, N, that relates the SFR surface density and the molecular gas surface density, {Sigma}{sub SFR}{proportional_to}{Sigma}{sub mol}{sup N}. We find N = 1 {+-} 0.15 for our full data set with some scatter from galaxy to galaxy. This also agrees with recent work, but we caution that a power-law treatment oversimplifies the topic given that we observe correlations between {tau}{sub dep}{sup mol} and other local and global quantities. The strongest of these are a decreased {tau}{sub dep}{sup mol} in low-mass, low-metallicity galaxies and a correlation of the kpc-scale {tau}{sub dep}{sup mol} with dust-to-gas ratio, D/G. These correlations can be explained by a CO-to-H{sub 2} conversion factor ({alpha}{sub CO}) that depends on dust shielding, and thus D/G, in the theoretically expected way. This is not a unique interpretation, but external evidence of conversion factor variations makes this the most conservative explanation of the strongest observed {tau}{sub dep}{sup mol} trends. After applying a D/G-dependent {alpha}{sub CO}, some weak correlations between {tau}{sub dep

  18. Knowing Our Neighbors: Four New Nearby High Proper Motion Systems

    Science.gov (United States)

    Bartlett, Jennifer L.; Lurie, John C.; Ianna, Philip A.; Riedel, Adric R.; Finch, Charlie T.; Winters, Jennifer G.; Jao, Wei-Chun; Subasavage, John P.; Henry, Todd J.

    2017-01-01

    Obtaining a well-understood, volume-limited (and ultimately volume-complete) sample of stellar systems within 25 pc is essential for determining the stellar luminosity function, the mass-luminosity relationship, the stellar velocity distribution, and the stellar multiplicity fraction. Such a sample also provides insight into the local star formation history. Towards that end, the Research Consortium On Nearby Stars (RECONS) team measures trigonometric parallaxes to establish which systems truly lie within the 25-pc radius of the Solar Neighborhood. Recent astrometric measurements with the CTIO/SMARTS 0.9-m telescope establish three high proper motion systems as members (2MASS J02511490-0352459, 2MASS J15345704-1418486, and 2MASS J09211410-2104446) and confirm a fourth (2MASS J23062928-0502285). All four proper motions exceed 0.9”/yr. 2MA0251 travels 2.1497±0.0009”/yr in 149.20±0.05° at a distance of 11.0±0.4 pc. 2M2306 moves 1.0344±0.0007”/yr in 118.50±0.08° at a distance of 12.7±0.2 pc. 2MA1534 goes 0.9726±0.0004”/yr in 251.50 ±0.05° at a distance of 10.93±0.10 pc. 2MA0921 shifts 0.9489±0.0003”/yr in 164.70±0.04° at a distance of 12.3±0.2 pc. The corresponding tangential velocities are 112.4, 62.4, 50.4, and 55.5 km/s whereas the median for parallaxes previously published by RECONS is 53 km/s. With radial velocities in the literature of -75.5 to 80.53 km/s, none of these is a candidate member of any young moving groups.To characterize these late M-early L systems more fully, RECONS obtained VRI photometry; their I -band magnitudes range from 14.10 to 16.55. Over their astrometric baselines of 7.75 to 8.99 years, these demonstrated long-term I-band variability of 0.0135 mag. or less, indicating they may be older systems.With each new confirmation, we come closer to completing the census of the Solar Neighborhood.NSF grants AST 05-07711 and AST 09-08402, NASA-SIM, Georgia State University, the University of Virginia, Hampden-Sydney College

  19. Probing the LHS Catalog. I. New Nearby Stars and the Coolest Subdwarf

    OpenAIRE

    Gizis, John E.; Reid, I. Neill

    1997-01-01

    We present moderate resolution spectroscopy of 112 cool dwarf stars to supplement the observations we have already presented in the Palomar/MSU Nearby-Star Spectroscopic Survey. The sample consists of 72 suspected nearby stars added to the The Preliminary Third Catalog of Nearby Stars since 1991 as well as 40 faint red stars selected from the LHS catalog. LHS 1826 is more metal-poor and cooler than the coolest previously known extreme subdwarf, LHS 1742a. LHS 2195 is a very late M dwarf of ty...

  20. Heaviest Stellar Black Hole Discovered in Nearby Galaxy

    Science.gov (United States)

    2007-10-01

    Astronomers have located an exceptionally massive black hole in orbit around a huge companion star. This result has intriguing implications for the evolution and ultimate fate of massive stars. The black hole is part of a binary system in M33, a nearby galaxy about 3 million light years from Earth. By combining data from NASA's Chandra X-ray Observatory and the Gemini telescope on Mauna Kea, Hawaii, the mass of the black hole, known as M33 X-7, was determined to be 15.7 times that of the Sun. This makes M33 X-7 the most massive stellar black hole known. A stellar black hole is formed from the collapse of the core of a massive star at the end of its life. Chandra X-ray Image of M33 X-7 Chandra X-ray Image of M33 X-7 "This discovery raises all sorts of questions about how such a big black hole could have been formed," said Jerome Orosz of San Diego State University, lead author of the paper appearing in the October 18th issue of the journal Nature. M33 X-7 orbits a companion star that eclipses the black hole every three and a half days. The companion star also has an unusually large mass, 70 times that of the Sun. This makes it the most massive companion star in a binary system containing a black hole. Hubble Optical Image of M33 X-7 Hubble Optical Image of M33 X-7 "This is a huge star that is partnered with a huge black hole," said coauthor Jeffrey McClintock of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. "Eventually, the companion will also go supernova and then we'll have a pair of black holes." The properties of the M33 X-7 binary system - a massive black hole in a close orbit around a massive companion star - are difficult to explain using conventional models for the evolution of massive stars. The parent star for the black hole must have had a mass greater than the existing companion in order to have formed a black hole before the companion star. Gemini Optical Image of M33 X-7 Gemini Optical Image of M33 X-7 Such a massive star would

  1. NASA Space Observatories Glimpse Faint Afterglow of Nearby Stellar Explosion

    Science.gov (United States)

    2005-10-01

    Intricate wisps of glowing gas float amid a myriad of stars in this image created by combining data from NASA's Hubble Space Telescope and Chandra X-ray Observatory. The gas is a supernova remnant, cataloged as N132D, ejected from the explosion of a massive star that occurred some 3,000 years ago. This titanic explosion took place in the Large Magellanic Cloud, a nearby neighbor galaxy of our own Milky Way. The complex structure of N132D is due to the expanding supersonic shock wave from the explosion impacting the interstellar gas of the LMC. Deep within the remnant, the Hubble visible light image reveals a crescent-shaped cloud of pink emission from hydrogen gas, and soft purple wisps that correspond to regions of glowing oxygen emission. A dense background of colorful stars in the LMC is also shown in the Hubble image. The large horseshoe-shaped gas cloud on the left-hand side of the remnant is glowing in X-rays, as imaged by Chandra. In order to emit X-rays, the gas must have been heated to a temperature of about 18 million degrees Fahrenheit (10 million degrees Celsius). A supernova-generated shock wave traveling at a velocity of more than four million miles per hour (2,000 kilometers per second) is continuing to propagate through the low-density medium today. The shock front where the material from the supernova collides with ambient interstellar material in the LMC is responsible for these high temperatures. Chandra image of N132D Chandra image of N132D, 2002 It is estimated that the star that exploded as a supernova to produce the N132D remnant was 10 to 15 times more massive than our own Sun. As fast-moving ejecta from the explosion slam into the cool, dense interstellar clouds in the LMC, complex shock fronts are created. A supernova remnant like N132D provides a rare opportunity for direct observation of stellar material, because it is made of gas that was recently hidden deep inside a star. Thus it provides information on stellar evolution and the

  2. Nearby supernova factory announces 34 supernovae in one year'; best Rookie year ever for supernova search

    CERN Multimedia

    2003-01-01

    The Nearby Supernova Factory (SNfactory), an international collaboration based at Lawrence Berkeley National Laboratory, announced that it had discovered 34 supernovae during the first year of the prototype system's operation (2 pages).

  3. THE GREEN BANK TELESCOPE MAPS THE DENSE, STAR-FORMING GAS IN THE NEARBY STARBURST GALAXY M82

    Energy Technology Data Exchange (ETDEWEB)

    Kepley, Amanda A.; Frayer, David [National Radio Astronomy Observatory, P.O. Box 2, Green Bank, WV 24944-0002 (United States); Leroy, Adam K. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903-2475 (United States); Usero, Antonio [Observatorio Astronómico Nacional, C/Alfonso XII, 3, E-28014 Madrid (Spain); Marvil, Josh [Department of Physics, New Mexico Tech., 801 Leroy Place, Socorro, NM 87801 (United States); Walter, Fabian, E-mail: akepley@nrao.edu [Max Planck Institute fur Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany)

    2014-01-01

    Observations of the Milky Way and nearby galaxies show that dense molecular gas correlates with recent star formation, suggesting that the formation of this gas phase may help regulate star formation. A key test of this idea requires wide-area, high-resolution maps of dense molecular gas in galaxies to explore how local physical conditions drive dense gas formation, but these observations have been limited because of the faintness of dense gas tracers like HCN and HCO{sup +}. Here we demonstrate the power of the Robert C. Byrd Green Bank Telescope (GBT)—the largest single-dish millimeter radio telescope—for mapping dense gas in galaxies by presenting the most sensitive maps yet of HCN and HCO{sup +} in the starburst galaxy M82. The HCN and HCO{sup +} in the disk of this galaxy correlates with both recent star formation and more diffuse molecular gas and shows kinematics consistent with a rotating torus. The HCO{sup +} emission extending to the north and south of the disk is coincident with the outflow previously identified in CO and traces the eastern edge of the hot outflowing gas. The central starburst region has a higher ratio of star formation to dense gas than the outer regions, pointing to the starburst as a key driver of this relationship. These results establish that the GBT can efficiently map the dense molecular gas at 90 GHz in nearby galaxies, a capability that will increase further with the 16 element feed array under construction.

  4. Robo-AO Kepler Survey. IV. The Effect of Nearby Stars on 3857 Planetary Candidate Systems

    Science.gov (United States)

    Ziegler, Carl; Law, Nicholas M.; Baranec, Christoph; Riddle, Reed; Duev, Dmitry A.; Howard, Ward; Jensen-Clem, Rebecca; Kulkarni, S. R.; Morton, Tim; Salama, Maïssa

    2018-04-01

    We present the overall statistical results from the Robo-AO Kepler planetary candidate survey, comprising of 3857 high-angular resolution observations of planetary candidate systems with Robo-AO, an automated laser adaptive optics system. These observations reveal previously unknown nearby stars blended with the planetary candidate host stars that alter the derived planetary radii or may be the source of an astrophysical false positive transit signal. In the first three papers in the survey, we detected 440 nearby stars around 3313 planetary candidate host stars. In this paper, we present observations of 532 planetary candidate host stars, detecting 94 companions around 88 stars; 84 of these companions have not previously been observed in high resolution. We also report 50 more-widely separated companions near 715 targets previously observed by Robo-AO. We derive corrected planetary radius estimates for the 814 planetary candidates in systems with a detected nearby star. If planetary candidates are equally likely to orbit the primary or secondary star, the radius estimates for planetary candidates in systems with likely bound nearby stars increase by a factor of 1.54, on average. We find that 35 previously believed rocky planet candidates are likely not rocky due to the presence of nearby stars. From the combined data sets from the complete Robo-AO KOI survey, we find that 14.5 ± 0.5% of planetary candidate hosts have a nearby star with 4″, while 1.2% have two nearby stars, and 0.08% have three. We find that 16% of Earth-sized, 13% of Neptune-sized, 14% of Saturn-sized, and 19% of Jupiter-sized planet candidates have detected nearby stars.

  5. Prospects of the "WSO-UV" Project for Star Formation Study in Nearby Dwarf Galaxies

    Science.gov (United States)

    Makarova, L. N.; Makarov, D. I.

    2017-12-01

    In the present work we consider the questions of star formation and evolution of nearby dwarf galaxies. We describe the method of star formation history determination based on multicolor photometry of resolved stars and models of color-magnitude diagrams of the galaxies. We present the results of star formation rate determination and its dependence on age and metallicity for dwarf irregular and dwarf spheroidal galaxies in the two nearby galaxy groups M81 and Cen A. Similar age of the last episode of star formation in the central part of the M81 group and also unusually high level of metal enrichment in the several galaxies of the Cen A group are mentioned. We pay special attention to the consideration of perspectives of star formation study in nearby dwarf galaxies with he new WSO-UV observatory.

  6. The environmental impact and recovery at two dumping sites for dredged material in the North Sea

    NARCIS (Netherlands)

    Stronkhorst, J.; Ariese, F.; Hattum, van B.; Postma, J.F.; Kluijver, de M.; Besten, den P.; Bergman, M.J.N.; Daan, R.; Murk, A.J.; Vethaak, A.D.

    2003-01-01

    The environmental impact and recovery associated with the long and uninterrupted disposal of large volumes of moderately contaminated dredged material from the port of Rotterdam was studied at nearby dumping sites in the North Sea. Observations were made on sediment contamination, ecotoxicity,

  7. Quark nugget dark matter: Comparison with radio observations of nearby galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Lawson, K., E-mail: klawson@phas.ubc.ca; Zhitnitsky, A.R.

    2016-06-10

    It has been recently claimed that radio observations of nearby spiral galaxies essentially rule out a dark matter source for the galactic haze [1]. Here we consider the low energy thermal emission from a quark nugget dark matter model in the context of microwave emission from the galactic centre and radio observations of nearby Milky Way like galaxies. We demonstrate that observed emission levels do not strongly constrain this specific dark matter candidate across a broad range of the allowed parameter space in drastic contrast with conventional dark matter models based on the WIMP paradigm.

  8. Nearby Type Ia Supernova Follow-up at the Thacher Observatory

    Science.gov (United States)

    Swift, Jonathan; O'Neill, Katie; Kilpatrick, Charles; Foley, Ryan

    2018-06-01

    Type Ia supernovae (SN Ia) provide an effective way to study the expansion of the universe through analyses of their photometry and spectroscopy. The interpretation of high-redshift SN Ia is dependent on accurate characterization of nearby, low-redshift targets. To help build up samples of nearby SN Ia, the Thacher Observatory has begun a photometric follow-up program in 4 photometric bands. Here we present the observations and analysis of multi-band photometry for several recent supernovae as well as FLOYDS spectra from the Las Cumbres Observatory.

  9. Measurement of radioactivity in the atmosphere and pollution nearby an atomic centre

    International Nuclear Information System (INIS)

    Labeyrie, J.; Weill, J.

    1955-01-01

    The French Atomic Energy Commission (CEA) is particularly interested in studies on atmospheric radioactivity by reason of the necessity to control the atmosphere nearby nuclear plants as uranium mines, nuclear reactors and hot laboratories or radioactive materials treatment plants. Thus, the CEA developed different apparatus to control and monitor the atmosphere nearby its sites. These air monitors are essentially of two types: the first one, called 'Babar', monitors smokes, fogs and dusts, the second type is an ionization chamber and measures the concentration of radioactive gas in the air. The functioning and sensitivity of these two systems are discussed. (M.P.)

  10. VLT/UVES abundances in four nearby dwarf spheroidal galaxies. II. Implications for understanding galaxy evolution

    NARCIS (Netherlands)

    Tolstoy, E; Venn, KA; Shetrone, M; Primas, F; Hill, [No Value; Kaufer, A; Szeifert, T

    We have used the Ultraviolet Visual-Echelle Spectrograph (UVES) on Kueyen (UT2) of the Very Large Telescope to take spectra of 15 individual red giant stars in the centers of four nearby dwarf spheroidal galaxies (dSph's) : Sculptor, Fornax, Carina, and Leo I. We measure the abundance variations of

  11. Why Seychelles Warblers fail to recolonize nearby islands : unwilling or unable to fly there?

    NARCIS (Netherlands)

    Komdeur, J; Piersma, T; Kraaijeveld, K; Kraaijeveld-Smit, F; Richardson, DS; Richardson, David S.

    The Seychelles Warbler Acrocephalus sechellensis is a rare island endemic which, from 1920 to 1988, occurred only on Cousin Island (29 ha) in the Seychelles. Despite the saturated nature of this population and the possibility of obtaining higher reproductive success on new nearby islands,

  12. Nearby supernova host galaxies from the CALIFA survey. II. Supernova environmental metallicity

    NARCIS (Netherlands)

    Galbany, L.; Stanishev, V.; Mourão, A. M.; Rodrigues, M.; Flores, H.; Walcher, C. J.; Sánchez, S. F.; García-Benito, R.; Mast, D.; Badenes, C.; González Delgado, R. M.; Kehrig, C.; Lyubenova, M.; Marino, R. A.; Mollá, M.; Meidt, S.; Pérez, E.; van de Ven, G.; Vílchez, J. M.

    2016-01-01

    The metallicity of a supernova progenitor, together with its mass, is one of the main parameters that can rule the progenitor's fate. We present the second study of nearby supernova (SN) host galaxies (0.005 ⊙) > 10 dex) by targeted searches. We neither found evidence that the metallicity at the SN

  13. XMM-Newton view of X-ray overdensities from nearby galaxy clusters : the environmental dependencies

    NARCIS (Netherlands)

    Caglar,; T.; Hudaverdi,; M.,

    2017-01-01

    In this work, we studied ten nearby (z≤0.038) galaxy clusters to understand possible interactions between hot plasma and member galaxies. A multi-band source detection was applied to detect point-like structures within the intra-cluster medium. We examined spectral properties of a total of 391 X-ray

  14. UVES abundances of stars in nearby galaxies : How good are theoretical isochrones?

    NARCIS (Netherlands)

    Tolstoy, E; Piotto, G; Meylan, G; Djougovski, SG; Riello, M

    2003-01-01

    Here we report some results from an ESO-VLT programme to observe individual stars in nearby dwarf galaxies at high resolution with the UVES spectrograph (Tolstoy, Venn, Shetrone, Primas, Hill, Kaufer & Szeifert 2002, submitted to AJ). We mainly concentrate on illustrating the issues and

  15. Properly Interpreting the Epidemiologic Evidence about the Health Effects of Industrial Wind Turbines on Nearby Residents

    Science.gov (United States)

    Phillips, Carl V.

    2011-01-01

    There is overwhelming evidence that wind turbines cause serious health problems in nearby residents, usually stress-disorder-type diseases, at a nontrivial rate. The bulk of the evidence takes the form of thousands of adverse event reports. There is also a small amount of systematically gathered data. The adverse event reports provide compelling…

  16. Metasurface Cloak Performance Near-by Multiple Line Sources and PEC Cylindrical Objects

    DEFF Research Database (Denmark)

    Arslanagic, Samel; Yatman, William H.; Pehrson, Signe

    2014-01-01

    The performance/robustness of metasurface cloaks to a complex field environment which may represent a realistic scenario of radiating sources is presently reported. Attention is devoted to the cloak operation near-by multiple line sources and multiple perfectly electrically conducting cylinders. ...

  17. Impact of Granite Quarrying on the Health of Workers and Nearby ...

    African Journals Online (AJOL)

    Impact of Granite Quarrying on the Health of Workers and Nearby Residents in Abeokuta Ogun State, Nigeria. ... Suspended Particulate Matter (SPM) meter was employed to monitor the level of particulate matter (PM10) within and around five quarry sites selected for this study. The data collected from hospital records of ...

  18. Correlation of the highest-energy cosmic rays with the positions of nearby active galactic nuclei

    NARCIS (Netherlands)

    Abraham, J.; Abreu, P.; Aglietta, M.; Aguirre, C.; Allard, D.; Allekotte, I.; Allen, J.; Allison, P.; Alvarez-Muniz, J.; Ambrosio, M.; Anchordoqui, L.; Andringa, S.; Anzalone, A.; Aramo, C.; Argiro, S.; Arisaka, K.; Armengaud, E.; Arneodo, F.; Arqueros, F.; Asch, T.; Asorey, H.; Assis, P.; Atulugama, B. S.; Aublin, J.; Ave, M.; Avila, G.; Baecker, T.; Badagnani, D.; Barbosa, A. F.; Barnhill, D.; Barroso, S. L. C.; Bauleo, P.; Beatty, J. J.; Beau, T.; Becker, B. R.; Becker, K. H.; Bellido, J. A.; BenZvi, S.; Berat, C.; Bergmann, T.; Bernardini, P.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blanch-Bigas, O.; Blanco, F.; Blasi, P.; Bleve, C.; Bluemer, H.; Bohacova, M.; Bonifazi, C.; Bonino, R.; Brack, J.; Brogueira, P.; Brown, W. C.; Buchholz, P.; Bueno, A.; Burton, R. E.; Busca, N. G.; Caballero-Mora, K. S.; Cai, B.; Camin, D. V.; Caramete, L.; Caruso, R.; Carvalho, W.; Castellina, A.; Catalano, O.; Cataldi, G.; Cazon, L.; Cester, R.; Chauvin, J.; Chiavassa, A.; Chinellato, J. A.; Chou, A.; Chye, J.; Clay, R. W.; Colombo, E.; Conceicao, R.; Connolly, B.; Contreras, F.; Coppens, J.; Cordier, A.; Cotti, U.; Coutu, S.; Covault, C. E.; Creusot, A.; Criss, A.; Cronin, J.; Curutiu, A.; Dagoret-Campagne, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; De Donato, C.; Bg, S. J. de Jong; De La Vega, G.; de Mello, W. J. M.; de Mello Neto, J. R. T.; De Mitri, I.; de Souza, V.; del Peral, L.; Deligny, O.; Della Selva, A.; Delle Fratte, C.; Dembinski, H.; Di Giulio, C.; Diaz, J. C.; Diep, P. N.; Dobrigkeit, C.; D'Olivo, J. C.; Dong, P. N.; Dornic, D.; Dorofeev, A.; dos Anjos, J. C.; Dova, M. T.; D'Urso, D.; Dutan, I.; DuVernois, M. A.; Engel, R.; Epele, L.; Escobar, C. O.; Etchegoyen, A.; Luis, P. Facal San; Falcke, H.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferrer, F.; Ferry, S.; Fick, B.; Filevich, A.; Filipcic, A.; Fleck, I.; Fracchiolla, C. E.; Fulgione, W.; Garcia, B.; Gaimez, D. Garcia; Garcia-Pinto, D.; Garrido, X.; Geenen, H.; Gelmini, G.; Gemmeke, H.; Ghia, P. L.; Giller, M.; Glass, H.; Gold, M. S.; Golup, G.; Albarracin, F. Gomez; Berisso, M. Gomez; Herrero, R. Gomez; Goncalves, P.; do Amaral, M. Goncalves; Gonzalez, D.; Gonzalezc, J. G.; Gonzalez, M.; Gora, D.; Gorgi, A.; Gouffon, P.; Grassi, V.; Grillo, A. F.; Grunfeld, C.; Guardincerri, Y.; Guarino, F.; Guedes, G. P.; Gutierrez, J.; Hague, J. D.; Hamilton, J. C.; Hansen, P.; Harari, D.; Harmsma, S.; Harton, J. L.; Haungs, A.; Hauschildt, T.; Healy, M. D.; Hebbeker, T.; Hebrero, G.; Heck, D.; Hojvat, C.; Holmes, V. C.; Homola, P.; Hoerandel, J.; Horneffer, A.; Horvat, M.; Hrabovsky, M.; Huege, T.; Hussain, M.; Larlori, M.; Insolia, A.; Ionita, F.; Italiano, A.; Kaducak, M.; Kampert, K. H.; Karova, T.; Kegl, B.; Keilhauer, B.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Knapik, R.; Knapp, J.; Koanga, V. -H.; Krieger, A.; Kroemer, O.; Kuempel, D.; Kunka, N.; Kusenko, A.; La Rosa, G.; Lachaud, C.; Lago, B. L.; Lebrun, D.; LeBrun, P.; Lee, J.; de Oliveira, M. A. Leigui; Lopez, R.; Letessier-Selvon, A.; Leuthold, M.; Lhenry-Yvon, I.; Aguera, A. Lopez; Bahilo, J. Lozano; Garcia, R. Luna; Maccarone, M. C.; Macolino, C.; Maldera, S.; Mancarella, G.; Mancenido, M. E.; Mandatat, D.; Mantsch, P.; Mariazzi, A. G.; Maris, I. C.; Falcon, H. R. Marquez; Martello, D.; Martinez, J.; Bravo, O. Martinez; Mathes, H. J.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurizio, D.; Mazur, P. O.; McCauley, T.; McEwen, M.; McNeil, R. R.; Medina, M. C.; Medina-Tanco, G.; Meli, A.; Melo, D.; Menichetti, E.; Menschikov, A.; Meurer, Chr.; Meyhandan, R.; Micheletti, M. I.; Miele, G.; Miller, W.; Mollerach, S.; Monasor, M.; Ragaigne, D. Monnier; Montanet, F.; Morales, B.; Morello, C.; Moreno, J. C.; Morris, C.; Mostafa, M.; Muller, M. A.; Mussa, R.; Navarra, G.; Navarro, J. L.; Navas, S.; Necesal, P.; Nellen, L.; Newman-Holmes, C.; Newton, D.; Nhung, P. T.; Nierstenhoefer, N.; Nitz, D.; Nosek, D.; Nozka, L.; Oehlschlaeger, J.; Ohnuki, T.; Olinto, A.; Olmos-Gilbaja, V. M.; Ortiz, M.; Ortolani, F.; Ostapchenko, S.; Otero, L.; Pacheco, N.; Selmi-Dei, D. Pakk; Palatka, M.; Pallotta, J.; Parente, G.; Parizot, E.; Parlati, S.; Pastor, S.; Patel, M.; Paul, T.; Pavlidou, V.; Payet, K.; Pech, M.; Pekala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Petrera, S.; Petrinca, P.; Petrov, Y.; Pichel, A.; Piegaia, R.; Pierog, T.; Pimenta, M.; Pinto, T.; Pirronello, V.; Pisanti, O.; Platino, M.; Pochon, J.; Privitera, P.; Prouza, M.; Quel, E. J.; Rautenberg, J.; Redondo, A.; Reucroft, S.; Revenu, B.; Rezende, F. A. S.; Ridky, J.; Riggi, S.; Risse, M.; Riviere, C.; Rizi, V.; Roberts, M.; Robledo, C.; Rodriguez, G.; Martino, J. Rodriguez; Rojo, J. Rodriguez; Rodriguez-Cabo, I.; Rodriguez-Frias, M. D.; Ros, G.; Rosado, J.; Roth, M.; Rouille-d'Orfeuil, B.; Roulet, E.; Roverok, A. C.; Salamida, F.; Salazar, H.; Salina, G.; Sanchez, F.; Santander, M.; Santo, C. E.; Santos, E. M.; Sarazin, F.; Sarkar, S.; Sato, R.; Scherini, V.; Schieler, H.; Schmidt, A.; Schmidt, F.; Schmidt, T.; Scholten, O.; Schovanek, P.; Schuessler, F.; Sciutto, S. J.; Scuderi, M.; Segreto, A.; Semikoz, D.; Settimo, M.; Shellard, R. C.; Sidelnik, I.; Siffert, B. B.; Sigl, G.; De Grande, N. Smetniansky; Smialkowski, A.; Smida, R.; Smith, A. G. K.; Smith, B. E.; Snow, G. R.; Sokolsky, P.; Sommers, P.; Sorokin, J.; Spinka, H.; Squartini, R.; Strazzeri, E.; Stutz, A.; Suarez, F.; Suomijarvi, T.; Supanitsky, A. D.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Takahashi, J.; Tamashiro, A.; Tamburro, A.; Tascau, O.; Tcaciuc, R.; Thao, N. T.; Thomas, D.; Ticona, R.; Tiffenberg, J.; Timmermans, C.; Tkaczyk, W.; Peixoto, C. J. Todero; Tome, B.; Tonachini, A.; Torres, I.; Travnicek, P.; Tripathi, A.; Tristram, G.; Tscherniakhovski, D.; Tueros, M.; Ulrich, R.; Unger, M.; Urban, M.; Galicia, J. F. Valdes; Valino, I.; Valore, L.; van den Berg, A. M.; van Elewyck, V.; Vazquez, R. A.; Veberic, D.; Veiga, A.; Velarde, A.; Venters, T.; Verzi, V.; Videla, M.; Villasenor, L.; Vorobiov, S.; Voyvodic, L.; Wahlberg, H.; Wainberg, O.; Warner, D.; Watson, A. A.; Westerhoff, S.; Wieczorek, G.; Wiencke, L.; Wilczynska, B.; Wilczynski, H.; Wileman, C.; Winnick, M. G.; Wu, H.; Wundheiler, B.; Yamamoto, T.; Younk, P.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zech, A.; Zepeda, A.; Ziolkowski, M.

    Data collected by the Pierre Auger Observatory provide evidence for anisotropy in the arrival directions of the cosmic rays with the highest-energies, which are correlated with the positions of relatively nearby active galactic nuclei (AGN) [Pierre Auger Collaboration, Science 318 (2007) 938]. The

  19. Direct imaging of haloes and truncations in face-on nearby galaxies

    NARCIS (Netherlands)

    Knapen, J. H.; Peters, S. P. C.; van der Kruit, P. C.; Trujillo, I.; Fliri, J.; Cisternas, M.; Kelvin, L. S.; Bragaglia, A.; Arnaboldi, M.; Rejkuba, M.; Romano, D.

    2016-01-01

    We use ultra-deep imaging from the IAC Stripe 82 Legacy Project to study the surface photometry of 22 nearby, face-on to moderately inclined spiral galaxies. The reprocessed and co-added SDSS/Stripe 82 imaging allows us to probe down to 29-30 r'-mag/arcsec2 and thus reach into the very faint

  20. CONSTRAINING THE SPIN-DOWN OF THE NEARBY ISOLATED NEUTRON STAR RX J0806.4-4123, AND IMPLICATIONS FOR THE POPULATION OF NEARBY NEUTRON STARS

    International Nuclear Information System (INIS)

    Kaplan, D. L.; Van Kerkwijk, M. H.

    2009-01-01

    The nearby isolated neutron stars (INSs) are a group of seven relatively slowly rotating neutron stars that show thermal X-ray spectra, most with broad absorption features. They are interesting both because they may allow one to determine fundamental neutron-star properties by modeling their spectra, and because they appear to be a large fraction of the overall neutron-star population. Here, we describe a series of XMM -Newton observations of the nearby INS RX J0806.4-4123, taken as part of larger program of timing studies. From these, we limit the spin-down rate to ν-dot=(-4.3±2.3)x10 -16 Hz s -1 . This constrains the dipole magnetic field to be 13 G at 2σ, significantly less than the field of ∼10 14 G implied by simple models for the X-ray absorption found at 0.45 keV. We confirm that the spectrum is thermal and stable (to within a few percent), but find that the 0.45 keV absorption feature is broader and more complex than previously thought. Considering the population of INSs, we find that magnetic field decay from an initial field of ∼ 14 G accounts most naturally for their timing and spectral properties, both qualitatively and in the context of the models for field decay of Pons and collaborators.

  1. PRE-DISCOVERY AND FOLLOW-UP OBSERVATIONS OF THE NEARBY SN 2009nr: IMPLICATIONS FOR PROMPT TYPE Ia SUPERNOVAE

    International Nuclear Information System (INIS)

    Khan, Rubab; Stanek, K. Z.; Beacom, J. F.; Szczygiel, D. M.; Mogren, K.; Eastman, J. D.; Martini, P.; Stoll, R.; Prieto, J. L.; Pojmanski, G.; Pilecki, B.

    2011-01-01

    We present photometric and spectroscopic observations of the Type Ia supernova SN 2009nr in UGC 8255 (z = 0.0122). Following the discovery announcement at what turned out to be 10 days after peak, we detected it at V ≅15.7 mag in data collected by the All-Sky Automated Survey (ASAS) North telescope 2 weeks prior to the peak, and then followed it up with telescopes ranging in aperture from 10 cm to 6.5 m. Using early photometric data available only from ASAS, we find that the supernova is similar to the overluminous Type Ia SN 1991T, with a peak at M V ≅ -19.6 mag, and a slow decline rate of Δm 15 (B) ≅ 0.95 mag. The early post-maximum spectra closely resemble those of SN 1991T, while the late-time spectra are more similar to those of normal Type Ia supernovae (SNe Ia). Interestingly, SN 2009nr has a projected distance of 13.0 kpc (∼4.3 disk scale lengths) from the nucleus of the small star-forming host galaxy UGC 8255. This indicates that the progenitor of SN 2009nr is not associated with a young stellar population, calling into question the conventional association of luminous SNe Ia with the 'prompt' component directly correlated with current star formation. The pre-discovery observation of SN 2009nr using ASAS demonstrates the science utility of high-cadence all sky surveys conducted using small telescopes for the discovery of nearby (d ∼< 50 Mpc) supernovae.

  2. Dynamic response of the high flux isotope reactor structure caused by nearby heavy load drop

    International Nuclear Information System (INIS)

    Chang, Shih-Jung.

    1995-01-01

    A heavy load of 50,000 lb is assumed to drop from 10 ft above the bottom of the High Flux Isotope Reactor (HFIR) pool at the loading station. The consequences of the dynamic impact to the bottom slab of the pool and to the nearby HFIR reactor vessel are analyzed by applying the ABAQUS computer code The results show that both the BM vessel structure and its supporting legs are subjected to elastic disturbances only and, therefore, will not be damaged. The bottom slab of the pool, however, will be damaged to about half of the slab thickness. The velocity response spectrum at the concrete floor next to the HFIR vessel as a result of the vibration caused by the impact is obtained. It is concluded, that the damage caused by heavy load drop at the loading station is controlled by the slab damage and the nearby HFIR vessel and the supporting legs will not be damaged

  3. Nearby CFTs in the operator formalism: the role of a connection

    International Nuclear Information System (INIS)

    Ranganathan, K.

    1993-01-01

    There are two methods to study families of conformal theories in the operator formalism. In the first method we begin with a theory and a family of deformed theories defined in the state space of the original theory. In the other there is a distinct state space for each theory in the family, with the collection of spaces forming a vector bundle. This paper establishes the equivalence of a deformed theory with that in a nearby state space in the bundle via a connection that defines maps between nearby state spaces. We find that an appropriate connection for establishing equivalence is one that arose in a recent paper by Kugo and Zwiebach. We discuss the affine geometry induced on the space of backgrounds by this connection. This geometry is the same as the one obtained from the Zamolodchikov metric. (orig.)

  4. Low dark matter content of the nearby early-type galaxy NGC 821

    Directory of Open Access Journals (Sweden)

    Samurović S.

    2014-01-01

    Full Text Available In this paper we analyze the kinematics and dynamics of the nearby early-type galaxy NGC 821 based on its globular clusters (GCs and planetary nebulae (PNe. We use PNe and GCs to extract the kinematics of NGC 821 which is then used for the dynamical modelling based on the Jeans equation. We apply the Jeans equation using the Newtonian mass-follows-light approach assuming constant mass-to-light ratio and find that using such an approach we can successfully fit the kinematic data. The inferred constant mass-to-light ratio, 4:2 < M=LB < 12:4 present throughout the whole galaxy, implies the lack of significant amount of dark matter. We also used three different MOND approaches and found that we can fit the kinematic data without the need for additional, dark, component. [Projekat Ministarstva nauke Republike Srbije, br. 176021: Visible and invisible matter in nearby galaxies: theory and observations

  5. Multiple Lightning Discharges in Wind Turbines Associated with Nearby Cloud-to-Ground Lightning

    DEFF Research Database (Denmark)

    Candela Garolera, Anna; Cummins, Kenneth L.; Madsen, Søren Find

    2015-01-01

    This paper presents the analysis of five events where simultaneous lightning currents were registered in different wind turbines of a wind farm with lightning monitoring equipment installed. Measurements from current monitoring devices installed at the wind turbines and observations from auto......-triggering video cameras were correlated with data from the U.S. National Lighting Detection Network. In all five events, the correlation showed that a cloud-to-ground (CG) lightning stroke with high peak current struck the ground within 10 km of the affected turbines at the time of the currents in the wind...... by the nearby CG strokes, involving mechanisms that vary depending on the polarity of the associated CG stroke. The analysis also suggests that the event of upward lightning from wind turbines triggered by nearby lightning activity occurs very often and therefore it should be considered carefully...

  6. AN ESTIMATE OF THE NEARBY INTERSTELLAR MAGNETIC FIELD USING NEUTRAL ATOMS

    International Nuclear Information System (INIS)

    Heerikhuisen, J.; Pogorelov, N. V.

    2011-01-01

    The strength and orientation of the magnetic field in the nearby interstellar medium have remained elusive, despite continual improvements in observations and models. Data from NASA's Voyager mission and the Solar Wind ANisotropies (SWAN) experiment on board Solar and Heliospheric Observatory (SOHO) have placed observational constraints on the magnetic field, and the more recent Interstellar Boundary Explorer (IBEX) data appear to also bear an imprint of the interstellar magnetic field (ISMF). In this paper, we combine computational models of the heliosphere with data from Voyager, SOHO/SWAN, and IBEX to estimate both the strength and direction of the nearby ISMF. On the basis of our simulations, we find that a field strength of 2-3 μG pointing from ecliptic coordinates (220-224, 39-44), combined with an interstellar hydrogen density of ∼0.15 cm -3 , produces results most consistent with observations.

  7. Reproduction of nearby sound sources using higher-order ambisonics with practical loudspeaker arrays

    DEFF Research Database (Denmark)

    Favrot, Sylvain Emmanuel; Buchholz, Jörg

    2012-01-01

    the impact of two existing and a new proposed regularization function on the reproduced sound fields and on the main auditory cue for nearby sound sources outside the median plane, i.e, low-frequencies interaural level differences (ILDs). The proposed regularization function led to a better reproduction......In order to reproduce nearby sound sources with distant loudspeakers to a single listener, the near field compensated (NFC) method for higher-order Ambisonics (HOA) has been previously proposed. In practical realization, this method requires the use of regularization functions. This study analyzes...... of point source sound fields compared to existing regularization functions for NFC-HOA. Measurements in realistic playback environments showed that, for very close sources, significant ILDs for frequencies above about 250 Hz can be reproduced with NFC-HOA and the proposed regularization function whereas...

  8. Underestimating nearby nature: affective forecasting errors obscure the happy path to sustainability.

    Science.gov (United States)

    Nisbet, Elizabeth K; Zelenski, John M

    2011-09-01

    Modern lifestyles disconnect people from nature, and this may have adverse consequences for the well-being of both humans and the environment. In two experiments, we found that although outdoor walks in nearby nature made participants much happier than indoor walks did, participants made affective forecasting errors, such that they systematically underestimated nature's hedonic benefit. The pleasant moods experienced on outdoor nature walks facilitated a subjective sense of connection with nature, a construct strongly linked with concern for the environment and environmentally sustainable behavior. To the extent that affective forecasts determine choices, our findings suggest that people fail to maximize their time in nearby nature and thus miss opportunities to increase their happiness and relatedness to nature. Our findings suggest a happy path to sustainability, whereby contact with nature fosters individual happiness and environmentally responsible behavior.

  9. Dependence of the velocity ellipsoid for nearby stars upon metallicity and spectral type

    International Nuclear Information System (INIS)

    Suchkov, A.A.

    1983-01-01

    For nearby dwarf stars the ratios of the dispersions in the velocity components along the axes of a rectangular galactic coordinate system depend on spectral type and chemical composition (metal abundance). Relationships are established which could provide clues to such problems as whether the component populations of the Galaxy are relaxing to a steady state and how stars come to be formed with differing mass at different times

  10. The phase-space structure of nearby dark matter as constrained by the SDSS

    International Nuclear Information System (INIS)

    Leclercq, Florent; Percival, Will; Jasche, Jens; Lavaux, Guilhem; Wandelt, Benjamin

    2017-01-01

    Previous studies using numerical simulations have demonstrated that the shape of the cosmic web can be described by studying the Lagrangian displacement field. We extend these analyses, showing that it is now possible to perform a Lagrangian description of cosmic structure in the nearby Universe based on large-scale structure observations. Building upon recent Bayesian large-scale inference of initial conditions, we present a cosmographic analysis of the dark matter distribution and its evolution, referred to as the dark matter phase-space sheet, in the nearby universe as probed by the Sloan Digital Sky Survey main galaxy sample. We consider its stretchings and foldings using a tetrahedral tessellation of the Lagrangian lattice. The method provides extremely accurate estimates of nearby density and velocity fields, even in regions of low galaxy density. It also measures the number of matter streams, and the deformation and parity reversals of fluid elements, which were previously thought inaccessible using observations. We illustrate the approach by showing the phase-space structure of known objects of the nearby Universe such as the Sloan Great Wall, the Coma cluster and the Boötes void. We dissect cosmic structures into four distinct components (voids, sheets, filaments, and clusters), using the Lagrangian classifiers DIVA, ORIGAMI, and a new scheme which we introduce and call LICH. Because these classifiers use information other than the sheer local density, identified structures explicitly carry physical information about their formation history. Accessing the phase-space structure of dark matter in galaxy surveys opens the way for new confrontations of observational data and theoretical models. We have made our data products publicly available.

  11. The Eating Habits of Giants and Dwarfs: Chemo-dynamics of Halo Assembly in Nearby Galaxies

    Science.gov (United States)

    Romanowsky, Aaron J.; SAGES Team

    2012-01-01

    I will present novel results on the halo assembly of nearby galaxies, from dwarfs to the most massive ellipticals, using Subaru imaging and Keck spectroscopy. Field stars, globular clusters, and planetary nebulae are used as wide-field chemo-dynamical tracers, mapping out halo substructures that were previously known and unknown. Comparisons are made with simulations of galaxy formation. Supported by the National Science Foundation Grants AST-0808099, AST-0909237, and AST-1109878.

  12. Imprecision in waggle dances of the honeybee (Apis mellifera) for nearby food sources : error or adaptation?

    OpenAIRE

    Weidenmüller, Anja; Seeley, Thomas

    1999-01-01

    A curious feature of the honeybee's waggle dance is the imprecision in the direction indication for nearby food sources. One hypothesis for the function of this imprecision is that it serves to spread recruits over a certain area and thus is an adaptation to the typical spatial configuration of the bees' food sources, i.e., flowers in sizable patches. We report an experiment that tests this tuned-error hypothesis. We measured the precision of direction indication in waggle dances advertising ...

  13. Nearby galaxies as pointers to a better theory of cosmic evolution.

    Science.gov (United States)

    Peebles, P J E; Nusser, Adi

    2010-06-03

    The great advances in the network of cosmological tests show that the relativistic Big Bang theory is a good description of our expanding Universe. However, the properties of nearby galaxies that can be observed in greatest detail suggest that a better theory would describe a mechanism by which matter is more rapidly gathered into galaxies and groups of galaxies. This more rapid growth occurs in some theoretical ideas now under discussion.

  14. What influences community positions towards nearby mining projects : eight cases from Brazil and Chile

    OpenAIRE

    Maher, Rajiv

    2014-01-01

    This thesis looks at the influences and dynamics of community positions towards nearby mining projects in Brazil and Chile from an affected communities perspective. This subject is important because even after many initiatives and guidance aimed at helping companies to obtain good community relations, also known as a social license to operate (SLO), conflict in many mining community contexts is still prevalent today. In considering this, the thesis draws from Stakeholder, Resou...

  15. The phase-space structure of nearby dark matter as constrained by the SDSS

    Energy Technology Data Exchange (ETDEWEB)

    Leclercq, Florent; Percival, Will [Institute of Cosmology and Gravitation (ICG), University of Portsmouth, Dennis Sciama Building, Burnaby Road, Portsmouth PO1 3FX (United Kingdom); Jasche, Jens [Excellence Cluster Universe, Technische Universität München, Boltzmannstrasse 2, D-85748 Garching (Germany); Lavaux, Guilhem; Wandelt, Benjamin, E-mail: florent.leclercq@polytechnique.org, E-mail: lavaux@iap.fr, E-mail: jasche@iap.fr, E-mail: wandelt@iap.fr, E-mail: will.percival@port.ac.uk [Institut d' Astrophysique de Paris (IAP), UMR 7095, CNRS – UPMC Université Paris 6, Sorbonne Universités, 98bis boulevard Arago, F-75014 Paris (France)

    2017-06-01

    Previous studies using numerical simulations have demonstrated that the shape of the cosmic web can be described by studying the Lagrangian displacement field. We extend these analyses, showing that it is now possible to perform a Lagrangian description of cosmic structure in the nearby Universe based on large-scale structure observations. Building upon recent Bayesian large-scale inference of initial conditions, we present a cosmographic analysis of the dark matter distribution and its evolution, referred to as the dark matter phase-space sheet, in the nearby universe as probed by the Sloan Digital Sky Survey main galaxy sample. We consider its stretchings and foldings using a tetrahedral tessellation of the Lagrangian lattice. The method provides extremely accurate estimates of nearby density and velocity fields, even in regions of low galaxy density. It also measures the number of matter streams, and the deformation and parity reversals of fluid elements, which were previously thought inaccessible using observations. We illustrate the approach by showing the phase-space structure of known objects of the nearby Universe such as the Sloan Great Wall, the Coma cluster and the Boötes void. We dissect cosmic structures into four distinct components (voids, sheets, filaments, and clusters), using the Lagrangian classifiers DIVA, ORIGAMI, and a new scheme which we introduce and call LICH. Because these classifiers use information other than the sheer local density, identified structures explicitly carry physical information about their formation history. Accessing the phase-space structure of dark matter in galaxy surveys opens the way for new confrontations of observational data and theoretical models. We have made our data products publicly available.

  16. The Influence of Galactic Outflows on the Formation of Nearby Dwarf Galaxies.

    Science.gov (United States)

    Scannapieco; Ferrara; Broadhurst

    2000-06-10

    We show that the gas in growing density perturbations is vulnerable to the influence of winds outflowing from nearby collapsed galaxies that have already formed stars. This suggests that the formation of nearby galaxies with masses less, similar10(9) M( middle dot in circle) is likely to be suppressed, irrespective of the details of galaxy formation. An impinging wind may shock-heat the gas of a nearby perturbation to above the virial temperature, thereby mechanically evaporating the gas, or the baryons may be stripped from the perturbation entirely if they are accelerated to above the escape velocity. We show that baryonic stripping is the most effective of these two processes, because shock-heated clouds that are too large to be stripped are able to radiatively cool within a sound crossing time, limiting evaporation. The intergalactic medium temperatures and star formation rates required for outflows to have a significant influence on the formation of low-mass galaxies are consistent with current observations, but may soon be examined directly via associated distortions in the cosmic microwave background and with near-infrared observations from the Next Generation Space Telescope, which may detect the supernovae from early-forming stars.

  17. Updated 34-band Photometry for the SINGS/KINGFISH Samples of Nearby Galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Dale, D. A.; Turner, J. A. [Department of Physics and Astronomy, University of Wyoming, Laramie WY (United States); Cook, D. O. [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena CA (United States); Roussel, H. [Institut d’Astrophysique de Paris, Sorbonne Universités, Paris (France); Armus, L.; Helou, G. [Spitzer Science Center, California Institute of Technology, Pasadena, CA (United States); Bolatto, A. D. [Department of Astronomy, University of Maryland, College Park, MD (United States); Boquien, M. [Unidad de Astronomía, Universidad de Antofagasta, Antofagasta (Chile); Brown, M. J. I. [School of Physics and Astronomy, Monash University, Victoria 3800 (Australia); Calzetti, D. [Department of Astronomy, University of Massachusetts, Amherst MA (United States); Looze, I. De [Sterrenkundig Observatorium, Universiteit Gent, Gent (Belgium); Galametz, M. [European Southern Observatory, Garching (Germany); Gordon, K. D. [Space Telescope Science Institute, Baltimore MD (United States); Groves, B. A. [Research School of Astronomy and Astrophysics, Australian National University, Canberra (Australia); Jarrett, T. H. [Astronomy Department, University of Capetown, Rondebosch (South Africa); Herrera-Camus, R. [Max-Planck-Institut für Extraterrestrische Physik, Garching (Germany); Hinz, J. L. [Steward Observatory, University of Arizona, Tucson AZ (United States); Hunt, L. K. [INAF—Osservatorio Astrofisico di Arcetri, Firenze (Italy); Kennicutt, R. C. [Institute of Astronomy, University of Cambridge, Cambridge (United Kingdom); Murphy, E. J., E-mail: ddale@uwyo.edu [National Radio Astronomy Observatory, Charlottesville, VA (United States); and others

    2017-03-01

    We present an update to the ultraviolet-to-radio database of global broadband photometry for the 79 nearby galaxies that comprise the union of the KINGFISH (Key Insights on Nearby Galaxies: A Far-Infrared Survey with Herschel ) and SINGS ( Spitzer Infrared Nearby Galaxies Survey) samples. The 34-band data set presented here includes contributions from observational work carried out with a variety of facilities including GALEX , SDSS, Pan-STARRS1, NOAO , 2MASS, Wide-Field Infrared Survey Explorer , Spitzer , Herschel , Planck , JCMT , and the VLA. Improvements of note include recalibrations of previously published SINGS BVR {sub C} I {sub C} and KINGFISH far-infrared/submillimeter photometry. Similar to previous results in the literature, an excess of submillimeter emission above model predictions is seen primarily for low-metallicity dwarf or irregular galaxies. This 33-band photometric data set for the combined KINGFISH+SINGS sample serves as an important multiwavelength reference for the variety of galaxies observed at low redshift. A thorough analysis of the observed spectral energy distributions is carried out in a companion paper.

  18. ARSENIC ADSORPTION AND REDUCTION IN IRON-RICH SOILS NEARBY LANDFILLS IN NORTHWEST FLORIDA

    Directory of Open Access Journals (Sweden)

    Hongqin Xue

    2016-01-01

    Full Text Available In Florida, soils are mainly composed of Myakka, an acid soil characterized by a subsurface accumulation of humus and Al(III and Fe(III oxides. Downgradient of the landfills in Northwest Florida, elevated levels of iron and arsenic observations had been made in the groundwater from monitoring wells, which was attributed to the geomicrobial iron and arsenic reduction. There is thus an immediate research need for a better understanding of the reduction reactions that are responsible for the mobilization of iron and arsenic in the subsurface soil nearby landfills. Owing to the high Fe(III oxide content, As(V adsorption reactions with Fe(III oxide surfaces are particularly important, which may control As(V reduction. This research focused on the investigation of the biogeochemical processes of the subsurface soil nearby landfills of Northwest Florida. Arsenic and iron reduction was studied in batch reactors and quantified based on Monod-type microbial kinetic growth simulations. As(V adsorption in iron-rich Northwest Floridian soils was further investigated to explain the reduction observations. It was demonstrated in this research that solubilization of arsenic in the subsurface soil nearby landfills in Northwest Florida would likely occur under conditions favoring Fe(III dissimilatory reduction.

  19. Updated 34-band Photometry for the SINGS/KINGFISH Samples of Nearby Galaxies

    International Nuclear Information System (INIS)

    Dale, D. A.; Turner, J. A.; Cook, D. O.; Roussel, H.; Armus, L.; Helou, G.; Bolatto, A. D.; Boquien, M.; Brown, M. J. I.; Calzetti, D.; Looze, I. De; Galametz, M.; Gordon, K. D.; Groves, B. A.; Jarrett, T. H.; Herrera-Camus, R.; Hinz, J. L.; Hunt, L. K.; Kennicutt, R. C.; Murphy, E. J.

    2017-01-01

    We present an update to the ultraviolet-to-radio database of global broadband photometry for the 79 nearby galaxies that comprise the union of the KINGFISH (Key Insights on Nearby Galaxies: A Far-Infrared Survey with Herschel ) and SINGS ( Spitzer Infrared Nearby Galaxies Survey) samples. The 34-band data set presented here includes contributions from observational work carried out with a variety of facilities including GALEX , SDSS, Pan-STARRS1, NOAO , 2MASS, Wide-Field Infrared Survey Explorer , Spitzer , Herschel , Planck , JCMT , and the VLA. Improvements of note include recalibrations of previously published SINGS BVR C I C and KINGFISH far-infrared/submillimeter photometry. Similar to previous results in the literature, an excess of submillimeter emission above model predictions is seen primarily for low-metallicity dwarf or irregular galaxies. This 33-band photometric data set for the combined KINGFISH+SINGS sample serves as an important multiwavelength reference for the variety of galaxies observed at low redshift. A thorough analysis of the observed spectral energy distributions is carried out in a companion paper.

  20. VLA-ANGST: A HIGH-RESOLUTION H I SURVEY OF NEARBY DWARF GALAXIES

    International Nuclear Information System (INIS)

    Ott, Jürgen; Stilp, Adrienne M.; Dalcanton, Julianne J.; Warren, Steven R.; Skillman, Evan D.; Walter, Fabian; De Blok, W. J. G.; Koribalski, Bärbel; West, Andrew A.

    2012-01-01

    We present the 'Very Large Array survey of Advanced Camera for Surveys Nearby Galaxy Survey Treasury galaxies (VLA-ANGST)'. VLA-ANGST is a National Radio Astronomy Observatory Large Program consisting of high spectral (0.6-2.6 km s –1 ) and spatial (∼6'') resolution observations of neutral, atomic hydrogen (H I) emission toward 35 nearby dwarf galaxies from the ANGST survey. ANGST is a systematic Hubble Space Telescope survey to establish a legacy of uniform multi-color photometry of resolved stars for a volume-limited sample of nearby galaxies (D ∼ –1 for the majority of the galaxies). The VLA-ANGST data products are made publicly available through a dedicated Web site (https://science.nrao.edu/science/surveys/vla-angst). With available star formation histories from resolved stellar populations and lower resolution ancillary observations from the far-infrared to the ultraviolet, VLA-ANGST will enable detailed studies of the relationship between the ISM and star formation in dwarf galaxies on a ∼100 pc scale.

  1. Reassessment of the Upper Fremont Glacier ice-core chronologies by synchronizing of ice-core-water isotopes to a nearby tree-ring chronology

    Science.gov (United States)

    Chellman, Nathan J.; McConnell, Joseph R.; Arienzo, Monica; Pederson, Gregory T.; Aarons, Sarah; Csank, Adam

    2017-01-01

    The Upper Fremont Glacier (UFG), Wyoming, is one of the few continental glaciers in the contiguous United States known to preserve environmental and climate records spanning recent centuries. A pair of ice cores taken from UFG have been studied extensively to document changes in climate and industrial pollution (most notably, mid-19th century increases in mercury pollution). Fundamental to these studies is the chronology used to map ice-core depth to age. Here, we present a revised chronology for the UFG ice cores based on new measurements and using a novel dating approach of synchronizing continuous water isotope measurements to a nearby tree-ring chronology. While consistent with the few unambiguous age controls underpinning the previous UFG chronologies, the new interpretation suggests a very different time scale for the UFG cores with changes of up to 80 years. Mercury increases previously associated with the mid-19th century Gold Rush now coincide with early-20th century industrial emissions, aligning the UFG record with other North American mercury records from ice and lake sediment cores. Additionally, new UFG records of industrial pollutants parallel changes documented in ice cores from southern Greenland, further validating the new UFG chronologies while documenting the extent of late 19th and early 20th century pollution in remote North America.

  2. Substellar objects in nearby young clusters (SONYC). VIII. Substellar population in Lupus 3

    Energy Technology Data Exchange (ETDEWEB)

    Mužić, Koraljka [European Southern Observatory, Alonso de Córdova 3107, Casilla 19, Santiago 19001 (Chile); Scholz, Alexander; Geers, Vincent C. [School of Cosmic Physics, Dublin Institute for Advanced Studies, 31 Fitzwilliam Place, Dublin 2 (Ireland); Jayawardhana, Ray [Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4 (Canada); Martí, Belén López, E-mail: kmuzic@eso.org [Centro de Astrobiología (INTA-CSIC), Departamento de Astrofísica, P.O. Box 78, E-28261 Villanueva de la Cañada, Madrid (Spain)

    2014-04-20

    SONYC—Substellar Objects in Nearby Young Clusters—is a survey program to investigate the frequency and properties of substellar objects in nearby star-forming regions. We present a new imaging and spectroscopic survey conducted in the young (∼1 Myr), nearby (∼200 pc) star-forming region Lupus 3. Deep optical and near-infrared images were obtained with MOSAIC-II and NEWFIRM at the CTIO 4 m telescope, covering ∼1.4 deg{sup 2} on the sky. The i-band completeness limit of 20.3 mag is equivalent to 0.009-0.02 M {sub ☉}, for A{sub V} ≤ 5. Photometry and 11-12 yr baseline proper motions were used to select candidate low-mass members of Lupus 3. We performed a spectroscopic follow-up of 123 candidates, using VIMOS at the Very Large Telescope, and we identify 7 probable members, among which 4 have spectral type later than M6.0 and T {sub eff} ≤ 3000 K, i.e., are probably substellar in nature. Two of the new probable members of Lupus 3 appear underluminous for their spectral class and exhibit emission line spectrum with strong H{sub α} or forbidden lines associated with active accretion. We derive a relation between the spectral type and effective temperature: T {sub eff} = (4120 ± 175) – (172 ± 26) × SpT, where SpT refers to the M spectral subtype between 1 and 9. Combining our results with the previous works on Lupus 3, we show that the spectral type distribution is consistent with that in other star-forming regions, as well as the derived star-to-brown dwarf ratio of 2.0-3.3. We compile a census of all spectroscopically confirmed low-mass members with spectral type M0 or later.

  3. TRACING COLD H I GAS IN NEARBY, LOW-MASS GALAXIES

    International Nuclear Information System (INIS)

    Warren, Steven R.; Skillman, Evan D.; Stilp, Adrienne M.; Dalcanton, Julianne J.; Ott, Jürgen; Walter, Fabian; Petersen, Eric A.; Koribalski, Bärbel; West, Andrew A.

    2012-01-01

    We analyze line-of-sight atomic hydrogen (H I) line profiles of 31 nearby, low-mass galaxies selected from the Very Large Array—ACS Nearby Galaxy Survey Treasury (VLA-ANGST) and The H I Nearby Galaxy Survey (THINGS) to trace regions containing cold (T ∼ –1 . Our galaxy sample spans four orders of magnitude in total H I mass and nine magnitudes in M B . We fit single and multiple component functions to each spectrum to isolate the cold, neutral medium given by a low-dispersion ( –1 ) component of the spectrum. Most H I spectra are adequately fit by a single Gaussian with a dispersion of 8-12 km s –1 . Cold H I is found in 23 of 27 (∼85%) galaxies after a reduction of the sample size due to quality-control cuts. The cold H I contributes ∼20% of the total line-of-sight flux when found with warm H I. Spectra best fit by a single Gaussian, but dominated by cold H I emission (i.e., have velocity dispersions of –1 ), are found primarily beyond the optical radius of the host galaxy. The cold H I is typically found in localized regions and is generally not coincident with the very highest surface density peaks of the global H I distribution (which are usually areas of recent star formation). We find a lower limit for the mass fraction of cold-to-total H I gas of only a few percent in each galaxy.

  4. State-of-the-art multi-wavelength observations of nearby brightest group/cluster galaxies

    Science.gov (United States)

    Gendron-Marsolais, Marie-Lou; Hlavacek-Larrondo, Julie

    2018-01-01

    Nearby galaxy groups and clusters are crucial to our understanding of the impact of nuclear outbursts on the intracluster medium as their proximity allows us to study in detail the processes of feedback from active galactic nuclei in these systems. In this talk, I will present state-of-the-art multi-wavelength observations signatures of this mechanism.I will first show results on multi-configuration 230-470 MHz observations of the Perseus cluster from the Karl G. Jansky Very Large Array, probing the non-thermal emission from the old particle population of the AGN outflows. These observations reveal a multitude of new structures associated with the “mini-halo” and illustrate the high-quality images that can be obtained with the new JVLA at low radio-frequencies.Second, I will present new observations with the optical imaging Fourier transform spectrometer SITELLE (CFHT) of NGC 1275, the Perseus cluster's brightest galaxy. With its wide field of view, it is the only integral field unit spectroscopy instrument able to cover the large emission-line filamentary nebula in NGC 1275. I will present the first detailed velocity map of this nebula in its entirety and tackle the question of its origin (residual cooling flow or dragged gas).Finally, I will present deep Chandra observations of the nearby early-type massive elliptical galaxy NGC 4472, the most optically luminous galaxy in the local Universe, lying on the outskirts of the Virgo cluster. Enhanced X-ray rims around the radio lobes are detected and interpreted as gas uplifted from the core by the buoyant rise of the radio bubbles. We estimate the energy required to lift the gas to constitute a significant fraction of the total outburst energy.I will thus show how these high-fidelity observations of nearby brightest group/cluster galaxies are improving our understanding of the AGN feedback mechanism taking place in galaxy groups and clusters.

  5. Substellar objects in nearby young clusters (SONYC). VIII. Substellar population in Lupus 3

    International Nuclear Information System (INIS)

    Mužić, Koraljka; Scholz, Alexander; Geers, Vincent C.; Jayawardhana, Ray; Martí, Belén López

    2014-01-01

    SONYC—Substellar Objects in Nearby Young Clusters—is a survey program to investigate the frequency and properties of substellar objects in nearby star-forming regions. We present a new imaging and spectroscopic survey conducted in the young (∼1 Myr), nearby (∼200 pc) star-forming region Lupus 3. Deep optical and near-infrared images were obtained with MOSAIC-II and NEWFIRM at the CTIO 4 m telescope, covering ∼1.4 deg 2 on the sky. The i-band completeness limit of 20.3 mag is equivalent to 0.009-0.02 M ☉ , for A V ≤ 5. Photometry and 11-12 yr baseline proper motions were used to select candidate low-mass members of Lupus 3. We performed a spectroscopic follow-up of 123 candidates, using VIMOS at the Very Large Telescope, and we identify 7 probable members, among which 4 have spectral type later than M6.0 and T eff ≤ 3000 K, i.e., are probably substellar in nature. Two of the new probable members of Lupus 3 appear underluminous for their spectral class and exhibit emission line spectrum with strong H α or forbidden lines associated with active accretion. We derive a relation between the spectral type and effective temperature: T eff = (4120 ± 175) – (172 ± 26) × SpT, where SpT refers to the M spectral subtype between 1 and 9. Combining our results with the previous works on Lupus 3, we show that the spectral type distribution is consistent with that in other star-forming regions, as well as the derived star-to-brown dwarf ratio of 2.0-3.3. We compile a census of all spectroscopically confirmed low-mass members with spectral type M0 or later.

  6. Binary Star Orbits. V. The Nearby White Dwarf/Red Dwarf Pair 40 Eri BC

    Science.gov (United States)

    Mason, Brian D.; Hartkopf, William I.; Miles, Korie N.

    2017-11-01

    A new relative orbit solution with new dynamical masses is determined for the nearby white dwarf-red dwarf pair 40 Eri BC. The period is 230.09 ± 0.68 years. It is predicted to close slowly over the next half-century, getting as close as 1.″32 in early 2066. We determine masses of 0.575 ± 0.018 {{ M }}⊙ for the white dwarf and 0.2041 ± 0.0064 {{ M }}⊙ for the red dwarf companion. The inconsistency of the masses determined by gravitational redshift and dynamical techniques, due to a premature orbit calculation, no longer exists.

  7. Inductive coupling between overhead power lines and nearby metallic pipelines. A neural network approach

    Directory of Open Access Journals (Sweden)

    Levente Czumbil

    2015-12-01

    Full Text Available The current paper presents an artificial intelligence based technique applied in the investigation of electromagnetic interference problems between high voltage power lines (HVPL and nearby underground metallic pipelines (MP. An artificial neural network (NN solution has been implemented by the authors to evaluate the inductive coupling between HVPL and MP for different constructive geometries of an electromagnetic interference problem considering a multi-layer soil structure. Obtained results are compared to solutions provided by a finite element method (FEM based analysis and considered as reference. The advantage of the proposed method yields in a simplified computation model compared to FEM, and implicitly a lower computational time.

  8. The structure of nearby clusters of galaxies Hierarchical clustering and an application to the Leo region

    CERN Document Server

    Materne, J

    1978-01-01

    A new method of classifying groups of galaxies, called hierarchical clustering, is presented as a tool for the investigation of nearby groups of galaxies. The method is free from model assumptions about the groups. The scaling of the different coordinates is necessary, and the level from which one accepts the groups as real has to be determined. Hierarchical clustering is applied to an unbiased sample of galaxies in the Leo region. Five distinct groups result which have reasonable physical properties, such as low crossing times and conservative mass-to-light ratios, and which follow a radial velocity- luminosity relation. Only 4 out of 39 galaxies were adopted as field galaxies. (27 refs).

  9. Optical observations of the nearby galaxy IC342 with narrow band [SII] and Hα filters. I

    Directory of Open Access Journals (Sweden)

    Vučetić M.M.

    2013-01-01

    Full Text Available We present observations of a portion of the nearby spiral galaxy IC342 using narrow band [SII] and Hα filters. These observations were carried out in November 2011 with the 2m RCC telescope at Rozhen National Astronomical Observatory in Bulgaria. In this paper we report coordinates, diameters, Hα and [SII] fluxes for 203 HII regions detected in two fields of view in IC342 galaxy. The number of detected HII regions is 5 times higher than previously known in these two parts of the galaxy. [Projekat Ministarstva nauke Republike Srbije, br. 176005: Emission nebulae: structure and evolution

  10. HII regions in IC 1613: The ISM in a nearby dwarf irregular galaxy

    Science.gov (United States)

    Price, Jill S.; Mason, Stephen F.; Gullixson, Craig A.

    1990-01-01

    IC 1613, a nearby (725 kpc distant) dwarf irregular galaxy, has always been known to contain large, ring-shaped HII regions in its northeast corner. A new H alpha image has been obtained using the Bell Labs Charge Coupled Device (CCD) camera, an RCA 320 X 512 pixel-thinned, back-illuminated CCD, an H alpha filter of central wavelength 6562 A and width (full width half maximum) of 30 A, and the 42 inch telescope at Lowell Observatory. The low resolution images exhibit many new, faint features.

  11. Hello Darkness My Old Friend: The Fading of the Nearby TDE ASASSN-14ae

    OpenAIRE

    Brown, Jonathan S.; Shappee, Benjamin J.; Holoien, T. W. -S; Stanek, K. Z.; Kochanek, C. S.; Prieto, J. L.

    2016-01-01

    We present late-time optical spectroscopy taken with the Large Binocular Telescope's Multi-Object Double Spectrograph, an improved ASAS-SN pre-discovery non-detection, and late-time SWIFT observations of the nearby ($d=193$ Mpc, $z=0.0436$) tidal disruption event (TDE) ASASSN-14ae. Our observations span from $\\sim$20 days before to $\\sim$750 days after discovery. The proximity of ASASSN-14ae allows us to study the optical evolution of the flare and the transition to a host dominated state wit...

  12. DETECTION OF A NEARBY HALO DEBRIS STREAM IN THE WISE AND 2MASS SURVEYS

    Energy Technology Data Exchange (ETDEWEB)

    Grillmair, Carl J. [Spitzer Science Center, 1200 E. California Blvd., Pasadena, CA 91125 (United States); Cutri, Roc; Masci, Frank J.; Conrow, Tim [Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States); Sesar, Branimir [Division of Physics, Mathematics, and Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Eisenhardt, Peter R. M. [Jet Propulsion Laboratory, California Institute of Technology, MS 169-327, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Wright, Edward L., E-mail: carl@ipac.caltech.edu, E-mail: roc@ipac.caltech.edu, E-mail: fmasci@ipac.caltech.edu, E-mail: tim@ipac.caltech.edu, E-mail: bsesar@astro.caltech.edu, E-mail: peter.r.eisenhardt@jpl.nasa.gov, E-mail: wright@astro.ucla.edu [Department of Physics, University of California, Los Angeles, CA 90095 (United States)

    2013-06-01

    Combining the Wide-Field Infrared Survey Explorer All-Sky Release with the Two Micron All Sky Survey Point Source Catalog, we detect a nearby, moderately metal-poor stellar debris stream spanning 24° across the southern sky. The stream, which we designate Alpheus, is at an estimated distance of ∼1.9 kpc. Its position, orientation, width, estimated metallicity, and, to some extent, its distance, are in approximate agreement with what one might expect of the leading tidal tail of the southern globular cluster NGC 288.

  13. Observational tests for the evolution of massive stars in nearby galaxies

    International Nuclear Information System (INIS)

    Leitherer, C.

    1990-01-01

    Population synthesis calculations applicable to the massive stellar content in nearby galaxies are presented. Stellar evolution calculations are combined with mass loss, model atmospheres with line blanketing, and a spectral type calibration to compute observable parameters of massive stars as a function of the star formation rate and the initial mass function slope. The number of O stars of given spectral types, the number of W-R stars, supernova rates, and fluxes of ionizing photons are predicted. Important constraints for the theories of stellar atmospheres and stellar evolution can be derived from observations if stellar number counts and ionizing flux data are available. 94 refs

  14. New nearby white dwarfs from Gaia DR1 TGAS and UCAC5/URAT

    Science.gov (United States)

    Scholz, R.-D.; Meusinger, H.; Jahreiß, H.

    2018-05-01

    Aims: Using an accurate Tycho-Gaia Astrometric Solution (TGAS) 25 pc sample that is nearly complete for GK stars and selecting common proper motion (CPM) candidates from the 5th United States Naval Observatory CCD Astrograph Catalog (UCAC5), we search for new white dwarf (WD) companions around nearby stars with relatively small proper motions. Methods: To investigate known CPM systems in TGAS and to select CPM candidates in TGAS+UCAC5, we took into account the expected effect of orbital motion on the proper motion and proper motion catalogue errors. Colour-magnitude diagrams (CMDs) MJ /J - Ks and MG /G - J were used to verify CPM candidates from UCAC5. Assuming their common distance with a given TGAS star, we searched for candidates that occupied similar regions in the CMDs as the few known nearby WDs (four in TGAS) and WD companions (three in TGAS+UCAC5). The CPM candidates with colours and absolute magnitudes corresponding neither to the main sequence nor to the WD sequence were considered as doubtful or subdwarf candidates. Results: With a minimum proper motion of 60 mas yr-1, we selected three WD companion candidates; two of which are also confirmed by their significant parallaxes measured in URAT data, whereas the third may also be a chance alignment of a distant halo star with a nearby TGAS star that has an angular separation of about 465 arcsec. One additional nearby WD candidate was found from its URAT parallax and GJKs photometry. With HD 166435 B orbiting a well-known G1 star at ≈24.6 pc with a projected physical separation of ≈700 AU, we discovered one of the hottest WDs, classified by us as DA2.0 ± 0.2, in the solar neighbourhood. We also found TYC 3980-1081-1 B, a strong cool WD companion candidate around a recently identified new solar neighbour with a TGAS parallax corresponding to a distance of ≈8.3 pc and our photometric classification as ≈M2 dwarf. This raises the question of whether previous assumptions on the completeness of the WD

  15. EnviroAtlas - Acres of crops that have no nearby pollinator habitat for the Conterminous United States

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset is a summary of crop acres without nearby pollinator habitat. Pollination habitat here is defined as trees (fruit, nut, deciduous, and evergreen). Crops...

  16. Heat loads to divertor nearby components from secondary radiation evolved during plasma instabilities

    Energy Technology Data Exchange (ETDEWEB)

    Sizyuk, V., E-mail: vsizyuk@purdue.edu; Hassanein, A., E-mail: hassanein@purdue.edu [Center for Materials under Extreme Environment, School of Nuclear Engineering, Purdue University, West Lafayette, IN 47907 (United States)

    2015-01-15

    A fundamental issue in tokamak operation related to power exhaust during plasma instabilities is the understanding of heat and particle transport from the core plasma into the scrape-off layer and to plasma-facing materials. During abnormal and disruptive operation in tokamaks, radiation transport processes play a critical role in divertor/edge-generated plasma dynamics and are very important in determining overall lifetimes of the divertor and nearby components. This is equivalent to or greater than the effect of the direct impact of escaped core plasma on the divertor plate. We have developed and implemented comprehensive enhanced physical and numerical models in the upgraded HEIGHTS package for simulating detailed photon and particle transport in the evolved edge plasma during various instabilities. The paper describes details of a newly developed 3D Monte Carlo radiation transport model, including optimization methods of generated plasma opacities in the full range of expected photon spectra. Response of the ITER divertor's nearby surfaces due to radiation from the divertor-developed plasma was simulated by using actual full 3D reactor design and magnetic configurations. We analyzed in detail the radiation emission spectra and compared the emission of both carbon and tungsten as divertor plate materials. The integrated 3D simulation predicted unexpectedly high damage risk to the open stainless steel legs of the dome structure in the current ITER design from the intense radiation during a disruption on the tungsten divertor plate.

  17. Mapping Nearby Terrain in 3D by Use of a Grid of Laser Spots

    Science.gov (United States)

    Padgett, Curtis; Liebe, Carl; Chang, Johnny; Brown, Kenneth

    2007-01-01

    A proposed optoelectronic system, to be mounted aboard an exploratory robotic vehicle, would be used to generate a three-dimensional (3D) map of nearby terrain and obstacles for purposes of navigating the vehicle across the terrain and avoiding the obstacles. The difference between this system and the other systems would lie in the details of implementation. In this system, the illumination would be provided by a laser. The beam from the laser would pass through a two-dimensional diffraction grating, which would divide the beam into multiple beams propagating in different, fixed, known directions. These beams would form a grid of bright spots on the nearby terrain and obstacles. The centroid of each bright spot in the image would be computed. For each such spot, the combination of (1) the centroid, (2) the known direction of the light beam that produced the spot, and (3) the known baseline would constitute sufficient information for calculating the 3D position of the spot.

  18. Analytical Model of Underground Train Induced Vibrations on Nearby Building Structures in Cameroon: Assessment and Prediction

    Directory of Open Access Journals (Sweden)

    Lezin Seba MINSILI

    2013-11-01

    Full Text Available The purpose of this research paper was to assess and predict the effect of vibrations induced by an underground railway on nearby-existing buildings prior to the construction of projected new railway lines of the National Railway Master Plan of Cameroon and after upgrading of the railway conceded to CAMRAIL linking the two most densely populated cities of Cameroon: Douala and Yaoundé. With the source-transmitter-receiver mathematical model as the train-soil-structure interaction model, taking into account sub-model parameters such as type of the train-railway system, typical geotechnical conditions of the ground and the sensitivity of the nearby buildings, the analysis is carried out over the entire system using the dynamic finite element method in the time domain. This subdivision of the model is a powerful tool that allows to consider different alternatives of sub-models with different characteristics, and thus to determine any critical excessive vibration impact. Based on semi-empirical analytical results obtained from presented models, the present work assesses and predicts characteristics of traffic-induced vibrations as a function of time duration, intensity and vehicle speed, as well as their influence on buildings at different levels.

  19. Absolute Distances to Nearby Type Ia Supernovae via Light Curve Fitting Methods

    Science.gov (United States)

    Vinkó, J.; Ordasi, A.; Szalai, T.; Sárneczky, K.; Bányai, E.; Bíró, I. B.; Borkovits, T.; Hegedüs, T.; Hodosán, G.; Kelemen, J.; Klagyivik, P.; Kriskovics, L.; Kun, E.; Marion, G. H.; Marschalkó, G.; Molnár, L.; Nagy, A. P.; Pál, A.; Silverman, J. M.; Szakáts, R.; Szegedi-Elek, E.; Székely, P.; Szing, A.; Vida, K.; Wheeler, J. C.

    2018-06-01

    We present a comparative study of absolute distances to a sample of very nearby, bright Type Ia supernovae (SNe) derived from high cadence, high signal-to-noise, multi-band photometric data. Our sample consists of four SNe: 2012cg, 2012ht, 2013dy and 2014J. We present new homogeneous, high-cadence photometric data in Johnson–Cousins BVRI and Sloan g‧r‧i‧z‧ bands taken from two sites (Piszkesteto and Baja, Hungary), and the light curves are analyzed with publicly available light curve fitters (MLCS2k2, SNooPy2 and SALT2.4). When comparing the best-fit parameters provided by the different codes, it is found that the distance moduli of moderately reddened SNe Ia agree within ≲0.2 mag, and the agreement is even better (≲0.1 mag) for the highest signal-to-noise BVRI data. For the highly reddened SN 2014J the dispersion of the inferred distance moduli is slightly higher. These SN-based distances are in good agreement with the Cepheid distances to their host galaxies. We conclude that the current state-of-the-art light curve fitters for Type Ia SNe can provide consistent absolute distance moduli having less than ∼0.1–0.2 mag uncertainty for nearby SNe. Still, there is room for future improvements to reach the desired ∼0.05 mag accuracy in the absolute distance modulus.

  20. Interaction dynamics of two diffusing particles: contact times and influence of nearby surfaces.

    Science.gov (United States)

    Tränkle, B; Ruh, D; Rohrbach, A

    2016-03-14

    Interactions of diffusing particles are governed by hydrodynamics on different length and timescales. The local hydrodynamics can be influenced substantially by simple interfaces. Here, we investigate the interaction dynamics of two micron-sized spheres close to plane interfaces to mimic more complex biological systems or microfluidic environments. Using scanned line optical tweezers and fast 3D interferometric particle tracking, we are able to track the motion of each bead with precisions of a few nanometers and at a rate of 10 kilohertz. From the recorded trajectories, all spatial and temporal information is accessible. This way, we measure diffusion coefficients for two coupling particles at varying distances h to one or two glass interfaces. We analyze their coupling strength and length by cross-correlation analysis relative to h and find a significant decrease in the coupling length when a second particle diffuses nearby. By analysing the times the particles are in close contact, we find that the influence of nearby surfaces and interaction potentials reduce the diffusivity strongly, although we found that the diffusivity hardly affects the contact times and the binding probability between the particles. All experimental results are compared to a theoretical model, which is based on the number of possible diffusion paths following the Catalan numbers and a diffusion probability, which is biased by the spheres' surface potential. The theoretical and experimental results agree very well and therefore enable a better understanding of hydrodynamically coupled interaction processes.

  1. Discovery of Temperate Earth-Sized Planets Transiting a Nearby Ultracool Dwarf Star

    Science.gov (United States)

    Jehin, Emmanuel; Gillon, Michael; Lederer, Susan M.; Delrez, Laetitia; De Wit, Julien; Burdanov, Artem; Van Grootel, Valerie; Burgasser, Adam; Triaud, Amaury; Demory, Brice-Olivier; hide

    2016-01-01

    We report the discovery of three short-period Earth-sized planets transiting a nearby ultracool dwarf star using data collected by the Liège TRAPPIST telescope, located in la Silla (Chile). TRAPPIST-1 is an isolated M8.0+/-0.5-type dwarf star at a distance of 12.0+/-0.4 parsecs as measured by its trigonometric parallax, with an age constrained to be > 500 Myr, and with a luminosity, mass, and radius of 0.05%, 8% and 11.5% those of the Sun, respectively. The small size of the host star, only slightly larger than Jupiter, translates into Earth-like radii for the three discovered planets, as deduced from their transit depths. The inner two planets receive four and two times the irradiation of Earth, respectively, placing them close to the inner edge of the habitable zone of the star. Several orbits remain possible for the third planet based on our current data. The infrared brightness of the host star combined with its Jupiter-like size offer the possibility of thoroughly characterizing the components of this nearby planetary system.

  2. The mass of the central black hole in the nearby Seyfert galaxy NGC 5273

    Energy Technology Data Exchange (ETDEWEB)

    Bentz, Misty C.; Horenstein, Daniel; Bazhaw, Craig; Manne-Nicholas, Emily R.; Ou-Yang, Benjamin J.; Anderson, Matthew; Jones, Jeremy; Norris, Ryan P.; Parks, J. Robert; Saylor, Dicy; Teems, Katherine G.; Turner, Clay, E-mail: bentz@astro.gsu.edu [Department of Physics and Astronomy, Georgia State University, 25 Park Place, Suite 600, Atlanta, GA 30303 (United States)

    2014-11-20

    We present the results of a reverberation-mapping program targeting NGC 5273, a nearby early-type galaxy with a broad-lined active galactic nucleus (AGN). Over the course of the monitoring program, NGC 5273 showed strong variability that allowed us to measure time delays in the responses of the broad optical recombination lines to changes in the continuum flux. A weighted average of these measurements results in a black hole mass determination of M {sub BH} = (4.7 ± 1.6) × 10{sup 6} M {sub ☉}. An estimate of the size of the black hole sphere of influence in NGC 5273 puts it just at the limit of the resolution achievable with current ground-based large aperture telescopes. NGC 5273 is therefore an important future target for a black hole mass determination from stellar dynamical modeling, especially because it is the only nearby early-type galaxy hosting an AGN with a reverberation-based mass, allowing the best comparison for the masses determined from these two techniques.

  3. More Than Filaments and Cores: Statistical Study of Structure Formation and Dynamics in Nearby Molecular Clouds

    Science.gov (United States)

    Chen, How-Huan; Goodman, Alyssa

    2018-01-01

    In the past decade, multiple attempts at understanding the connection between filaments and star forming cores have been made using observations across the entire epectrum. However, the filaments and the cores are usually treated as predefined--and well-defined--entities, instead of structures that often come at different sizes, shapes, with substantially different dynamics, and inter-connected at different scales. In my dissertation, I present an array of studies using different statistical methods, including the dendrogram and the probability distribution function (PDF), of structures at different size scales within nearby molecular clouds. These structures are identified using observations of different density tracers, and where possible, in the multi-dimensional parameter space of key dynamic properties--the LSR velocity, the velocity dispersion, and the column density. The goal is to give an overview of structure formation in nearby star-forming clouds, as well as of the dynamics in these structures. I find that the overall statistical properties of a larger structure is often the summation/superposition of sub-structures within, and that there could be significant variations due to local physical processes. I also find that the star formation process within molecular clouds could in fact take place in a non-monolithic manner, connecting potentially merging and/or transient structures, at different scales.

  4. Hunting for Supermassive Black Holes in Nearby Galaxies With the Hobby-Eberly Telescope

    Science.gov (United States)

    van den Bosch, Remco C. E.; Gebhardt, Karl; Gültekin, Kayhan; Yıldırım, Akin; Walsh, Jonelle L.

    2015-05-01

    We have conducted an optical long-slit spectroscopic survey of 1022 galaxies using the 10 m Hobby-Eberly Telescope (HET) at McDonald Observatory. The main goal of the HET Massive Galaxy Survey (HETMGS) is to find nearby galaxies that are suitable for black hole mass measurements. In order to measure accurately the black hole mass, one should kinematically resolve the region where the black hole dominates the gravitational potential. For most galaxies, this region is much less than an arcsecond. Thus, black hole masses are best measured in nearby galaxies with telescopes that obtain high spatial resolution. The HETMGS focuses on those galaxies predicted to have the largest sphere-of-influence, based on published stellar velocity dispersions or the galaxy fundamental plane. To ensure coverage over galaxy types, the survey targets those galaxies across a face-on projection of the fundamental plane. We present the sample selection and resulting data products from the long-slit observations, including central stellar kinematics and emission line ratios. The full data set, including spectra and resolved kinematics, is available online. Additionally, we show that the current crop of black hole masses are highly biased toward dense galaxies and that especially large disks and low dispersion galaxies are under-represented. This survey provides the necessary groundwork for future systematic black hole mass measurement campaigns.

  5. HUNTING FOR SUPERMASSIVE BLACK HOLES IN NEARBY GALAXIES WITH THE HOBBY–EBERLY TELESCOPE

    International Nuclear Information System (INIS)

    Bosch, Remco C. E. van den; Yıldırım, Akin; Gebhardt, Karl; Walsh, Jonelle L.; Gültekin, Kayhan

    2015-01-01

    We have conducted an optical long-slit spectroscopic survey of 1022 galaxies using the 10 m Hobby–Eberly Telescope (HET) at McDonald Observatory. The main goal of the HET Massive Galaxy Survey (HETMGS) is to find nearby galaxies that are suitable for black hole mass measurements. In order to measure accurately the black hole mass, one should kinematically resolve the region where the black hole dominates the gravitational potential. For most galaxies, this region is much less than an arcsecond. Thus, black hole masses are best measured in nearby galaxies with telescopes that obtain high spatial resolution. The HETMGS focuses on those galaxies predicted to have the largest sphere-of-influence, based on published stellar velocity dispersions or the galaxy fundamental plane. To ensure coverage over galaxy types, the survey targets those galaxies across a face-on projection of the fundamental plane. We present the sample selection and resulting data products from the long-slit observations, including central stellar kinematics and emission line ratios. The full data set, including spectra and resolved kinematics, is available online. Additionally, we show that the current crop of black hole masses are highly biased toward dense galaxies and that especially large disks and low dispersion galaxies are under-represented. This survey provides the necessary groundwork for future systematic black hole mass measurement campaigns

  6. Isopod fauna, excluding Epicaridea, from the Strait of Gibraltar and nearby areas (Southern Iberian Peninsula

    Directory of Open Access Journals (Sweden)

    José Castelló

    2001-09-01

    Full Text Available A total of 42 isopod species from the Strait of Gibraltar and nearby areas were found, including the first record of Munna fabricii, Monodanthura maroccana, Campecopea hirsute, and Natatolana gallica from the Mediterranean; Synisoma nadejda and Uromunna petiti from the Atlantic; and Munna fabricii, Uromunna petiti, Monodanthura maroccana, Stellanthura cryptobia and Natatolana gallica from the Iberian waters. This article includes the previous records from the Iberian waters for all the species. The greatest number of species were found in Tarifa (16 species, located in the transition zone between the Atlantic Ocean and the Mediterranean Sea. According to depth, the distribution of species was as follows: 18 species were collected in the intertidal zone, mostly Dynamene edwardsi and Ischyromene lacazei; 33 species were found between 1 and 10 m, 13 species were found between 11 and 20 m, and 6 species were found between 21 and 28 m, mostly Janira maculosa. According to habitat, 16 species were collected on soft bottoms, 2 species on Zostera, and 22 species on algae substrata, mostly Halopteris, Asparagopsis and Cystoseira. The most diverse genus was Cymodoce (5 species. This paper contributes to the taxonomic, faunistic and biogeographical knowledge of the benthic communities from the Strait of Gibraltar and nearby areas.

  7. IDENTIFYING NEARBY, YOUNG, LATE-TYPE STARS BY MEANS OF THEIR CIRCUMSTELLAR DISKS

    International Nuclear Information System (INIS)

    Schneider, Adam; Song, Inseok; Melis, Carl; Zuckerman, B.; Bessell, Mike

    2012-01-01

    It has recently been shown that a significant fraction of late-type members of nearby, very young associations (age ∼<10 Myr) display excess emission at mid-IR wavelengths indicative of dusty circumstellar disks. We demonstrate that the detection of mid-IR excess emission can be utilized to identify new nearby, young, late-type stars including two definite new members ('TWA 33' and 'TWA 34') of the TW Hydrae Association (TWA). Both new TWA members display mid-IR excess emission in the Wide-field Infrared Survey Explorer catalog and they show proper motion and youthful spectroscopic characteristics—namely, Hα emission, strong lithium absorption, and low surface gravity features consistent with known TWA members. We also detect mid-IR excess—the first unambiguous evidence of a dusty circumstellar disk—around a previously identified UV-bright, young, accreting star (2M1337) that is a likely member of the Lower-Centaurus Crux region of the Scorpius-Centaurus Complex.

  8. Testing the Presence of Multiple Photometric Components in Nearby Early-type Galaxies Using SDSS

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Semyeong; Greene, Jenny E. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Lackner, Claire N., E-mail: semyeong@astro.princeton.edu [Kavli Institute for the Physics and Mathematics of the Universe (WPI), Todai Institutes for Advanced Study, the University of Tokyo, Kashiwa (Japan)

    2017-02-10

    We investigate two-dimensional image decomposition of nearby, morphologically selected early-type galaxies (ETGs). We are motivated by recent observational evidence of significant size growth of quiescent galaxies and theoretical development advocating a two-phase formation scenario for ETGs. We find that a significant fraction of nearby ETGs show changes in isophotal shape that require multi-component models. The characteristic sizes of the inner and outer component are ∼3 and ∼15 kpc. The inner component lies on the mass–size relation of ETGs at z ∼ 0.25–0.75, while the outer component tends to be more elliptical and hints at a stochastic buildup process. We find real physical differences between single- and double-component ETGs, with double-component galaxies being younger and more metal-rich. The fraction of double-component ETGs increases with increasing σ and decreases in denser environments. We hypothesize that double-component systems were able to accrete gas and small galaxies until later times, boosting their central densities, building up their outer parts, and lowering their typical central ages. In contrast, the oldest galaxies, perhaps due to residing in richer environments, have no remaining hints of their last accretion episode.

  9. Where is North?

    OpenAIRE

    Macmillan, Susan; Shanahan, Tom

    2010-01-01

    To find your way using a magnetic compass with a map, you need to know the difference between magnetic north and map north. This difference is called ‘grid magnetic angle’, and in the UK it is derived from a model of the Earth’s magnetic field, which is updated every year. The variation To go north, you just follow your compass towards magnetic north, right? Not quite. Geophysicists have to work hard so we can continue to navigate with map and compass. Susan Macm...

  10. North Korean Relationships

    Science.gov (United States)

    2012-12-18

    partner, holding 18 percent of all trade. North Korea’s leading export items to Japan were men’s suits, mushrooms , and coal. Japan’s main export items...credited with providing resources to North Korea in efforts to help establish and cultivate a much stronger military force as well as begin to

  11. North-South precipitation patterns in western North America on interannual-to-decadal timescales

    Science.gov (United States)

    Dettinger, M.D.; Cayan, D.R.; Diaz, Henry F.; Meko, D.M.

    1998-01-01

    The overall amount of precipitation deposited along the West Coast and western cordillera of North America from 25??to 55??N varies from year to year, and superimposed on this domain-average variability are varying north-south contrasts on timescales from at least interannual to interdecadal. In order to better understand the north-south precipitation contrasts, their interannual and decadal variations are studied in terms of how much they affect overall precipitation amounts and how they are related to large-scale climatic patterns. Spatial empirical orthogonal functions (EOFs) and spatial moments (domain average, central latitude, and latitudinal spread) of zonally averaged precipitation anomalies along the westernmost parts of North America are analyzed, and each is correlated with global sea level pressure (SLP) and sea surface temperature series, on interannual (defined here as 3-7 yr) and decadal (>7 yr) timescales. The interannual band considered here corresponds to timescales that are particularly strong in tropical climate variations and thus is expected to contain much precipitation variability that is related to El Nino-Southern Oscillation; the decadal scale is defined so as to capture the whole range of long-term climatic variations affecting western North America. Zonal EOFs of the interannual and decadal filtered versions of the zonal-precipitation series are remarkably similar. At both timescales, two leading EOFs describe 1) a north-south seesaw of precipitation pivoting near 40??N and 2) variations in precipitation near 40??N, respectively. The amount of overall precipitation variability is only about 10% of the mean and is largely determined by precipitation variations around 40??-45??N and most consistently influenced by nearby circulation patterns; in this sense, domain-average precipitation is closely related to the second EOF. The central latitude and latitudinal spread of precipitation distributions are strongly influenced by precipitation

  12. CLIL in the North: finding true north?

    NARCIS (Netherlands)

    Smit, Nienke

    CLIL teaching in the Netherlands is very popular: roughly 130 secondary schools offer CLIL education. But did you know that only nine secondary schools in the north of the Netherlands currently offer bilingual education? This means that CLIL education is still not at cycling distance for every

  13. An atlas of high-resolution IRAS maps on nearby galaxies

    Science.gov (United States)

    Rice, Walter

    1993-01-01

    An atlas of far-infrared IRAS maps with near 1 arcmin angular resolution of 30 optically large galaxies is presented. The high-resolution IRAS maps were produced with the Maximum Correlation Method (MCM) image construction and enhancement technique developed at IPAC. The MCM technique, which recovers the spatial information contained in the overlapping detector data samples of the IRAS all-sky survey scans, is outlined and tests to verify the structural reliability and photometric integrity of the high-resolution maps are presented. The infrared structure revealed in individual galaxies is discussed. The atlas complements the IRAS Nearby Galaxy High-Resolution Image Atlas, the high-resolution galaxy images encoded in FITS format, which is provided to the astronomical community as an IPAC product.

  14. The bright optical afterglow of the nearby gamma-ray burst of 29 March 2003.

    Science.gov (United States)

    Price, P A; Fox, D W; Kulkarni, S R; Peterson, B A; Schmidt, B P; Soderberg, A M; Yost, S A; Berger, E; Djorgovski, S G; Frail, D A; Harrison, F A; Sari, R; Blain, A W; Chapman, S C

    2003-06-19

    Past studies of cosmological gamma-ray bursts (GRBs) have been hampered by their extreme distances, resulting in faint afterglows. A nearby GRB could potentially shed much light on the origin of these events, but GRBs with a redshift z burst of 29 March 2003 (GRB030329; ref. 2). The brightness of the afterglow and the prompt report of its position resulted in extensive follow-up observations at many wavelengths, along with the measurement of the redshift, z = 0.169 (ref. 4). The gamma-ray and afterglow properties of GRB030329 are similar to those of GRBs at cosmological redshifts. Observations have already identified the progenitor as a massive star that exploded as a supernova.

  15. Forming an ad-hoc nearby storage, based on IKAROS and social networking services

    International Nuclear Information System (INIS)

    Filippidis, Christos; Cotronis, Yiannis; Markou, Christos

    2014-01-01

    We present an ad-hoc 'nearby' storage, based on IKAROS and social networking services, such as Facebook. By design, IKAROS is capable to increase or decrease the number of nodes of the I/O system instance on the fly, without bringing everything down or losing data. IKAROS is capable to decide the file partition distribution schema, by taking on account requests from the user or an application, as well as a domain or a Virtual Organization policy. In this way, it is possible to form multiple instances of smaller capacity higher bandwidth storage utilities capable to respond in an ad-hoc manner. This approach, focusing on flexibility, can scale both up and down and so can provide more cost effective infrastructures for both large scale and smaller size systems. A set of experiments is performed comparing IKAROS with PVFS2 by using multiple clients requests under HPC IOR benchmark and MPICH2.

  16. A New Offset Debris Ring around a Nearby Star Observed with the HST/STIS

    Science.gov (United States)

    Krist, John; Stapelfeldt, Karl; Bryden, Geoffrey

    2011-01-01

    We are conducting an HST/STIS coronagraphic imaging study of nearby stars that have Spitzer-measured infrared excesses indicating that they are surrounded by debris disks. Around one of the stars we have imaged a debris ring with a sharp inner edge and extending from about 165 AU to 250 AU. The ring center is offset from the star by -8 AU with a visually estimated intrinsic ellipticity of e-0.1 , suggestive of gravitational perturbation of the disk by a planet, like the Fomalhaut disk. Assuming a neutral disk color, the mean surface brightness of V=22.3 mag/square arcsec makes this the second faintest disk yet imaged in scattered light, second to HD 207129.

  17. Negative and Positive Outflow-Feedback in Nearby (U)LIRGs

    Energy Technology Data Exchange (ETDEWEB)

    Cazzoli, Sara, E-mail: sara@iaa.es [Instituto de Astrofisica de Andalucia (CSIC), Granada (Spain)

    2017-12-15

    The starburst-AGN coexistence in local (U)LIRGs makes these galaxies excellent laboratories for the study of stellar and AGN outflows and feedback. Outflows regulate star formation and AGN activity, redistributing gas, dust and metals over large scales in the interstellar and intergalactic media (negative feedback) being also considered to be able to undergo vigorous star formation (positive feedback). In this contribution, I will summarize the results from a search for outflows in a sample of nearby 38 local (U)LIRG systems observed with VIMOS/VLT integral field unit. For two galaxies of the sample I will detail the outflow properties and discuss the observational evidence for negative and positive outflow-feedback. The assessment of both negative and positive feedback effects represent a novel approach toward a comprehensive understanding of the impact of outflow feedback in the galaxy evolution.

  18. THE CONTRIBUTION OF TP-AGB STARS TO THE MID-INFRARED COLORS OF NEARBY GALAXIES

    Energy Technology Data Exchange (ETDEWEB)

    Chisari, Nora E. [Department of Astrophysical Sciences, Princeton University, 4 Ivy Lane, Princeton, NJ 08544 (United States); Kelson, Daniel D., E-mail: nchisari@astro.princeton.edu [Observatories of the Carnegie Institution of Science, 813 Santa Barbara St., Pasadena, CA 91101 (United States)

    2012-07-10

    We study the mid-infrared color space of 30 galaxies from the Spitzer Infrared Nearby Galaxies Survey (SINGS) survey for which Sloan Digital Sky Survey data are also available. We construct two-color maps for each galaxy and compare them to results obtained from combining Maraston evolutionary synthesis models, galactic thermally pulsating asymptotic giant branch (TP-AGB) colors, and smooth star formation histories. For most of the SINGS sample, the spatially extended mid-IR emission seen by Spitzer in normal galaxies is consistent with our simple model in which circumstellar dust from TP-AGB stars dominates at 8 and 24 {mu}m. There is a handful of exceptions that we identify as galaxies that have high star formation rates presumably with star formation histories that cannot be assumed to be smooth, or anemic galaxies, which were depleted of their H I at some point during their evolution and have very low ongoing star formation rates.

  19. Relativistic deflection of background starlight measures the mass of a nearby white dwarf star.

    Science.gov (United States)

    Sahu, Kailash C; Anderson, Jay; Casertano, Stefano; Bond, Howard E; Bergeron, Pierre; Nelan, Edmund P; Pueyo, Laurent; Brown, Thomas M; Bellini, Andrea; Levay, Zoltan G; Sokol, Joshua; Dominik, Martin; Calamida, Annalisa; Kains, Noé; Livio, Mario

    2017-06-09

    Gravitational deflection of starlight around the Sun during the 1919 total solar eclipse provided measurements that confirmed Einstein's general theory of relativity. We have used the Hubble Space Telescope to measure the analogous process of astrometric microlensing caused by a nearby star, the white dwarf Stein 2051 B. As Stein 2051 B passed closely in front of a background star, the background star's position was deflected. Measurement of this deflection at multiple epochs allowed us to determine the mass of Stein 2051 B-the sixth-nearest white dwarf to the Sun-as 0.675 ± 0.051 solar masses. This mass determination provides confirmation of the physics of degenerate matter and lends support to white dwarf evolutionary theory. Copyright © 2017, American Association for the Advancement of Science.

  20. THE CONTRIBUTION OF TP-AGB STARS TO THE MID-INFRARED COLORS OF NEARBY GALAXIES

    International Nuclear Information System (INIS)

    Chisari, Nora E.; Kelson, Daniel D.

    2012-01-01

    We study the mid-infrared color space of 30 galaxies from the Spitzer Infrared Nearby Galaxies Survey (SINGS) survey for which Sloan Digital Sky Survey data are also available. We construct two-color maps for each galaxy and compare them to results obtained from combining Maraston evolutionary synthesis models, galactic thermally pulsating asymptotic giant branch (TP-AGB) colors, and smooth star formation histories. For most of the SINGS sample, the spatially extended mid-IR emission seen by Spitzer in normal galaxies is consistent with our simple model in which circumstellar dust from TP-AGB stars dominates at 8 and 24 μm. There is a handful of exceptions that we identify as galaxies that have high star formation rates presumably with star formation histories that cannot be assumed to be smooth, or anemic galaxies, which were depleted of their H I at some point during their evolution and have very low ongoing star formation rates.

  1. Hole Defects Affect the Dynamic Fracture Behavior of Nearby Running Cracks

    Directory of Open Access Journals (Sweden)

    R. S. Yang

    2018-01-01

    Full Text Available Effects of defects on the dynamic fracture behavior of engineering materials cannot be neglected. Using the experimental system of digital laser dynamic caustics, the effects of defects on the dynamic fracture behavior of nearby running cracks are studied. When running cracks propagate near to defects, the crack path deflects toward the defect; the degree of deflection is greater for larger defect diameters. When the running crack propagates away from the defect, the degree of deflection gradually reduces and the original crack path is restored. The intersection between the caustic spot and the defect is the direct cause of the running crack deflection; the intersection area determines the degree of deflection. In addition, the defect locally inhibits the dynamic stress intensity factor of running cracks when they propagate toward the defect and locally promotes the dynamic stress intensity factor of running cracks when they propagate away from the defect.

  2. KNOW YOUR NEIGHBORHOOD: A DETAILED MODEL ATMOSPHERE ANALYSIS OF NEARBY WHITE DWARFS

    Energy Technology Data Exchange (ETDEWEB)

    Giammichele, N.; Bergeron, P. [Kitt Peak National Observatory, National Optical Astronomy Observatory, which is operated by the Association of Universities for Research in Astronomy (AURA) under cooperative agreement with the National Science Foundation (United States); Dufour, P., E-mail: noemi.giammichele@astro.umontreal.ca, E-mail: pierre.bergeron@astro.umontreal.ca, E-mail: patrick.dufour@astro.umontreal.ca [Departement de Physique, Universite de Montreal, C.P. 6128, Succ. Centre-Ville, Montreal, Quebec H3C 3J7 (Canada)

    2012-04-01

    We present improved atmospheric parameters of nearby white dwarfs lying within 20 pc of the Sun. The aim of the current study is to obtain the best statistical model of the least-biased sample of the white dwarf population. A homogeneous analysis of the local population is performed combining detailed spectroscopic and photometric analyses based on improved model atmosphere calculations for various spectral types including DA, DB, DC, DQ, and DZ stars. The spectroscopic technique is applied to all stars in our sample for which optical spectra are available. Photometric energy distributions, when available, are also combined to trigonometric parallax measurements to derive effective temperatures, stellar radii, as well as atmospheric compositions. A revised catalog of white dwarfs in the solar neighborhood is presented. We provide, for the first time, a comprehensive analysis of the mass distribution and the chemical distribution of white dwarf stars in a volume-limited sample.

  3. A DEEP, WIDE-FIELD Hα SURVEY OF NEARBY CLUSTERS OF GALAXIES: DATA

    International Nuclear Information System (INIS)

    Sakai, Shoko; Kennicutt, Robert C. Jr.; Moss, Chris

    2012-01-01

    We present the results of a wide-field Hα imaging survey of eight nearby (z = 0.02-0.03) Abell clusters. We have measured Hα fluxes and equivalent widths for 465 galaxies, of which 360 are new detections. The survey was designed to obtain complete emission-line-selected inventories of star-forming galaxies in the inner regions of these clusters, extending to star formation rates below 0.1 M ☉ yr –1 . This paper describes the observations, data processing, and source identification procedures, and presents an Hα and R-band catalog of detected cluster members and other candidates. Future papers in the series will use these data to study the completeness of spectroscopically based star formation surveys, and to quantify the effects of cluster environment on the present-day populations of star-forming galaxies. The data will also provide a valuable foundation for imaging surveys of redshifted Hα emission in more distant clusters.

  4. Concentration of 210Po in local foodstuffs grown nearby High Background Areas (HBRA)

    International Nuclear Information System (INIS)

    Kamesh Viswanathan, B.; Arunachalam, Kantha D.; Sathesh Kumar, A.; Jayakrishna, K.; Rao, D.D.

    2012-01-01

    210 Po is the decay product of natural radionuclide of 238 U series. The presence of a radionuclide migrates from soil > plant > food and ingested by the humans residing in the areas of syentite rocks nearby the High Background Radiation Area's (HBRA). The food samples were studied by Market Basket Study (MBS). The average concentration of 210 Po in foodstuffs like green leafy vegetables, other vegetables, roots and tubers; fruits, fish, other flesh foods, milk and cereals were 1671 ± 163.3, 28.2 ± 7.3, 320 ± 99, 53 ± 17.5, 251.5 ± 54.5, 37 ± 14.5, 16 ± 6 and 230 ± 75 mBq. Kg -1 fresh weight. (author)

  5. [Sheng's acupuncture manipulation at bone-nearby acupoints and the academic thoughts].

    Science.gov (United States)

    Sheng, Ji-li; Jin, Xiao-qing

    2014-11-01

    Sheng's acupuncture manipulation at bone-nearby acupoints is a set of needling manipulation of the chief physician of TCM, SHENG Xie-sun, summarized through his over 50 years clinical experiences and on the basis of Internal Classic. Regarding this manipulation, on the premise of acupoint selection based on syndrome differentiation, the acupoints close to bone are possibly selected and punctured, with the needle tip toward bone edge, and followed by the technique to achieve reducing purpose. Clinically, the significant immediate analgesia can be achieved in pain disorders such as headache and toothache. Professor Sheng thought, corresponding to the location of needle insertion and needling depth, the tissue layers of needle tip passing through should be considered specially. The site of needle insertion should be changeable so as to ensure the needle tip reaching the bone. This manipulation for analgesia provides a certain guide for acupuncture study, especially for the mechanism study on acupuncture analgesia.

  6. Contribution from individual nearby sources to the spectrum of high-energy cosmic-ray electrons

    International Nuclear Information System (INIS)

    Sedrati, R.; Attallah, R.

    2014-01-01

    In the last few years, very important data on high-energy cosmic-ray electrons and positrons from high-precision space-born and ground-based experiments have attracted a great deal of interest. These particles represent a unique probe for studying local comic-ray accelerators because they lose energy very rapidly. These energy losses reduce the lifetime so drastically that high-energy cosmic-ray electrons can attain the Earth only from rather local astrophysical sources. This work aims at calculating, by means of Monte Carlo simulation, the contribution from some known nearby astrophysical sources to the cosmic-ray electron/positron spectra at high energy (≥10GeV). The background to the electron energy spectrum from distant sources is determined with the help of the GALPROP code. The obtained numerical results are compared with a set of experimental data

  7. Contribution from individual nearby sources to the spectrum of high-energy cosmic-ray electrons

    Energy Technology Data Exchange (ETDEWEB)

    Sedrati, R., E-mail: rafik.sedrati@univ-annaba.org; Attallah, R.

    2014-04-01

    In the last few years, very important data on high-energy cosmic-ray electrons and positrons from high-precision space-born and ground-based experiments have attracted a great deal of interest. These particles represent a unique probe for studying local comic-ray accelerators because they lose energy very rapidly. These energy losses reduce the lifetime so drastically that high-energy cosmic-ray electrons can attain the Earth only from rather local astrophysical sources. This work aims at calculating, by means of Monte Carlo simulation, the contribution from some known nearby astrophysical sources to the cosmic-ray electron/positron spectra at high energy (≥10GeV). The background to the electron energy spectrum from distant sources is determined with the help of the GALPROP code. The obtained numerical results are compared with a set of experimental data.

  8. HUBBLE RESIDUALS OF NEARBY TYPE Ia SUPERNOVAE ARE CORRELATED WITH HOST GALAXY MASSES

    International Nuclear Information System (INIS)

    Kelly, Patrick L.; Burke, David L.; Hicken, Malcolm; Mandel, Kaisey S.; Kirshner, Robert P.

    2010-01-01

    From Sloan Digital Sky Survey u'g'r'i'z' imaging, we estimate the stellar masses of the host galaxies of 70 low-redshift Type Ia supernovae (SNe Ia, 0.015 10.8 M sun in a cosmology fit yields 1 + w = 0.22 +0.152 -0.108 , while a combination where the 30 nearby SNe instead have host masses greater than 10 10.8 M sun yields 1 + w = -0.03 +0.217 -0.143 . Progenitor metallicity, stellar population age, and dust extinction correlate with galaxy mass and may be responsible for these systematic effects. Host galaxy measurements will yield improved distances to SNe Ia.

  9. Forming an ad-hoc nearby storage, based on IKAROS and social networking services

    Science.gov (United States)

    Filippidis, Christos; Cotronis, Yiannis; Markou, Christos

    2014-06-01

    We present an ad-hoc "nearby" storage, based on IKAROS and social networking services, such as Facebook. By design, IKAROS is capable to increase or decrease the number of nodes of the I/O system instance on the fly, without bringing everything down or losing data. IKAROS is capable to decide the file partition distribution schema, by taking on account requests from the user or an application, as well as a domain or a Virtual Organization policy. In this way, it is possible to form multiple instances of smaller capacity higher bandwidth storage utilities capable to respond in an ad-hoc manner. This approach, focusing on flexibility, can scale both up and down and so can provide more cost effective infrastructures for both large scale and smaller size systems. A set of experiments is performed comparing IKAROS with PVFS2 by using multiple clients requests under HPC IOR benchmark and MPICH2.

  10. New insights into the X-ray properties of nearby barred spiral galaxy NGC 1672

    Science.gov (United States)

    Jenkins, L. P.; Brnadt, W. N.; Colbert, E. J. M.; Levan, A. J.; Roberts, T. P.; Ward, M. J.; Zezas, A.

    2008-02-01

    We present some preliminary results from new Chandra and XMM-Newton X-ray observations of the nearby barred spiral galaxy NGC1672. It shows dramatic nuclear and extra-nuclear star formation activity, including starburst regions located near each end of its strong bar, both of which host ultraluminous X-ray sources (ULXs). With the new high-spatial-resolution Chandra imaging, we show for the first time that NGC1672 possesses a faint ($L(X)~10^39 erg/s), hard central X-ray source surrounded by an X-ray bright circumnuclear starburst ring that dominates the X-ray emission in the region. The central source may represent low-level AGN activity, or alternatively the emission from X-ray binaries associated with star-formation in the nucleus.

  11. First results from the BOXING (Birmingham-OCIW XMM and IMACS Nearby Groups) project.

    Science.gov (United States)

    Miles, T. A.; Raychaudhury, S.; Mulchaey, J. S.

    2004-12-01

    We present the first results from the BOXING (Birmingham-OCIW XMM and IMACS Nearby Groups) project, a collaboration between the Observatories of the Carnegie Institute of Washington (OCIW) and the University of Birmingham U.K. to study a sample of 25 galaxy groups (z ˜ 0.06) by means of optical photometry and spectroscopy (du Pont 2.5m; IMACS/Magellan) combined with x-ray observations (XMM). The combination of x-ray with optical data allows us to study the nature of the relationship between the properties of the groups and the galaxies that they contain. In this preliminary study, we present optical luminosity functions, which shows bimodal behavior in the poorer systems, interpreted as result of rapid merging. We also examine the dependence of galaxy morphology on local environment. Once spectroscopic observations are completed, we will be able to study velocity dispersions, star formation and nuclear activity in individual galaxies.

  12. THE NATURE OF STARBURSTS. I. THE STAR FORMATION HISTORIES OF EIGHTEEN NEARBY STARBURST DWARF GALAXIES

    International Nuclear Information System (INIS)

    McQuinn, Kristen B. W.; Skillman, Evan D.; Stark, David; Weisz, Daniel; Cannon, John M.; Dalcanton, Julianne; Williams, Benjamin; Dolphin, Andrew; Hidalgo-RodrIguez, Sebastian; Holtzman, Jon

    2010-01-01

    We use archival Hubble Space Telescope observations of resolved stellar populations to derive the star formation histories (SFHs) of 18 nearby starburst dwarf galaxies. In this first paper, we present the observations, color-magnitude diagrams (CMDs), and the SFHs of the 18 starburst galaxies, based on a homogeneous approach to the data reduction, differential extinction, and treatment of photometric completeness. We adopt a star formation rate (SFR) threshold normalized to the average SFR of the individual system as a metric for classifying starbursts in SFHs derived from resolved stellar populations. This choice facilitates finding not only the currently bursting galaxies but also 'fossil' bursts increasing the sample size of starburst galaxies in the nearby (D 100 Myr temporal baseline is thus fundamental to any starburst definition or identification method. The longer lived bursts rule out rapid 'self-quenching' of starbursts on global scales. The bursting galaxies' gas consumption timescales are shorter than the Hubble time for all but one galaxy confirming the short-lived nature of starbursts based on fuel limitations. Additionally, we find that the strength of the Hα emission usually correlates with the CMD-based SFR during the last 4-10 Myr. However, in four cases, the Hα emission is significantly less than what is expected for models of starbursts; the discrepancy is due to the SFR changing on timescales of a few Myr. The inherently short timescale of the Hα emission limits identifying galaxies as starbursts based on the current characteristics which may or may not be representative of the recent SFH of a galaxy.

  13. The Leoncino Dwarf: The Lowest Metallicity Star-Forming Galaxy in the Nearby Universe

    Science.gov (United States)

    McQuinn, Kristen

    2017-08-01

    Extremely metal-poor (XMP) galaxies are dwarf irregular galaxies with very low metallicities, traced by their gas-phase oxygen abundance. Galaxy evolution scenarios suggest three pathways to form an XMP: (1) secular evolution at low galaxy masses, (2) slow evolution in voids, or (3) dilution of measured abundances from infall of pristine gas. These scenarios have proven challenging to test because, despite concerted efforts, XMP galaxies in the nearby universe have proven hard to find. A notable exception is the recently discovered dwarf galaxy Leoncino. Leoncino has the lowest gas-phase oxygen abundance ever measured in a galaxy in the local Universe. From optical spectroscopy, the oxygen abundance is 12+log(O/H)=7.02+/-0.03, more than 40% lower than the iconic low-metallicity galaxy I Zw 18 and less than 2% Z_sun. Despite a precision oxygen abundance measurement, the evolutionary context of Leoncino remains uncertain without a secure distance. We propose HST WFC3 high-resolution optical imaging of Leoncino to accurately measure the distance to the galaxy using the tip of the red giant branch (TRGB) method. The distance will determine whether Leoncino is located in a typical field environment or in a void, and whether the galaxy is consistent with the luminosity-metallicity relation at low galaxy masses. The detailed study of Leoncino will provide benchmark results for future XMP discoveries in the nearby Universe, and an exceptionally timely comparison for studies of chemically primitive, high-redshift galaxies that will be observable in the JWST era.

  14. Astrophysical tests of modified gravity: Constraints from distance indicators in the nearby universe

    International Nuclear Information System (INIS)

    Jain, Bhuvnesh; Vikram, Vinu; Sakstein, Jeremy

    2013-01-01

    We use distance measurements in the nearby universe to carry out new tests of gravity, surpassing other astrophysical tests by over two orders of magnitude for chameleon theories. The three nearby distance indicators—cepheids, tip of the red giant branch (TRGB) stars, and water masers—operate in gravitational fields of widely different strengths. This enables tests of scalar-tensor gravity theories because they are screened from enhanced forces to different extents. Inferred distances from cepheids and TRGB stars are altered (in opposite directions) over a range of chameleon gravity theory parameters well below the sensitivity of cosmological probes. Using published data, we have compared cepheid and TRGB distances in a sample of unscreened dwarf galaxies within 10 Mpc. We use a comparable set of screened galaxies as a control sample. We find no evidence for the order unity force enhancements expected in these theories. Using a two-parameter description of the models (the coupling strength and background field value), we obtain constraints on both the chameleon and symmetron screening scenarios. In particular we show that f(R) models with background field values f R0 above 5 × 10 –7 are ruled out at the 95% confidence level. We also compare TRGB and maser distances to the galaxy NGC 4258 as a second test for larger field values. While there are several approximations and caveats in our study, our analysis demonstrates the power of gravity tests in the local universe. We discuss the prospects for additional improved tests with future observations.

  15. Extinction Maps and Dust-to-gas Ratios in Nearby Galaxies with LEGUS

    Science.gov (United States)

    Kahre, L.; Walterbos, R. A.; Kim, H.; Thilker, D.; Calzetti, D.; Lee, J. C.; Sabbi, E.; Ubeda, L.; Aloisi, A.; Cignoni, M.; Cook, D. O.; Dale, D. A.; Elmegreen, B. G.; Elmegreen, D. M.; Fumagalli, M.; Gallagher, J. S., III; Gouliermis, D. A.; Grasha, K.; Grebel, E. K.; Hunter, D. A.; Sacchi, E.; Smith, L. J.; Tosi, M.; Adamo, A.; Andrews, J. E.; Ashworth, G.; Bright, S. N.; Brown, T. M.; Chandar, R.; Christian, C.; de Mink, S. E.; Dobbs, C.; Evans, A. S.; Herrero, A.; Johnson, K. E.; Kennicutt, R. C.; Krumholz, M. R.; Messa, M.; Nair, P.; Nota, A.; Pellerin, A.; Ryon, J. E.; Schaerer, D.; Shabani, F.; Van Dyk, S. D.; Whitmore, B. C.; Wofford, A.

    2018-03-01

    We present a study of the dust-to-gas ratios in five nearby galaxies: NGC 628 (M74), NGC 6503, NGC 7793, UGC 5139 (Holmberg I), and UGC 4305 (Holmberg II). Using Hubble Space Telescope broadband WFC3/UVIS UV and optical images from the Treasury program Legacy ExtraGalactic UV Survey (LEGUS) combined with archival HST/Advanced Camera for Surveys data, we correct thousands of individual stars for extinction across these five galaxies using an isochrone-matching (reddening-free Q) method. We generate extinction maps for each galaxy from the individual stellar extinctions using both adaptive and fixed resolution techniques and correlate these maps with neutral H I and CO gas maps from the literature, including the H I Nearby Galaxy Survey and the HERA CO-Line Extragalactic Survey. We calculate dust-to-gas ratios and investigate variations in the dust-to-gas ratio with galaxy metallicity. We find a power-law relationship between dust-to-gas ratio and metallicity, consistent with other studies of dust-to-gas ratio compared to metallicity. We find a change in the relation when H2 is not included. This implies that underestimation of {N}{{{H}}2} in low-metallicity dwarfs from a too-low CO-to-H2 conversion factor X CO could have produced too low a slope in the derived relationship between dust-to-gas ratio and metallicity. We also compare our extinctions to those derived from fitting the spectral energy distribution (SED) using the Bayesian Extinction and Stellar Tool for NGC 7793 and find systematically lower extinctions from SED fitting as compared to isochrone matching.

  16. Emission-line diagnostics of nearby H II regions including interacting binary populations

    Science.gov (United States)

    Xiao, Lin; Stanway, Elizabeth R.; Eldridge, J. J.

    2018-06-01

    We present numerical models of the nebular emission from H II regions around young stellar populations over a range of compositions and ages. The synthetic stellar populations include both single stars and interacting binary stars. We compare these models to the observed emission lines of 254 H II regions of 13 nearby spiral galaxies and 21 dwarf galaxies drawn from archival data. The models are created using the combination of the BPASS (Binary Population and Spectral Synthesis) code with the photoionization code CLOUDY to study the differences caused by the inclusion of interacting binary stars in the stellar population. We obtain agreement with the observed emission line ratios from the nearby star-forming regions and discuss the effect of binary-star evolution pathways on the nebular ionization of H II regions. We find that at population ages above 10 Myr, single-star models rapidly decrease in flux and ionization strength, while binary-star models still produce strong flux and high [O III]/H β ratios. Our models can reproduce the metallicity of H II regions from spiral galaxies, but we find higher metallicities than previously estimated for the H II regions from dwarf galaxies. Comparing the equivalent width of H β emission between models and observations, we find that accounting for ionizing photon leakage can affect age estimates for H II regions. When it is included, the typical age derived for H II regions is 5 Myr from single-star models, and up to 10 Myr with binary-star models. This is due to the existence of binary-star evolution pathways, which produce more hot Wolf-Rayet and helium stars at older ages. For future reference, we calculate new BPASS binary maximal starburst lines as a function of metallicity, and for the total model population, and present these in Appendix A.

  17. Astrophysical tests of modified gravity: Constraints from distance indicators in the nearby universe

    Energy Technology Data Exchange (ETDEWEB)

    Jain, Bhuvnesh; Vikram, Vinu [Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104 (United States); Sakstein, Jeremy [Department of Applied Mathematics and Theoretical Physics, Cambridge CB3 0WA (United Kingdom)

    2013-12-10

    We use distance measurements in the nearby universe to carry out new tests of gravity, surpassing other astrophysical tests by over two orders of magnitude for chameleon theories. The three nearby distance indicators—cepheids, tip of the red giant branch (TRGB) stars, and water masers—operate in gravitational fields of widely different strengths. This enables tests of scalar-tensor gravity theories because they are screened from enhanced forces to different extents. Inferred distances from cepheids and TRGB stars are altered (in opposite directions) over a range of chameleon gravity theory parameters well below the sensitivity of cosmological probes. Using published data, we have compared cepheid and TRGB distances in a sample of unscreened dwarf galaxies within 10 Mpc. We use a comparable set of screened galaxies as a control sample. We find no evidence for the order unity force enhancements expected in these theories. Using a two-parameter description of the models (the coupling strength and background field value), we obtain constraints on both the chameleon and symmetron screening scenarios. In particular we show that f(R) models with background field values f {sub R0} above 5 × 10{sup –7} are ruled out at the 95% confidence level. We also compare TRGB and maser distances to the galaxy NGC 4258 as a second test for larger field values. While there are several approximations and caveats in our study, our analysis demonstrates the power of gravity tests in the local universe. We discuss the prospects for additional improved tests with future observations.

  18. A super-Earth transiting a nearby low-mass star.

    Science.gov (United States)

    Charbonneau, David; Berta, Zachory K; Irwin, Jonathan; Burke, Christopher J; Nutzman, Philip; Buchhave, Lars A; Lovis, Christophe; Bonfils, Xavier; Latham, David W; Udry, Stéphane; Murray-Clay, Ruth A; Holman, Matthew J; Falco, Emilio E; Winn, Joshua N; Queloz, Didier; Pepe, Francesco; Mayor, Michel; Delfosse, Xavier; Forveille, Thierry

    2009-12-17

    A decade ago, the detection of the first transiting extrasolar planet provided a direct constraint on its composition and opened the door to spectroscopic investigations of extrasolar planetary atmospheres. Because such characterization studies are feasible only for transiting systems that are both nearby and for which the planet-to-star radius ratio is relatively large, nearby small stars have been surveyed intensively. Doppler studies and microlensing have uncovered a population of planets with minimum masses of 1.9-10 times the Earth's mass (M[symbol:see text]), called super-Earths. The first constraint on the bulk composition of this novel class of planets was afforded by CoRoT-7b (refs 8, 9), but the distance and size of its star preclude atmospheric studies in the foreseeable future. Here we report observations of the transiting planet GJ 1214b, which has a mass of 6.55M[symbol:see text]), and a radius 2.68 times Earth's radius (R[symbol:see text]), indicating that it is intermediate in stature between Earth and the ice giants of the Solar System. We find that the planetary mass and radius are consistent with a composition of primarily water enshrouded by a hydrogen-helium envelope that is only 0.05% of the mass of the planet. The atmosphere is probably escaping hydrodynamically, indicating that it has undergone significant evolution during its history. The star is small and only 13 parsecs away, so the planetary atmosphere is amenable to study with current observatories.

  19. Ultrahigh energy neutrino afterglows of nearby long duration gamma-ray bursts

    Science.gov (United States)

    Thomas, Jessymol K.; Moharana, Reetanjali; Razzaque, Soebur

    2017-11-01

    Detection of ultrahigh energy (UHE, ≳1 PeV ) neutrinos from astrophysical sources will be a major advancement in identifying and understanding the sources of UHE cosmic rays (CRs) in nature. Long duration gamma-ray burst (GRB) blast waves have been considered as potential acceleration sites of UHECRs. These CRs are expected to interact with GRB afterglow photons, which are synchrotron radiation from relativistic electrons coaccelerated with CRs in the blast wave, and naturally produce UHE neutrinos. Fluxes of these neutrinos are uncertain, however, and crucially depend on the observed afterglow modeling. We have selected a sample of 23 long duration GRBs within redshift 0.5 for which adequate electromagnetic afterglow data are available and which could produce high flux of UHE afterglow neutrinos, being nearby. We fit optical, x-ray, and γ -ray afterglow data with an adiabatic blast wave model in a constant density interstellar medium and in a wind environment where the density of the wind decreases as the inverse square of the radius from the center of the GRB. The blast wave model parameters extracted from these fits are then used for calculating UHECR acceleration and p γ interactions to produce UHE neutrino fluxes from these GRBs. We have also explored the detectability of these neutrinos by currently running and upcoming large area neutrino detectors, such as the Pierre Auger Observatory, IceCube Gen-2, and KM3NeT observatories. We find that our realistic flux models from nearby GRBs will be unconstrained in the foreseeable future.

  20. Constraints on the Equation-of-State of neutron stars from nearby neutron star observations

    International Nuclear Information System (INIS)

    Neuhäuser, R; Hambaryan, V V; Hohle, M M; Eisenbeiss, T

    2012-01-01

    We try to constrain the Equation-of-State (EoS) of supra-nuclear-density matter in neutron stars (NSs) by observations of nearby NSs. There are seven thermally emitting NSs known from X-ray and optical observations, the so-called Magnificent Seven (M7), which are young (up to few Myrs), nearby (within a few hundred pc), and radio-quiet with blackbody-like X-ray spectra, so that we can observe their surfaces. As bright X-ray sources, we can determine their rotational (pulse) period and their period derivative from X-ray timing. From XMM and/or Chandra X-ray spectra, we can determine their temperature. With precise astrometric observations using the Hubble Space Telescope, we can determine their parallax (i.e. distance) and optical flux. From flux, distance, and temperature, one can derive the emitting area - with assumptions about the atmosphere and/or temperature distribution on the surface. This was recently done by us for the two brightest M7 NSs RXJ1856 and RXJ0720. Then, from identifying absorption lines in X-ray spectra, one can also try to determine gravitational redshift. Also, from rotational phase-resolved spectroscopy, we have for the first time determined the compactness (mass/radius) of the M7 NS RBS1223. If also applied to RXJ1856, radius (from luminosity and temperature) and compactness (from X-ray data) will yield the mass and radius - for the first time for an isolated single neutron star. We will present our observations and recent results.

  1. Development of smartphone application that aids stroke screening and identifying nearby acute stroke care hospitals.

    Science.gov (United States)

    Nam, Hyo Suk; Heo, JoonNyung; Kim, Jinkwon; Kim, Young Dae; Song, Tae Jin; Park, Eunjeong; Heo, Ji Hoe

    2014-01-01

    The benefits of thrombolytic treatment are time-dependent. We developed a smartphone application that aids stroke patient self-screening and hospital selection, and may also decrease hospital arrival time. The application was developed for iPhone and Android smartphones. Map data for the application were adopted from the open map. For hospital registration, a web page (http://stroke119.org) was developed using PHP and MySQL. The Stroke 119 application includes a stroke screening tool and real-time information on nearby hospitals that provide thrombolytic treatment. It also provides information on stroke symptoms, thrombolytic treatment, and prescribed actions when stroke is suspected. The stroke screening tool was adopted from the Cincinnati Prehospital Stroke Scale and is displayed in a cartoon format. If the user taps a cartoon image that represents abnormal findings, a pop-up window shows that the user may be having a stroke, informs the user what to do, and directs the user to call emergency services. Information on nearby hospitals is provided in map and list views, incorporating proximity to the user's location using a Global Positioning System (a built-in function of smartphones). Users can search for a hospital according to specialty and treatment levels. We also developed a web page for hospitals to register in the system. Neurology training hospitals and hospitals that provide acute stroke care in Korea were invited to register. Seventy-seven hospitals had completed registration. This application may be useful for reducing hospital arrival times for thrombolytic candidates.

  2. Astrophysical Implications of a New Dynamical Mass for the Nearby White Dwarf 40 Eridani B

    Science.gov (United States)

    Bond, Howard E.; Bergeron, P.; Bédard, A.

    2017-10-01

    The bright, nearby DA-type white dwarf (WD) 40 Eridani B is orbited by the M dwarf 40 Eri C, allowing determination of the WD’s mass. Until recently, however, the mass depended on orbital elements determined four decades ago, and that mass was so low that it created several astrophysical puzzles. Using new astrometric measurements, the binary-star group at the U.S. Naval Observatory has revised the dynamical mass upward, to 0.573 ± 0.018 M ⊙. In this paper, we use model-atmosphere analysis to update other parameters of the WD, including effective temperature, surface gravity, radius, and luminosity. We then compare these results with WD interior models. Within the observational uncertainties, theoretical cooling tracks for CO-core WDs of its measured mass are consistent with the position of 40 Eri B in the H-R diagram; equivalently, the theoretical mass-radius relation (MRR) is consistent with the star’s location in the mass-radius plane. This consistency is, however, achieved only if we assume a “thin” outer hydrogen layer, with q H = M H/M WD ≃ 10-10. We discuss other evidence that a significant fraction of DA WDs have such thin H layers, in spite of the expectation from canonical stellar-evolution theory of “thick” H layers with q H ≃ 10-4. The cooling age of 40 Eri B is ˜122 Myr, and its total age is ˜1.8 Gyr. We present the MRRs for 40 Eri B and three other nearby WDs in visual binaries with precise mass determinations, and show that the agreement of current theory with observations is excellent in all cases.

  3. A survey of the molecular ISM properties of nearby galaxies using the Herschel FTS

    Energy Technology Data Exchange (ETDEWEB)

    Kamenetzky, J. [Also at Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721, USA. (United States); Rangwala, N. [Visiting Scientist, Space Science and Astrobiology Division, NASA Ames Research Center. (United States); Glenn, J.; Maloney, P. R.; Conley, A., E-mail: jkamenetzky@as.arizona.edu [Center for Astrophysics and Space Astronomy, University of Colorado at Boulder, 389-UCB, Boulder, CO (United States)

    2014-11-10

    The {sup 12}CO J = 4 → 3 to J = 13 → 12 lines of the interstellar medium from nearby galaxies, newly observable with the Herschel SPIRE Fourier transform spectrometer, offer an opportunity to study warmer, more luminous molecular gas than that traced by {sup 12}CO J = 1 → 0. Here we present a survey of 17 nearby infrared-luminous galaxy systems (21 pointings). In addition to photometric modeling of dust, we modeled full {sup 12}CO spectral line energy distributions from J = 1 → 0 to J = 13 → 12 with two components of warm and cool CO gas, and included LTE analysis of [C I], [C II], [N II], and H{sub 2} lines. CO is emitted from a low-pressure/high-mass component traced by the low-J lines and a high-pressure/low-mass component that dominates the luminosity. We found that, on average, the ratios of the warm/cool pressure, mass, and {sup 12}CO luminosity are 60 ± 30, 0.11 ± 0.02, and 15.6 ± 2.7. The gas-to-dust-mass ratios are <120 throughout the sample. The {sup 12}CO luminosity is dominated by the high-J lines and is 4 × 10{sup –4} L {sub FIR} on average. We discuss systematic effects of single-component and multi-component CO modeling (e.g., single-component J ≤ 3 models overestimate gas pressure by ∼0.5 dex), as well as compare to Galactic star-forming regions. With this comparison, we show the molecular interstellar medium of starburst galaxies is not simply an ensemble of Galactic-type giant molecular clouds. The warm gas emission is likely dominated by regions resembling the warm extended cloud of Sgr B2.

  4. The solar neighborhood. XXXIV. A search for planets orbiting nearby M dwarfs using astrometry

    International Nuclear Information System (INIS)

    Lurie, John C.; Henry, Todd J.; Ianna, Philip A.; Jao, Wei-Chun; Quinn, Samuel N.; Winters, Jennifer G.; Koerner, David W.; Riedel, Adric R.; Subasavage, John P.

    2014-01-01

    Astrometric measurements are presented for seven nearby stars with previously detected planets: six M dwarfs (GJ 317, GJ 667C, GJ 581, GJ 849, GJ 876, and GJ 1214) and one K dwarf (BD-10 -3166). Measurements are also presented for six additional nearby M dwarfs without known planets, but which are more favorable to astrometric detections of low mass companions, as well as three binary systems for which we provide astrometric orbit solutions. Observations have baselines of 3 to 13 years, and were made as part of the RECONS long-term astrometry and photometry program at the CTIO/SMARTS 0.9 m telescope. We provide trigonometric parallaxes and proper motions for all 16 systems, and perform an extensive analysis of the astrometric residuals to determine the minimum detectable companion mass for the 12 M dwarfs not having close stellar secondaries. For the six M dwarfs with known planets, we are not sensitive to planets, but can rule out the presence of all but the least massive brown dwarfs at periods of 2–12 years. For the six more astrometrically favorable M dwarfs, we conclude that none have brown dwarf companions, and are sensitive to companions with masses as low as 1 M Jup for periods longer than two years. In particular, we conclude that Proxima Centauri has no Jovian companions at orbital periods of 2–12 years. These results complement previously published M dwarf planet occurrence rates by providing astrometrically determined upper mass limits on potential super-Jupiter companions at orbits of two years and longer. As part of a continuing survey, these results are consistent with the paucity of super-Jupiter and brown dwarf companions we find among the over 250 red dwarfs within 25 pc observed longer than five years in our astrometric program.

  5. Flares of Nearby, Mid-to-late M-dwarfs Characterized by the MEarth Project

    Science.gov (United States)

    Mondrik, Nicholas; Charbonneau, David; Irwin, Jonathan; Newton, Elisabeth R.

    2017-01-01

    Stellar flares are both a curse and a blessing: Transit and radial velocity searches for exoplanets are hindered by the variability caused by flares, while the characteristics of this variability offer valuable insight into the magnetic properties of the star. We present an analysis of flare events of nearby, mid-to-late M-dwarfs from the MEarth Project. MEarth consists of a northern and a southern array of 8 telescopes each that photometrically monitors most mid-to-late M-dwarfs within 30 parsecs. Although the initial motivation was to search for exoplanet transits, the cadence of approximately 20 minutes is well-suited to capturing long-lived flares. However, MEarth employs a single, wide, red bandpass, which poses challenges to the robust detection of flare events, which are typically bluer in color. Using MEarth data, our team has recently published trigonometric parallaxes and estimates of rotation periods for an unprecedented number of nearby low-mass stars. We also gathered supplementary optical and near infrared spectra of a subset of these stars. We describe here the properties of the flares detected by MEarth, and explore the relation of the presence of flares on individual stars with stellar parameters such as rotational period, mass, and H-alpha equivalent width. We also provide an estimate of flare rate for individual stars by injecting flares into our pipeline.The MEarth project acknowledges funding from the National Science Foundation and the David and Lucile Packard Foundation Fellowship for Science and Engineering. This work was made possible through the support of a grant from the John Templeton Foundation.

  6. Nuclear mid-infrared properties of nearby low-luminosity AGN

    International Nuclear Information System (INIS)

    Asmus, D; Duschl, W J; Hönig, S F; Gandhi, P; Smette, A

    2012-01-01

    We present ground-based high-spatial resolution mid-infrared (MIR) observations of 20 nearby low-luminosity AGN (LLAGN) with VLT/VISIR and the preliminary analysis of a new sample of 10 low-luminosity Seyferts observed with Gemini/Michelle. LLAGN are of great interest because these objects are the most common among active galaxies, especially in the nearby universe. Studying them in great detail makes it possible to investigate the AGN evolution over cosmic timescale. Indeed, many LLAGN likely represent the final stage of an AGN's lifetime. We show that even at low luminosities and accretion rates nuclear unresolved MIR emission is present in most objects. Compared to lower spatial resolution Spitzer/IRS spectra, the high-resolution MIR photometry exhibits significantly lower fluxes and different PAH emission feature properties in many cases. By using scaled Spitzer/IRS spectra of typical starburst galaxies, we show that the star formation contribution to the 12 μm emission is minor in the central parsecs of most LLAGN. Therefore, the observed MIR emission in the VISIR and Michelle data is most likely emitted by the AGN itself, which, for higher luminosity AGN, is interpreted as thermal emission from a dusty torus. Furthermore, the 12 /amemission of the LLAGN is strongly correlated with the absorption corrected 2-10 keV luminosity and the MIR- X-ray correlation found previously for AGN is extended to a range from 10 40 to 10 45 erg/s. This correlation is independent of the object type, and in particular the low-luminosity Seyferts observed with Michelle fall exactly on the power-law fit valid for brighter AGN. In addition, no dependency of the MIR-X-ray ratio on the accretion rate is found. These results are consistent with the unification model being applicable even in the probed low-luminosity regime.

  7. The solar neighborhood. XXXIV. A search for planets orbiting nearby M dwarfs using astrometry

    Energy Technology Data Exchange (ETDEWEB)

    Lurie, John C. [Department of Astronomy, University of Washington, Seattle, WA 98195 (United States); Henry, Todd J.; Ianna, Philip A. [RECONS Institute, Chambersburg, PA 17201 (United States); Jao, Wei-Chun; Quinn, Samuel N.; Winters, Jennifer G. [Department of Physics and Astronomy, Georgia State University, Atlanta, GA 30302 (United States); Koerner, David W. [Department of Physics and Astronomy, Northern Arizona University, Flagstaff, AZ 86011 (United States); Riedel, Adric R. [Department of Astrophysics, American Museum of Natural History, New York, NY 10034 (United States); Subasavage, John P., E-mail: lurie@uw.edu [United States Naval Observatory, Flagstaff, AZ 86001 (United States)

    2014-11-01

    Astrometric measurements are presented for seven nearby stars with previously detected planets: six M dwarfs (GJ 317, GJ 667C, GJ 581, GJ 849, GJ 876, and GJ 1214) and one K dwarf (BD-10 -3166). Measurements are also presented for six additional nearby M dwarfs without known planets, but which are more favorable to astrometric detections of low mass companions, as well as three binary systems for which we provide astrometric orbit solutions. Observations have baselines of 3 to 13 years, and were made as part of the RECONS long-term astrometry and photometry program at the CTIO/SMARTS 0.9 m telescope. We provide trigonometric parallaxes and proper motions for all 16 systems, and perform an extensive analysis of the astrometric residuals to determine the minimum detectable companion mass for the 12 M dwarfs not having close stellar secondaries. For the six M dwarfs with known planets, we are not sensitive to planets, but can rule out the presence of all but the least massive brown dwarfs at periods of 2–12 years. For the six more astrometrically favorable M dwarfs, we conclude that none have brown dwarf companions, and are sensitive to companions with masses as low as 1 M{sub Jup} for periods longer than two years. In particular, we conclude that Proxima Centauri has no Jovian companions at orbital periods of 2–12 years. These results complement previously published M dwarf planet occurrence rates by providing astrometrically determined upper mass limits on potential super-Jupiter companions at orbits of two years and longer. As part of a continuing survey, these results are consistent with the paucity of super-Jupiter and brown dwarf companions we find among the over 250 red dwarfs within 25 pc observed longer than five years in our astrometric program.

  8. Sloan Digital Sky Survey IV: Mapping the Milky Way, Nearby Galaxies, and the Distant Universe

    Science.gov (United States)

    Blanton, Michael R.; Bershady, Matthew A.; Abolfathi, Bela; Albareti, Franco D.; Allende Prieto, Carlos; Almeida, Andres; Alonso-García, Javier; Anders, Friedrich; Anderson, Scott F.; Andrews, Brett; Aquino-Ortíz, Erik; Aragón-Salamanca, Alfonso; Argudo-Fernández, Maria; Armengaud, Eric; Aubourg, Eric; Avila-Reese, Vladimir; Badenes, Carles; Bailey, Stephen; Barger, Kathleen A.; Barrera-Ballesteros, Jorge; Bartosz, Curtis; Bates, Dominic; Baumgarten, Falk; Bautista, Julian; Beaton, Rachael; Beers, Timothy C.; Belfiore, Francesco; Bender, Chad F.; Berlind, Andreas A.; Bernardi, Mariangela; Beutler, Florian; Bird, Jonathan C.; Bizyaev, Dmitry; Blanc, Guillermo A.; Blomqvist, Michael; Bolton, Adam S.; Boquien, Médéric; Borissova, Jura; van den Bosch, Remco; Bovy, Jo; Brandt, William N.; Brinkmann, Jonathan; Brownstein, Joel R.; Bundy, Kevin; Burgasser, Adam J.; Burtin, Etienne; Busca, Nicolás G.; Cappellari, Michele; Delgado Carigi, Maria Leticia; Carlberg, Joleen K.; Carnero Rosell, Aurelio; Carrera, Ricardo; Chanover, Nancy J.; Cherinka, Brian; Cheung, Edmond; Gómez Maqueo Chew, Yilen; Chiappini, Cristina; Doohyun Choi, Peter; Chojnowski, Drew; Chuang, Chia-Hsun; Chung, Haeun; Cirolini, Rafael Fernando; Clerc, Nicolas; Cohen, Roger E.; Comparat, Johan; da Costa, Luiz; Cousinou, Marie-Claude; Covey, Kevin; Crane, Jeffrey D.; Croft, Rupert A. C.; Cruz-Gonzalez, Irene; Garrido Cuadra, Daniel; Cunha, Katia; Damke, Guillermo J.; Darling, Jeremy; Davies, Roger; Dawson, Kyle; de la Macorra, Axel; Dell'Agli, Flavia; De Lee, Nathan; Delubac, Timothée; Di Mille, Francesco; Diamond-Stanic, Aleks; Cano-Díaz, Mariana; Donor, John; Downes, Juan José; Drory, Niv; du Mas des Bourboux, Hélion; Duckworth, Christopher J.; Dwelly, Tom; Dyer, Jamie; Ebelke, Garrett; Eigenbrot, Arthur D.; Eisenstein, Daniel J.; Emsellem, Eric; Eracleous, Mike; Escoffier, Stephanie; Evans, Michael L.; Fan, Xiaohui; Fernández-Alvar, Emma; Fernandez-Trincado, J. G.; Feuillet, Diane K.; Finoguenov, Alexis; Fleming, Scott W.; Font-Ribera, Andreu; Fredrickson, Alexander; Freischlad, Gordon; Frinchaboy, Peter M.; Fuentes, Carla E.; Galbany, Lluís; Garcia-Dias, R.; García-Hernández, D. A.; Gaulme, Patrick; Geisler, Doug; Gelfand, Joseph D.; Gil-Marín, Héctor; Gillespie, Bruce A.; Goddard, Daniel; Gonzalez-Perez, Violeta; Grabowski, Kathleen; Green, Paul J.; Grier, Catherine J.; Gunn, James E.; Guo, Hong; Guy, Julien; Hagen, Alex; Hahn, ChangHoon; Hall, Matthew; Harding, Paul; Hasselquist, Sten; Hawley, Suzanne L.; Hearty, Fred; Gonzalez Hernández, Jonay I.; Ho, Shirley; Hogg, David W.; Holley-Bockelmann, Kelly; Holtzman, Jon A.; Holzer, Parker H.; Huehnerhoff, Joseph; Hutchinson, Timothy A.; Hwang, Ho Seong; Ibarra-Medel, Héctor J.; da Silva Ilha, Gabriele; Ivans, Inese I.; Ivory, KeShawn; Jackson, Kelly; Jensen, Trey W.; Johnson, Jennifer A.; Jones, Amy; Jönsson, Henrik; Jullo, Eric; Kamble, Vikrant; Kinemuchi, Karen; Kirkby, David; Kitaura, Francisco-Shu; Klaene, Mark; Knapp, Gillian R.; Kneib, Jean-Paul; Kollmeier, Juna A.; Lacerna, Ivan; Lane, Richard R.; Lang, Dustin; Law, David R.; Lazarz, Daniel; Lee, Youngbae; Le Goff, Jean-Marc; Liang, Fu-Heng; Li, Cheng; Li, Hongyu; Lian, Jianhui; Lima, Marcos; Lin, Lihwai; Lin, Yen-Ting; Bertran de Lis, Sara; Liu, Chao; de Icaza Lizaola, Miguel Angel C.; Long, Dan; Lucatello, Sara; Lundgren, Britt; MacDonald, Nicholas K.; Deconto Machado, Alice; MacLeod, Chelsea L.; Mahadevan, Suvrath; Geimba Maia, Marcio Antonio; Maiolino, Roberto; Majewski, Steven R.; Malanushenko, Elena; Malanushenko, Viktor; Manchado, Arturo; Mao, Shude; Maraston, Claudia; Marques-Chaves, Rui; Masseron, Thomas; Masters, Karen L.; McBride, Cameron K.; McDermid, Richard M.; McGrath, Brianne; McGreer, Ian D.; Medina Peña, Nicolás; Melendez, Matthew; Merloni, Andrea; Merrifield, Michael R.; Meszaros, Szabolcs; Meza, Andres; Minchev, Ivan; Minniti, Dante; Miyaji, Takamitsu; More, Surhud; Mulchaey, John; Müller-Sánchez, Francisco; Muna, Demitri; Munoz, Ricardo R.; Myers, Adam D.; Nair, Preethi; Nandra, Kirpal; Correa do Nascimento, Janaina; Negrete, Alenka; Ness, Melissa; Newman, Jeffrey A.; Nichol, Robert C.; Nidever, David L.; Nitschelm, Christian; Ntelis, Pierros; O'Connell, Julia E.; Oelkers, Ryan J.; Oravetz, Audrey; Oravetz, Daniel; Pace, Zach; Padilla, Nelson; Palanque-Delabrouille, Nathalie; Alonso Palicio, Pedro; Pan, Kaike; Parejko, John K.; Parikh, Taniya; Pâris, Isabelle; Park, Changbom; Patten, Alim Y.; Peirani, Sebastien; Pellejero-Ibanez, Marcos; Penny, Samantha; Percival, Will J.; Perez-Fournon, Ismael; Petitjean, Patrick; Pieri, Matthew M.; Pinsonneault, Marc; Pisani, Alice; Poleski, Radosław; Prada, Francisco; Prakash, Abhishek; Queiroz, Anna Bárbara de Andrade; Raddick, M. Jordan; Raichoor, Anand; Barboza Rembold, Sandro; Richstein, Hannah; Riffel, Rogemar A.; Riffel, Rogério; Rix, Hans-Walter; Robin, Annie C.; Rockosi, Constance M.; Rodríguez-Torres, Sergio; Roman-Lopes, A.; Román-Zúñiga, Carlos; Rosado, Margarita; Ross, Ashley J.; Rossi, Graziano; Ruan, John; Ruggeri, Rossana; Rykoff, Eli S.; Salazar-Albornoz, Salvador; Salvato, Mara; Sánchez, Ariel G.; Aguado, D. S.; Sánchez-Gallego, José R.; Santana, Felipe A.; Santiago, Basílio Xavier; Sayres, Conor; Schiavon, Ricardo P.; da Silva Schimoia, Jaderson; Schlafly, Edward F.; Schlegel, David J.; Schneider, Donald P.; Schultheis, Mathias; Schuster, William J.; Schwope, Axel; Seo, Hee-Jong; Shao, Zhengyi; Shen, Shiyin; Shetrone, Matthew; Shull, Michael; Simon, Joshua D.; Skinner, Danielle; Skrutskie, M. F.; Slosar, Anže; Smith, Verne V.; Sobeck, Jennifer S.; Sobreira, Flavia; Somers, Garrett; Souto, Diogo; Stark, David V.; Stassun, Keivan; Stauffer, Fritz; Steinmetz, Matthias; Storchi-Bergmann, Thaisa; Streblyanska, Alina; Stringfellow, Guy S.; Suárez, Genaro; Sun, Jing; Suzuki, Nao; Szigeti, Laszlo; Taghizadeh-Popp, Manuchehr; Tang, Baitian; Tao, Charling; Tayar, Jamie; Tembe, Mita; Teske, Johanna; Thakar, Aniruddha R.; Thomas, Daniel; Thompson, Benjamin A.; Tinker, Jeremy L.; Tissera, Patricia; Tojeiro, Rita; Hernandez Toledo, Hector; de la Torre, Sylvain; Tremonti, Christy; Troup, Nicholas W.; Valenzuela, Octavio; Martinez Valpuesta, Inma; Vargas-González, Jaime; Vargas-Magaña, Mariana; Vazquez, Jose Alberto; Villanova, Sandro; Vivek, M.; Vogt, Nicole; Wake, David; Walterbos, Rene; Wang, Yuting; Weaver, Benjamin Alan; Weijmans, Anne-Marie; Weinberg, David H.; Westfall, Kyle B.; Whelan, David G.; Wild, Vivienne; Wilson, John; Wood-Vasey, W. M.; Wylezalek, Dominika; Xiao, Ting; Yan, Renbin; Yang, Meng; Ybarra, Jason E.; Yèche, Christophe; Zakamska, Nadia; Zamora, Olga; Zarrouk, Pauline; Zasowski, Gail; Zhang, Kai; Zhao, Gong-Bo; Zheng, Zheng; Zheng, Zheng; Zhou, Xu; Zhou, Zhi-Min; Zhu, Guangtun B.; Zoccali, Manuela; Zou, Hu

    2017-07-01

    We describe the Sloan Digital Sky Survey IV (SDSS-IV), a project encompassing three major spectroscopic programs. The Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) is observing hundreds of thousands of Milky Way stars at high resolution and high signal-to-noise ratios in the near-infrared. The Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey is obtaining spatially resolved spectroscopy for thousands of nearby galaxies (median z˜ 0.03). The extended Baryon Oscillation Spectroscopic Survey (eBOSS) is mapping the galaxy, quasar, and neutral gas distributions between z˜ 0.6 and 3.5 to constrain cosmology using baryon acoustic oscillations, redshift space distortions, and the shape of the power spectrum. Within eBOSS, we are conducting two major subprograms: the SPectroscopic IDentification of eROSITA Sources (SPIDERS), investigating X-ray AGNs and galaxies in X-ray clusters, and the Time Domain Spectroscopic Survey (TDSS), obtaining spectra of variable sources. All programs use the 2.5 m Sloan Foundation Telescope at the Apache Point Observatory; observations there began in Summer 2014. APOGEE-2 also operates a second near-infrared spectrograph at the 2.5 m du Pont Telescope at Las Campanas Observatory, with observations beginning in early 2017. Observations at both facilities are scheduled to continue through 2020. In keeping with previous SDSS policy, SDSS-IV provides regularly scheduled public data releases; the first one, Data Release 13, was made available in 2016 July.

  9. Astrophysical Implications of a New Dynamical Mass for the Nearby White Dwarf 40 Eridani B

    Energy Technology Data Exchange (ETDEWEB)

    Bond, Howard E. [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States); Bergeron, P.; Bédard, A., E-mail: heb11@psu.edu [Département de Physique, Université de Montréal, C.P. 6128, Succ. Centre-Ville, Montréal, QC H3C 3J7 (Canada)

    2017-10-10

    The bright, nearby DA-type white dwarf (WD) 40 Eridani B is orbited by the M dwarf 40 Eri C, allowing determination of the WD’s mass. Until recently, however, the mass depended on orbital elements determined four decades ago, and that mass was so low that it created several astrophysical puzzles. Using new astrometric measurements, the binary-star group at the U.S. Naval Observatory has revised the dynamical mass upward, to 0.573 ± 0.018 M {sub ☉}. In this paper, we use model-atmosphere analysis to update other parameters of the WD, including effective temperature, surface gravity, radius, and luminosity. We then compare these results with WD interior models. Within the observational uncertainties, theoretical cooling tracks for CO-core WDs of its measured mass are consistent with the position of 40 Eri B in the H-R diagram; equivalently, the theoretical mass–radius relation (MRR) is consistent with the star’s location in the mass–radius plane. This consistency is, however, achieved only if we assume a “thin” outer hydrogen layer, with q {sub H} = M {sub H}/ M {sub WD} ≃ 10{sup −10}. We discuss other evidence that a significant fraction of DA WDs have such thin H layers, in spite of the expectation from canonical stellar-evolution theory of “thick” H layers with q {sub H} ≃ 10{sup −4}. The cooling age of 40 Eri B is ∼122 Myr, and its total age is ∼1.8 Gyr. We present the MRRs for 40 Eri B and three other nearby WDs in visual binaries with precise mass determinations, and show that the agreement of current theory with observations is excellent in all cases.

  10. Healthy environment--indoor air quality of Brazilian elementary schools nearby petrochemical industry.

    Science.gov (United States)

    Godoi, Ricardo H M; Godoi, Ana F L; Gonçalves Junior, Sérgio J; Paralovo, Sarah L; Borillo, Guilherme C; Gonçalves Gregório Barbosa, Cybelli; Arantes, Manoela G; Charello, Renata C; Rosário Filho, Nelson A; Grassi, Marco T; Yamamoto, Carlos I; Potgieter-Vermaak, Sanja; Rotondo, Giuliana G; De Wael, Karolien; van Grieken, Rene

    2013-10-01

    The mitigation of pollution released to the environment originating from the industrial sector has been the aim of all policy-makers and its importance is evident if the adverse health effects on the world population are considered. Although this concern is controversial, petroleum refinery has been linked to some adverse health effects for people living nearby. Apart from home, school is the most important indoor environment for children and there is increasing concern about the school environment and its impact on health, also in developing countries where the prevalence of pollution is higher. As most of the children spend more than 40% of their time in schools, it is critical to evaluate the pollution level in such environment. In the metropolitan region of Curitiba, South Brazil, five schools nearby industries and highways with high density traffic, were selected to characterize the aerosol and gaseous compounds indoor and outdoor of the classrooms, during 2009-2011. Size segregated aerosol samples were collected for analyses of bulk and single particle elemental profiles. They were analyzed by electron probe X-ray micro-analysis (EPXMA), and by energy-dispersive X-ray fluorescence (EDXRF), to investigate the elemental composition of individual particles and bulk samples. The concentrations of benzene, toluene, ethylbenzene, and xylene (BTEX); NO2; SO2; acetic acid; and formic acid were assessed indoor and outdoor using passive diffusion tubes. BTEX were analyzed by GC-MS and other collected gasses by ion chromatography. Individual exposition of BTEX was assessed by personal passive diffusion tubes. Results are interpreted separately and as a whole with the specific aim of identifying compounds that could affect the health of the scholars. In view of the chemical composition and size distribution of the aerosol particles, local deposition efficiencies in the children's respiratory systems were calculated, revealing the deposition of particles at extrathoracic

  11. North Korean nuclear negotiation drama

    International Nuclear Information System (INIS)

    Kim, Jai Bok

    1995-06-01

    This book reports negotiation on North Korean nuclear among South Korea, North Korea and U. S. It includes an account about international issues on North Korean nuclear activities, a new aspect on the problems of North Korean nuclear, pressure on North Korea and startup for dialogue trying to solve problems by communication, investigation by IAEA, IAEA resolution and high tension on Korean peninsula with North Korean nuclear.

  12. North Korean nuclear negotiation drama

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jai Bok

    1995-06-15

    This book reports negotiation on North Korean nuclear among South Korea, North Korea and U. S. It includes an account about international issues on North Korean nuclear activities, a new aspect on the problems of North Korean nuclear, pressure on North Korea and startup for dialogue trying to solve problems by communication, investigation by IAEA, IAEA resolution and high tension on Korean peninsula with North Korean nuclear.

  13. The mossy north

    DEFF Research Database (Denmark)

    Mateo, Ruben G.; Broennimann, Olivier; Normand, Signe

    2016-01-01

    , as predicted by theory, and whether the assembly mechanisms differ among taxonomic groups. SR increases towards the south in spermatophytes, but towards the north in ferns and bryophytes. SR patterns in spermatophytes are consistent with their patterns of beta diversity, with high levels of nestedness...... and turnover in the north and in the south, respectively, indicating species exclusion towards the north and increased opportunities for speciation in the south. Liverworts exhibit the highest levels of nestedness, suggesting that they represent the most sensitive group to the impact of past climate change...

  14. North Korea Conundrum

    Energy Technology Data Exchange (ETDEWEB)

    Samore, G

    2002-07-01

    Proliferation has become an important political issue over the last decades, marked simultaneously by the nuclearization of South Asia, the strengthening of international regimes (TNP, CW, MTCR) and the discovery of fraud and trafficking. This paper presents the motivations and strategy of North Korea in violating existing agreements and developing an alternative source of weapons grade material. Then it analyses the US gradual economical and political strategy to pressure North Korea to eliminate its nuclear weapons program. The future position of the US will depend on the Iraq outcome and on the results of its pressure policy on North Korea. (J.S.)

  15. North Korea Conundrum

    International Nuclear Information System (INIS)

    Samore, G.

    2002-01-01

    Proliferation has become an important political issue over the last decades, marked simultaneously by the nuclearization of South Asia, the strengthening of international regimes (TNP, CW, MTCR) and the discovery of fraud and trafficking. This paper presents the motivations and strategy of North Korea in violating existing agreements and developing an alternative source of weapons grade material. Then it analyses the US gradual economical and political strategy to pressure North Korea to eliminate its nuclear weapons program. The future position of the US will depend on the Iraq outcome and on the results of its pressure policy on North Korea. (J.S.)

  16. I-15 North Project

    Science.gov (United States)

    2013-11-05

    Goals of this project were as follows: (1) Conduct a comprehensive evaluation study on Nevada's I-15 North Design Build Project; (2) Analyze project implementation with respect to construction zone rules by which the contractor had to abide; (3) Anal...

  17. Poet North Manchester Approval

    Science.gov (United States)

    This update August 9, 2016 letter from EPA approves, with modifications, the petition from Poet Biorefining-North Manchester, LLC, regarding non-grandfathered ethanol produced through a dry mill process, qualifying under the Clean Air Act for renewable

  18. Census in North Vietnam

    National Research Council Canada - National Science Library

    1960-01-01

    This population census decree aims at collecting the most fundamental and accurate data on the population situation of North Vietnam to lay the foundation for all plans and public administration policies...

  19. HUBBLE'S ULTRAVIOLET VIEWS OF NEARBY GALAXIES YIELD CLUES TO EARLY UNIVERSE

    Science.gov (United States)

    2002-01-01

    Astronomers are using these three NASA Hubble Space Telescope images to help tackle the question of why distant galaxies have such odd shapes, appearing markedly different from the typical elliptical and spiral galaxies seen in the nearby universe. Do faraway galaxies look weird because they are truly weird? Or, are they actually normal galaxies that look like oddballs, because astronomers are getting an incomplete picture of them, seeing only the brightest pieces? Light from these galaxies travels great distances (billions of light-years) to reach Earth. During its journey, the light is 'stretched' due to the expansion of space. As a result, the light is no longer visible, but has been shifted to the infrared where present instruments are less sensitive. About the only light astronomers can see comes from regions where hot, young stars reside. These stars emit mostly ultraviolet light. But this light is stretched, appearing as visible light by the time it reaches Earth. Studying these distant galaxies is like trying to put together a puzzle with some of the pieces missing. What, then, do distant galaxies really look like? Astronomers studied 37 nearby galaxies to find out. By viewing these galaxies in ultraviolet light, astronomers can compare their shapes with those of their distant relatives. These three Hubble telescope pictures, taken with the Wide Field and Planetary Camera 2, represent a sampling from that survey. Astronomers observed the galaxies in ultraviolet and visible light to study all the stars that make up these 'cities of stars.' The results of their survey support the idea that astronomers are detecting the 'tip of the iceberg' of very distant galaxies. Based on these Hubble ultraviolet images, not all the faraway galaxies necessarily possess intrinsically odd shapes. The results are being presented today at the 197th meeting of the American Astronomical Society in San Diego, CA. The central region of the 'star-burst' spiral galaxy at far left

  20. Healthy environment — indoor air quality of Brazilian elementary schools nearby petrochemical industry

    International Nuclear Information System (INIS)

    Godoi, Ricardo H.M.; Godoi, Ana F.L.; Gonçalves Junior, Sérgio J.; Paralovo, Sarah L.; Borillo, Guilherme C.; Gonçalves Gregório Barbosa, Cybelli; Arantes, Manoela G.; Charello, Renata C.; Rosário Filho, Nelson A.; Grassi, Marco T.; Yamamoto, Carlos I.; Potgieter-Vermaak, Sanja; Rotondo, Giuliana G.; De Wael, Karolien; Grieken, Rene van

    2013-01-01

    The mitigation of pollution released to the environment originating from the industrial sector has been the aim of all policy-makers and its importance is evident if the adverse health effects on the world population are considered. Although this concern is controversial, petroleum refinery has been linked to some adverse health effects for people living nearby. Apart from home, school is the most important indoor environment for children and there is increasing concern about the school environment and its impact on health, also in developing countries where the prevalence of pollution is higher. As most of the children spend more than 40% of their time in schools, it is critical to evaluate the pollution level in such environment. In the metropolitan region of Curitiba, South Brazil, five schools nearby industries and highways with high density traffic, were selected to characterize the aerosol and gaseous compounds indoor and outdoor of the classrooms, during 2009–2011. Size segregated aerosol samples were collected for analyses of bulk and single particle elemental profiles. They were analyzed by electron probe X-ray micro-analysis (EPXMA), and by energy-dispersive X-ray fluorescence (EDXRF), to investigate the elemental composition of individual particles and bulk samples. The concentrations of benzene, toluene, ethylbenzene, and xylene (BTEX); NO 2 ; SO 2 ; acetic acid; and formic acid were assessed indoor and outdoor using passive diffusion tubes. BTEX were analyzed by GC–MS and other collected gasses by ion chromatography. Individual exposition of BTEX was assessed by personal passive diffusion tubes. Results are interpreted separately and as a whole with the specific aim of identifying compounds that could affect the health of the scholars. In view of the chemical composition and size distribution of the aerosol particles, local deposition efficiencies in the children's respiratory systems were calculated, revealing the deposition of particles at

  1. Healthy environment — indoor air quality of Brazilian elementary schools nearby petrochemical industry

    Energy Technology Data Exchange (ETDEWEB)

    Godoi, Ricardo H.M., E-mail: rhmgodoi@ufpr.br [Department of Environmental Engineering, Federal University of Paran UFPR, Curitiba, PR (Brazil); Godoi, Ana F.L.; Gonçalves Junior, Sérgio J.; Paralovo, Sarah L.; Borillo, Guilherme C.; Gonçalves Gregório Barbosa, Cybelli; Arantes, Manoela G.; Charello, Renata C. [Department of Environmental Engineering, Federal University of Paran UFPR, Curitiba, PR (Brazil); Rosário Filho, Nelson A. [Department of Pediatric, Div. of Allergy and Pneumol, Federal University of Paran Curitiba, PR (Brazil); Grassi, Marco T. [Department of Chemistry, Federal University of Paraná, Curitiba, PR (Brazil); Yamamoto, Carlos I. [Department of Chemistry Engineering, Federal University of Paraná, Curitiba, PR (Brazil); Potgieter-Vermaak, Sanja [Division of Chemistry and Environmental Science, School of Science and the Environment, Manchester Metropolitan University, Manchester (United Kingdom); Rotondo, Giuliana G.; De Wael, Karolien; Grieken, Rene van [Department of Chemistry, University of Antwerp, Universiteitsplein 1, B-2610 Antwerp (Belgium)

    2013-10-01

    The mitigation of pollution released to the environment originating from the industrial sector has been the aim of all policy-makers and its importance is evident if the adverse health effects on the world population are considered. Although this concern is controversial, petroleum refinery has been linked to some adverse health effects for people living nearby. Apart from home, school is the most important indoor environment for children and there is increasing concern about the school environment and its impact on health, also in developing countries where the prevalence of pollution is higher. As most of the children spend more than 40% of their time in schools, it is critical to evaluate the pollution level in such environment. In the metropolitan region of Curitiba, South Brazil, five schools nearby industries and highways with high density traffic, were selected to characterize the aerosol and gaseous compounds indoor and outdoor of the classrooms, during 2009–2011. Size segregated aerosol samples were collected for analyses of bulk and single particle elemental profiles. They were analyzed by electron probe X-ray micro-analysis (EPXMA), and by energy-dispersive X-ray fluorescence (EDXRF), to investigate the elemental composition of individual particles and bulk samples. The concentrations of benzene, toluene, ethylbenzene, and xylene (BTEX); NO{sub 2}; SO{sub 2}; acetic acid; and formic acid were assessed indoor and outdoor using passive diffusion tubes. BTEX were analyzed by GC–MS and other collected gasses by ion chromatography. Individual exposition of BTEX was assessed by personal passive diffusion tubes. Results are interpreted separately and as a whole with the specific aim of identifying compounds that could affect the health of the scholars. In view of the chemical composition and size distribution of the aerosol particles, local deposition efficiencies in the children's respiratory systems were calculated, revealing the deposition of

  2. Tiny intraplate earthquakes triggered by nearby episodic tremor and slip in Cascadia

    Science.gov (United States)

    Vidale, J.E.; Hotovec, A.J.; Ghosh, A.; Creager, K.C.; Gomberg, J.

    2011-01-01

    Episodic tremor and slip (ETS) has been observed in many subduction zones, but its mechanical underpinnings as well as its potential for triggering damaging earthquakes have proven difficult to assess. Here we use a seismic array in Cascadia of unprecedented density to monitor seismicity around a moderate 16 day ETS episode. In the 4 months of data we examine, we observe five tiny earthquakes within the subducting slab during the episode and only one more in the same area, which was just before and nearby the next ETS burst. These earthquakes concentrate along the sides and updip edge of the ETS region, consistent with greater stress concentration there than near the middle and downdip edge of the tremor area. Most of the seismicity is below the megathrust, with a similar depth extent to the background intraslab seismicity. The pattern of earthquakes that we find suggests slow slip has a more continuous temporal and spatial pattern than the tremor loci, which notoriously appear in bursts, jumps, and streaks. Copyright 2011 by the American Geophysical Union.

  3. Near-IR TRGB Distance to Nearby Dwarf Irregular Galaxy NGC 6822

    Directory of Open Access Journals (Sweden)

    Y.-J. Sohn

    2008-09-01

    Full Text Available We report the distance modulus of nearby dwarf irregular galaxy NGC 6822 estimated from the so-called Tip of Red-giant Branch (TRGB method. To detect the apparent magnitudes of the TRGB we use the color-magnitude diagrams (CMDs and luminosity functions (LFs in the near-infrared JHK bands. Foreground stars, main-sequence stars, and supergiant stars have been classified on the (g - K, g plane and removed on the near-infrared CMDs, from which only RGB and AGB stars are remained on the CMDs and LFs. By applying the Savitzky-Golay filter to the obtained LFs and detecting the peak in the second derivative of the observed LFs, we determined the apparent magnitudes of the TRGB. Theoretical absolute magnitudes of the TRGB are estimated from Yonsei-Yale isochrones with the age of 12Gyr and the metallicity range of -2.0 <[Fe/H]< -0.5. The derived values of distance modulus to NGC 6822 are (m - M

  4. Testing modified gravity at large distances with the HI Nearby Galaxy Survey's rotation curves

    Science.gov (United States)

    Mastache, Jorge; Cervantes-Cota, Jorge L.; de la Macorra, Axel

    2013-03-01

    Recently a new—quantum motivated—theory of gravity has been proposed that modifies the standard Newtonian potential at large distances when spherical symmetry is considered. Accordingly, Newtonian gravity is altered by adding an extra Rindler acceleration term that has to be phenomenologically determined. Here we consider a standard and a power-law generalization of the Rindler modified Newtonian potential. The new terms in the gravitational potential are hypothesized to play the role of dark matter in galaxies. Our galactic model includes the mass of the integrated gas, and stars for which we consider three stellar mass functions (Kroupa, diet-Salpeter, and free mass model). We test this idea by fitting rotation curves of seventeen low surface brightness galaxies from the HI Nearby Galaxy Survey (THINGS). We find that the Rindler parameters do not perform a suitable fit to the rotation curves in comparison to standard dark matter profiles (Navarro-Frenk-White and Burkert) and, in addition, the computed parameters of the Rindler gravity show a high spread, posing the model as a nonacceptable alternative to dark matter.

  5. Simultaneous, multi-wavelength flare observations of nearby low-mass stars

    Science.gov (United States)

    Thackeray, Beverly; Barclay, Thomas; Quintana, Elisa; Villadsen, Jacqueline; Wofford, Alia; Schlieder, Joshua; Boyd, Patricia

    2018-01-01

    Low-mass stars are the most common stars in the Galaxy and have been targeted in the tens-of-thousands by K2, the re-purposed Kepler mission, as they are prime targets to search for and characterize small, Earth-like planets. Understanding how these fully convective stars drive magnetic activity that manifests as stochastic, short-term brightenings, or flares, provides insight into the prospects of planetary habitability. High energy radiation and energetic particle emission associated with these stars can erode atmospheres, and impact habitability. An innovative campaign to study low mass stars through simultaneous multi-wavelength observations is currently underway with observations ongoing in the X-ray, UV, optical, and radio. I will present early results of our pilot study of the nearby M-Dwarf star Wolf 359 (CN Leo) using K2, SWIFT, and ground based radio observatories, forming a comprehensive picture of flare activity from an M-Dwarf, and discuss the potential impact of these results on exoplanets. "This material is based upon work supported by the National Science Foundation Graduate Research Fellowship Program under Grant No. DGE1322106. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation."

  6. Probing the Gas Fueling and Outflows in Nearby AGN with ALMA

    Energy Technology Data Exchange (ETDEWEB)

    Audibert, Anelise [Observatoire de Paris, LERMA, Centre National de la Recherche Scientifique, PSL University, Sorbonne University, UPMC, Paris (France); Combes, Françoise [Observatoire de Paris, LERMA, Centre National de la Recherche Scientifique, PSL University, Sorbonne University, UPMC, Paris (France); College de France, Paris (France); García-Burillo, Santiago [Observatorio Astronómico Nacional, Observatorio de Madrid, Madrid (Spain); Salomé, Philippe, E-mail: anelise.audibert@obspm.fr [Observatoire de Paris, LERMA, Centre National de la Recherche Scientifique, PSL University, Sorbonne University, UPMC, Paris (France)

    2017-12-12

    Feeding and feedback in AGN play a very important role to gain a proper understanding of galaxy formation and evolution. The interaction between activity mechanisms in the nucleus and its influence in the host galaxy are related to the physical processes involved in feedback and the gas fueling of the black hole. The discovery of many massive molecular outflows in the last few years have been promoting the idea that winds may be major actors in sweeping the gas out of galaxies. Also, the widely observed winds from the central regions of AGN are promising candidates to explain the scaling relations (e.g., the black hole-bulge mass relation, BH accretion rate tracking the star formation history) under the AGN feedback scenario. Out goal is to probe these phenomena through the kinematic and morphology of the gas inside the central kpc in nearby AGN. This has recently been possible due to the unprecedented ALMA spatial resolution and sensitivity. We present results on NGC7213 and NGC1808, the latter is part of a new ALMA follow-up of the NuGa project, a previous high-resolution (0.5–1″) CO survey of low luminosity AGN performed with the IRAM PdBI.

  7. Measurement of 65Zn in 5-yen coin present in the houses nearby JCO

    International Nuclear Information System (INIS)

    Kono, Masuchika; Koizumi, Yoshinobu

    2000-01-01

    In 1999, a critical accident occurred in Calder-Hall type power reactor of JCO for the first in Japan. This study aimed to estimate γ exposure dose utilizing a five-yen coin present in the houses nearby JCO at the time of accident. The coin, which is composed of Cu-Zn alloy is present every houses and its quality is well controlled by Ministry of Finance. In addition, Zn isotope ( 65 Zn) produced by neutron exposure has a long half-life (244.1 days) and emits γ ray with high energy of 1115.5 keV, which allows measurement at a low level radiation. So, five-yen coin was used as the subject. The exposure dose of inhabitant was estimated based on the activity on 5-yen coins collected from the houses at 13 points at different distances from JCO, which was determined by a low-level measurement system equipped with a pure-Ge semiconductor. The relationship between dose equivalent (mSv) and the distance from JCO was presented. At the time of JCO accident, the evacuation order was given to the inhabitants living within 300 m from the company. However, the present study indicated that the exposure dose was as high as 220 mSv at the site 100 m apart from JCO. Therefore, it is concluded that the inhabitants living in the area more than 350 m from JCO should also have taken refuge. (M.N.)

  8. Urban Imperviousness Effects on Summer Surface Temperatures Nearby Residential Buildings in Different Urban Zones of Parma

    Directory of Open Access Journals (Sweden)

    Marco Morabito

    2017-12-01

    Full Text Available Rapid and unplanned urban growth is responsible for the continuous conversion of green or generally natural spaces into artificial surfaces. The high degree of imperviousness modifies the urban microclimate and no studies have quantified its influence on the surface temperature (ST nearby residential building. This topic represents the aim of this study carried out during summer in different urban zones (densely urbanized or park/rural areas of Parma (Northern Italy. Daytime and nighttime ASTER images, the local urban cartography and the Italian imperviousness databases were used. A reproducible/replicable framework was implemented named “Building Thermal Functional Area” (BTFA useful to lead building-proxy thermal analyses by using remote sensing data. For each residential building (n = 8898, the BTFA was assessed and the correspondent ASTER-LST value (ST_BTFA and the imperviousness density were calculated. Both daytime and nighttime ST_BTFA significantly (p < 0.001 increased when high levels of imperviousness density surrounded the residential buildings. These relationships were mostly consistent during daytime and in densely urbanized areas. ST_BTFA differences between urban and park/rural areas were higher during nighttime (above 1 °C than daytime (about 0.5 °C. These results could help to identify “urban thermal Hot-Spots” that would benefit most from mitigation actions.

  9. Hello darkness my old friend: the fading of the nearby TDE ASASSN-14ae

    Science.gov (United States)

    Brown, Jonathan S.; Shappee, Benjamin J.; Holoien, T. W.-S.; Stanek, K. Z.; Kochanek, C. S.; Prieto, J. L.

    2016-11-01

    We present late-time optical spectroscopy taken with the Large Binocular Telescope's Multi-Object Double Spectrograph, an improved All-Sky Automated Survey for SuperNovae pre-discovery non-detection, and late-time Swift observations of the nearby (d = 193 Mpc, z = 0.0436) tidal disruption event (TDE) ASASSN-14ae. Our observations span from ˜20 d before to ˜750 d after discovery. The proximity of ASASSN-14ae allows us to study the optical evolution of the flare and the transition to a host-dominated state with exceptionally high precision. We measure very weak Hα emission 300 d after discovery (LH α ≃ 4 × 1039 erg s-1) and the most stringent upper limit to date on the Hα luminosity ˜750 d after discovery (LH α ≲ 1039 erg s-1), suggesting that the optical emission arising from a TDE can vanish on a time-scale as short as 1 yr. Our results have important implications for both spectroscopic detection of TDE candidates at late times, as well as the nature of TDE host galaxies themselves.

  10. Twitter location (sometimes matters: Exploring the relationship between georeferenced tweet content and nearby feature classes

    Directory of Open Access Journals (Sweden)

    Stefan Hahmann

    2014-12-01

    Full Text Available In this paper, we investigate whether microblogging texts (tweets produced on mobile devices are related to the geographical locations where they were posted. For this purpose, we correlate tweet topics to areas. In doing so, classified points of interest from OpenStreetMap serve as validation points. We adopted the classification and geolocation of these points to correlate with tweet content by means of manual, supervised, and unsupervised machine learning approaches. Evaluation showed the manual classification approach to be highest quality, followed by the supervised method, and that the unsupervised classification was of low quality. We found that the degree to which tweet content is related to nearby points of interest depends upon topic (that is, upon the OpenStreetMap category. A more general synthesis with prior research leads to the conclusion that the strength of the relationship of tweets and their geographic origin also depends upon geographic scale (where smaller scale correlations are more significant than those of larger scale.

  11. Exploring the physics of the accretion and jet in nearby narrow-line Seyfert 1 galaxies

    Science.gov (United States)

    Yao, Su; Qiao, Erlin; Wu, Xue-Bing; You, B.

    2018-06-01

    In this paper, we explore the physics of the accretion and jet in narrow-line Seyfert 1 (NLS1) galaxy. Specifically, we compile a sample composed of 16 nearby NLS1 with Lbol/LEdd ≳ 0.1. We investigate the mutual correlation between their radio luminosity LR, X-ray luminosity LX, optical luminosity L5100, and black hole mass MBH. By adopting partial correlation analysis, we find (1) a positive correlation between LX and MBH and (2) a weak positive correlation between LR and L5100. However, we don't find significant correlations between LR and LX or between LX and L5100 after considering the effect of the black hole mass, which leads to a finding that LX/LEdd is independent of L5100/LEdd. Interestingly, the findings that LX is correlated with MBH and LX/LEdd is not correlated with L5100/LEdd support that the X-ray emission is saturated with increasing \\dot{M} for Lbol/LEdd ≳ 0.1 in NLS1, which may be understood in the framework of slim disc scenario. Finally, we suggest that a larger NLS1 sample with high-quality radio and X-ray data is needed to further confirm this result in the future.

  12. Biomonitoring for creosote and pentachlorophenol in nearby residents of a wood treatment plant

    Energy Technology Data Exchange (ETDEWEB)

    Dahlgren, J. [UCLA School of Medicine, CA (United States); Schecter, A. [Univ. of Texas School of Public Health, Dallas, TX (United States); Phillips, D.H.; Hewer, A. [Inst. of Cancer Research, Sutton, Surrey (United Kingdom); Takhar, H. [Comprehensive Health Screening Services, Santa Monica, CA (United States); Paepke, O. [ERGO Lab., Hamburg (Germany); Warshaw, R. [Workers' Disease Detection Services, Inc. (United States)

    2004-09-15

    Contaminated wood treatment sites can result in adverse health effects to nearby residents. Environmental exposure can be estimated by measuring concentrations of pollutants in air, water, food, or wipe tests. This environmental exposure value can be used as a surrogate to estimate individual exposure. The objective of this study was to determine whether or not pentachlorophenol (PCP) could be found in potentially exposed residents and if the dioxin levels are consistent with PCP exposure. A further objective of the study was to determine whether or not PAH-DNA adducts could be found in the potentially exposed residents. We present results of biomonitoring studies in residents living near a wood treatment plant that used coal-derived creosote and PCP to process and treat wood for over 100 years. The plant was built in 1904 and used creosote and PCP. Creosote is a complex mixture that contains numerous polycyclic aromatic hydrocarbons (PAHs). PCP is contaminated with polychlorinated dioxin and furans. The residents' exposure pathways include air, soil and surface water.

  13. Astrophysical tests of gravity: a screening map of the nearby universe

    Energy Technology Data Exchange (ETDEWEB)

    Cabré, Anna; Vikram, Vinu; Jain, Bhuvnesh [Center for Particle Cosmology, Department of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104-6396 (United States); Zhao, Gong-Bo; Koyama, Kazuya, E-mail: annanusca@gmail.com, E-mail: vinu@sas.upenn.edu, E-mail: gong-bo.zhao@port.ac.uk, E-mail: bjain@physics.upenn.edu, E-mail: Kazuya.Koyama@port.ac.uk [Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building, Burnaby Road, Portsmouth, PO1 3FX (United Kingdom)

    2012-07-01

    Astrophysical tests of modified gravity theories in the nearby universe have been emphasized recently by Hui 2009 and Jain 2011. A key element of such tests is the screening mechanism whereby general relativity is restored in massive halos or high density environments like the Milky Way. In chameleon theories of gravity, including all f(R) models, field dwarf galaxies may be unscreened and therefore feel an extra force, as opposed to screened galaxies. The first step to study differences between screened and unscreened galaxies is to create a 3D screening map. We use N-body simulations to test and calibrate simple approximations to determine the level of screening in galaxy catalogs. Sources of systematic errors in the screening map due to observational inaccuracies are modeled and their contamination is estimated. We then apply our methods to create a map out to 200 Mpc in the Sloan Digital Sky Survey footprint using data from the Sloan survey and other sources. In two companion papers this map will be used to carry out new tests of gravity using distance indicators and the disks of dwarf galaxies. We also make our screening map publicly available.

  14. {sup 13}CO/C{sup 18}O Gradients across the Disks of Nearby Spiral Galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Jiménez-Donaire, María J.; Cormier, Diane; Bigiel, Frank [Institut für theoretische Astrophysik, Zentrum für Astronomie der Universität Heidelberg, Albert-Ueberle Str. 2, D-69120 Heidelberg (Germany); Leroy, Adam K.; Gallagher, Molly [Department of Astronomy, The Ohio State University, 140 W 18th St, Columbus, OH 43210 (United States); Krumholz, Mark R. [Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2611 (Australia); Usero, Antonio [Observatorio Astronómico Nacional, Alfonso XII 3, E-28014, Madrid (Spain); Hughes, Annie [CNRS, IRAP, 9 Av. colonel Roche, BP 44346, F-31028 Toulouse cedex 4 (France); Kramer, Carsten [Instituto de Astrofísica de Andalucía IAA-CSIC, Glorieta de la Astronomía s/n, E-18008, Granada (Spain); Meier, David [Department of Physics, New Mexico Institute of Mining and Technology, 801 Leroy Pl, Soccoro, NM 87801 (United States); Murphy, Eric [National Radio Astronomy Observatory, 520 Edgemont Rd, Charlottesville, VA 22903 (United States); Pety, Jérôme; Schuster, Karl [Institut de Radioastronomie Millimétrique (IRAM), 300 Rue de la Piscine, F-38406 Saint Martin d’Hères (France); Schinnerer, Eva; Sliwa, Kazimierz; Tomicic, Neven [Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany); Schruba, Andreas, E-mail: m.jimenez@zah.uni-heidelberg.de [Max-Planck-Institut für extraterrestrische Physik, Giessenbachstrasse 1, D-85748 Garching (Germany)

    2017-02-20

    We use the IRAM Large Program EMPIRE and new high-resolution ALMA data to measure {sup 13}CO(1-0)/C{sup 18}O(1-0) intensity ratios across nine nearby spiral galaxies. These isotopologues of {sup 12}CO are typically optically thin across most of the area in galaxy disks, and this ratio allows us to gauge their relative abundance due to chemistry or stellar nucleosynthesis effects. Resolved {sup 13}CO/C{sup 18}O gradients across normal galaxies have been rare due to the faintness of these lines. We find a mean {sup 13}CO/C{sup 18}O ratio of 6.0 ± 0.9 for the central regions of our galaxies. This agrees well with results in the Milky Way, but differs from results for starburst galaxies (3.4 ± 0.9) and ultraluminous infrared galaxies (1.1 ± 0.4). In our sample, the {sup 13}CO/C{sup 18}O ratio consistently increases with increasing galactocentric radius and decreases with increasing star formation rate surface density. These trends could be explained if the isotopic abundances are altered by fractionation; the sense of the trends also agrees with those expected for carbon and oxygen isotopic abundance variations due to selective enrichment by massive stars.

  15. A Herschel-Resolved Debris Disk Around the Nearby G Star HIP 32480

    Science.gov (United States)

    Stapelfeldt, K.

    2011-01-01

    The Herschel Space Observatory is providing unprecedented sensitivity and angular resolution in the far-infrared. The DUNES Key Project (DUst around NEarby Stars, PI Carlos Eiroa) has finished its survey of 133 FGK stars within 25 pc of the Sun using the PACS photometer at 100 and 160 microns. We report the detection of a resolved debris ring around HIP 32480, a G0 star 16.5 parsecs distant. The ring is almost 300 AU in diameter and inclined 30 degrees from edge-on. We present a thermal emission model for the system that fits the Spitzer spectroscopy and Herschel images of the system. We find a minimum grainsize of approximately 4 microns in the main ring and a distinct warm dust population interior to it. Faint detached emission features just outside the ring may trace a separate, more distant ring in the system. The non-detection of the ring in archival HST/ACS coronagraphic images limits the dust grain albedo in the ring to be no more than 10%.

  16. A Resolved Debris Disk Around the Nearby G Star HIP 32480

    Science.gov (United States)

    Stapelfeldt, K. R.; Bryden, G. C.; Marshall, J.; Eiroa, C.; Absil, O.; Mora, A.; Krist, J. E.; Su, K. Y. L.

    2012-01-01

    The Herschel Space Observatory is providing unprecedented sensitivity and angular resolution in the far-infrared. The DUNES Key Project (DUst around NEarby Stars, PI Carlos Eiroa) has finished its survey of 133 FGK stars within 25 pc of the Sun using the PACS photometer at 100 and 160 microns. We report the detection of a resolved debris ring around HIP 32480, a GO star 16.5 parsecs distant. The ring is almost 300 AU in diameter and inclined 30 degrees from edge-on. We present a thermal emission model for the system that fits the Spitzer spectroscopy and Herschel images of the system. We find a minimum grain-size of 4 microns in the main ring and a distinct warm dust population interior to it. Faint detached emission features just outside the ring may trace a separate, more distant ring in the system. The non-detection of the ring in archival HST/ACS coronagraphic images limits the dust grain albedo in the ring to be no more than 10%.

  17. Observations of EMIC Waves in the Exterior Cusp Region and in the Nearby Magnetosheath

    Science.gov (United States)

    Grison, B.; Escoubet, C. P.; Santolik, O.; Lavraud, B.; Cornilleau-Wehrlin, N.

    2014-12-01

    In the early years (2000-2004) of the mission, Cluster crossed the most distant part of the polar cusps. On 05/01/2002, Cluster enters the distant cusp region on the duskside of the southern hemisphere (inbound). The spacecraft are successively crossing the magnetopause between 19:50 UT (SC4) and 20:15 UT (SC3). The interplanetary conditions during the crossing were stable with a dominant negative By. The magnetometer (FGM) data indicates that the entry into the cusp takes place in a region where the magnetic field lines in the magnetosheath are anti-parallel with the field lines in the magnetosphere. Despite this clear picture, the global encounter is rather complex: one can notice partial magnetopause crossings, magnetic null points, and intense monochromatic waves on both sides of the magnetopause.We investigate electromagnetic ion cyclotron (EMIC) waves observed in the cusp and in the nearby magnetosheath, just before the magnetopause crossing by the spacecraft. Left-handed monochromatic waves observed in the cusp display different duration and frequency (below and above the local proton gyrofrequency) on each spacecraft. Both the Poynting flux of these emissions and the simultaneously recorded ion flows propagate in the same direction - toward the Earth. The wavenumber are determined in two ways: considering the Doppler shift and from direct measurements of the refractive index. We analyze these wave parameters and the local plasma conditions to explain the wave generation process on each side of the magnetopause.

  18. Swift UVOT Grism Observations of Nearby Type Ia Supernovae - I. Observations and Data Reduction

    Science.gov (United States)

    Pan, Y.-C.; Foley, R. J.; Filippenko, A. V.; Kuin, N. P. M.

    2018-05-01

    Ultraviolet (UV) observations of Type Ia supernovae (SNe Ia) are useful tools for understanding progenitor systems and explosion physics. In particular, UV spectra of SNe Ia, which probe the outermost layers, are strongly affected by the progenitor metallicity. In this work, we present 120 Neil Gehrels Swift Observatory UV spectra of 39 nearby SNe Ia. This sample is the largest UV (λ Ia to date, doubling the number of UV spectra and tripling the number of SNe with UV spectra. The sample spans nearly the full range of SN Ia light-curve shapes (Δm15(B) ≈ 0.6-1.8 mag). The fast turnaround of Swift allows us to obtain UV spectra at very early times, with 13 out of 39 SNe having their first spectra observed ≳ 1 week before peak brightness and the earliest epoch being 16.5 days before peak brightness. The slitless design of the Swift UV grism complicates the data reduction, which requires separating SN light from underlying host-galaxy light and occasional overlapping stellar light. We present a new data-reduction procedure to mitigate these issues, producing spectra that are significantly improved over those of standard methods. For a subset of the spectra we have nearly simultaneous Hubble Space Telescope UV spectra; the Swift spectra are consistent with these comparison data.

  19. Ionization of Local Interstellar Gas Based on STIS and FUSE spectra of Nearby Stars

    Science.gov (United States)

    Redfield, Seth; Linsky, J. L.

    2009-01-01

    The ultraviolet contains many resonance line transitions that are sensitive to a range of ionization stages of ions present in the local interstellar medium (LISM). We couple observations of high resolution ultraviolet spectrographs, STIS and GHRS on the Hubble Space Telescope (HST) and the Far-Ultraviolet Spectroscopic Explorer (FUSE) in order to make a comprehensive survey of the ionization structure of the local interstellar medium. In particular, we focus on the sight line toward G191-B2B, a nearby (69 pc) white dwarf. We present interstellar detections of highly ionized elements (e.g., SiIII, CIII, CIV, etc) and compare them directly to neutral or singly ionized LISM detections (e.g., SiII, CII, etc). The extensive observations of G191-B2B provides an opportunity for a broad study of ionization stages of several elements, while a survey of several sight lines provides a comprehensive look at the ionization structure of the LISM. We acknowledge support for this project through NASA FUSE Grant NNX06AD33G.

  20. Tracing the Baryon Cycle within Nearby Galaxies with a next-generation VLA

    Science.gov (United States)

    Kepley, Amanda A.; Leroy, Adam; Murphy, Eric J.; ngVLA Baryon Cycle Science Working Group

    2017-01-01

    The evolution of galaxies over cosmic time is shaped by the cycling of baryons through these systems, namely the inflow of atomic gas, the formation of molecular structures, the birth of stars, and the expulsion of gas due to associated feedback processes. The best way to study this cycle in detail are observations of nearby galaxies. These systems provide a complete picture of baryon cycling over a wide range of astrophysical conditions. In the next decade, higher resolution/sensitivity observations of such galaxies will fundamentally improve our knowledge of galaxy formation and evolution, allowing us to better interpret higher redshift observations of sources that were rapidly evolving at epochs soon after the Big Bang. In particular, the centimeter-to-millimeter part of the spectrum provides critical diagnostics for each of the key baryon cycling processes and access to almost all phases of gas in galaxies: cool and cold gas (via emission and absorption lines), ionized gas (via free-free continuum and recombination lines), cosmic rays and hot gas (via synchrotron emission and the Sunyaev-Zeldovich effect). This poster highlights a number of key science problems in this area whose solutions require a next-generation radio-mm interferometer such as the next-generation VLA.

  1. Can nearby eutrophic reservoirs sustain a differentiated biodiversity of planktonic microcrustaceans in a tropical semiarid basin?

    Science.gov (United States)

    Diniz, Leidiane P; Melo-Júnior, Mauro DE

    2017-01-01

    This paper aims to compare alpha and beta diversities of planktonic microcrustaceans from three reservoirs located nearby in a tropical semiarid basin. Our hypothesis was that alpha and beta diversities of the community are different, although the ecosystems are located close to each other. We carried out two sampling campaigns: dry and rainy seasons. The sampling of microcrustaceans and environmental variables (dissolved oxygen, chlorophyll a and nutrient) was performed at twelve stations and were distributed throughout the three zones (river, transition, and lacustrine), using a plankton net (45 µm). The reservoirs showed different uses and types of nitrogen predominance: Cachoeira (supply/nitrate), Borborema (sewage/ammonia) and Saco (aquaculture/ammonia). Seventeen species were recorded whose richness was assessed as particularly specific to each one of the studied reservoirs. Seasonally, both reservoirs with high anthropogenic alteration showed greater richness in the dry season. The three reservoirs located in a same basin showed different richness and composition, but the diversity did not differ between the zones of the reservoirs. Although communities are close to each other, their composition and richness were found to be distinct for each reservoir. This may be in response to the peculiar particularities, such as nitrogen sources and the different uses.

  2. How complementary are epibenthic assemblages in artificial and nearby natural rocky reefs?

    KAUST Repository

    Carvalho, Susana

    2013-12-01

    The present study analyses the composition, structure and trophic function of epibenthic assemblages in two artificial reefs (ARs) 16 years after deployment and in nearby natural reefs (NRs), aiming at providing insights on the complementarity between both habitats. Current findings suggest that after 16 years the ARs (concrete blocks), located in southern Portugal, do not act as surrogates for NRs, as epibenthic assemblages differed between reef types in composition, structure and trophic function. NRs showed higher diversity and complementarity (i.e. beta-diversity) than ARs, evidencing higher redundancy. Higher heterogeneity within NRs was also evidenced by the multi-dimensional scaling analysis based on abundance, biomass and trophic composition. NRs presented higher abundance of molluscs and biomass of sponges, resulting in differences in the trophic function: suspension-feeding dominated the NRs, while within ARs there was an ascendency of carnivory. Although not acting as surrogates for NRs and provided that no adverse effects (e.g. establishment of non-native species) were detected, ARs may have a significant contribution for the increase of regional diversity, as evidenced by the highest complementarity levels observed between assemblages in both reefs. © 2013 Elsevier Ltd.

  3. DIRECTED SEARCHES FOR BROADBAND EXTENDED GRAVITATIONAL WAVE EMISSION IN NEARBY ENERGETIC CORE-COLLAPSE SUPERNOVAE

    Energy Technology Data Exchange (ETDEWEB)

    Van Putten, Maurice H. P. M., E-mail: mvp@sejong.ac.kr [Room 614, Astronomy and Space Science, Sejong University, 98 Gunja-Dong Gwangin-gu, Seoul 143-747 (Korea, Republic of)

    2016-03-10

    Core-collapse supernovae (CC-SNe) are factories of neutron stars and stellar-mass black holes. SNe Ib/c stand out as potentially originating in relatively compact stellar binaries and they have a branching ratio of about 1% into long gamma-ray bursts. The most energetic events probably derive from central engines harboring rapidly rotating black holes, wherein the accretion of fall-back matter down to the innermost stable circular orbit (ISCO) offers a window into broadband extended gravitational wave emission (BEGE). To search for BEGE, we introduce a butterfly filter in time–frequency space by time-sliced matched filtering. To analyze long epochs of data, we propose using coarse-grained searches followed by high-resolution searches on events of interest. We illustrate our proposed coarse-grained search on two weeks of LIGO S6 data prior to SN 2010br (z = 0.002339) using a bank of up to 64,000 templates of one-second duration covering a broad range in chirp frequencies and bandwidth. Correlating events with signal-to-noise ratios > 6 from the LIGO L1 and H1 detectors reduces the total to a few events of interest. Lacking any further properties reflecting a common excitation by broadband gravitational radiation, we disregarded these as spurious. This new pipeline may be used to systematically search for long-duration chirps in nearby CC-SNe from robotic optical transient surveys using embarrassingly parallel computing.

  4. Temperate Earth-sized planets transiting a nearby ultracool dwarf star.

    Science.gov (United States)

    Gillon, Michaël; Jehin, Emmanuël; Lederer, Susan M; Delrez, Laetitia; de Wit, Julien; Burdanov, Artem; Van Grootel, Valérie; Burgasser, Adam J; Triaud, Amaury H M J; Opitom, Cyrielle; Demory, Brice-Olivier; Sahu, Devendra K; Bardalez Gagliuffi, Daniella; Magain, Pierre; Queloz, Didier

    2016-05-12

    Star-like objects with effective temperatures of less than 2,700 kelvin are referred to as 'ultracool dwarfs'. This heterogeneous group includes stars of extremely low mass as well as brown dwarfs (substellar objects not massive enough to sustain hydrogen fusion), and represents about 15 per cent of the population of astronomical objects near the Sun. Core-accretion theory predicts that, given the small masses of these ultracool dwarfs, and the small sizes of their protoplanetary disks, there should be a large but hitherto undetected population of terrestrial planets orbiting them--ranging from metal-rich Mercury-sized planets to more hospitable volatile-rich Earth-sized planets. Here we report observations of three short-period Earth-sized planets transiting an ultracool dwarf star only 12 parsecs away. The inner two planets receive four times and two times the irradiation of Earth, respectively, placing them close to the inner edge of the habitable zone of the star. Our data suggest that 11 orbits remain possible for the third planet, the most likely resulting in irradiation significantly less than that received by Earth. The infrared brightness of the host star, combined with its Jupiter-like size, offers the possibility of thoroughly characterizing the components of this nearby planetary system.

  5. Hybrid 3D model for the interaction of plasma thruster plumes with nearby objects

    Science.gov (United States)

    Cichocki, Filippo; Domínguez-Vázquez, Adrián; Merino, Mario; Ahedo, Eduardo

    2017-12-01

    This paper presents a hybrid particle-in-cell (PIC) fluid approach to model the interaction of a plasma plume with a spacecraft and/or any nearby object. Ions and neutrals are modeled with a PIC approach, while electrons are treated as a fluid. After a first iteration of the code, the domain is split into quasineutral and non-neutral regions, based on non-neutrality criteria, such as the relative charge density and the Debye length-to-cell size ratio. At the material boundaries of the former quasineutral region, a dedicated algorithm ensures that the Bohm condition is met. In the latter non-neutral regions, the electron density and electric potential are obtained by solving the coupled electron momentum balance and Poisson equations. Boundary conditions for both the electric current and potential are finally obtained with a plasma sheath sub-code and an equivalent circuit model. The hybrid code is validated by applying it to a typical plasma plume-spacecraft interaction scenario, and the physics and capabilities of the model are finally discussed.

  6. The Study of Nebular Emission on Nearby Spiral Galaxies in the IFU Era

    Directory of Open Access Journals (Sweden)

    Fernando Fabián Rosales-Ortega

    2013-01-01

    Full Text Available A new generation of wide-field emission-line surveys based on integral field units (IFU is allowing us to obtain spatially resolved information of the gas-phase emission in nearby late-type galaxies, based on large samples of HII regions and full two-dimensional coverage. These observations are allowing us to discover and characterise abundance differentials between galactic substructures and new scaling relations with global physical properties. Here I review some highlights of our current studies employing this technique: (1 the case study of NGC 628, the largest galaxy ever sampled with an IFU; (2 a statistical approach to the abundance gradients of spiral galaxies, which indicates a universal radial gradient for oxygen abundance; and (3 the discovery of a new scaling relation of HII regions in spiral galaxies, the local mass-metallicity relation of star-forming galaxies. The observational properties and constrains found in local galaxies using this new technique will allow us to interpret the gas-phase abundance of analogue high-z systems.

  7. New prospects for detecting high-energy neutrinos from nearby supernovae

    Science.gov (United States)

    Murase, Kohta

    2018-04-01

    Neutrinos from supernovae (SNe) are crucial probes of explosive phenomena at the deaths of massive stars and neutrino physics. High-energy neutrinos are produced through hadronic processes by cosmic rays, which are accelerated during interaction between the supernova (SN) ejecta and circumstellar material (CSM). Recent observations of extragalactic SNe have revealed that a dense CSM is commonly expelled by the progenitor star. We provide new quantitative predictions of time-dependent high-energy neutrino emission from diverse types of SNe. We show that IceCube and KM3Net can detect ˜103 events from a SN II-P (and ˜3 ×105 events from a SN IIn) at a distance of 10 kpc. The new model also enables us to critically optimize the time window for dedicated searches for nearby SNe. A successful detection will give us a multienergy neutrino view of SN physics and new opportunities to study neutrino properties, as well as clues to the cosmic-ray origin. GeV-TeV neutrinos may also be seen by KM3Net, Hyper-Kamiokande, and PINGU.

  8. Mass outflow in the nearby proto-planetary system, Beta Pictoris

    International Nuclear Information System (INIS)

    Bruhweiler, F.C.; Grady, C.A.; Kondo, Yoji

    1991-01-01

    Previous spectral studies of circumstallar dust around the nearby, candidate proto-planetary system, Beta Pictoris, has detected only infalling gas. The lack of detectable mass outflow has been critical in the interpretation of the origin of the circumstellar gas and in our understanding of the evolutionary status of the Beta Pictoris system. IUE high-dispersion spectra are presented which show, in addition to infall, the presence of mass outflow, with a maximum observed outflow velocity of -60 km/s, and a corresponding instantaneous outflow rate of 1.1 x 10 to the -14th solar mass/yr, or 1.1 x 10 to the -11th Jupiter mass/yr. This mass outflow rate and terminal velocity are comparable to the magnitudes of mass infall rates and terminal velocities observed from late 1986 through early 1988. The implications of these observations on our understanding of the mechanisms producing infall from the surrounding circumstellar disk are discussed, as are the implications for our understanding of the evolutionary status of the Beta Pic system. 23 refs

  9. The Nearby, Young, Argus Association: Membership, Age, and Dusty Debris Disks

    Science.gov (United States)

    Zuckerman, Ben

    2018-01-01

    The Argus Association (AA) defined by Torres et al. (2008) is distinguished from other nearby young moving groups by virtue of its unusual Galactic U-velocity. As defined by Torres et al, their initial AA consisted of 35 members of the IC 2391 open cluster (~135 pc from Earth) and 29 “field members”, 15 of which are within 100 pc of Earth. The spectral types range from F through K with the exception of two M-type members of IC 2391. Zuckerman et al. (2011 & 2012) proposed 13 additional field members – 12 A-type and one F-type -- all of which lie within 80 pc of Earth. Additional AA members have been proposed, typically a few at a time, by other researchers. Deduced ages of the AA (via various techniques) lie, typically, between 40 and 60 Myr. Bell et al (2015) consider the membership and age of a subset of proposed AA stars via color-magnitude diagrams combined with a Bayesian analysis (following Malo et al 2013 & 2014). For the sample of AA stars that they considered, the group age, membership status of individual stars, and even the reality of a coeval moving group were in some doubt. The purpose of the present communication is to consider all proposed AA members – including the frequency of dusty debris disks -- in an attempt to bring some clarity to what is going on.

  10. Geochemical markers of soil anthropogenic contaminants in polar scientific stations nearby (Antarctica, King George Island).

    Science.gov (United States)

    Prus, Wojciech; Fabiańska, Monika J; Łabno, Radosław

    2015-06-15

    The organic contamination of Antarctic soils and terrestrial sediments from nearby of five polar scientific stations on King George Island (Antarctica) was investigated. Gas chromatography-mass spectrometry (GC-MS) was applied to find composition of dichloromethane extracts of soil and terrestrial sediments. The presence of geochemical markers, such as n-alkanes, steranes, pentacyclic triterpenoids, and alkyl PAHs, their distribution types, and values of their ratios indicates the predominating source of organic fossil fuels and products of their refining rather than from the natural Antarctic environment. Fossil fuel-originated compounds well survived in conditions of Antarctic climate over long times thus enabling to characterize geochemical features of source fossil fuel identified as petroleum expelled from kerogen II of algal/bacterial origins deposited in sub-oxic conditions and being in the middle of catagenesis. Both microbial activity and water leaching play an important role in degradation of terrestrial oil spills in the Antarctica climate, and petroleum alteration occurs lowly over long periods of time. Synthetic anthropogenic compounds found in terrestrial Antarctica sediments included diisopropylnaphthalenes, products of their sulfonates degradation in paper combustion, and organophosporus compounds used as retardants and plasticizers. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Can nearby eutrophic reservoirs sustain a differentiated biodiversity of planktonic microcrustaceans in a tropical semiarid basin?

    Directory of Open Access Journals (Sweden)

    LEIDIANE P. DINIZ

    Full Text Available ABSTRACT This paper aims to compare alpha and beta diversities of planktonic microcrustaceans from three reservoirs located nearby in a tropical semiarid basin. Our hypothesis was that alpha and beta diversities of the community are different, although the ecosystems are located close to each other. We carried out two sampling campaigns: dry and rainy seasons. The sampling of microcrustaceans and environmental variables (dissolved oxygen, chlorophyll a and nutrient was performed at twelve stations and were distributed throughout the three zones (river, transition, and lacustrine, using a plankton net (45 µm. The reservoirs showed different uses and types of nitrogen predominance: Cachoeira (supply/nitrate, Borborema (sewage/ammonia and Saco (aquaculture/ammonia. Seventeen species were recorded whose richness was assessed as particularly specific to each one of the studied reservoirs. Seasonally, both reservoirs with high anthropogenic alteration showed greater richness in the dry season. The three reservoirs located in a same basin showed different richness and composition, but the diversity did not differ between the zones of the reservoirs. Although communities are close to each other, their composition and richness were found to be distinct for each reservoir. This may be in response to the peculiar particularities, such as nitrogen sources and the different uses.

  12. How the First Stars Regulated Star Formation. II. Enrichment by Nearby Supernovae

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Ke-Jung [Division of Theoretical Astronomy, National Astronomical Observatory of Japan, Tokyo 181-8588 (Japan); Whalen, Daniel J. [Institute of Cosmology and Gravitation, Portsmouth University, Portsmouth (United Kingdom); Wollenberg, Katharina M. J.; Glover, Simon C. O.; Klessen, Ralf S., E-mail: ken.chen@nao.ac.jp [Zentrum für Astronomie, Institut für Theoretische Astrophysik, Universität Heidelberg (Germany)

    2017-08-01

    Metals from Population III (Pop III) supernovae led to the formation of less massive Pop II stars in the early universe, altering the course of evolution of primeval galaxies and cosmological reionization. There are a variety of scenarios in which heavy elements from the first supernovae were taken up into second-generation stars, but cosmological simulations only model them on the largest scales. We present small-scale, high-resolution simulations of the chemical enrichment of a primordial halo by a nearby supernova after partial evaporation by the progenitor star. We find that ejecta from the explosion crash into and mix violently with ablative flows driven off the halo by the star, creating dense, enriched clumps capable of collapsing into Pop II stars. Metals may mix less efficiently with the partially exposed core of the halo, so it might form either Pop III or Pop II stars. Both Pop II and III stars may thus form after the collision if the ejecta do not strip all the gas from the halo. The partial evaporation of the halo prior to the explosion is crucial to its later enrichment by the supernova.

  13. Gravitational Waves from Stellar Black Hole Binaries and the Impact on Nearby Sun-like Stars

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Ilídio [Centro Multidisciplinar de Astrofísica, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Silk, Joseph, E-mail: ilidio.lopes@tecnico.ulisboa.pt, E-mail: silk@astro.ox.ac.uk [Institut d’Astrophysique de Paris, UMR 7095 CNRS, Université Pierre et Marie Curie, 98 bis Boulevard Arago, Paris F-75014 (France)

    2017-07-20

    We investigate the impact of resonant gravitational waves on quadrupole acoustic modes of Sun-like stars located nearby stellar black hole binary systems (such as GW150914 and GW151226). We find that the stimulation of the low-overtone modes by gravitational radiation can lead to sizeable photometric amplitude variations, much larger than the predictions for amplitudes driven by turbulent convection, which in turn are consistent with the photometric amplitudes observed in most Sun-like stars. For accurate stellar evolution models, using up-to-date stellar physics, we predict photometric amplitude variations of 1–10{sup 3} ppm for a solar mass star located at a distance between 1 au and 10 au from the black hole binary and belonging to the same multi-star system. The observation of such a phenomenon will be within the reach of the Plato mission because the telescope will observe several portions of the Milky Way, many of which are regions of high stellar density with a substantial mixed population of Sun-like stars and black hole binaries.

  14. THE ORIGIN OF NEUTRAL HYDROGEN CLOUDS IN NEARBY GALAXY GROUPS: EXPLORING THE RANGE OF GALAXY INTERACTIONS

    International Nuclear Information System (INIS)

    Chynoweth, Katie M.; Polisensky, Emil; Holley-Bockelmann, Kelly; Langston, Glen I.

    2011-01-01

    We combine high-resolution N-body simulations with deep observations of neutral hydrogen (H I) in nearby galaxy groups in order to explore two well-known theories of H I cloud formation: H I stripping by galaxy interactions and dark-matter minihalos with embedded H I gas. This paper presents new data from three galaxy groups-Canes Venatici I, NGC 672, and NGC 45-and assembles data from our previous galaxy group campaign to generate a rich H I cloud archive to compare to our simulated data. We find no H I clouds in the Canes Venatici I, NGC 672, or NGC 45 galaxy groups. We conclude that H I clouds in our detection space are most likely to be generated through recent, strong galaxy interactions. We find no evidence of H I clouds associated with dark-matter halos above M HI ∼ 10 6 M sun , within ±700 km s -1 of galaxies, and within 50 kpc projected distance of galaxies.

  15. M31 in the Chandra Era: A High Definition Movie of a Nearby Galaxy

    Science.gov (United States)

    Kong, Albert; di Stefano, Rosanne

    2009-09-01

    M31 has been a prime targets for all X-ray missions since the first detection in 1974. With its superb spatial resolution, Chandra is unique in resolving dense source regions and detecting faint sources. Since the launch of Chandra, M31 has been regularly observed. It is perhaps the only nearby galaxy which is observed by an X-ray telescope regularly throughout operation. With 10 years of observations, the center of M31 has been observed with Chandra for nearly 1 Msec. The X-ray skies of M31 not only consist of many transients and variables, globular cluster X-ray sources in M31 are also different from our Milky Way. They are in general more luminous and one of them may even host an intermediate-mass black hole. Supersoft and quasi-soft X-ray sources in M31 are the best kept secret to unlock the nature of the progenitor of Type Ia supernova. In this talk, I will review some of the important Chandra discoveries in M31 in the past 10 years.

  16. How complementary are epibenthic assemblages in artificial and nearby natural rocky reefs?

    KAUST Repository

    Carvalho, Susana; Moura, Ana; Cú rdia, Joã o; Cancela da Fonseca, Luí s; Santos, Miguel N.

    2013-01-01

    The present study analyses the composition, structure and trophic function of epibenthic assemblages in two artificial reefs (ARs) 16 years after deployment and in nearby natural reefs (NRs), aiming at providing insights on the complementarity between both habitats. Current findings suggest that after 16 years the ARs (concrete blocks), located in southern Portugal, do not act as surrogates for NRs, as epibenthic assemblages differed between reef types in composition, structure and trophic function. NRs showed higher diversity and complementarity (i.e. beta-diversity) than ARs, evidencing higher redundancy. Higher heterogeneity within NRs was also evidenced by the multi-dimensional scaling analysis based on abundance, biomass and trophic composition. NRs presented higher abundance of molluscs and biomass of sponges, resulting in differences in the trophic function: suspension-feeding dominated the NRs, while within ARs there was an ascendency of carnivory. Although not acting as surrogates for NRs and provided that no adverse effects (e.g. establishment of non-native species) were detected, ARs may have a significant contribution for the increase of regional diversity, as evidenced by the highest complementarity levels observed between assemblages in both reefs. © 2013 Elsevier Ltd.

  17. Development of helium porosity near-by grain boundaries in nickel-carbon alloys

    International Nuclear Information System (INIS)

    Reutov, I.V.; Reutov, V.F.

    1995-01-01

    The peculiarities of development of helium porosity near grain boundaries in nickel with 0.002-0.065 at.% carbon uniformly doped with helium up to 2·10 -2 at.% in the process of post-irradiation isothermal annealing at 800 deg C for 1-50 hours are studied. It is stated that at this annealing temperature intensive nucleation and growth of bubbles are observed in near-boundary region whose width grows both with increase of annealing time and carbon content. The TEM studies have shown that in near-boundary zone itself the process of bubble growth is non-uniform: bubble size increases and their density decreases as the distance from grain boundary is increased. The effect observed is discussed from the point of view of formation of two zones with different level of swelling in a grain (near-by boundary and matrix) and consequently, hydrostatic stress as well conditioning the flux of vacancies and helium-vacancy complexes from matrix to grain boundary. 8 refs., 5 figs

  18. HOST GALAXIES OF TYPE Ia SUPERNOVAE FROM THE NEARBY SUPERNOVA FACTORY

    International Nuclear Information System (INIS)

    Childress, M.; Aldering, G.; Aragon, C.; Bailey, S.; Fakhouri, H. K.; Hsiao, E. Y.; Kim, A. G.; Loken, S.; Antilogus, P.; Bongard, S.; Canto, A.; Cellier-Holzem, F.; Guy, J.; Baltay, C.; Buton, C.; Kerschhaggl, M.; Kowalski, M.; Chotard, N.; Copin, Y.; Gangler, E.

    2013-01-01

    We present photometric and spectroscopic observations of galaxies hosting Type Ia supernovae (SNe Ia) observed by the Nearby Supernova Factory. Combining Galaxy Evolution Explorer (GALEX) UV data with optical and near-infrared photometry, we employ stellar population synthesis techniques to measure SN Ia host galaxy stellar masses, star formation rates (SFRs), and reddening due to dust. We reinforce the key role of GALEX UV data in deriving accurate estimates of galaxy SFRs and dust extinction. Optical spectra of SN Ia host galaxies are fitted simultaneously for their stellar continua and emission lines fluxes, from which we derive high-precision redshifts, gas-phase metallicities, and Hα-based SFRs. With these data we show that SN Ia host galaxies present tight agreement with the fiducial galaxy mass-metallicity relation from Sloan Digital Sky Survey (SDSS) for stellar masses log(M * /M ☉ ) > 8.5 where the relation is well defined. The star formation activity of SN Ia host galaxies is consistent with a sample of comparable SDSS field galaxies, though this comparison is limited by systematic uncertainties in SFR measurements. Our analysis indicates that SN Ia host galaxies are, on average, typical representatives of normal field galaxies.

  19. A High Definition View of AGN Feedback: Chandra Imaging of Nearby Seyfert Galaxies

    Science.gov (United States)

    Wang, Junfeng; Fabbiano, G.; Risaliti, G.; Elvis, M.; Karovska, M.; Zezas, A.; Mundell, C. G.

    2010-03-01

    To improve the physics of AGN feedback, it is crucial to evaluate the true role of outflows on galaxy evolution observationally. I will present new results from Chandra spectral imaging of nearby Seyfert galaxies, which offer unique opportunities to examine feedback in action in much greater detail than at high redshift. Exploiting Chandra's highest possible resolution, we are able to study structures in NGC 4151 on spatial scales of 0.5 arcsec (30 pc), showing an extended X-ray morphology overall consistent with the optical NLR. We find that most of the NLR clouds in NGC 4151 have [OIII] to soft X-ray ratio consistent with the values observed in NLRs of some Seyfert 2 galaxies, which indicates a uniform ionization parameter even at large radii. We examine various X-ray emission mechanisms of the radio jet and consider thermal emission from interaction between radio outflow and the NLR clouds the most probable origin for the X-ray emission associated with the jet.

  20. THE RISE OF SN 2014J IN THE NEARBY GALAXY M82

    International Nuclear Information System (INIS)

    Goobar, A.; Johansson, J.; Amanullah, R.; Ferretti, R.; Cao, Y.; Perley, D. A.; Tendulkar, S. P.; Kasliwal, M. M.; Nugent, P. E.; Harris, C.; Gal-Yam, A.; Ofek, E. O.; Dennefeld, M.; Valenti, S.; Arcavi, I.; Banerjee, D. P. K.; Venkataraman, V.; Joshi, V.; Ashok, N. M.; Cenko, S. B.

    2014-01-01

    We report on the discovery of SN 2014J in the nearby galaxy M82. Given its proximity, it offers the best opportunity to date to study a thermonuclear supernova (SN) over a wide range of the electromagnetic spectrum. Optical, near-IR, and mid-IR observations on the rising light curve, orchestrated by the intermediate Palomar Transient Factory, show that SN 2014J is a spectroscopically normal Type Ia supernova (SN Ia), albeit exhibiting high-velocity features in its spectrum and heavily reddened by dust in the host galaxy. Our earliest detections start just hours after the fitted time of explosion. We use high-resolution optical spectroscopy to analyze the dense intervening material and do not detect any evolution in the resolved absorption features during the light curve rise. Similar to other highly reddened SNe Ia, a low value of total-to-selective extinction, R V ≲ 2, provides the best match to our observations. We also study pre-explosion optical and near-IR images from Hubble Space Telescope with special emphasis on the sources nearest to the SN location

  1. Gradients of stellar population properties and evolution clues in a nearby galaxy M101

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Lin; Kong, Xu; Lin, Xuanbin; Mao, Yewei; Cheng, Fuzhen [Center for Astrophysics, University of Science and Technology of China, Hefei 230026 (China); Zou, Hu; Jiang, Zhaoji; Zhou, Xu, E-mail: linlin@mail.ustc.edu.cn, E-mail: xkong@ustc.edu.cn, E-mail: zouhu@nao.cas.cn [National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)

    2013-06-01

    Multiband photometric images from ultraviolet and optical to infrared are collected to derive spatially resolved properties of the nearby Scd-type galaxy M101. With evolutionary stellar population synthesis models, two-dimensional distributions and radial profiles of age, metallicity, dust attenuation, and star formation timescale in the form of the Sandage star formation history are obtained. When fitting with the models, we use the IRX-A {sub FUV} relation, found to depend on a second parameter of birth rate b (ratio of present- and past-averaged star formation rates), to constrain the dust attenuation. There are obvious parameter gradients in the disk of M101, which supports the theory of an 'inside-out' disk growth scenario. Two distinct disk regions with different gradients of age and color are discovered, similar to another late-type galaxy, NGC 628. The metallicity gradient of the stellar content is flatter than that of H II regions. The stellar disk is optically thicker inside than outside and the global dust attenuation of this galaxy is lower compared with galaxies of similar and earlier morphological type. We note that a variational star formation timescale describes the real star formation history of a galaxy. The timescale increases steadily from the center to the outskirt. We also confirm that the bulge in this galaxy is a disk-like pseudobulge, whose evolution is likely to be induced by some secular processes of the small bar which is relatively young, metal-rich, and contains much dust.

  2. RUPRECHT 147: THE OLDEST NEARBY OPEN CLUSTER AS A NEW BENCHMARK FOR STELLAR ASTROPHYSICS

    International Nuclear Information System (INIS)

    Curtis, Jason L.; Wright, Jason T.; Wolfgang, Angie; Brewer, John M.; Johnson, John Asher

    2013-01-01

    Ruprecht 147 is a hitherto unappreciated open cluster that holds great promise as a standard in fundamental stellar astrophysics. We have conducted a radial velocity survey of astrometric candidates with Lick, Palomar, and MMT observatories and have identified over 100 members, including 5 blue stragglers, 11 red giants, and 5 double-lined spectroscopic binaries (SB2s). We estimate the cluster metallicity from spectroscopic analysis, using Spectroscopy Made Easy (SME), and find it to be [M/H] = +0.07 ± 0.03. We have obtained deep CFHT/MegaCam g'r'i'z' photometry and fit Padova isochrones to the (g' – i') and Two Micron All Sky Survey (J – K S ) color-magnitude diagrams, using the τ 2 maximum-likelihood procedure of Naylor, and an alternative method using two-dimensional cross-correlations developed in this work. We find best fits for Padova isochrones at age t = 2.5 ± 0.25 Gyr, m – M = 7.35 ± 0.1, and A V = 0.25 ± 0.05, with additional uncertainty from the unresolved binary population and possibility of differential extinction across this large cluster. The inferred age is heavily dependent on our choice of stellar evolution model: fitting Dartmouth and PARSEC models yield age parameters of 3 Gyr and 3.25 Gyr, respectively. At ∼300 pc and ∼3 Gyr, Ruprecht 147 is by far the oldest nearby star cluster.

  3. Probing the gas fuelling and outflows in nearby AGN with ALMA

    Science.gov (United States)

    Audibert, Anelise; Combes, Françoise; García-Burillo, Santiago; Salomé, Philippe

    2017-12-01

    Feeding and feedback in AGN play a very important role to gain a proper understanding of galaxy formation and evolution. The interaction between activity mechanisms in the nucleus and its influence in the host galaxy are related to the physical processes involved in feedback and the gas fuelling of the black hole. The discovery of many massive molecular outflows in the last few years have been promoting the idea that winds may be major actors in sweeping the gas out of galaxies. Also, the widely observed winds from the central regions of AGN are promising candidates to explain the scaling relations (e.g. the black hole-bulge mass relation, BH accretion rate tracking the star formation history) under the AGN feedback scenario. Out goal is to probe these phenomena through the kinematic and morphology of the gas inside the central kpc in nearby AGN. This has recently been possible due to the unprecedented ALMA spatial resolution and sensitivity. We present results on NGC7213 and NGC1808, the latter is part of a new ALMA follow-up of the NuGa project, a previous high-resolution (0.5-1”) CO survey of low luminosity AGN performed with the IRAM PdBI.

  4. Origins Space Telescope: Nearby Galaxies, the Milky Way, and the Interstellar Medium

    Science.gov (United States)

    Battersby, Cara; Sandstrom, Karin; Origins Space Telescope Science and Technology Definition Team

    2018-01-01

    The Origins Space Telescope (OST) is the mission concept for the Far-Infrared Surveyor, one of the four science and technology definition studies of NASA Headquarters for the 2020 Astronomy and Astrophysics Decadal survey. Origins will enable flagship-quality general observing programs led by the astronomical community in the 2030s. We welcome you to contact the Science and Technology Definition Team (STDT) with your science needs and ideas by emailing us at ost_info@lists.ipac.caltech.eduThis presentation will summarize the science case related to Nearby Galaxies, the Milky Way, and the Interstellar Medium (Interstellar Medium). The Origins Space Telescope will enable a wealth of unprecedented scientific advances in this area, both those we know to expect, and the discovery space that lies unexplored. Origins will enable a comprehensive view of magnetic fields, turbulence, and the multiphase ISM; connecting these physics across scales of galaxies to protostellar cores. With unprecedented sensitivity, Origins will measure and characterize the mechanisms of feedback from star formation and Active Galactic Nuclei, and their interplay, over cosmic time. Origins will unveil the abundance and availability of water for habitable planets by allowing us to trace the trail of water from interstellar clouds to protoplanetary disks, to Earth itself.

  5. Probing the Gas Fueling and Outflows in Nearby AGN with ALMA

    Directory of Open Access Journals (Sweden)

    Anelise Audibert

    2017-12-01

    Full Text Available Feeding and feedback in AGN play a very important role to gain a proper understanding of galaxy formation and evolution. The interaction between activity mechanisms in the nucleus and its influence in the host galaxy are related to the physical processes involved in feedback and the gas fueling of the black hole. The discovery of many massive molecular outflows in the last few years have been promoting the idea that winds may be major actors in sweeping the gas out of galaxies. Also, the widely observed winds from the central regions of AGN are promising candidates to explain the scaling relations (e.g., the black hole-bulge mass relation, BH accretion rate tracking the star formation history under the AGN feedback scenario. Out goal is to probe these phenomena through the kinematic and morphology of the gas inside the central kpc in nearby AGN. This has recently been possible due to the unprecedented ALMA spatial resolution and sensitivity. We present results on NGC7213 and NGC1808, the latter is part of a new ALMA follow-up of the NuGa project, a previous high-resolution (0.5–1″ CO survey of low luminosity AGN performed with the IRAM PdBI.

  6. Alma observations of nearby luminous infrared galaxies with various agn energetic contributions using dense gas tracers

    Energy Technology Data Exchange (ETDEWEB)

    Imanishi, Masatoshi [Subaru Telescope, 650 North A' ohoku Place, Hilo, HI 96720 (United States); Nakanishi, Kouichiro, E-mail: masa.imanishi@nao.ac.jp [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)

    2014-07-01

    We present the results of our ALMA Cycle 0 observations, using HCN/HCO{sup +}/HNC J = 4-3 lines, of six nearby luminous infrared galaxies with various energetic contributions from active galactic nuclei (AGNs) estimated from previous infrared spectroscopy. These lines are very effective for probing the physical properties of high-density molecular gas around the hidden energy sources in the nuclear regions of these galaxies. We find that HCN to HCO{sup +} J = 4-3 flux ratios tend to be higher in AGN-important galaxies than in starburst-dominated regions, as was seen at the J = 1-0 transition, while there is no clear difference in the HCN-to-HNC J = 4-3 flux ratios among observed sources. A galaxy with a starburst-type infrared spectral shape and very large molecular line widths shows a high HCN-to-HCO{sup +} J = 4-3 flux ratio, which could be due to turbulence-induced heating. We propose that enhanced HCN J = 4-3 emission relative to HCO{sup +} J = 4-3 could be used to detect more energetic activity than normal starbursts, including deeply buried AGNs, in dusty galaxy populations.

  7. The SAURON project : XIX. Optical and near-infrared scaling relations of nearby elliptical, lenticular and Sa galaxies

    NARCIS (Netherlands)

    Falcon-Barroso, J.; van de Ven, G.; Peletier, R. F.; Bureau, M.; Jeong, H.; Bacon, R.; Cappellari, M.; Davies, R. L.; de Zeeuw, P. T.; Emsellem, E.; Krajnovic, D.; Kuntschner, H.; McDermid, R. M.; Sarzi, M.; Shapiro, K. L.; van den Bosch, R.C.E.; van der Wolk, G.; Weijmans, A.; Yi, S.

    2011-01-01

    We present ground-based MDM Observatory V-band and Spitzer/InfraRed Array Camera 3.6-mu m-band photometric observations of the 72 representative galaxies of the SAURON survey. Galaxies in our sample probe the elliptical E, lenticular S0 and spiral Sa populations in the nearby Universe, both in field

  8. The SAURON project - XIX. Optical and near-infrared scaling relations of nearby elliptical, lenticular and Sa galaxies

    NARCIS (Netherlands)

    Falcón-Barroso, J.; van de Ven, G.; Peletier, R. F.; Bureau, M.; Jeong, H.; Bacon, R.; Cappellari, M.; Davies, R. L.; de Zeeuw, P. T.; Emsellem, E.; Krajnović, D.; Kuntschner, H.; McDermid, R. M.; Sarzi, M.; Shapiro, K. L.; van den Bosch, R. C. E.; van der Wolk, G.; Weijmans, A.; Yi, S.

    2011-01-01

    We present ground-based MDM Observatory V-band and Spitzer/InfraRed Array Camera 3.6-?m-band photometric observations of the 72 representative galaxies of the SAURON survey. Galaxies in our sample probe the elliptical E, lenticular S0 and spiral Sa populations in the nearby Universe, both in field

  9. Overview of the SDSS-IV MaNGA Survey: Mapping nearby Galaxies at Apache Point Observatory

    NARCIS (Netherlands)

    Bundy, Kevin; Bershady, Matthew A.; Law, David R.; Yan, Renbin; Drory, Niv; MacDonald, Nicholas; Wake, David A.; Cherinka, Brian; Sánchez-Gallego, José R.; Weijmans, Anne-Marie; Thomas, Daniel; Tremonti, Christy; Masters, Karen; Coccato, Lodovico; Diamond-Stanic, Aleksandar M.; Aragón-Salamanca, Alfonso; Avila-Reese, Vladimir; Badenes, Carles; Falcón-Barroso, Jésus; Belfiore, Francesco; Bizyaev, Dmitry; Blanc, Guillermo A.; Bland-Hawthorn, Joss; Blanton, Michael R.; Brownstein, Joel R.; Byler, Nell; Cappellari, Michele; Conroy, Charlie; Dutton, Aaron A.; Emsellem, Eric; Etherington, James; Frinchaboy, Peter M.; Fu, Hai; Gunn, James E.; Harding, Paul; Johnston, Evelyn J.; Kauffmann, Guinevere; Kinemuchi, Karen; Klaene, Mark A.; Knapen, Johan H.; Leauthaud, Alexie; Li, Cheng; Lin, Lihwai; Maiolino, Roberto; Malanushenko, Viktor; Malanushenko, Elena; Mao, Shude; Maraston, Claudia; McDermid, Richard M.; Merrifield, Michael R.; Nichol, Robert C.; Oravetz, Daniel; Pan, Kaike; Parejko, John K.; Sanchez, Sebastian F.; Schlegel, David; Simmons, Audrey; Steele, Oliver; Steinmetz, Matthias; Thanjavur, Karun; Thompson, Benjamin A.; Tinker, Jeremy L.; van den Bosch, Remco C. E.; Westfall, Kyle B.; Wilkinson, David; Wright, Shelley; Xiao, Ting; Zhang, Kai

    We present an overview of a new integral field spectroscopic survey called MaNGA (Mapping Nearby Galaxies at Apache Point Observatory), one of three core programs in the fourth-generation Sloan Digital Sky Survey (SDSS-IV) that began on 2014 July 1. MaNGA will investigate the internal kinematic

  10. North-south interdependence

    Energy Technology Data Exchange (ETDEWEB)

    Norse, D

    1979-01-01

    The sound eco-development of agriculture can help to establish a cooperative and harmonious north-south interdependence. The interdependence pattern is seen when the major agricultural suppliers (energy, fertilizers, and pesticides) are examined in the context of commodity transfers of grain and rubber. The consumers of either the north or south would be unable to find alternative sources without major production or social disruption. The Organization of Economic Co-operation and Development (OECD) INTERFUTURES study examines the chain of dependencies between raw materials and markets and the implications for economic development, employment, and environmental hazards. If interdependence is to benefit both the north and the south, technological fixes will not be adequate or appropriate to deal with the potential hazards. (DCK)

  11. North Korea, Quo Vadis?

    Directory of Open Access Journals (Sweden)

    Karl H. Stingeder

    2014-03-01

    Full Text Available North Korean politics appears neither irrational nor unpredictable: the logic of its actions may at first seem opaque, but it nonetheless displays its own rationale and patterns. – North Korea: a ruthless political actor, now under the leadership of Kim Jong-Un who inherited the regime’s leadership from his father and "Supreme Leader", Kim Jong-Il, in 2011. The country’s policy is based on its ongoing political agenda of (nuclear brinkmanship, a true threat to the world – or at least that's how the Western hemisphere sees it. Yet our factual knowledge of this post-Leninist and totalitarian regime is extremely limited and relatively distorted; it is largely circumstantial evidence and judgmental speculation that accounts for our perception of this East Asian state. Northeast Asia (China, Japan, South and North Korea, Taiwan is a region dominated by the legacy of the Cold War. The North Korean leadership has indeed established its priorities, primarily its isolationist orientation, but in the long term the regime cannot survive without external stimulus. Most importantly, even in a long-term, non-violent and gradual transformation of North Korea considerable danger can ultimately result in the demise of the regime. Apart from few signs of a North Korean "civil society", currently only the army might have the resources to see through a regime change. In the meantime, the strategies of isolationism as well as tight control of the media remain as fundamental cornerstones of the regime. A close-knit network of social control has been established and access to the internet for the most part is limited to the regime’s entrusted cadre.

  12. Astronomers See First Stages of Planet-Building Around Nearby Star

    Science.gov (United States)

    2005-06-01

    about the same size are present," Claussen said. Not only does TW Hydrae show evidence of ongoing planet formation, it also shows signs that at least one giant planet may have formed already. Wilner's colleague, Nuria Calvet (CfA), has created a computer simulation of the disk around TW Hydrae using previously published infrared observations. She showed that a gap extends from the star out to a distance of about 400 million miles - similar to the distance to the asteroid belt in our solar system. The gap likely formed when a giant planet sucked up all the nearby material, leaving a hole in the middle of the disk. Located about 180 light-years away in the constellation Hydra the Water Snake, TW Hydrae consists of a 10 million-year-old star about four-fifths as massive as the Sun. The protoplanetary disk surrounding TW Hydrae contains about one-tenth as much material as the Sun -- more than enough to form one or more Jupiter-sized worlds. "TW Hydrae is unique," said Wilner. "It's nearby, and it's just the right age to be forming planets. We'll be studying it for decades to come." This research was published in the June 20, 2005, issue of the Astrophysical Journal Letters. Headquartered in Cambridge, Mass., the Harvard-Smithsonian Center for Astrophysics (CfA) is a joint collaboration between the Smithsonian Astrophysical Observatory and the Harvard College Observatory. CfA scientists, organized into six research divisions, study the origin, evolution and ultimate fate of the universe. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

  13. North American refining

    International Nuclear Information System (INIS)

    Osten, James; Haltmaier, Susan

    2000-01-01

    This article examines the current status of the North American refining industry, and considers the North American economy and the growth in demand in the petroleum industry, petroleum product demand and quality, crude oil upgrading to meet product standards, and changes in crude oil feedstocks such as the use of heavier crudes and bitumens. Refining expansion, the declining profits in refining, and changes due to environmental standards are discussed. The Gross Domestic Product and oil demand for the USA, Canada, Mexico, and Venezuela for the years 1995-2020 are tabulated

  14. Wide cool and ultracool companions to nearby stars from Pan-STARRS 1

    International Nuclear Information System (INIS)

    Deacon, Niall R.; Liu, Michael C.; Magnier, Eugene A.; Aller, Kimberly M.; Best, William M. J.; Bowler, Brendan P.; Burgett, William S.; Chambers, Kenneth C.; Flewelling, H.; Kaiser, Nick; Kudritzki, Rolf-Peter; Morgan, Jeff S.; Tonry, John L.; Dupuy, Trent; Mann, Andrew W.; Redstone, Joshua A.; Draper, Peter W.; Metcalfe, Nigel; Hodapp, Klaus W.; Price, Paul A.

    2014-01-01

    We present the discovery of 57 wide (>5'') separation, low-mass (stellar and substellar) companions to stars in the solar neighborhood identified from Pan-STARRS 1 (PS1) data and the spectral classification of 31 previously known companions. Our companions represent a selective subsample of promising candidates and span a range in spectral type of K7-L9 with the addition of one DA white dwarf. These were identified primarily from a dedicated common proper motion search around nearby stars, along with a few as serendipitous discoveries from our Pan-STARRS 1 brown dwarf search. Our discoveries include 23 new L dwarf companions and one known L dwarf not previously identified as a companion. The primary stars around which we searched for companions come from a list of bright stars with well-measured parallaxes and large proper motions from the Hipparcos catalog (8583 stars, mostly A-K dwarfs) and fainter stars from other proper motion catalogs (79170 stars, mostly M dwarfs). We examine the likelihood that our companions are chance alignments between unrelated stars and conclude that this is unlikely for the majority of the objects that we have followed-up spectroscopically. We also examine the entire population of ultracool (>M7) dwarf companions and conclude that while some are loosely bound, most are unlikely to be disrupted over the course of ∼10 Gyr. Our search increases the number of ultracool M dwarf companions wider than 300 AU by 88% and increases the number of L dwarf companions in the same separation range by 82%. Finally, we resolve our new L dwarf companion to HIP 6407 into a tight (0.''13, 7.4 AU) L1+T3 binary, making the system a hierarchical triple. Our search for these key benchmarks against which brown dwarf and exoplanet atmosphere models are tested has yielded the largest number of discoveries to date.

  15. In situ measurements of rock salt permeability changes due to nearby excavation

    International Nuclear Information System (INIS)

    Stormont, J.C.; Howard, C.L.; Daemen, J.J.K.

    1991-07-01

    The Small-Scale Mine-By was an in situ experiment to measure changes in brine and gas permeability of rock salt as a result of nearby excavation. A series of small-volume pressurized brine- and gas-filled test intervals were established 8 m beneath the floor of Room L1 in the WIPP underground. The test intervals were isolated in the bottom of the 4.8-cm diameter monitoring boreholes with inflatable rubber packers, and are initially pressurized to about 2 MPa. Both brine- and gas-filled test intervals were located 1.25, 1.5, 2, 3, and 4 r from the center of a planned large-diameter hole, where r is the radius of the large-diameter hole. Prior to the drilling of the large-diameter borehole, the responses of both the brine- and gas-filled test intervals were consistent with the formation modeled as a very low permeability, low porosity porous medium with a significant pore (brine) pressure and no measurable gas permeability. The drilling of the mine-by borehole created a zone of dilated, partially saturated rock out to about 1.5 r. The formation pressure increases from near zero at 1.5 r to the pre-excavation value at 4 r. Injection tests reveal a gradient of brine permeabilities from 5 x 10 -18 m 2 at 1.25 r to about the pre-excavation value (10 -21 m 2 ) by 3 r. Gas-injection tests reveal measurable gas permeability is limited to within 1.5 r. 17 refs., 24 figs., 6 tabs

  16. THE ACS NEARBY GALAXY SURVEY TREASURY. XI. THE REMARKABLY UNDISTURBED NGC 2403 DISK

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Benjamin F.; Dalcanton, Julianne J.; Stilp, Adrienne; Radburn-Smith, David [Department of Astronomy, Box 351580, University of Washington, Seattle, WA 98195 (United States); Dolphin, Andrew [Raytheon, 1151 E. Hermans Road, Tucson, AZ 85706 (United States); Skillman, Evan D., E-mail: ben@astro.washington.edu, E-mail: jd@astro.washington.edu, E-mail: adrienne@astro.washington.edu, E-mail: dolphin@raytheon.com, E-mail: skillman@astro.umn.edu [Department of Astronomy, University of Minnesota, 116 Church St. SE, Minneapolis, MN 55455 (United States)

    2013-03-10

    We present detailed analysis of color-magnitude diagrams of NGC 2403, obtained from a deep (m {approx}< 28) Hubble Space Telescope (HST) Wide Field Planetary Camera 2 observation of the outer disk of NGC 2403, supplemented by several shallow (m {approx}< 26) HST Advanced Camera for Surveys fields. We derive the spatially resolved star formation history of NGC 2403 out to 11 disk scale lengths. In the inner portions of the galaxy, we compare the recent star formation rates (SFRs) we derive from the resolved stars with those measured using GALEX FUV + Spitzer 24{mu} fluxes, finding excellent agreement between the methods. Our measurements also show that the radial gradient in recent SFR mirrors the disk exponential profile to 11 scale lengths with no break, extending to SFR densities a factor of {approx}100 lower than those that can be measured with GALEX and Spitzer ({approx}2 Multiplication-Sign 10{sup -6} M{sub Sun} yr{sup -1} kpc{sup -2}). Furthermore, we find that the cumulative stellar mass of the disk was formed at similar times at all radii. We compare these characteristics of NGC 2403 to those of its ''morphological twins'', NGC 300 and M 33, showing that the structure and age distributions of the NGC 2403 disk are more similar to those of the relatively isolated system NGC 300 than to those of the Local Group analog M 33. We also discuss the environments and HI morphologies of these three nearby galaxies, comparing them to integrated light studies of larger samples of more distant galaxy disks. Taken together, the physical properties and evolutionary history of NGC 2403 suggest that the galaxy has had no close encounters with other M 81 group members and may be falling into the group for the first time.

  17. CONSTRAINTS ON PLANET OCCURRENCE AROUND NEARBY MID-TO-LATE M DWARFS FROM THE MEARTH PROJECT

    International Nuclear Information System (INIS)

    Berta, Zachory K.; Irwin, Jonathan; Charbonneau, David

    2013-01-01

    The MEarth Project is a ground-based photometric survey intended to find planets transiting the closest and smallest main-sequence stars. In its first four years, MEarth discovered one transiting exoplanet, the 2.7 R ⊕ planet GJ1214b. Here, we answer an outstanding question: in light of the bounty of small planets transiting small stars uncovered by the Kepler mission, should MEarth have found more than just one planet so far? We estimate MEarth's ensemble sensitivity to exoplanets by performing end-to-end simulations of 1.25 × 10 6 observations of 988 nearby mid-to-late M dwarfs, gathered by MEarth between 2008 October and 2012 June. For 2-4 R ⊕ planets, we compare this sensitivity to results from Kepler and find that MEarth should have found planets at a rate of 0.05-0.36 planets yr –1 in its first four years. As part of this analysis, we provide new analytic fits to the Kepler early M dwarf planet occurrence distribution. When extrapolating between Kepler's early M dwarfs and MEarth's mid-to-late M dwarfs, we find that assuming the planet occurrence distribution stays fixed with respect to planetary equilibrium temperature provides a good match to our detection of a planet with GJ1214b's observed properties. For larger planets, we find that the warm (600-700 K), Neptune-sized (4 R ⊕ ) exoplanets that transit early M dwarfs like Gl436 and GJ3470 occur at a rate of –1 (at 95% confidence) around MEarth's later M dwarf targets. We describe a strategy with which MEarth can increase its expected planet yield by 2.5 × without new telescopes by shifting its sensitivity toward the smaller and cooler exoplanets that Kepler has demonstrated to be abundant

  18. Degradation of some ceria electrolytes under hydrogen contact nearby anode in solid oxide fuel cells (SOFCs

    Directory of Open Access Journals (Sweden)

    Malta Luiz Fernando Brum

    2004-01-01

    Full Text Available This work is concerned with thermodynamic analysis of the stability of some ceria electrolytes under contact with hydrogen gas nearby anode in fuel cells. It was considered the following types of ceria-electrolytes: pure ceria, strontium-doped ceria, calcium-doped ceria and calcium-bismuth-doped ceria. The equilibrium Log (pH2O/pH2 vs. T diagrams were constructed for x = 0.1 and 0.01, where x is the fraction of initial ceria converted to Ce2O3 (proportional to the ratio between activities of Ce3+ and Ce4+ in the ceria electrolyte, which is proportional to the fraction of electronic conduction in the electrolyte at a given temperature. The predictions of the diagrams are as follows: (a Ce1.9Ca0.1Bi0.8O5.1 and Ce0.9Sr0.1O1.9 are less stable than pure ceria for the whole temperature range (from 0 to 1000 °C; (b Ce0.9Ca0.1O1.9 is more stable than pure ceria below about 650 °C for x = 0.1 and below about 400 °C for x = 0.01; (c at each temperature in the considered range the pressure ratio pH2O(g/pH2(g has to be higher than thermodynamically predicted in order to keep CeO2 stable in the electrolyte contacting hydrogen gas. Thermodynamic predictions are entirely capable of explaining experimental data published on the subject (irreversible cell degradation in the case of SrO-doped ceria; weight loss from doped-ceria electrolyte above 700 °C; oxygen gas release during sintering of ceria.

  19. OPTICAL MONITORING OF TWO BRIGHTEST NEARBY QUASARS, PHL 1811 AND 3C 273

    International Nuclear Information System (INIS)

    Fan, J. H.; Liu, Y.; Yuan, Y. H.; Kurtanidze, O.; Chanishvili, R.; Richter, G. M.

    2014-01-01

    Variability is one of the most observable characteristics of active galactic nuclei, and it is important when considering the emission mechanism. In this paper, we report optical photometry monitoring of two nearby brightest quasars, PHL 1811 and 3C 273, using the ST-6 camera attached to the Newtonian focus and the Ap6E CCD camera attached to the primary focus of the 70 cm meniscus telescope at the Abastumani Observatory, Georgia. PHL 1811 was monitored during the period from 2002 September to 2012 December, while 3C 273 was monitored during the period from 1998 February to 2008 May. During our monitoring period, the two sources did not show any significant intra-day variability. The largest detected variations are ΔR = 0.112 ± 0.010 mag. for PHL 1811, ΔB = 0.595 ± 0.099 mag, ΔV = 0.369 ± 0.028 mag, ΔR = 0.495 ± 0.076 mag, and ΔI = 0.355 ± 0.009 mag for 3C 273. When the periodicity analysis methods are adopted for the observations of the sources, a period of p = 5.80 ± 1.12 yr is obtained for PHL 1811 in the R light curve in the present work, and periods of p = 21.10 ± 0.14, 10.00 ± 0.14, 7.30 ± 0.09, 13.20 ± 0.09, 2.10 ± 0.06, and 0.68 ± 0.05 yr are obtained for 3C 273 based on the data in the present work combined with historical works

  20. OPTICAL MONITORING OF TWO BRIGHTEST NEARBY QUASARS, PHL 1811 AND 3C 273

    Energy Technology Data Exchange (ETDEWEB)

    Fan, J. H.; Liu, Y.; Yuan, Y. H. [Center for Astrophysics, Guangzhou University, Guangzhou 510006 (China); Kurtanidze, O.; Chanishvili, R. [Abastumani Observatory, Mt. Kanobili, 0301 Abastumani, Georgia (United States); Richter, G. M. [Astrophysikalisches Institut Potsdam, An der Sternwarte 16, D-14482 Potsdam (Germany)

    2014-08-01

    Variability is one of the most observable characteristics of active galactic nuclei, and it is important when considering the emission mechanism. In this paper, we report optical photometry monitoring of two nearby brightest quasars, PHL 1811 and 3C 273, using the ST-6 camera attached to the Newtonian focus and the Ap6E CCD camera attached to the primary focus of the 70 cm meniscus telescope at the Abastumani Observatory, Georgia. PHL 1811 was monitored during the period from 2002 September to 2012 December, while 3C 273 was monitored during the period from 1998 February to 2008 May. During our monitoring period, the two sources did not show any significant intra-day variability. The largest detected variations are ΔR = 0.112 ± 0.010 mag. for PHL 1811, ΔB = 0.595 ± 0.099 mag, ΔV = 0.369 ± 0.028 mag, ΔR = 0.495 ± 0.076 mag, and ΔI = 0.355 ± 0.009 mag for 3C 273. When the periodicity analysis methods are adopted for the observations of the sources, a period of p = 5.80 ± 1.12 yr is obtained for PHL 1811 in the R light curve in the present work, and periods of p = 21.10 ± 0.14, 10.00 ± 0.14, 7.30 ± 0.09, 13.20 ± 0.09, 2.10 ± 0.06, and 0.68 ± 0.05 yr are obtained for 3C 273 based on the data in the present work combined with historical works.

  1. Radio haloes in nearby galaxies modelled with 1D cosmic ray transport using SPINNAKER

    Science.gov (United States)

    Heesen, V.; Krause, M.; Beck, R.; Adebahr, B.; Bomans, D. J.; Carretti, E.; Dumke, M.; Heald, G.; Irwin, J.; Koribalski, B. S.; Mulcahy, D. D.; Westmeier, T.; Dettmar, R.-J.

    2018-05-01

    We present radio continuum maps of 12 nearby (D ≤ 27 Mpc), edge-on (i ≥ 76°), late-type spiral galaxies mostly at 1.4 and 5 GHz, observed with the Australia Telescope Compact Array, Very Large Array, Westerbork Synthesis Radio Telescope, Effelsberg 100-m, and Parkes 64-m telescopes. All galaxies show clear evidence of radio haloes, including the first detection in the Magellanic-type galaxy NGC 55. In 11 galaxies, we find a thin and a thick disc that can be better fitted by exponential rather than Gaussian functions. We fit our SPINNAKER (SPectral INdex Numerical Analysis of K(c)osmic-ray Electron Radio-emission) 1D cosmic ray transport models to the vertical model profiles of the non-thermal intensity and to the non-thermal radio spectral index in the halo. We simultaneously fit for the advection speed (or diffusion coefficient) and magnetic field scale height. In the thick disc, the magnetic field scale heights range from 2 to 8 kpc with an average across the sample of 3.0 ± 1.7 kpc; they show no correlation with either star formation rate (SFR), SFR surface density (ΣSFR), or rotation speed (Vrot). The advection speeds range from 100 to 700 km s - 1 and display correlations of V∝SFR0.36 ± 0.06 and V∝ Σ _SFR^{0.39± 0.09}; they agree remarkably well with the escape velocities (0.5 ≤ V/Vesc ≤ 2), which can be explained by cosmic ray-driven winds. Radio haloes show the presence of disc winds in galaxies with ΣSFR > 10 - 3 M⊙ yr - 1 kpc - 2 that extend over several kpc and are driven by processes related to the distributed star formation in the disc.

  2. Measurement of ground and nearby building vibration and noise induced by trains in a metro depot.

    Science.gov (United States)

    Zou, Chao; Wang, Yimin; Wang, Peng; Guo, Jixing

    2015-12-01

    Metro depots are where subway trains are parked and where maintenance is carried out. They usually occupy the largest ground areas in metro projects. Due to land utilization problems, Chinese cities have begun to develop over-track buildings above metro depots for people's life and work. The frequently moving trains, when going into and out of metro depots, can cause excessive vibration and noise to over-track buildings and adversely affect the living quality of the building occupants. Considering the current need of reliable experimental data for the construction of metro depots, field measurements of vibration and noise on the ground and inside a nearby 3-story building subjected to moving subway trains were conducted in a metro depot at Guangzhou, China. The amplitudes and frequency contents of velocity levels were quantified and compared. The composite A-weighted equivalent sound levels and maximum sound levels were captured. The predicted models for vibration and noise of metro depot were proposed based on existing models and verified. It was found that the vertical vibrations were significantly greater than the horizontal vibrations on the ground and inside the building near the testing line. While at the throat area, the horizontal vibrations near the curved track were remarkably greater than the vertical vibrations. The attenuation of the vibrations with frequencies above 50 Hz was larger than the ones below 50 Hz, and the frequencies of vibration transmitting to adjacent buildings were mainly within 10-50 Hz. The largest equivalent sound level generated in the throat area was smaller than the testing line one, but the instantaneous maximum sound level induced by wheels squeal, contact between wheels and rail joints as well as turnout was close to or even greater than the testing line one. The predicted models gave a first estimation for design and assessment of newly built metro depots. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Geology of the Nevada Test Site and nearby areas, southern Nevada

    International Nuclear Information System (INIS)

    Sinnock, S.

    1982-10-01

    The Department of Energy's Nevada Test Site (NTS) lies in the southern part of the Great Basin Section of the Basin and Range Physiographic Province. This report addresses the geological setting of the NTS in the context of the current waste isolation policy. The intent is to provide a synthesis of geological conditions at the NTS and nearby areas so that a general background of information is available for assessing the possible role of geology in providing protections for humans from buried radioactive wastes. The NTS is characterized by alluvium-filled, topgraphically closed valleys surrounded by ranges composed of Paleozoic sedimentary rocks and Tertiary volcanic tuffs and lavas. The Paleozoic rocks are a miogeosynclinal sequence of about 13,000 ft of pre-Cambrian to Cambrian clastic deposits (predominantly quartzites) overlain by about 14,000 ft of Cambrian through Devonian carbonates, 8000 ft of Mississippian argillites and quartzites, and 3000 ft of Pennsylvanian to Permian limestones. Tertiary volcanic rocks are predominatly silicic composition and were extruded from numerous eruptive centers during Miocene and Pliocene epochs. Within eruptive caldera depressions, volcanic deposits accumulated to perhaps 10,000 ft in total thickness, thinning to extinction outward from the calderas. Extrusion of minor amounts of basalts accompanied Pliocene and Pleistocene filling of structural basins with detritus from the ranges. Regional compressional and extensional structures as well as local volcanic structures occur in the NTS region. Normal extensional faulting coincided with the outbreak of volcanism during the Miocene and was superimposed on existing Mesozoic structures. Continued extensional deformation may be occurring at the present time

  4. Exploring the Dust Content of Galactic Winds with Herschel. II. Nearby Dwarf Galaxies*

    Science.gov (United States)

    McCormick, Alexander; Veilleux, Sylvain; Meléndez, Marcio; Martin, Crystal L.; Bland-Hawthorn, Joss; Cecil, Gerald; Heitsch, Fabian; Müller, Thomas; Rupke, David S. N.; Engelbracht, Chad

    2018-03-01

    We present results from analysis of deep Herschel Space Observatory observations of six nearby dwarf galaxies known to host galactic-scale winds. The superior far-infrared sensitivity and angular resolution of Herschel have allowed detection of cold circumgalactic dust features beyond the stellar components of the host galaxies traced by Spitzer 4.5 μm images. Comparisons of these cold dust features with ancillary data reveal an imperfect spatial correlation with the ionized gas and warm dust wind components. We find that typically ˜10-20% of the total dust mass in these galaxies resides outside of their stellar disks, but this fraction reaches ˜60% in the case of NGC 1569. This galaxy also has the largest metallicity (O/H) deficit in our sample for its stellar mass. Overall, the small number of objects in our sample precludes drawing strong conclusions on the origin of the circumgalactic dust. We detect no statistically significant trends with star formation properties of the host galaxies, as might be expected if the dust were lifted above the disk by energy inputs from on-going star formation activity. Although a case for dust entrained in a galactic wind is seen in NGC 1569, in all cases, we cannot rule out the possibility that some of the circumgalactic dust might be associated instead with gas accreted or removed from the disk by recent galaxy interaction events, or that it is part of the outer gas-rich portion of the disk that lies below the sensitivity limit of the Spitzer 4.5 μm data.

  5. REVISED MASS-TO-LIGHT RATIOS FOR NEARBY GALAXY GROUPS AND CLUSTERS

    International Nuclear Information System (INIS)

    Shan, Yutong; Courteau, Stéphane; McDonald, Michael

    2015-01-01

    We present a detailed investigation of the cluster stellar mass-to-light (M*/L) ratio and cumulative stellar masses, derived on a galaxy-by-galaxy basis, for 12 massive (M 500 ∼ 10 14 -10 15 M ☉ ), nearby clusters with available optical imaging data from the Sloan Digital Sky Survey Data Release 10 and X-ray data from the Chandra X-ray Observatory. Our method involves a statistical cluster membership using both photometric and spectroscopic redshifts when available to maximize completeness while minimizing contamination effects. We show that different methods of estimating the stellar mass-to-light ratio from observed photometry result in systematic discrepancies in the total stellar masses and average mass-to-light ratios of cluster galaxies. Nonetheless, all conversion methodologies point to a lack of correlation between M*/L i and total cluster mass, even though low-mass groups contain relatively more blue galaxies. We also find no statistically significant correlation between M*/L i and the fraction of blue galaxies (g – i < 0.85). For the mass range covered by our sample, the assumption of a Chabrier initial mass function (IMF) yields an integrated M*/L i ≅ 1.7 ± 0.2 M ☉ /L i, ☉ , a lower value than used in most similar studies, though consistent with the study of low-mass galaxy groups by Leauthaud et al. A light (diet) Salpeter IMF would imply a ∼60% increase in M*/L i

  6. Exploring the dust content of galactic winds with Herschel - II. Nearby dwarf galaxies

    Science.gov (United States)

    McCormick, Alexander; Veilleux, Sylvain; Meléndez, Marcio; Martin, Crystal L.; Bland-Hawthorn, Joss; Cecil, Gerald; Heitsch, Fabian; Müller, Thomas; Rupke, David S. N.; Engelbracht, Chad

    2018-06-01

    We present the results from an analysis of deep Herschel Space Observatory observations of six nearby dwarf galaxies known to host galactic-scale winds. The superior far-infrared sensitivity and angular resolution of Herschel have allowed detection of cold circumgalactic dust features beyond the stellar components of the host galaxies traced by Spitzer 4.5 μm images. Comparisons of these cold dust features with ancillary data reveal an imperfect spatial correlation with the ionized gas and warm dust wind components. We find that typically ˜10-20 per cent of the total dust mass in these galaxies resides outside of their stellar discs, but this fraction reaches ˜60 per cent in the case of NGC 1569. This galaxy also has the largest metallicity (O/H) deficit in our sample for its stellar mass. Overall, the small number of objects in our sample precludes drawing strong conclusions on the origin of the circumgalactic dust. We detect no statistically significant trends with star formation properties of the host galaxies, as might be expected if the dust were lifted above the disc by energy inputs from ongoing star formation activity. Although a case for dust entrained in a galactic wind is seen in NGC 1569, in all cases, we cannot rule out the possibility that some of the circumgalactic dust might be associated instead with gas accreted or removed from the disc by recent galaxy interaction events, or that it is part of the outer gas-rich portion of the disc that lies below the sensitivity limit of the Spitzer 4.5 μm data.

  7. THE H α EMISSION OF NEARBY M DWARFS AND ITS RELATION TO STELLAR ROTATION

    Energy Technology Data Exchange (ETDEWEB)

    Newton, Elisabeth R.; Irwin, Jonathan; Charbonneau, David; Berlind, Perry; Calkins, Michael L.; Mink, Jessica [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

    2017-01-01

    The high-energy emission from low-mass stars is mediated by the magnetic dynamo. Although the mechanisms by which fully convective stars generate large-scale magnetic fields are not well understood, it is clear that, as for solar-type stars, stellar rotation plays a pivotal role. We present 270 new optical spectra of low-mass stars in the Solar Neighborhood. Combining our observations with those from the literature, our sample comprises 2202 measurements or non-detections of H α emission in nearby M dwarfs. This includes 466 with photometric rotation periods. Stars with masses between 0.1 and 0.6 M {sub ⊙} are well-represented in our sample, with fast and slow rotators of all masses. We observe a threshold in the mass–period plane that separates active and inactive M dwarfs. The threshold coincides with the fast-period edge of the slowly rotating population, at approximately the rotation period at which an era of rapid rotational evolution appears to cease. The well-defined active/inactive boundary indicates that H α activity is a useful diagnostic for stellar rotation period, e.g., for target selection for exoplanet surveys, and we present a mass-period relation for inactive M dwarfs. We also find a significant, moderate correlation between L{sub Hα} / L{sub bol} and variability amplitude: more active stars display higher levels of photometric variability. Consistent with previous work, our data show that rapid rotators maintain a saturated value of L{sub Hα} / L {sub bol}. Our data also show a clear power-law decay in L{sub Hα} / L{sub bol} with Rossby number for slow rotators, with an index of −1.7 ± 0.1.

  8. THE STAR CLUSTER SYSTEM IN THE NEARBY STARBURST GALAXY M82

    International Nuclear Information System (INIS)

    Lim, Sungsoon; Lee, Myung Gyoon; Hwang, Narae

    2013-01-01

    We present a photometric study of star clusters in the nearby starburst galaxy M82 based on the UBVI-, YJ- and H-band Hubble Space Telescope images. We find 1105 star clusters with V 0 ≈ 0.45, and a weaker red population. The luminosity function of the disk clusters shows a power-law distribution with a power-law index α = –2.04 ± 0.03, and the scale height of their distribution is h z = 9.''64 ± 0.''40 (164 ± 7 pc), similar to that of the stellar thin disk of M82. We have derived the ages of ∼630 star clusters using the spectral energy distribution fit method by comparing UBVI(YJ)H-band photometric data with the simple stellar population models. The age distribution of the disk clusters shows that the most dominant cluster population has ages ranging from 100 Myr to 1 Gyr, with a peak at about 500 Myr. This suggests that M82 has undergone a disk-wide star formation about 500 Myr ago, probably through the interaction with M81. The brightest star clusters in the nuclear region are much brighter than those in other regions, indicating that more massive star clusters are formed in the denser environments. On the other hand, the colors of the halo clusters are similar to those of globular clusters in the Milky Way, and their ages are estimated to be older than 1 Gyr. These are probably genuine old globular clusters in M82.

  9. RUPRECHT 147: THE OLDEST NEARBY OPEN CLUSTER AS A NEW BENCHMARK FOR STELLAR ASTROPHYSICS

    Energy Technology Data Exchange (ETDEWEB)

    Curtis, Jason L.; Wright, Jason T. [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); Wolfgang, Angie [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Brewer, John M. [Department of Astronomy, Yale University, New Haven, CT 06511 (United States); Johnson, John Asher, E-mail: jcurtis@psu.edu [Department of Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States)

    2013-05-15

    Ruprecht 147 is a hitherto unappreciated open cluster that holds great promise as a standard in fundamental stellar astrophysics. We have conducted a radial velocity survey of astrometric candidates with Lick, Palomar, and MMT observatories and have identified over 100 members, including 5 blue stragglers, 11 red giants, and 5 double-lined spectroscopic binaries (SB2s). We estimate the cluster metallicity from spectroscopic analysis, using Spectroscopy Made Easy (SME), and find it to be [M/H] = +0.07 {+-} 0.03. We have obtained deep CFHT/MegaCam g'r'i'z' photometry and fit Padova isochrones to the (g' - i') and Two Micron All Sky Survey (J - K{sub S} ) color-magnitude diagrams, using the {tau}{sup 2} maximum-likelihood procedure of Naylor, and an alternative method using two-dimensional cross-correlations developed in this work. We find best fits for Padova isochrones at age t = 2.5 {+-} 0.25 Gyr, m - M = 7.35 {+-} 0.1, and A{sub V} = 0.25 {+-} 0.05, with additional uncertainty from the unresolved binary population and possibility of differential extinction across this large cluster. The inferred age is heavily dependent on our choice of stellar evolution model: fitting Dartmouth and PARSEC models yield age parameters of 3 Gyr and 3.25 Gyr, respectively. At {approx}300 pc and {approx}3 Gyr, Ruprecht 147 is by far the oldest nearby star cluster.

  10. CHANG-ES - XI. Circular polarization in the cores of nearby galaxies

    Science.gov (United States)

    Irwin, Judith A.; Henriksen, Richard N.; WeŻgowiec, Marek; Damas-Segovia, Ancor; Wang, Q. Daniel; Krause, Marita; Heald, George; Dettmar, Ralf-Jürgen; Li, Jiang-Tao; Wiegert, Theresa; Stein, Yelena; Braun, Timothy T.; Im, Jisung; Schmidt, Philip; Macdonald, Scott; Miskolczi, Arpad; Merritt, Alison; Mora-Partiarroyo, S. C.; Saikia, D. J.; Sotomayor, Carlos; Yang, Yang

    2018-06-01

    We detect five galaxies in the Continuum Halos in Nearby Galaxies - an EVLA Survey (CHANG-ES) sample that show circular polarization (CP) at L band in our high-resolution data sets. Two of the galaxies (NGC 4388 and NGC 4845) show strong Stokes V/I ≡ mC ˜ 2 per cent, two (NGC 660 and NGC 3628) have values of mC ˜ 0.3 per cent, and NGC 3079 is a marginal detection at mC ˜ 0.2 per cent. The two strongest mC galaxies also have the most luminous X-ray cores and the strongest internal absorption in X-rays. We have expanded on our previous Faraday conversion interpretation and analysis and provide analytical expressions for the expected V signal for a general case in which the cosmic ray (CR) electron energy spectral index can take on any value. We provide examples as to how such expressions could be used to estimate magnetic field strengths and the lower energy cut-off for CR electrons. Four of our detections are resolved, showing unique structures, including a jet in NGC 4388 and a CP `conversion disc' in NGC 4845. The conversion disc is inclined to the galactic disc but is perpendicular to a possible outflow direction. Such CP structures have never before been seen in any galaxy to our knowledge. None of the galaxy cores show linear polarization at L band. Thus radio CP may provide a unique probe of the physical conditions in the cores of active galactic nuclei.

  11. Probing dark matter decay and annihilation with Fermi LAT observations of nearby galaxy clusters

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Xiaoyuan [Chinese Academy of Sciences, Beijing (China). National Astronomical Observatories; Max-Planck-Institut fuer Physik, Muenchen (Germany); Vertongen, Gilles [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Institut d' Astrophysique de Paris, 75 - Paris (France); Weniger, Christoph [Max-Planck-Institut fuer Physik, Muenchen (Germany)

    2011-09-15

    Galaxy clusters are promising targets for indirect dark matter searches. Gamma-ray signatures from the decay or annihilation of dark matter particles inside these clusters could be observable with the Fermi Large Area Telescope (LAT). Based on three years of Fermi LAT gamma-ray data, we analyze the flux coming from eight nearby clusters individually as well as in a combined likelihood analysis. Concentrating mostly on signals from dark matter decay, we take into account uncertainties of the cluster masses as determined by X-ray observations and model the cluster emission with extended sources. We do not find significant emission from any of the considered clusters and present limits on the dark matter lifetime and annihilation cross-section. We compare our lifetime limits derived from cluster observations with the limits that can be obtained from the extragalactic gamma-ray background, and find that in case of hadronic decay the cluster limits become competitive at dark matter masses below a few hundred GeV. Finally, we show that in presence of dark matter substructures down to 10{sup -6} solar masses the limits on the dark matter annihilation cross-section could improve by a factor of a few hundred, possibly going down to the thermal cross-section of 3 x 10{sup -26} cm{sup 3}s{sup -1} for dark matter masses

  12. DISCOVERY OF FIVE CANDIDATE ANALOGS FOR η CARINAE IN NEARBY GALAXIES

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Rubab [NASA Goddard Space Flight Center, MC 665, 8800 Greenbelt Road, Greenbelt, MD 20771 (United States); Adams, Scott M.; Stanek, K. Z.; Kochanek, C. S. [Department of Astronomy, The Ohio State University, 140 W. 18th Avenue, Columbus, OH 43210 (United States); and others

    2015-12-20

    The late-stage evolution of very massive stars such as η Carinae may be dominated by episodic mass ejections that may later lead to Type II superluminous supernova (SLSN-II; e.g., SN 2006gy). However, as long as η Car is one of a kind, it is nearly impossible to quantitatively evaluate these possibilities. Here, we announce the discovery of five objects in the nearby (∼4–8 Mpc) massive star-forming galaxies M51, M83, M101, and NGC 6946 that have optical through mid-infrared (mid-IR) photometric properties consistent with the hitherto unique η Car. The Spitzer mid-IR spectral energy distributions of these L{sub bol} ≃ 3–8 × 10{sup 6} L{sub ⊙} objects rise steeply in the 3.6–8 μm bands and then turn over between 8 and 24 μm, indicating the presence of warm (∼400–600 K) circumstellar dust. Their optical counterparts in HST images are ∼1.5–2 dex fainter than their mid-IR peaks and require the presence of ∼5–10 M{sub ⊙} of obscuring material. Our finding implies that the rate of η Car–like events is a fraction f = 0.094 (0.040 < f < 0.21 at 90% confidence) of the core-collapse supernova (ccSN) rate. If there is only one eruption mechanism and Type II superluminous supernovae are due to ccSNe occurring inside these dense shells, then the ejection mechanism is likely associated with the onset of carbon burning (∼10{sup 3}–10{sup 4} years), which is also consistent with the apparent ages of massive Galactic shells.

  13. Free-field ground motions for the nonproliferation experiment: Preliminary comparisons with nearby nuclear events

    International Nuclear Information System (INIS)

    Olsen, K.H.; Peratt, A.L.

    1994-01-01

    Since 1987, we have installed fixed arrays of tri-axial accelerometers in the fire-field near the shot horizons for low-yield (≤ 20 kt) nuclear events in the N-tunnel complex beneath Rainier Mesa. For the Nonproliferation Experiment (NPE) we augmented the array to achieve 23 free-field stations. Goals are: (a) to examine robustness and stability of various free-field source function estimates -- e.g., reduced displacement potentials (RDP) and spectra; (b) to compare close-in with regional estimates to test whether detailed close-in free-field and/or surface ground motion data can improve predictability of regional-teleseismic source functions; (c) to provide experimental data for checking two-dimensional numerical simulations. We report preliminary comparisons between experimental free-field data for NPE (1993) and three nearby nuclear events (MISTY ECHO, 1988; MINERAL QUARRY, 1990; HUNTERS TROPHY, 1992). All four working points are within 1 km of each other in the same wet tuff bed, thus reducing concerns about possible large differences in material properties between widely separated shots. Initial comparison of acceleration and velocity seismograms for the four events reveals: (1) There is a large departure from the spherical symmetry commonly assumed in analytic treatments of source theory; both vertical and tangential components are surprisingly large. (2) All shots show similar first-peak particle-velocity amplitude decay rates suggesting significant attenuation even in the supposedly purely elastic region. (3) Sharp (>20 Hz) arrivals are not observed at tunnel level from near-surface pP reflections or spall-closure sources -- but broadened peaks are seen that suggest more diffuse reflected energy from the surface and from the Paleozoic limestone basement below tunnel level

  14. FINDING η CAR ANALOGS IN NEARBY GALAXIES USING SPITZER. I. CANDIDATE SELECTION

    International Nuclear Information System (INIS)

    Khan, Rubab; Stanek, K. Z.; Kochanek, C. S.

    2013-01-01

    The late-stage evolution of the most massive stars such as η Carinae is controlled by the effects of mass loss, which may be dominated by poorly understood eruptive mass ejections. Understanding this population is challenging because no true analogs of η Car have been clearly identified in the Milky Way or other galaxies. We utilize Spitzer IRAC images of seven nearby (∼ 10 5 L ☉ in the IRAC bands (3.6 to 8.0 μm) and are not known to be background sources. Based on our estimates for the expected number of background sources, we expect that follow-up observations will show that most of these candidates are not dust enshrouded massive stars, with an expectation of only 6 ± 6 surviving candidates. Since we would detect true analogs of η Car for roughly 200 years post-eruption, this implies that the rate of eruptions like η Car is less than the core-collapse supernova rate. It is possible, however, that every M > 40 M ☉ star undergoes such eruptions given our initial results. In Paper II we will characterize the candidates through further analysis and follow-up observations, and there is no barrier to increasing the galaxy sample by an order of magnitude. The primary limitation of the present search is that Spitzer's resolution limits us to the shorter wavelength IRAC bands. With the James Webb Space Telescope, such surveys can be carried out at the far more optimal wavelengths of 10-30 μm, allowing identification of η Car analogs for millennia rather than centuries post-eruption.

  15. Presence of a consensus DNA motif at nearby DNA sequence of the mutation susceptible CG nucleotides.

    Science.gov (United States)

    Chowdhury, Kaushik; Kumar, Suresh; Sharma, Tanu; Sharma, Ankit; Bhagat, Meenakshi; Kamai, Asangla; Ford, Bridget M; Asthana, Shailendra; Mandal, Chandi C

    2018-01-10

    Complexity in tissues affected by cancer arises from somatic mutations and epigenetic modifications in the genome. The mutation susceptible hotspots present within the genome indicate a non-random nature and/or a position specific selection of mutation. An association exists between the occurrence of mutations and epigenetic DNA methylation. This study is primarily aimed at determining mutation status, and identifying a signature for predicting mutation prone zones of tumor suppressor (TS) genes. Nearby sequences from the top five positions having a higher mutation frequency in each gene of 42 TS genes were selected from a cosmic database and were considered as mutation prone zones. The conserved motifs present in the mutation prone DNA fragments were identified. Molecular docking studies were done to determine putative interactions between the identified conserved motifs and enzyme methyltransferase DNMT1. Collective analysis of 42 TS genes found GC as the most commonly replaced and AT as the most commonly formed residues after mutation. Analysis of the top 5 mutated positions of each gene (210 DNA segments for 42 TS genes) identified that CG nucleotides of the amino acid codons (e.g., Arginine) are most susceptible to mutation, and found a consensus DNA "T/AGC/GAGGA/TG" sequence present in these mutation prone DNA segments. Similar to TS genes, analysis of 54 oncogenes not only found CG nucleotides of the amino acid Arg as the most susceptible to mutation, but also identified the presence of similar consensus DNA motifs in the mutation prone DNA fragments (270 DNA segments for 54 oncogenes) of oncogenes. Docking studies depicted that, upon binding of DNMT1 methylates to this consensus DNA motif (C residues of CpG islands), mutation was likely to occur. Thus, this study proposes that DNMT1 mediated methylation in chromosomal DNA may decrease if a foreign DNA segment containing this consensus sequence along with CG nucleotides is exogenously introduced to dividing

  16. Probing dark matter decay and annihilation with Fermi LAT observations of nearby galaxy clusters

    International Nuclear Information System (INIS)

    Huang, Xiaoyuan; Vertongen, Gilles; Weniger, Christoph

    2011-09-01

    Galaxy clusters are promising targets for indirect dark matter searches. Gamma-ray signatures from the decay or annihilation of dark matter particles inside these clusters could be observable with the Fermi Large Area Telescope (LAT). Based on three years of Fermi LAT gamma-ray data, we analyze the flux coming from eight nearby clusters individually as well as in a combined likelihood analysis. Concentrating mostly on signals from dark matter decay, we take into account uncertainties of the cluster masses as determined by X-ray observations and model the cluster emission with extended sources. We do not find significant emission from any of the considered clusters and present limits on the dark matter lifetime and annihilation cross-section. We compare our lifetime limits derived from cluster observations with the limits that can be obtained from the extragalactic gamma-ray background, and find that in case of hadronic decay the cluster limits become competitive at dark matter masses below a few hundred GeV. Finally, we show that in presence of dark matter substructures down to 10 -6 solar masses the limits on the dark matter annihilation cross-section could improve by a factor of a few hundred, possibly going down to the thermal cross-section of 3 x 10 -26 cm 3 s -1 for dark matter masses < or similar 150 GeV and annihilation into b anti b. As a direct application of our results, we derive limits on the lifetime of gravitino dark matter in scenarios with R-parity violation. Implications of these limits for the possible observation of long-lived superparticles at the LHC are discussed. (orig.)

  17. NGC 1277: A MASSIVE COMPACT RELIC GALAXY IN THE NEARBY UNIVERSE

    Energy Technology Data Exchange (ETDEWEB)

    Trujillo, Ignacio; Vazdekis, Alexandre [Instituto de Astrofísica de Canarias, c/Vía Láctea s/n, E-38205-La Laguna, Tenerife (Spain); Ferré-Mateu, Anna [Subaru Telescope, 650 North A' ohoku Place, Hilo, HI 96720 (United States); Balcells, Marc [Isaac Newton Group of Telescopes, E-38700 Santa Cruz de La Palma, Canary Islands (Spain); Sánchez-Blázquez, Patricia, E-mail: trujillo@iac.es [Departamento de Física Teórica, Universidad Autónoma de Madrid, E-28049, Cantoblanco, Madrid (Spain)

    2014-01-10

    As early as 10 Gyr ago, galaxies with more than 10{sup 11} M {sub ☉} of stars already existed. While most of these massive galaxies must have subsequently transformed through on-going star formation and mergers with other galaxies, a small fraction (≲0.1%) may have survived untouched until today. Searches for such relic galaxies, useful windows to explore the early universe, have been inconclusive to date: galaxies with masses and sizes like those observed at high redshift (M {sub *} ≳ 10{sup 11} M {sub ☉}; R{sub e} ≲ 1.5 kpc) have been found in the local universe, but their stars are far too young for the galaxy to be a relic galaxy. This paper explores the first case of a nearby galaxy, NGC 1277 (at a distance of 73 Mpc in the Perseus galaxy cluster), which fulfills many criteria to be considered a relic galaxy. Using deep optical spectroscopy, we derive the star formation history along the structure of the galaxy: the stellar populations are uniformly old (>10 Gyr) with no evidence for more recent star formation episodes. The metallicity of their stars is super-solar ([Fe/H] = 0.20 ± 0.04 with a smooth decline toward the outer regions) and α-enriched ([α/Fe] = 0.4 ± 0.1). This suggests a very short formation time scale for the bulk of the stars in this galaxy. This object also rotates very fast (V {sub rot} ∼ 300 km s{sup –1}) and has a large central velocity dispersion (σ > 300 km s{sup –1}). NGC 1277 allows the exploration in full detail of properties such as the structure, internal dynamics, metallicity, and initial mass function as they were at ∼10-12 Gyr ago when the first massive galaxies were built.

  18. HALOGAS: H I OBSERVATIONS AND MODELING OF THE NEARBY EDGE-ON SPIRAL GALAXY NGC 4565

    Energy Technology Data Exchange (ETDEWEB)

    Zschaechner, Laura K.; Rand, Richard J. [Department of Physics and Astronomy, University of New Mexico, 1919 Lomas Boulevard NE, Albuquerque, NM 87131-1156 (United States); Heald, George H.; Jozsa, Gyula [Netherlands Institute for Radio Astronomy (ASTRON), Postbus 2, NL-7990 AA Dwingeloo (Netherlands); Gentile, Gianfranco, E-mail: zschaech@unm.edu, E-mail: rjr@phys.unm.edu, E-mail: heald@astron.nl, E-mail: jozsa@astron.nl, E-mail: gianfranco.gentile@ugent.be [Sterrenkundig Observatorium, Ghent University, Krijgslaan 281 S9, B-9000 Ghent (Belgium)

    2012-11-20

    We present 21 cm observations and models of the neutral hydrogen in NGC 4565, a nearby, edge-on spiral galaxy, as part of the Westerbork Hydrogen Accretion in LOcal GAlaxieS survey. These models provide insight concerning both the morphology and kinematics of H I above, as well as within, the disk. NGC 4565 exhibits a distinctly warped and asymmetric disk with a flaring layer. Our modeling provides no evidence for a massive, extended H I halo. We see evidence for a bar and associated radial motions. Additionally, there are indications of radial motions within the disk, possibly associated with a ring of higher density. We see a substantial decrease in rotational velocity with height above the plane of the disk (a lag) of -40{sup +5} {sub -20} km s{sup -1} kpc{sup -1} and -30{sup +5} {sub -30} km s{sup -1} kpc{sup -1} in the approaching and receding halves, respectively. This lag is only seen within the inner {approx}4.'75 (14.9 kpc) on the approaching half and {approx}4.'25 (13.4 kpc) on the receding half, making this a radially shallowing lag, which is now seen in the H I layers of several galaxies. When comparing results for NGC 4565 and those for other galaxies, there are tentative indications of high star formation rate per unit area being associated with the presence of a halo. Finally, H I is found in two companion galaxies, one of which is clearly interacting with NGC 4565.

  19. OT2_amoor_4: A census of debris disks in nearby young moving groups with Herschel.

    Science.gov (United States)

    Moór, A.

    2011-09-01

    Nearly all young stars harbour circumstellar disks, that serve as the reservoir for mass accretion onto the star, and later become the birthplace of planetary systems. After the disappearance of the gas component from the disk a dusty debris disk is formed that is believed to mark the location of the planetesimal belt as well. For outlining the evolution of such debris disks traditionally open clusters and field stars were studied, however we argue that the recently discovered young moving groups are more suitable objects for such analyses, due to their proximity and good coverage of the first 50 Myr period of the planetary system evolution. In this proposal we request 70/160 um Herschel/PACS photometric observations for so-far unobserved moving group members. These observations will provide a complete coverage of all known members within 80 pc of five nearby young moving groups (beta Pic Moving Group, Tucana-Horologium, Carina, Columba, and Argus), in the A to K spectral range. Based on the new observations we will identify new debris disks, characterize the disk population within individual moving groups, and study disk evolution by comparing the groups of different ages. The results will be used to verify predictions of the self-stirring model of the evolution of planetesimal disks. We will also compare the properties of debris disks in groups of the same age, looking for additional 'environmental' parameters that affect disk structure over a whole moving group. Our study will be a significant contribution to the census of debris disks in young moving groups, increasing the number of observed sources by a factor of 1.5. Since Spitzer could perform only a limited census and the so-far approved Herschel programs added very few additional moving group obervations, our programme is expected to have a high legacy value.

  20. Characterization of particulate and dissolved phosphorus in tile and nearby riverine systems

    Science.gov (United States)

    Jiang, X.; Arai, Y.; David, M.; Gentry, L.

    2017-12-01

    In the Midwestern U.S., the drainage of agricultural land is predominantly managed by the tile drain system because of its poorly drain properties of clay rich indigenous soils. An accelerated subsurface flow of phosphorus (P) has recently been documented as a primary P transport path in contrast to the typical surface runoff events observed in the Eastern U.S. Recent studies suggested the important role of particulate P (PP) load in agricultural tile drainage water during high flow events. It was hypothesized that PP in the tile water is transported to riverine system contributing to the negative environmental impacts in the Midwestern U.S. In this study, correlation assessment of physicochemical properties of PP in agricultural tile drainage and nearby river samples after a storm event was conducted using a combination of 31P-nuclear magnetic resonance spectroscopy, P K-edge X-ray absorption near edge structure spectroscopy, X-ray diffraction, zetasizer, and transmission electron microscopy. Results show that significantly more colloidal (i.e. 1 nm- 2 µm) and silt-sized (i.e. > 2 µm) particles as well as higher dissolved total P (DTP) and dissolved reactive P (DRP) concentrations existed in river samples than tile samples. Tile and river samples showed similar zeta potential in each particle-size fraction and similar element distributions on colloidal fraction. However, colloidal P concentration and distribution are slightly different between tile and river samples: more colloidal total P and organic P existed in tile colloids than river colloids. The results of P speciation and mineralogical assessment will also be discussed.

  1. Addressing Ionization and Depletion in the ISM of Nearby Star-Forming Galaxies

    Science.gov (United States)

    Aloisi, Alessandra

    2017-08-01

    Measuring galaxy metallicity with cosmic time is of paramount importance to understand galaxy formation. ISM abundances are typically determined using emission-line spectroscopy of HII regions. However, HII regions may be self-enriched and not typical of the whole galaxy. This is particularly true for star-forming galaxies (SFGs) where the bulk of metals may be in the neutral gas. Quantifying metals in the ISM is thus important to assess how reliably HII regions trace galaxy abundances at any redshift. We were awarded 34 HST orbits (Cycle 17) to measure abundances in the neutral ISM of 9 nearby SFGs using absorption lines in the COS G130M/1291 spectra of bright UV background sources within the galaxy itself. We found metallicities that differ by up to 2 dex depending on the element. These variations could be real or due to observational effects. Here we request 22 orbits in the new G130M/1222 and in G160M/1623 to access new FUV spectral transitions that will help us characterize ionized-gas contamination and dust depletion, and ultimately nail down the abundances of the different elements. These new data will nicely complement our Cycle 17 COS and Gemini/GMOS IFU programs, the latter aimed at deriving nebular abundances along the same COS sightlines. This first detailed and spatially-accurate comparison between neutral- and ionized-gas abundances in local (z 0) SFGs will provide crucial insights into the metallicity of galaxies at any redshift. If this UV spectroscopic study is not undertaken before HST ceases operation, the (in)homogeneity of the ISM in galaxies of the local Universe will continue to remain uncertain for at least another decade.

  2. IceCube Sensitivity for Low-Energy Neutrinos from Nearby Supernovae

    Science.gov (United States)

    Stamatikos, M.; Abbasi, R.; Berghaus, P.; Chirkin, D.; Desiati, P.; Diaz-Velez, J.; Dumm, J. P.; Eisch, J.; Feintzeig, J.; Hanson, K.; hide

    2012-01-01

    This paper describes the response of the IceCube neutrino telescope located at the geographic South Pole to outbursts of MeV neutrinos from the core collapse of nearby massive stars. IceCube was completed in December 2010 forming a lattice of 5160 photomultiplier tubes that monitor a volume of approx. 1 cu km in the deep Antarctic ice for particle induced photons. The telescope was designed to detect neutrinos with energies greater than 100 GeV. Owing to subfreezing ice temperatures, the photomultiplier dark noise rates are particularly low. Hence IceCube can also detect large numbers of MeV neutrinos by observing a collective rise in all photomultiplier rates on top of the dark noise. With 2 ms timing resolution, IceCube can detect subtle features in the temporal development of the supernova neutrino burst. For a supernova at the galactic center, its sensitivity matches that of a background-free megaton-scale supernova search experiment. The sensitivity decreases to 20 standard deviations at the galactic edge (30 kpc) and 6 standard deviations at the Large Magellanic Cloud (50 kpc). IceCube is sending triggers from potential supernovae to the Supernova Early Warning System. The sensitivity to neutrino properties such as the neutrino hierarchy is discussed, as well as the possibility to detect the neutronization burst, a short outbreak's released by electron capture on protons soon after collapse. Tantalizing signatures, such as the formation of a quark star or a black hole as well as the characteristics of shock waves, are investigated to illustrate IceCube's capability for supernova detection.

  3. THE H α EMISSION OF NEARBY M DWARFS AND ITS RELATION TO STELLAR ROTATION

    International Nuclear Information System (INIS)

    Newton, Elisabeth R.; Irwin, Jonathan; Charbonneau, David; Berlind, Perry; Calkins, Michael L.; Mink, Jessica

    2017-01-01

    The high-energy emission from low-mass stars is mediated by the magnetic dynamo. Although the mechanisms by which fully convective stars generate large-scale magnetic fields are not well understood, it is clear that, as for solar-type stars, stellar rotation plays a pivotal role. We present 270 new optical spectra of low-mass stars in the Solar Neighborhood. Combining our observations with those from the literature, our sample comprises 2202 measurements or non-detections of H α emission in nearby M dwarfs. This includes 466 with photometric rotation periods. Stars with masses between 0.1 and 0.6 M ⊙ are well-represented in our sample, with fast and slow rotators of all masses. We observe a threshold in the mass–period plane that separates active and inactive M dwarfs. The threshold coincides with the fast-period edge of the slowly rotating population, at approximately the rotation period at which an era of rapid rotational evolution appears to cease. The well-defined active/inactive boundary indicates that H α activity is a useful diagnostic for stellar rotation period, e.g., for target selection for exoplanet surveys, and we present a mass-period relation for inactive M dwarfs. We also find a significant, moderate correlation between L Hα / L bol and variability amplitude: more active stars display higher levels of photometric variability. Consistent with previous work, our data show that rapid rotators maintain a saturated value of L Hα / L bol . Our data also show a clear power-law decay in L Hα / L bol with Rossby number for slow rotators, with an index of −1.7 ± 0.1.

  4. The Hα Emission of Nearby M Dwarfs and its Relation to Stellar Rotation

    Science.gov (United States)

    Newton, Elisabeth R.; Irwin, Jonathan; Charbonneau, David; Berlind, Perry; Calkins, Michael L.; Mink, Jessica

    2017-01-01

    The high-energy emission from low-mass stars is mediated by the magnetic dynamo. Although the mechanisms by which fully convective stars generate large-scale magnetic fields are not well understood, it is clear that, as for solar-type stars, stellar rotation plays a pivotal role. We present 270 new optical spectra of low-mass stars in the Solar Neighborhood. Combining our observations with those from the literature, our sample comprises 2202 measurements or non-detections of Hα emission in nearby M dwarfs. This includes 466 with photometric rotation periods. Stars with masses between 0.1 and 0.6 M⊙ are well-represented in our sample, with fast and slow rotators of all masses. We observe a threshold in the mass-period plane that separates active and inactive M dwarfs. The threshold coincides with the fast-period edge of the slowly rotating population, at approximately the rotation period at which an era of rapid rotational evolution appears to cease. The well-defined active/inactive boundary indicates that Hα activity is a useful diagnostic for stellar rotation period, e.g., for target selection for exoplanet surveys, and we present a mass-period relation for inactive M dwarfs. We also find a significant, moderate correlation between LHα/Lbol and variability amplitude: more active stars display higher levels of photometric variability. Consistent with previous work, our data show that rapid rotators maintain a saturated value of LHα/Lbol. Our data also show a clear power-law decay in LHα/Lbol with Rossby number for slow rotators, with an index of -1.7 ± 0.1.

  5. Urban farmers' markets: accessibility, offerings, and produce variety, quality, and price compared to nearby stores.

    Science.gov (United States)

    Lucan, Sean C; Maroko, Andrew R; Sanon, Omar; Frias, Rafael; Schechter, Clyde B

    2015-07-01

    Most food-environment research has focused narrowly on select stores and restaurants. There has been comparatively less attention to non-storefront food sources like farmers' markets (FMs), particularly in urban communities. The objective of the present study was to assess FMs' potential contribution to an urban food environment in terms of specific foods offered, and compare FM accessibility as well as produce variety, quality, and price to that of nearby stores. Investigators conducted a detailed cross-sectional assessment of all FMs in Bronx County, NY, and of the nearest store(s) selling produce within a half-mile walking distance (up to two stores per FM). The study included 26 FMs and 44 stores. Investigators assessed accessibility (locations of FMs and stores relative to each other, and hours of operation for each), variety (the number and type of all food items offered at FMs and all fresh produce items offered at stores), quality (where produce items were grown and if they were organic), and price (including any sales prices or promotional discounts). Analyses included frequencies, proportions, and variable distributions, as well as mixed-effect regressions, paired t-tests, and signed rank tests to compare FMs to stores. Geographic information systems (GIS) allowed for mapping of FM and store locations and determining street-network distances between them. The mean distance between FMs and the nearest store selling fresh produce was 0.15 miles (range 0.02-0.36 miles). FMs were open substantially fewer months, days, and hours than stores. FMs offered 26.4 fewer fresh produce items on average than stores (p values operation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. THE SPITZER INFRARED NEARBY GALAXIES SURVEY: A HIGH-RESOLUTION SPECTROSCOPY ANTHOLOGY

    International Nuclear Information System (INIS)

    Dale, D. A.; Schlawin, E. A.; Cohen, S. A.; Johnson, L. C.; Staudaher, S.; Smith, J. D. T.; Armus, L.; Helou, G.; Jarrett, T. H.; Murphy, E. J.; Sheth, K.; Buckalew, B. A.; Moustakas, J.; Roussel, H.; Bot, C.; Calzetti, D.; Engelbracht, C. W.; Gordon, K. D.; Hollenbach, D. J.; Kennicutt, R. C.

    2009-01-01

    High-resolution mid-infrared spectra are presented for 155 nuclear and extranuclear regions from the Spitzer Infrared Nearby Galaxies Survey (SINGS). The fluxes for nine atomic forbidden and three molecular hydrogen mid-infrared emission lines are also provided, along with upper limits in key lines for infrared-faint targets. The SINGS sample shows a wide range in the ratio of [S III] 18.71 μm/[S III] 33.48 μm, but the average ratio of the ensemble indicates a typical interstellar electron density of 300-400 cm -3 on ∼23'' x 15'' scales and 500-600 cm -3 using ∼11'' x 9'' apertures, independent of whether the region probed is a star-forming nuclear, a star-forming extranuclear, or an active galactic nuclei (AGN) environment. Evidence is provided that variations in gas-phase metallicity play an important role in driving variations in radiation field hardness, as indicated by [Ne III] 15.56 μm/[Ne II] 12.81 μm, for regions powered by star formation. Conversely, the radiation hardness for galaxy nuclei powered by accretion around a massive black hole is independent of metal abundance. Furthermore, for metal-rich environments AGN are distinguishable from star-forming regions by significantly larger [Ne III] 15.56 μm/[Ne II] 12.81 μm ratios. Finally, [Fe II] 25.99 μm/[Ne II] 12.81 μm versus [Si II] 34.82 μm/[S III] 33.48 μm also provides an empirical method for discerning AGN from normal star-forming sources. However, similar to [Ne III] 15.56 μm/[Ne II] 12.81 μm, these mid-infrared line ratios lose their AGN/star-formation diagnostic powers for very low metallicity star-forming systems with hard radiation fields.

  7. Volume activity of 222Rn in the atmosphere of the nearby localities with the different orography

    International Nuclear Information System (INIS)

    Bulko, M.; Holy, K.; Polaskova, A.; Simon, J.; Hola, O.

    2006-01-01

    The monitoring of the volume activity of 222 Rn in the outdoor atmosphere was carried out in two areas - on the Faculty of Mathematics, Physics and Informatics, Comenius University (FMPI CU) and on the Slovak Metrological Institute (SMI) in Bratislava. The most significant differences were found out in the average daily courses of the 222 Rn volume activity for summer months, which show the different amplitudes and a relative displacement of a couple of hours. A possible reason for this can be that while on the FMPI CU there the solar radiation flux is not shielded by the terrain obstacles, the SMI measurement area is exposed to the solar radiation due to the shielding of the hills from the west only until 3 p.m. in summer and until 12 a.m. in winter. This produces the conditions for an earlier decrease of an intensity of the vertical exchange processes and therefore an earlier increase of the radon volume activity in 'SMI air', always in a couple of hours earlier than a similar observed increase in F MPI CU air . The daily course analysis also showed that the equivalent mixing height in the SMI area is about 30% lower than that one in the FMPI CU area. The analyses presented in this paper show that the daily courses of the 222 Rn volume activity can differ significantly even for two nearby areas with the different orography and that 222 Rn concentration is sensitive to these differences. It was also found out that if the long-term radon data should be collected in order to obtain the representative data for a larger area, an adequate attention should be paid to the selection of the measurement area. (authors)

  8. BAYESIAN ANALYSIS TO IDENTIFY NEW STAR CANDIDATES IN NEARBY YOUNG STELLAR KINEMATIC GROUPS

    International Nuclear Information System (INIS)

    Malo, Lison; Doyon, René; Lafrenière, David; Artigau, Étienne; Gagné, Jonathan; Baron, Frédérique; Riedel, Adric

    2013-01-01

    We present a new method based on a Bayesian analysis to identify new members of nearby young kinematic groups. The analysis minimally takes into account the position, proper motion, magnitude, and color of a star, but other observables can be readily added (e.g., radial velocity, distance). We use this method to find new young low-mass stars in the β Pictoris and AB Doradus moving groups and in the TW Hydrae, Tucana-Horologium, Columba, Carina, and Argus associations. Starting from a sample of 758 mid-K to mid-M (K5V-M5V) stars showing youth indicators such as Hα and X-ray emission, our analysis yields 214 new highly probable low-mass members of the kinematic groups analyzed. One is in TW Hydrae, 37 in β Pictoris, 17 in Tucana-Horologium, 20 in Columba, 6 in Carina, 50 in Argus, 32 in AB Doradus, and the remaining 51 candidates are likely young but have an ambiguous membership to more than one association. The false alarm rate for new candidates is estimated to be 5% for β Pictoris and TW Hydrae, 10% for Tucana-Horologium, Columba, Carina, and Argus, and 14% for AB Doradus. Our analysis confirms the membership of 58 stars proposed in the literature. Firm membership confirmation of our new candidates will require measurement of their radial velocity (predicted by our analysis), parallax, and lithium 6708 Å equivalent width. We have initiated these follow-up observations for a number of candidates, and we have identified two stars (2MASSJ01112542+1526214, 2MASSJ05241914-1601153) as very strong candidate members of the β Pictoris moving group and one strong candidate member (2MASSJ05332558-5117131) of the Tucana-Horologium association; these three stars have radial velocity measurements confirming their membership and lithium detections consistent with young age.

  9. ALMA MULTI-LINE IMAGING OF THE NEARBY STARBURST NGC 253

    Energy Technology Data Exchange (ETDEWEB)

    Meier, David S. [New Mexico Institute of Mining and Technology, 801 Leroy Place, Socorro, NM 87801 (United States); Walter, Fabian; Zschaechner, Laura K. [Max-Planck Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany); Bolatto, Alberto D.; Veilleux, Sylvain; Warren, Steven R. [Department of Astronomy and Joint Space-Science Institute, University of Maryland, College Park, MD 20742 (United States); Leroy, Adam K. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States); Ott, Jürgen [National Radio Astronomy Observatory, Pete V. Domenici Array Science Center, P.O. Box O, Socorro, NM 87801 (United States); Rosolowsky, Erik [Department of Physics, University of Alberta, Edmonton, AB T6G 2E1 (Canada); Weiß, Axel [Max Planck Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany); Zwaan, Martin A., E-mail: dmeier@nmt.edu [European Southern Observatory, Karl-Schwarzschild-Str. 2, D-85748 Garching bei München (Germany)

    2015-03-01

    We present spatially resolved (∼50 pc) imaging of molecular gas species in the central kiloparsec of the nearby starburst galaxy NGC 253, based on observations taken with the Atacama Large Millimeter/submillimeter Array. A total of 50 molecular lines are detected over a 13 GHz bandwidth imaged in the 3 mm band. Unambiguous identifications are assigned for 27 lines. Based on the measured high CO/C{sup 17}O isotopic line ratio (≳350), we show that {sup 12}CO(1-0) has moderate optical depths. A comparison of the HCN and HCO{sup +} with their {sup 13}C-substituted isotopologues shows that the HCN(1-0) and HCO{sup +}(1-0) lines have optical depths at least comparable to CO(1-0). H{sup 13}CN/H{sup 13}CO{sup +} (and H{sup 13}CN/HN{sup 13}C) line ratios provide tighter constraints on dense gas properties in this starburst. SiO has elevated abundances across the nucleus. HNCO has the most distinctive morphology of all the bright lines, with its global luminosity dominated by the outer parts of the central region. The dramatic variation seen in the HNCO/SiO line ratio suggests that some of the chemical signatures of shocked gas are being erased in the presence of dominating central radiation fields (traced by C{sub 2}H and CN). High density molecular gas tracers (including HCN, HCO{sup +}, and CN) are detected at the base of the molecular outflow. We also detect hydrogen β recombination lines that, like their α counterparts, show compact, centrally peaked morphologies, distinct from the molecular gas tracers. A number of sulfur based species are mapped (CS, SO, NS, C{sub 2}S, H{sub 2}CS, and CH{sub 3}SH) and have morphologies similar to SiO.

  10. North Dakota's forests 2005

    Science.gov (United States)

    David E. Haugen; Michael Kangas; Susan J. Crocker; Charles H. Perry; Christopher W. Woodall; Brett J. Butler; Barry T. Wilson; Dan J. Kaisershot

    2009-01-01

    The first completed annual inventory of North Dakota's forests reports estimates of more than 724,000 acres of forest land. Information about forest attributes and forest health is presented along with information on agents of change including changing land use patterns and the introduction of nonnative plants, insects, and disease.

  11. Apollo in the North

    DEFF Research Database (Denmark)

    Østermark-Johansen, Lene

    2015-01-01

    Walter Pater’s fascination with the Hyperborean Apollo, who according to myth resided north of the home of the northern wind, is explored in two of his pieces of short fiction, ‘Duke Carl of Rosenmold’ (1887) and ‘Apollo in Picardy’ (1893). The essay discusses some of Pater’s complex dialogue wit...

  12. Moving farther north

    International Nuclear Information System (INIS)

    Boswell, R.

    2000-01-01

    According to predictions by the National Petroleum Council, North American demand for natural gas is likely to increase from 20 Tcf currently to 29 Tcf by the year 2010 and could increase to beyond 31 Tcf by 2015. In view of this and other similar predictions it is prudent to examine the potential sources of supply and to assess their capacity to meet this ever increasing demand. This paper provides an overview of North America's gas potential, proved reserves and current production. One of the sources much depended upon to meet future demand is the deepwater Gulf of Mexico which, however, would have to grow at the compounded rate of 21 per cent annually to meet expectations of 4.5 Tcf per year by 2010, a staggering rate of growth that would require 250 to 300 completions per year (current rate is about 100 per year) and two to three times the number of rigs currently working in the Gulf. If the deepwater Gulf of Mexico cannot meet this target, the incremental supply will most likely come from the North, namely the Fort Liard, Norman Wells, and the Mackenzie Delta/Beaufort Sea regions of Canada and Alaska's Cook Inlet, Copper River, North Slope and Susitna Basin. The economics of developing each of these regions is examined, using field size, reserves per well, exploration and development costs and cycle time as the bases for comparison. Obstacles to development such as access to pipelines, government regulations, and opposition by environmental groups are also discussed

  13. ITS Platform North Denmark

    DEFF Research Database (Denmark)

    Lahrmann, Harry; Agerholm, Niels; Juhl, Jens

    2012-01-01

    This paper presents the project entitled “ITS Platform North Denmark” which is used as a test platform for Intelligent Transportation System (ITS) solutions. The platform consists of a newly developed GNSS/GPRS On Board Unit (OBU) to be installed in 500 cars, a backend server and a specially...

  14. Dynamical analysis of nearby clusters. Automated astrometry from the ground: precision proper motions over a wide field

    Science.gov (United States)

    Bouy, H.; Bertin, E.; Moraux, E.; Cuillandre, J.-C.; Bouvier, J.; Barrado, D.; Solano, E.; Bayo, A.

    2013-06-01

    Context. The kinematic properties of the different classes of objects in a given association hold important clues about the history of its members, and offer a unique opportunity to test the predictions of the various models of stellar formation and evolution. Aims: DANCe (standing for dynamical analysis of nearby clusters) is a survey program aimed at deriving a comprehensive and homogeneous census of the stellar and substellar content of a number of nearby (history, and the presence of reference extragalactic sources for the anchoring onto the ICRS. Based on observations obtained with MegaPrime/MegaCam, a joint project of CFHT and CEA/DAPNIA, at the Canada-France-Hawaii Telescope (CFHT) which is operated by the National Research Council (NRC) of Canada, the Institut National des Science de l'Univers of the Centre National de la Recherche Scientifique (CNRS) of France, and the University of Hawaii.

  15. 2XMM ultraluminous X-ray source candidates in nearby galaxies

    Science.gov (United States)

    Walton, D. J.; Roberts, T. P.; Mateos, S.; Heard, V.

    2011-09-01

    Ultraluminous X-ray sources (ULXs) are some of the most enigmatic X-ray bright sources known to date. It is generally accepted that they cannot host black holes as large as those associated with active galaxies, but they appear to be significantly more luminous than their better understood Galactic X-ray binary (XRB) cousins, while displaying an intriguing combination of differences and similarities with them. Through studying large, representative samples of these sources we may hope to enhance our understanding of them. To this end, we derive a large catalogue of 650 X-ray detections of 470 ULX candidates, located in 238 nearby galaxies, by cross-correlating the 2XMM Serendipitous Survey with the Third Reference Catalogue of Bright Galaxies. The presented dedicated catalogue offers a significant improvement over those previously published in terms of both the number and the contribution of background contaminants, e.g. distant quasars, which we estimate to be at most 24 per cent, but more likely ˜17 per cent. To undertake population studies, we define a 'complete' sub-sample of sources compiled from observations of galaxies with sensitivity limits below 1039 erg s-1. The luminosity function of this sample is consistent with a simple power law of form N(>LX) ∝ L-0.96 ± 0.11X. Although we do not find any statistical requirement for a cut-off luminosity of Lc˜ 1040 erg s-1, as has been reported previously, we are not able to rule out its presence. Also, we find that the number of ULXs per unit galaxy mass, Su, decreases with increasing galaxy mass for ULXs associated with spiral galaxies, and is well modelled with a power law of form Su ∝ M-0.64 ± 0.07. This is in broad agreement with previous results, and is likely to be a consequence of the decrease in specific star formation and increase in metallicity with increasing spiral galaxy mass. Su is consistent with being constant with galaxy mass for sources associated with elliptical galaxies, implying this

  16. Host galaxies of type ia supernovae from the nearby supernova factory

    Science.gov (United States)

    Childress, Michael Joseph

    Type Ia Supernovae (SNe Ia) are excellent distance indicators, yet the full details of the underlying physical mechanism giving rise to these dramatic stellar deaths remain unclear. As large samples of cosmological SNe Ia continue to be collected, the scatter in brightnesses of these events is equally affected by systematic errors as statistical. Thus we need to understand the physics of SNe Ia better, and in particular we must know more about the progenitors of these SNe so that we can derive better estimates for their true intrinsic brightnesses. The host galaxies of SNe Ia provide important indirect clues as to the nature of SN Ia progenitors. In this Thesis we utilize the host galaxies of SNe Ia discovered by the Nearby Supernova Factory (SNfactory) to pursue several key investigations into the nature of SN Ia progenitors and their effects on SN Ia brightnesses. We first examine the host galaxy of SN 2007if, an important member of the subclass of SNe Ia whose extreme brightnesses indicate a progenitor that exceeded the canonical Chandrasekhar-mass value presumed for normal SNe Ia, and show that the host galaxy of this SN is composed of very young stars and has extremely low metallicity, providing important constraints on progenitor scenarios for this SN. We then utilize the full sample of SNfactory host galaxy masses (measured from photometry) and metallicities (derived from optical spectroscopy) to examine several global properties of SN Ia progenitors: (i) we show that SN Ia hosts show tight agreement with the normal galaxy mass-metallicity relation; (ii) comparing the observed distribution of SN Ia host galaxy masses to a theoretical model that couples galaxy physics to the SN Ia delay time distribution (DTD), we show the power of the SN Ia host mass distribution in constraining the SN Ia DTD; and (iii) we show that the lack of ultra-low metallicities in the SNfactory SN Ia host sample gives provisional support for the theorized low-metallicity inhibition of

  17. Dark matter searches with Cherenkov telescopes: nearby dwarf galaxies or local galaxy clusters?

    Energy Technology Data Exchange (ETDEWEB)

    Sánchez-Conde, Miguel A. [SLAC National Laboratory and Kavli Institute for Particle Astrophysics and Cosmology, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Cannoni, Mirco; Gómez, Mario E. [Dpto. Física Aplicada, Facultad de Ciencias Experimentales, Universidad de Huelva, 21071 Huelva (Spain); Zandanel, Fabio; Prada, Francisco, E-mail: masc@stanford.edu, E-mail: mirco.cannoni@dfa.uhu.es, E-mail: fabio@iaa.es, E-mail: mario.gomez@dfa.uhu.es, E-mail: fprada@iaa.es [Instituto de Astrofísica de Andalucía (CSIC), E-18008, Granada (Spain)

    2011-12-01

    In this paper, we compare dwarf galaxies and galaxy clusters in order to elucidate which object class is the best target for gamma-ray DM searches with imaging atmospheric Cherenkov telescopes (IACTs). We have built a mixed dwarfs+clusters sample containing some of the most promising nearby dwarf galaxies (Draco, Ursa Minor, Wilman 1 and Segue 1) and local galaxy clusters (Perseus, Coma, Ophiuchus, Virgo, Fornax, NGC 5813 and NGC 5846), and then compute their DM annihilation flux profiles by making use of the latest modeling of their DM density profiles. We also include in our calculations the effect of DM substructure. Willman 1 appears as the best candidate in the sample. However, its mass modeling is still rather uncertain, so probably other candidates with less uncertainties and quite similar fluxes, namely Ursa Minor and Segue 1, might be better options. As for galaxy clusters, Virgo represents the one with the highest flux. However, its large spatial extension can be a serious handicap for IACT observations and posterior data analysis. Yet, other local galaxy cluster candidates with more moderate emission regions, such as Perseus, may represent good alternatives. After comparing dwarfs and clusters, we found that the former exhibit annihilation flux profiles that, at the center, are roughly one order of magnitude higher than those of clusters, although galaxy clusters can yield similar, or even higher, integrated fluxes for the whole object once substructure is taken into account. Even when any of these objects are strictly point-like according to the properties of their annihilation signals, we conclude that dwarf galaxies are best suited for observational strategies based on the search of point-like sources, while galaxy clusters represent best targets for analyses that can deal with rather extended emissions. Finally, we study the detection prospects for present and future IACTs in the framework of the constrained minimal supersymmetric standard model. We

  18. Trace element profiles of the sea anemone Anemonia viridis living nearby a natural CO2 vent

    Directory of Open Access Journals (Sweden)

    Rael Horwitz

    2014-09-01

    Full Text Available Ocean acidification (OA is not an isolated threat, but acts in concert with other impacts on ecosystems and species. Coastal marine invertebrates will have to face the synergistic interactions of OA with other global and local stressors. One local factor, common in coastal environments, is trace element contamination. CO2 vent sites are extensively studied in the context of OA and are often considered analogous to the oceans in the next few decades. The CO2 vent found at Levante Bay (Vulcano, NE Sicily, Italy also releases high concentrations of trace elements to its surrounding seawater, and is therefore a unique site to examine the effects of long-term exposure of nearby organisms to high pCO2 and trace element enrichment in situ. The sea anemone Anemonia viridis is prevalent next to the Vulcano vent and does not show signs of trace element poisoning/stress. The aim of our study was to compare A. viridis trace element profiles and compartmentalization between high pCO2 and control environments. Rather than examining whole anemone tissue, we analyzed two different body compartments—the pedal disc and the tentacles, and also examined the distribution of trace elements in the tentacles between the animal and the symbiotic algae. We found dramatic changes in trace element tissue concentrations between the high pCO2/high trace element and control sites, with strong accumulation of iron, lead, copper and cobalt, but decreased concentrations of cadmium, zinc and arsenic proximate to the vent. The pedal disc contained substantially more trace elements than the anemone’s tentacles, suggesting the pedal disc may serve as a detoxification/storage site for excess trace elements. Within the tentacles, the various trace elements displayed different partitioning patterns between animal tissue and algal symbionts. At both sites iron was found primarily in the algae, whereas cadmium, zinc and arsenic were primarily found in the animal tissue. Our data

  19. Mapping Nearby Galaxies at APO: The MaNGA IFU Galaxy Survey

    Science.gov (United States)

    Law, David R.; MaNGA Team

    2014-01-01

    MaNGA is a new survey that will begin in August 2014 as part of SDSS-IV with the aim of obtaining integral-field spectroscopy for an unprecedented sample of 10,000 nearby galaxies. MaNGA's key goals are to understand the "life cycle" of present day galaxies from imprinted clues of their birth and assembly, through their ongoing growth via star formation and merging, to their death from quenching at late times. To achieve these goals, MaNGA will channel the impressive capabilities of the SDSS-III BOSS spectrographs in a fundamentally new direction by marshaling the unique power of 2D spectroscopy. MaNGA will deploy 17 pluggable Integral Field Units (IFUs) made by grouping fibers into hexagonal bundles ranging from 19 to 127 fibers each. The spectra obtained by MaNGA will cover the wavelength range 3600-10,000 Angstroms (with a velocity resolution of ~ 60 km/s) and will characterize the internal composition and the dynamical state of a sample of 10,000 galaxies with stellar masses greater than 10^9 Msun and an average redshift of z ~ 0.03. Such IFU observations enable a leap forward because they provide an added dimension to the information available for each galaxy. MaNGA will provide two-dimensional maps of stellar velocity and velocity dispersion, mean stellar age and star formation history, stellar metallicity, element abundance ratio, stellar mass surface density, ionized gas velocity, ionized gas metallicity, star formation rate, and dust extinction for a statistically powerful sample. This legacy dataset will address urgent questions in our understanding of galaxy formation, including 1) The formation history of galaxy subcomponents, including the disk, bulge, and dark matter halo, 2) The nature of present-day galaxy growth via merging and gas accretion, and 3) The processes responsible for terminating star formation in galaxies. Finally, MaNGA will also play a vital role in the coming era of advanced IFU instrumentation, serving as the low-z anchor for

  20. Trace element profiles of the sea anemone Anemonia viridis living nearby a natural CO2 vent.

    Science.gov (United States)

    Horwitz, Rael; Borell, Esther M; Fine, Maoz; Shaked, Yeala

    2014-01-01

    Ocean acidification (OA) is not an isolated threat, but acts in concert with other impacts on ecosystems and species. Coastal marine invertebrates will have to face the synergistic interactions of OA with other global and local stressors. One local factor, common in coastal environments, is trace element contamination. CO2 vent sites are extensively studied in the context of OA and are often considered analogous to the oceans in the next few decades. The CO2 vent found at Levante Bay (Vulcano, NE Sicily, Italy) also releases high concentrations of trace elements to its surrounding seawater, and is therefore a unique site to examine the effects of long-term exposure of nearby organisms to high pCO2 and trace element enrichment in situ. The sea anemone Anemonia viridis is prevalent next to the Vulcano vent and does not show signs of trace element poisoning/stress. The aim of our study was to compare A. viridis trace element profiles and compartmentalization between high pCO2 and control environments. Rather than examining whole anemone tissue, we analyzed two different body compartments-the pedal disc and the tentacles, and also examined the distribution of trace elements in the tentacles between the animal and the symbiotic algae. We found dramatic changes in trace element tissue concentrations between the high pCO2/high trace element and control sites, with strong accumulation of iron, lead, copper and cobalt, but decreased concentrations of cadmium, zinc and arsenic proximate to the vent. The pedal disc contained substantially more trace elements than the anemone's tentacles, suggesting the pedal disc may serve as a detoxification/storage site for excess trace elements. Within the tentacles, the various trace elements displayed different partitioning patterns between animal tissue and algal symbionts. At both sites iron was found primarily in the algae, whereas cadmium, zinc and arsenic were primarily found in the animal tissue. Our data suggests that A. viridis

  1. BROAD Lyα EMISSION FROM THREE NEARBY BL LACERTAE OBJECTS

    International Nuclear Information System (INIS)

    Stocke, John T.; Danforth, Charles W.; Perlman, Eric S.

    2011-01-01

    We present far-UV HST/COS spectra of four nearby BL Lac objects. BL Lac spectra are dominated by a smooth, power-law continuum which arises in a relativistic jet. However, the spectra are not necessarily featureless; weak, broad- and/or narrow-line emission is sometimes seen in high-quality optical spectra. We present detections of Lyα emission in HST/COS spectra of Mrk 421 (z = 0.030) and PKS 2005-489 (z = 0.071) as well as an archival HST/GHRS observation of Mrk 501 (z = 0.0337). Archival HST/STIS observations of PKS 2155-304 (z = 0.116) show no Lyα emission to a very low upper limit. Using the assumption that the broad-line region (BLR) clouds are symmetrically placed around the active galactic nucleus (AGN), we use these measured Lyα emission features to constrain either the relativistic Γ values for the ionizing continuum produced by the jet (in the ionization-bounded case) or the mass of warm gas (in the density-bounded case). While realistic Γ values can be obtained for all four cases, the values for Mrk 421 and PKS 2155-304 are high enough to suggest that covering factors of BLR clouds of ∼1%-2% might be required to provide consistency with earlier values of Doppler boosting and viewing angles suggested for this class of BL Lacs. This discrepancy also exists in the case of M 87, where the amount of Doppler boosting in our direction is expected to be minimal, again suggestive of a small covering factor of BLR clouds. If, as these small covering factors might suggest, the assumptions of a density-bounded model could be more correct, then the observed Lyα luminosities require that BL Lac/FR 1 nuclei possess very little warm gas (10 -4 to 10 -5 M sun ) as suggested by Guilbert et al. If these clouds are in pressure balance with a hotter (∼10 6 K) gas, the BLR contains too little mass to power the AGN by accretion alone.

  2. Environmental propagation of noise in mines and nearby villages: A study through noise mapping

    Directory of Open Access Journals (Sweden)

    Veena D Manwar

    2016-01-01

    Full Text Available Background: Noise mapping being an established practice in Europe is hardly practiced for noise management in India although it is mandatory in Indian mines as per guidelines of the Directorate General of Mines Safety (DGMS. As a pilot study, noise mapping was conducted in an opencast mine with three different models; one based on the baseline operating conditions in two shifts (Situation A, and two other virtual situations where either production targets were enhanced by extending working hours to three shifts (Situation B or only by increased mechanization and not changing the duration of work (Situation C. Methods: Noise sources were categorized as point, line, area, and moving sources. Considering measured power of the sources, specific meteorological and geographical parameters, noise maps were generated using Predictor LimA software. Results: In all three situations, Lden values were 95 dB(A and 70–80 dB(A near drill machine and haul roads, respectively. Noise contours were wider in Situation C due to increase in frequency of dumpers. Lden values near Shovel 1 and Shovel 2 under Situation B increased by 5 dB and 3 dB, respectively due to expansion of working hours. In Situation C, noise levels were >82 dB(A around shovels. Noise levels on both sides of conveyor belts were in the range of 80–85 dB(A in Situations A and C whereas it was 85–90 dB(A in Situation B. Near crusher plants, it ranged from 80 to 90 dB(A in Situations A and C and between 85 and 95 dB(A in Situation B. In all situations, noise levels near residential areas exceeded the Central Pollution Control Board (CPCB limits, i.e., 55 dB(A. Conclusions: For all situations, predicted noise levels exceeded CPCB limits within the mine and nearby residential area. Residential areas near the crusher plants are vulnerable to increased noise propagation. It is recommended to put an acoustic barrier near the crusher plant to attenuate the noise propagation.

  3. THE STAR FORMATION HISTORY AND CHEMICAL EVOLUTION OF STAR-FORMING GALAXIES IN THE NEARBY UNIVERSE

    International Nuclear Information System (INIS)

    Torres-Papaqui, J. P.; Coziol, R.; Ortega-Minakata, R. A.; Neri-Larios, D. M.

    2012-01-01

    We have determined the metallicity (O/H) and nitrogen abundance (N/O) of a sample of 122,751 star-forming galaxies (SFGs) from the Data Release 7 of the Sloan Digital Sky Survey. For all these galaxies we have also determined their morphology and obtained a comprehensive picture of their star formation history (SFH) using the spectral synthesis code STARLIGHT. The comparison of the chemical abundance with the SFH allows us to describe the chemical evolution of the SFGs in the nearby universe (z ≤ 0.25) in a manner consistent with the formation of their stellar populations and morphologies. A high fraction (45%) of the SFGs in our sample show an excess abundance of nitrogen relative to their metallicity. We also find this excess to be accompanied by a deficiency of oxygen, which suggests that this could be the result of effective starburst winds. However, we find no difference in the mode of star formation of the nitrogen-rich and nitrogen-poor SFGs. Our analysis suggests that they all form their stars through a succession of bursts of star formation extended over a period of few Gyr. What produces the chemical differences between these galaxies seems therefore to be the intensity of the bursts: the galaxies with an excess of nitrogen are those that are presently experiencing more intense bursts or have experienced more intense bursts in their past. We also find evidence relating the chemical evolution process to the formation of the galaxies: the galaxies with an excess of nitrogen are more massive, and have more massive bulges and earlier morphologies than those showing no excess. Contrary to expectation, we find no evidence that the starburst wind efficiency decreases with the mass of the galaxies. As a possible explanation we propose that the loss of metals consistent with starburst winds took place during the formation of the galaxies, when their potential wells were still building up, and consequently were weaker than today, making starburst winds more

  4. New neighbours. III. 21 new companions to nearby dwarfs, discovered with adaptive optics

    Science.gov (United States)

    Beuzit, J.-L.; Ségransan, D.; Forveille, T.; Udry, S.; Delfosse, X.; Mayor, M.; Perrier, C.; Hainaut, M.-C.; Roddier, C.; Roddier, F.; Martín, E. L.

    2004-10-01

    We present some results of a CFHT adaptive optics search for companions to nearby dwarfs. We identify 21 new components in solar neighbourhood systems, of which 13 were found while surveying a volume-limited sample of M dwarfs within 12 pc. We are obtaining complete observations for this subsample, to derive unbiased multiplicity statistics for the very-low-mass disk population. Additionally, we resolve for the first time 6 known spectroscopic or astrometric binaries, for a total of 27 newly resolved companions. A significant fraction of the new binaries has favourable parameters for accurate mass determinations. The newly resolved companion of Gl 120.1C was thought to have a spectroscopic minimum mass in the brown-dwarf range (Duquennoy & Mayor \\cite{duquennoy91}), and it contributed to the statistical evidence that a few percent of solar-type stars might have close-in brown-dwarf companions. We find that Gl 120.1C actually is an unrecognised double-lined spectroscopic pair. Its radial-velocity amplitude had therefore been strongly underestimated by Duquennoy & Mayor (\\cite{duquennoy91}), and it does not truly belong to their sample of single-lined systems with minimum spectroscopic mass below the substellar limit. We also present the first direct detection of Gl 494B, an astrometric brown-dwarf candidate. Its luminosity straddles the substellar limit, and it is a brown dwarf if its age is less than ˜300 Myr. A few more years of observations will ascertain its mass and status from first principles. Based on observations made at Canada-France-Hawaii Telescope, operated by the National Research Council of Canada, the Centre National de la Recherche Scientifique de France and the University of Hawaii. Some of the data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The

  5. TWO NEARBY SUB-EARTH-SIZED EXOPLANET CANDIDATES IN THE GJ 436 SYSTEM

    International Nuclear Information System (INIS)

    Stevenson, Kevin B.; Harrington, Joseph; Lust, Nate B.; Blecic, Jasmina; Hardy, Ryan A.; Cubillos, Patricio; Campo, Christopher J.; Lewis, Nikole K.; Montagnier, Guillaume; Moses, Julianne I.; Visscher, Channon

    2012-01-01

    We report the detection of UCF-1.01, a strong exoplanet candidate with a radius 0.66 ± 0.04 times that of Earth (R ⊕ ). This sub-Earth-sized planet transits the nearby M-dwarf star GJ 436 with a period of 1.365862 ± 8 × 10 –6 days. We also report evidence of a 0.65 ± 0.06 R ⊕ exoplanet candidate (labeled UCF-1.02) orbiting the same star with an undetermined period. Using the Spitzer Space Telescope, we measure the dimming of light as the planets pass in front of their parent star to assess their sizes and orbital parameters. If confirmed today, UCF-1.01 and UCF-1.02 would be designated GJ 436c and GJ 436d, respectively, and would be part of the first multiple-transiting-planet system outside of the Kepler field. Assuming Earth-like densities of 5.515 g cm –3 , we predict both candidates to have similar masses (∼0.28 Earth-masses, M ⊕ , 2.6 Mars-masses) and surface gravities of ∼0.65 g (where g is the gravity on Earth). UCF-1.01's equilibrium temperature (T eq , where emitted and absorbed radiation balance for an equivalent blackbody) is 860 K, making the planet unlikely to harbor life as on Earth. Its weak gravitational field and close proximity to its host star imply that UCF-1.01 is unlikely to have retained its original atmosphere; however, a transient atmosphere is possible if recent impacts or tidal heating were to supply volatiles to the surface. We also present additional observations of GJ 436b during secondary eclipse. The 3.6 μm light curve shows indications of stellar activity, making a reliable secondary eclipse measurement impossible. A second non-detection at 4.5 μm supports our previous work in which we find a methane-deficient and carbon monoxide-rich dayside atmosphere.

  6. Dark Matter Searches with Cherenkov Telescopes: Nearby Dwarf Galaxies or Local Galaxy Clusters?

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Conde, Miguel A.; /KIPAC, Menlo Park /SLAC /IAC, La Laguna /Laguna U., Tenerife; Cannoni, Mirco; /Huelva U.; Zandanel, Fabio; /IAA, Granada; Gomez, Mario E.; /Huelva U.; Prada, Francisco; /IAA, Granada

    2012-06-06

    In this paper, we compare dwarf galaxies and galaxy clusters in order to elucidate which object class is the best target for gamma-ray DM searches with imaging atmospheric Cherenkov telescopes (IACTs). We have built a mixed dwarfs+clusters sample containing some of the most promising nearby dwarf galaxies (Draco, Ursa Minor, Wilman 1 and Segue 1) and local galaxy clusters (Perseus, Coma, Ophiuchus, Virgo, Fornax, NGC 5813 and NGC 5846), and then compute their DM annihilation flux profiles by making use of the latest modeling of their DM density profiles. We also include in our calculations the effect of DM substructure. Willman 1 appears as the best candidate in the sample. However, its mass modeling is still rather uncertain, so probably other candidates with less uncertainties and quite similar fluxes, namely Ursa Minor and Segue 1, might be better options. As for galaxy clusters, Virgo represents the one with the highest flux. However, its large spatial extension can be a serious handicap for IACT observations and posterior data analysis. Yet, other local galaxy cluster candidates with more moderate emission regions, such as Perseus, may represent good alternatives. After comparing dwarfs and clusters, we found that the former exhibit annihilation flux profiles that, at the center, are roughly one order of magnitude higher than those of clusters, although galaxy clusters can yield similar, or even higher, integrated fluxes for the whole object once substructure is taken into account. Even when any of these objects are strictly point-like according to the properties of their annihilation signals, we conclude that dwarf galaxies are best suited for observational strategies based on the search of point-like sources, while galaxy clusters represent best targets for analyses that can deal with rather extended emissions. Finally, we study the detection prospects for present and future IACTs in the framework of the constrained minimal supersymmetric standard model. We

  7. VizieR Online Data Catalog: Radio haloes in nearby galaxies (Heesen+, 2018)

    Science.gov (United States)

    Heesen, V.; Krause, M.; Beck, R.; Adebahr, B.; Bomans, D. J.; Carretti, E.; Dumke, M.; Heald, G.; Irwin, J.; Koribalski, B. S.; Mulcahy, D. D.; Westmeier, T.; Dettmar, R.-J.

    2018-02-01

    We present radio continuum observations of 12 nearby (D=2-27Mpc) edge-on galaxies at two different frequencies, namely at 1.4 and 5GHz (one galaxy at 8.5GHz instead of 5GHz). Our sample includes 11 late-type spiral (Sb or Sc) galaxies and one Magellanic-type barred galaxy (SBm), which are all highly inclined (i>=76°). As part of our study we have obtained several additional radio continuum maps. We make these maps publicly available (as well as all the other radio continuum maps in the paper). For 4 galaxies (NGC 55, 253, 891 and 4631) we have used single-dish maps, to correct for the missing zero-spacing flux where necessary. The Effelsberg maps of NGC 253 and 4631 were already presented in Heesen et al. (2009A&A...494..563H) and Mora & Krause (2013A&A...560A..42M), respectively, and the Effelsberg map of NGC 891 was already presented in Dumke (1997, PhD thesis, University of Bonn). We present these maps for completeness. The 4.80-GHz map of NGC 55 obtained with the 64-m Parkes telescope is so far unpublished. Furthermore, we show two maps of NGC 4631 at 1.35 and 1.65GHz observed with the VLA in D- configuration (R. Beck 2016, priv. comm.). The data were observed in August 1996, with 12 h on-source (ID: AG486) and reduced in standard fashion with AIPS. The maps have an angular resolution of 52 arcsec, so that we did not use them in the analysis, but they also show the halo of this galaxy very well. Lastly, we obtained maps of three further edge-on galaxies observed with the VLA (NGC 4157, 4217 and 4634). We reduced the data as described in Section 2, but since we had only one frequency available and no spectral index map, we did not use them in the analysis. The maps of NGC 4157 and 4217 were created by re-reducing archive data (IDs AI23, AF85, AH457 and AS392 for NGC 4157 and ID AM573 for NGC 4217). The map of NGC 4634 was created by using so far unpublished data from the VLA (ID: AD538). (3 data files).

  8. Two nearby Sub-Earth-sized Exoplanet Candidates in the GJ 436 System

    Science.gov (United States)

    Stevenson, Kevin B.; Harrington, Joseph; Lust, Nate B.; Lewis, Nikole K.; Montagnier, Guillaume; Moses, Julianne I.; Visscher, Channon; Blecic, Jasmina; Hardy, Ryan A.; Cubillos, Patricio; Campo, Christopher J.

    2012-08-01

    We report the detection of UCF-1.01, a strong exoplanet candidate with a radius 0.66 ± 0.04 times that of Earth (R ⊕). This sub-Earth-sized planet transits the nearby M-dwarf star GJ 436 with a period of 1.365862 ± 8 × 10-6 days. We also report evidence of a 0.65 ± 0.06 R ⊕ exoplanet candidate (labeled UCF-1.02) orbiting the same star with an undetermined period. Using the Spitzer Space Telescope, we measure the dimming of light as the planets pass in front of their parent star to assess their sizes and orbital parameters. If confirmed today, UCF-1.01 and UCF-1.02 would be designated GJ 436c and GJ 436d, respectively, and would be part of the first multiple-transiting-planet system outside of the Kepler field. Assuming Earth-like densities of 5.515 g cm-3, we predict both candidates to have similar masses (~0.28 Earth-masses, M ⊕, 2.6 Mars-masses) and surface gravities of ~0.65 g (where g is the gravity on Earth). UCF-1.01's equilibrium temperature (T eq, where emitted and absorbed radiation balance for an equivalent blackbody) is 860 K, making the planet unlikely to harbor life as on Earth. Its weak gravitational field and close proximity to its host star imply that UCF-1.01 is unlikely to have retained its original atmosphere; however, a transient atmosphere is possible if recent impacts or tidal heating were to supply volatiles to the surface. We also present additional observations of GJ 436b during secondary eclipse. The 3.6 μm light curve shows indications of stellar activity, making a reliable secondary eclipse measurement impossible. A second non-detection at 4.5 μm supports our previous work in which we find a methane-deficient and carbon monoxide-rich dayside atmosphere.

  9. Library Programs in North Carolina

    Data.gov (United States)

    Town of Chapel Hill, North Carolina — Count of programs offered and program attendance numbers at public libraries in North CarolinaData is from the 2014-15 NC Statistical Report of NC Public Libraries:...

  10. Acceleration of H, He, and heavy ions observed in the magnetosheath, magnetotail, and near-by interplanetary space

    International Nuclear Information System (INIS)

    Fan, C.Y.; Gloeckler, G.; Hovestadt, D.

    1975-01-01

    Pulses of electrons and ions composed of H, He, and heavier elements were observed in the magnetosheath, magnetotail, and near-by interplanetary space. From the spatial positions where these particles were detected and the ion flow directions we conclude that they were accelerated at the bow shock near the sub-solar point and in the near-earth region of the neutral sheet of the magnetotail. (orig.) [de

  11. Rock Outcrops Redistribute Organic Carbon and Nutrients to Nearby Soil Patches in Three Karst Ecosystems in SW China.

    Directory of Open Access Journals (Sweden)

    Dianjie Wang

    Full Text Available Emergent rock outcrops are common in terrestrial ecosystems. However, little research has been conducted regarding their surface function in redistributing organic carbon and nutrient fluxes to soils nearby. Water that fell on and ran off 10 individual rock outcrops was collected in three 100 × 100 m plots within a rock desertification ecosystem, an anthropogenic forest ecosystem, and a secondary forest ecosystem between June 2013 and June 2014 in Shilin, SW China. The concentrations of total organic carbon (TOC, total nitrogen (N, total phosphorus (P, and potassium (K in the water samples were determined during three seasons, and the total amounts received by and flowing out from the outcrops were calculated. In all three ecosystems, TOC and N, P, and K were found throughout the year in both the water received by and delivered to nearby soil patches. Their concentrations and amounts were generally greater in forested ecosystems than in the rock desertification ecosystem. When rock outcrops constituted a high percentage (≥ 30% of the ground surface, the annual export of rock outcrop runoff contributed a large amount of organic carbon and N, P, and K nutrients to soil patches nearby by comparison to the amount soil patches received via atmospheric deposition. These contributions may increase the spatial heterogeneity of soil fertility within patches, as rock outcrops of different sizes, morphologies, and emergence ratios may surround each soil patch.

  12. Dissecting the assembly and star formation history of disks and bulges in nearby spirals using the VENGA IFU survey

    Science.gov (United States)

    Carrillo, Andreia Jessica; Jogee, Shardha; Kaplan, Kyle; Weinzirl, Tim; Blanc, Guillermo A.

    2017-06-01

    Integral field spectroscopy of nearby galaxies provides a powerful and unparalleled tool for studying how galaxies assemble the different components -- the bulge, bar, and disk-- that define the Hubble sequence. We explore the assembly and star formation history of these components using galaxies in the VIRUS-P Exploration of Nearby Galaxies (VENGA) survey of 30 nearby spiral galaxies. Compared to other integral field spectroscopy studies of spirals, our study benefits from high spatial sampling and resolution (typically a few 100 pc), large coverage from the bulge to the outer disk, broad wavelength range (3600-6800 A), and medium spectral resolution (120 km/s at 5000 A). In this poster, we present the methodology and data illustrating the exquisite, high-quality, spatially-resolved spectra out to large radii, and the distribution, kinematics, and metallicity of stars and ionized gas. We discuss the next steps in deriving the star formation history (SFH) of bulge, bar, and disk components, and elucidating their assembly pathway by comparing their SFH and structural properties to theoretical models of galaxy evolution. This project is supported by the NSF grants AST-1614798 and AST-1413652.

  13. VizieR Online Data Catalog: Solar neighborhood. XXXIX. Nearby white dwarfs (Subasavage+, 2017)

    Science.gov (United States)

    Subasavage, J. P.; Jao, W.-C.; Henry, T. J.; Harris, H. C.; Dahn, C. C.; Bergeron, P.; Dufour, P.; Dunlap, B. H.; Barlow, B. N.; Ianna, P. A.; Lepine, S.; Margheim, S. J.

    2017-10-01

    Standardized photometric observations were carried out at three separate telescopes. The Small & Moderate Aperture Research Telescope System (SMARTS) 0.9m telescope at Cerro Tololo Inter-American Observatory (CTIO) was used during Cerro Tololo Inter-American Observatory Parallax Investigation (CTIOPI) observing runs when conditions were photometric. A Tektronics 2K*2K detector was used in region-of-interest mode centered on the central quarter of the full CCD producing a Field Of View (FOV) of 6.8'*6.8'. The SMARTS 1.0m telescope at CTIO was used with the Y4KCam 4K*4K imager, producing a 19.7'*19.7' FOV. Finally, the Ritchey 40-in telescope at USNO Flagstaff Station (NOFS) was used with a Tektronics 2K*2K detector with a 20.0'*20.0' FOV. Near-infrared JHKs photometry was collected for WD0851-246, at the CTIO 4.0 m Blanco telescope using the NEWFIRM during an engineering night on 2011.27 UT. National Optical Astronomy Observatory (NOAO) Extremely Wide-field Infrared Image (NEWFIRM) is a 4K*4K InSb mosaic that provides a 28'*28' FOV on the Blanco telescope. Additional photometry values were extracted from the Sloan Digital Sky Survey (SDSS) DR12 (Alam et al. 2015, Cat. V/147), 2MASS, and the United Kingdom Infra-Red Telescope (UKIRT) Infrared Sky Survey (UKIDSS) DR9 Large Area Survey (LAS; see Lawrence et al. 2012, Cat. II/319), when available. Two White Dwarfs (WDs) presented here (WD1743-545 and WD2057-493) are newly discovered nearby WDs identified during a spectroscopic survey of WD candidates in the southern hemisphere (J. Subasavage et al. 2017, in preparation) taken from the SUPERBLINK catalog (Lepine & Shara 2015ASPC..493..455S). A third WD included here (WD2307-691) was previously unclassified, yet is a common proper-motion companion to a Hipparcos star within 25pc (HIP114416). A fourth WD (WD2028-171) was suspected to be a WD by the authors based on a trawl of the New Luyten Two Tenths (NLTT) catalog (Luyten 1979, Cat. I/98). Finally, a fifth WD (WD1241

  14. Meanwhile, North Korea

    International Nuclear Information System (INIS)

    Hautecouverture, Benjamin

    2014-08-01

    The progress regarding weapons of mass destruction (WMD) programmes in North Korea and the instability on the Korean Peninsula have taken a back seat in the international community's analysis and perhaps its concerns for more than a year. The last event to provoke a wave of protest and tangible renewed interest occurred on 12 February 2013 when Pyongyang carried out its third nuclear test with an estimated yield of 6 to 8 kilo-tonnes. The United Nations Security Council condemned the test on 7 March (Resolution 2094). With the exception of several recent Security Council declarations, it is clear that activity on the part of the international community has been sparse. The same can be said with regard to the European Union and the United States. This state of affairs is not surprising. The analysis takes note of it by ceasing, there or thereabouts, to produce new material. Firstly, the North Korean crisis is a long-term one and the diplomatic process that is meant to lead to its resolution has been interrupted; the Six-Party Talks have been at a standstill since the end of 2008. A agreement between the United States and North Korea, concluded on 29 February 2012 under which the North Korean regime accepted the principle of a moratorium on long-range missile tests, nuclear tests, and all activity at the Yongbyon nuclear complex lastly barely a few days. Many actors involved in the management of this crisis are suffering from a weariness whose acknowledgement is politically incorrect: with regard to Pyongyang's launch of missiles and rockets last spring, the U.S. admiral Samuel Locklear told the Associated Press in July 'you become somewhat numb, you start to say, well, it's not so much of a big deal'. Moreover, since 2013, the focus of international security with regard to WMD and beyond has also largely shifted from North-East Asia to the Middle East and Eastern Europe. Pell-mell, the worsening and broadening of the war in Syria, the terrorist surge in Iraq, the

  15. Lignite in North Dakota

    International Nuclear Information System (INIS)

    Porter, C.R.

    1995-01-01

    The State of North Dakota and the lignite industry are working together in a partnership called the Lignite Research, Development and Marketing Program. The program provides funds and supports activities which: preserve and enhance jobs and lignite production; ensure economic growth, stability and opportunity; and maintain a stable and competitive tax base. Since 1987, 70 grants totaling $24 million have been awarded. Each program dollar has resulted in nearly five of matching dollars. These program investments have yielded returns for the state and industry, including an additional $20 million annually from by-products at the Great Plains Synfuels Plant; about $1 million annually from improved reclamation practices; and combustion options, which preserve 2,000 megawatts of existing generation capacity. Research activities have identified future opportunities, including: the SynCoal demonstration plant, requiring 800,000 tons per year of new production; new chemical feedstock by-products from Great Plains worth an additional $26 million annually; revised reclamation practices that could substantially reduce cost; and potential new markets for upgraded lignite of about 12 million tons annually. This program helps ensure a healthy future for the North Dakota lignite industry, which currently represents 10% of the state's total economic base. Such a program is important because it will encourage the development of new and better uses of North Dakota's most abundant resource--lignite coal

  16. North American Regional Report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-11-15

    North America is an energy community fortunate to be endowed with a rich and varied resource base. It consumes about a third of the world's energy and produces about one quarter of world energy supply. North America depends on a mix of complementary energy sources that should remain competitive but not in conflict. The current supply mix varies between Canada, the United States and Mexico, but fossil fuels are dominant across the region, leaving the three member countries vulnerable to a myriad of risks associated with traditional supply sources. Energy trade between all three countries is also a major contributor to the region's economy. Thus, the impetus for collaboration across the region has grown out of the common goals of energy security and economic prosperity. The goal of the WEC regional group was to discuss avenues for advancing North American cooperation and coordination on a range of energy issues. An additional objective was to develop policy recommendations that will facilitate effective development and use of the region's energy resources. Results and recommendtaions are summarized from three forums that focused on the pertinent issues of energy trade, energy efficiency and energy diversification. The inaugural forum (Energy Trade) was held in Washington, D.C. in the fall of 2005. The following summer, the second forum (Energy Efficiency) took place in Mexico City. The third forum (Energy Diversification) was hosted in Halifax, Nova Scotia.

  17. North American Regional Report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-11-15

    North America is an energy community fortunate to be endowed with a rich and varied resource base. It consumes about a third of the world's energy and produces about one quarter of world energy supply. North America depends on a mix of complementary energy sources that should remain competitive but not in conflict. The current supply mix varies between Canada, the United States and Mexico, but fossil fuels are dominant across the region, leaving the three member countries vulnerable to a myriad of risks associated with traditional supply sources. Energy trade between all three countries is also a major contributor to the region's economy. Thus, the impetus for collaboration across the region has grown out of the common goals of energy security and economic prosperity. The goal of the WEC regional group was to discuss avenues for advancing North American cooperation and coordination on a range of energy issues. An additional objective was to develop policy recommendations that will facilitate effective development and use of the region's energy resources. Results and recommendtaions are summarized from three forums that focused on the pertinent issues of energy trade, energy efficiency and energy diversification. The inaugural forum (Energy Trade) was held in Washington, D.C. in the fall of 2005. The following summer, the second forum (Energy Efficiency) took place in Mexico City. The third forum (Energy Diversification) was hosted in Halifax, Nova Scotia.

  18. 76 FR 30695 - Environmental Management Site-Specific Advisory Board Chairs

    Science.gov (United States)

    2011-05-26

    .... ADDRESSES: Aliante Station Hotel, 7300 Aliante Parkway, North Las Vegas, Nevada 89084. FOR FURTHER... Topics and Achievements, [cir] EM Headquarters Budget Update, [cir] EM Headquarters Waste Disposition...

  19. A MOLECULAR STAR FORMATION LAW IN THE ATOMIC-GAS-DOMINATED REGIME IN NEARBY GALAXIES

    International Nuclear Information System (INIS)

    Schruba, Andreas; Walter, Fabian; Dumas, Gaelle; Sandstrom, Karin; Leroy, Adam K.; Bigiel, Frank; Brinks, Elias; De Blok, W. J. G.; Kramer, Carsten; Rosolowsky, Erik; Schuster, Karl; Usero, Antonio; Weiss, Axel; Wiesemeyer, Helmut

    2011-01-01

    We use the IRAM HERACLES survey to study CO emission from 33 nearby spiral galaxies down to very low intensities. Using 21 cm line atomic hydrogen (H I) data, mostly from THINGS, we predict the local mean CO velocity based on the mean H I velocity. By re-normalizing the CO velocity axis so that zero corresponds to the local mean H I velocity we are able to stack spectra coherently over large regions. This enables us to measure CO intensities with high significance as low as I CO ∼ 0.3 K km s -1 (Σ H 2 ∼1 M sun pc -2 ), an improvement of about one order of magnitude over previous studies. We detect CO out to galactocentric radii r gal ∼ r 25 and find the CO radial profile to follow a remarkably uniform exponential decline with a scale length of ∼0.2 r 25 . Here we focus on stacking as a function of radius, comparing our sensitive CO profiles to matched profiles of H I, Hα, far-UV (FUV), and Infrared (IR) emission at 24 μm and 70 μm. We observe a tight, roughly linear relationship between CO and IR intensity that does not show any notable break between regions that are dominated by molecular gas (Σ H 2 >Σ H i ) and those dominated by atomic gas (Σ H 2 H i ). We use combinations of FUV+24 μm and Hα+24 μm to estimate the recent star formation rate (SFR) surface density, Σ SFR , and find approximately linear relations between Σ SFR and Σ H 2 . We interpret this as evidence of stars forming in molecular gas with little dependence on the local total gas surface density. While galaxies display small internal variations in the SFR-to-H 2 ratio, we do observe systematic galaxy-to-galaxy variations. These galaxy-to-galaxy variations dominate the scatter in relationships between CO and SFR tracers measured at large scales. The variations have the sense that less massive galaxies exhibit larger ratios of SFR-to-CO than massive galaxies. Unlike the SFR-to-CO ratio, the balance between atomic and molecular gas depends strongly on the total gas surface density

  20. THE NEAR-INFRARED CORONAL LINE SPECTRUM OF 54 NEARBY ACTIVE GALACTIC NUCLEI

    International Nuclear Information System (INIS)

    Rodríguez-Ardila, A.; Prieto, M. A.; Portilla, J. G.; Tejeiro, J. M.

    2011-01-01

    The relationship between the emission of coronal lines (CLs) and nuclear activity in 36 Type 1 and 18 Type 2 active galactic nuclei (AGNs) is analyzed, for the first time, based on near-infrared (0.8-2.4 μm) spectra. The eight CLs studied, of Si, S, Fe, Al, and Ca elements and corresponding to ionization potentials (IPs) in the range 125-450 eV, are detected (3σ) in 67% (36 AGNs) of the sample. Our analysis shows that the four most frequent CLs [Si VI] 1.963 μm, [S VIII] 0.9913 μm, [S IX] 1.252 μm, and [Si X] 1.430 μm display a narrow range in luminosity, with most lines located in the interval log L 39-40 erg s –1 . We found that the non-detection is largely associated with either loss of spatial resolution or increasing object distance: CLs are essentially nuclear and easily lose contrast in the continuum stellar light for nearby sources or get diluted by the strong AGN continuum as the redshift increases. Yet, there are AGNs where the lack of coronal emission, i.e., lines with IP ≥ 100 eV, may be genuine. The absence of these lines reflects a non-standard AGN ionizing continuum, namely, a very hard spectrum lacking photons below a few Kev. The analysis of the line profiles points out a trend of increasing FWHM with increasing IPs up to energies around 300 eV, where a maximum in the FWHM is reached. For higher IP lines, the FWHM remains nearly constant or decreases with increasing IPs. We ascribe this effect to an increasing density environment as we approach the innermost regions of these AGNs, where densities above the critical density of the CLs with IPs larger than 300 eV are reached. This sets a strict range limit for the density in the boundary region between the narrow and the broad region of 10 8 -10 9 cm –3 . A relationship between the luminosity of the CLs and that of the soft and hard X-ray emission and the soft X-ray photon index is observed: the coronal emission becomes stronger with both increasing X-ray emission (soft and hard) and

  1. The Local ISM and its Interaction with the Winds of Nearby Late-type Stars

    Science.gov (United States)

    Wood, Brian E.; Linsky, Jeffrey L.

    1998-01-01

    We present new Goddard High-Resolution Spectrograph (GHRS) observations of the Ly-alpha and Mg II absorption lines seen toward the nearby stars 61 Cyg A and 40 Eri A. We use these data to measure interstellar properties along these lines of sight and to search for evidence of circumstellar hydrogen walls, which are produced by collisions between the stellar winds and the Local InterStellar Medium (LISM). We were able to model the Ly-alpha lines of both stars without hydrogen-wall absorption components, but for 61 Cyg A the fit required a stellar Ly-alpha, line profile with an improbably deep self-reversal, and for 40 Eri A the fit required a very low deuterium-to-hydrogen ratio that is inconsistent with previous GHRS measurements. Since these problems could be rectified simply by including stellar hydrogen-wall components with reasonable attributes, our preferred fits to the data include these components. We have explored several ways in which the hydrogen-wall properties measured here and in previous work can be used to study stellar winds and the LISM. We argue that the existence of a hydrogen wall around 40 Eri A and a low H I column density along that line of sight imply that either the interstellar density must decrease toward 40 Eri A or the hydrogen ionization fraction (chi) must increase. We find that hydrogen-wall temperatures are larger for stars with faster velocities through the LISM. The observed temperature-velocity relation is consistent with the predictions of hydromagnetic shock jump conditions. More precise comparison of the data and the jump conditions suggests crude upper limits for both chi and the ratio of magnetic to thermal pressure in the LISM (alpha): chi less than 0.6 and alpha less than 2. The latter upper limit corresponds to a limit on the LISM magnetic field of B less than 5 micro G. These results imply that the plasma Mach number of the interstellar wind flowing into the heliosphere is M(sub A) greater than 1.3, which indicates that

  2. SUB-MILLIMETER TELESCOPE CO (2-1) OBSERVATIONS OF NEARBY STAR-FORMING GALAXIES

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Xue-Jian; Gu, Qiusheng [School of Astronomy and Space Science, Nanjing University, Nanjing 210093 (China); Wang, Zhong [Harvard-Smithsonian Center for Astrophysics, MS 66, 60 Garden Street, Cambridge, MA 02138 (United States); Wang, Junzhi [Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai 200030 (China); Zhang, Zhi-Yu, E-mail: xjjiang@nju.edu.cn [The UK Astronomy Technology Centre, Royal Observatory Edinburgh, Blackford Hill, Edinburgh, EH9 3HJ (United Kingdom)

    2015-01-20

    We present CO J = 2-1 observations toward 32 nearby gas-rich star-forming galaxies selected from the ALFALFA and Wide-field Infrared Survey Explorer (WISE) catalogs, using the Sub-millimeter Telescope (SMT). Our sample is selected to be dominated by intermediate-M {sub *} galaxies. The scaling relations between molecular gas, atomic gas, and galactic properties (stellar mass, NUV – r, and WISE color W3 – W2) are examined and discussed. Our results show the following. (1) In the galaxies with stellar mass M {sub *} ≤10{sup 10} M {sub ☉}, the H I fraction (f {sub H} {sub I} ≡ M {sub H} {sub I}/M {sub *}) is significantly higher than that of more massive galaxies, while the H{sub 2} gas fraction (f{sub H{sub 2}} ≡ M{sub H{sub 2}}/M {sub *}) remains nearly unchanged. (2) Compared to f{sub H{sub 2}}, f {sub H} {sub I} correlates better with both M {sub *} and NUV – r. (3) A new parameter, WISE color W3 – W2 (12-4.6 μm), is introduced, which is similar to NUV – r in tracing star formation activity, and we find that W3 – W2 has a tighter anti-correlation with log f{sub H{sub 2}} than the anti-correlation of (NUV – r)-f {sub H} {sub I}, (NUV – r)-f{sub H{sub 2}}, and (W3 – W2)-f {sub H} {sub I}. This indicates that W3 – W2 can trace the H{sub 2} fraction in galaxies. For the gas ratio M{sub H{sub 2}}/M {sub H} {sub I} , only in the intermediate-M {sub *} galaxies it appears to depend on M {sub *} and NUV – r. We find a tight correlation between the molecular gas mass M{sub H{sub 2}} and 12 μm (W3) luminosities (L {sub 12} {sub μm}), and the slope is close to unity (1.03 ± 0.06) for the SMT sample. This correlation may reflect that the cold gas and dust are well mixed on a global galactic scale. Using the all-sky 12 μm (W3) data available in WISE, this correlation can be used to estimate CO flux for molecular gas observations and can even predict H{sub 2} mass for star-forming galaxies.

  3. Toward the comprehension of the infrared to submillimeter view of the interstellar medium of nearby galaxies

    International Nuclear Information System (INIS)

    Galametz, Maud

    2010-01-01

    This thesis aims to study the interstellar medium (ISM) of nearby galaxies to characterize the physical properties of the gas and dust. We especially focused our study on low-metallicity galaxies of the Local Universe, ideal candidates to study the influence of metal enrichment on the ISM properties of galaxies. Previous studies have shown that the Spectral Energy Distributions (SEDs) of low metallicity galaxies differ significantly from those of massive galaxies and that the dust-to-gas mass ratio (D/G) of the galaxy could be dependent of the metallicity. Observations of low-metallicity galaxies also often led to the detection of an excess at submillimeter (sub-mm) wavelengths not always accounted for in usual SED models. Further studies and observations had to be performed to better cover the far-IR to sub-mm range and probe the coldest phase of dust. We adopt a multi-wavelength approach to model and analyse the SEDs of 4 low-metallicity galaxies observed with LABOCA at 870 μm. We estimated the fraction of cool dust to be significant compared to the total dust mass of the galaxies. Some D/Gs are incoherent compared to what is expected from the current chemical evolution model, revealing possible reservoirs of gas not detected by current HI or CO observations. I enlarged the first sample to a wider range of metallicities and showed that sub-mm measurements significantly affect the dust mass estimates of galaxies. For dustier galaxies for which the SED usually peaks at longer wavelengths, sub-mm fluxes are crucial to position the peak and the Rayleigh-Jeans slope of their SED. For low-metallicity galaxies, the sub-mm wavelength domain harbours an excess that may imply a large amount of very cold dust. Our results confirm that low-metallicity galaxies can exhibit a sub-mm excess when observed at longer wavelengths. Obtaining a more precise inventory of the cold dust and resolve the main actors of dust evolution in massive star forming regions and molecular clouds

  4. Dust spectral energy distributions of nearby galaxies: an insight from the Herschel Reference Survey

    Science.gov (United States)

    Ciesla, L.; Boquien, M.; Boselli, A.; Buat, V.; Cortese, L.; Bendo, G. J.; Heinis, S.; Galametz, M.; Eales, S.; Smith, M. W. L.; Baes, M.; Bianchi, S.; De Looze, I.; di Serego Alighieri, S.; Galliano, F.; Hughes, T. M.; Madden, S. C.; Pierini, D.; Rémy-Ruyer, A.; Spinoglio, L.; Vaccari, M.; Viaene, S.; Vlahakis, C.

    2014-05-01

    correlated, suggesting that the diffuse dust component is heated by both the young stars in star-forming regions and the diffuse evolved population. We use these results to provide a new set of infrared templates calibrated with Herschel observations on nearby galaxies and a mean SED template to provide the z = 0 reference for cosmological studies. For the same purpose, we place our sample on the SFR - M∗ diagram. The templates are compared to the most popular infrared SED libraries, enlightening a large discrepancy between all of them in the 20-100 μm range. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.Table 4 and appendices are available in electronic form at http://www.aanda.org

  5. A mass census of the nearby universe with the RESOLVE survey

    Science.gov (United States)

    Eckert, Kathleen

    The galaxy mass function, i.e., the distribution of galaxies as a function of mass, is a useful way to characterize the galaxy population. In this work, we examine the stellar and baryonic mass function, and the velocity function of galaxies and galaxy groups for two volume-limited surveys of the nearby universe. Stellar masses are estimated from multi-band photometry, and we add cold atomic gas from measurements and a newly calibrated estimator to obtain baryonic mass. Velocities are measured from the internal motions of galaxies and groups and account for all matter within the system. We compare our observed mass and velocity functions with the halo mass function from theoretical simulations of dark matter, which predict a much more steeply rising low-mass slope than is normally observed for the galaxy mass function. We show that taking into account the cold gas mass, which dominates the directly detectable mass of low-mass galaxies, steepens the low-mass slope of the galaxy mass function. The low- mass slope of the baryonic mass function, however, is still much shallower than that of the halo mass function. The discrepancy in low-mass slope persists when examining the velocity function, which accounts for all matter in galaxies (detectable or not), suggesting that some mechanism must reduce the mass in halos or destroy them completely. We investigate the role of environment by performing group finding and examining the mass and velocity functions as a function of group halo mass. Broken down by halo mass regime, we find dips and varying low-mass slopes in the mass and velocity functions, suggesting that group formation processes such as merging and stripping, which destroy and lower the mass of low-mass satellites respectively, potentially contribute to the discrepancy in low-mass slope. In particular, we focus on the nascent group regime, groups of mass 10 11.4-12 [solar mass] with few members, which has a depressed and flat low-mass slope in the galaxy mass

  6. Study of the malaria situation in forested foothill and nearby plain areas of Myanmar.

    Science.gov (United States)

    Myint, L; Ye, H

    1991-12-01

    A longitudinal demographic-parasitological survey on malaria was conducted at 10 weekly intervals starting from September in one foothill village with the population of 1,095 and one epidemiologically comparable plain village with the population of 962 in Kyauktaga township, Bago division, 120 miles north of Yangon. The objective was to describe and analyse the current malaria situation in a forested foothill area and an adjacent plain area. Ten weekly blood film collections for malaria parasite examination, six monthly sera collections on filter paper for serological examination from the whole study population and ten weekly splenic measurements from 2-9 year children were done. The malaria parasite rate in the foothill area was invariably higher than that in the plain area in all age groups throughout the study period. Moreover, the parasite rate decreased with the increase in distance from the forested foothill area indicating that the deep forest malaria may have some influence on the foothill villages. The total age specific parasite rate in foothill villages was found to be highest in the 5-8 year age group and decreased as the age advanced which may be due to the increasing immunity. The study revealed the presence of local transmission in the foothill village. From these data it is evident that new village sites should be chosen at least 5 miles away from the forest fringe and the malaria control measures in the plain area should utilize chemoprophylaxis and effective chemotherapy focusing on the people who travel into the forest.

  7. North America: Chapter 5

    Science.gov (United States)

    Schwartz, Mark D.; Beaubien, Elisabeth G.; Crimmins, Theresa M.; Weltzin, Jake F.; Edited by Schwartz, Mark D.

    2013-01-01

    Plant phenological observations and networks in North America have been largely local and regional in extent until recent decades. In the USA, cloned plant monitoring networks were the exception to this pattern, with data collection spanning the late 1950s until approximately the early 1990s. Animal observation networks, especially for birds have been more extensive. The USA National Phenology Network (USA-NPN), established in the mid-2000s is a recent effort to operate a comprehensive national-scale network in the United States. In Canada, PlantWatch, as part of Nature Watch, is the current national-scale plant phenology program.

  8. Fargo, North Dakota, USA

    Science.gov (United States)

    2009-01-01

    [figure removed for brevity, see original site] Annotated version Click on the image for high resolution TIFF file Why does Fargo flood? The Red River of the North, which forms the border between North Dakota and Minnesota, has a long history of severe floods. Major floods include those of 1826, 1897, 1950, 1997, and now 2009. The 1997 flood caused billions of dollars of damage, with greatest impact to the city of Grand Forks, north of and downstream from Fargo. The 2009 flood, which has primarily impacted Fargo, appears to have peaked early on March 28. Several factors combine to cause floods. Obviously, rainfall and snowmelt rates (and their geographic distribution) are the fundamental variables that create flooding in some years and not others. But the repetition of flooding in Fargo (and areas downstream), rather than in adjacent regions, can be attributed largely to its topographic setting and geologic history. The formation of landforms in the geologic past is often interpretable from digital topographic data, such as that supplied by the Shuttle Radar Topography Mission (SRTM). This image, covering parts of North Dakota, Minnesota, and South Dakota, displays ground elevation as brightness (higher is brighter) plus has simulated shading (with illumination from the north) to enhance topographic detail such as stream channels, ridges, and cliffs. The Red River of the North is the only major river that flows northward from the United States into Canada. In this scene it flows almost straight north from Fargo. North of this image it continues past the city of Winnipeg, Manitoba, and into Lake Winnipeg, which in turn drains to Hudson Bay. In the United States, the river lies in a trough that was shaped by continental glaciers that pushed south from Canada during the Pleistocene epoch, up to about 10,000 years ago. This trough is about 70 km (45 miles) wide and tens of meters (very generally about 100 feet) deep. Here near Fargo it lies on the east side of a much

  9. North America pipeline map

    International Nuclear Information System (INIS)

    Anon.

    2005-01-01

    This map presents details of pipelines currently in place throughout North America. Fifty-nine natural gas pipelines are presented, as well as 16 oil pipelines. The map also identifies six proposed natural gas pipelines. Major cities, roads and highways are included as well as state and provincial boundaries. The National Petroleum Reserve is identified, as well as the Arctic National Wildlife Refuge. The following companies placed advertisements on the map with details of the services they provide relating to pipeline management and construction: Ferus Gas Industries Trust; Proline; SulfaTreat Direct Oxidation; and TransGas. 1 map

  10. OVERVIEW OF THE SDSS-IV MaNGA SURVEY: MAPPING NEARBY GALAXIES AT APACHE POINT OBSERVATORY

    Energy Technology Data Exchange (ETDEWEB)

    Bundy, Kevin [Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU, WPI), Todai Institutes for Advanced Study, the University of Tokyo, Kashiwa 277-8583 (Japan); Bershady, Matthew A.; Wake, David A.; Tremonti, Christy; Diamond-Stanic, Aleksandar M. [Department of Astronomy, University of Wisconsin-Madison, 475 North Charter Street, Madison, WI 53706 (United States); Law, David R.; Cherinka, Brian [Dunlap Institute for Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, Ontario M5S 3H4 (Canada); Yan, Renbin; Sánchez-Gallego, José R. [Department of Physics and Astronomy, University of Kentucky, 505 Rose Street, Lexington, KY 40506-0055 (United States); Drory, Niv [McDonald Observatory, Department of Astronomy, University of Texas at Austin, 1 University Station, Austin, TX 78712-0259 (United States); MacDonald, Nicholas [Department of Astronomy, Box 351580, University of Washington, Seattle, WA 98195 (United States); Weijmans, Anne-Marie [School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews KY16 9SS (United Kingdom); Thomas, Daniel; Masters, Karen; Coccato, Lodovico [Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth (United Kingdom); Aragón-Salamanca, Alfonso [School of Physics and Astronomy, University of Nottingham, University Park, Nottingham NG7 2RD (United Kingdom); Avila-Reese, Vladimir [Instituto de Astronomia, Universidad Nacional Autonoma de Mexico, A.P. 70-264, 04510 Mexico D.F. (Mexico); Badenes, Carles [Department of Physics and Astronomy and Pittsburgh Particle Physics, Astrophysics and Cosmology Center (PITT PACC), University of Pittsburgh, 3941 OHara St, Pittsburgh, PA 15260 (United States); Falcón-Barroso, Jésus [Instituto de Astrofísica de Canarias, E-38200 La Laguna, Tenerife (Spain); Belfiore, Francesco [Cavendish Laboratory, University of Cambridge, 19 J. J. Thomson Avenue, Cambridge CB3 0HE (United Kingdom); and others

    2015-01-01

    We present an overview of a new integral field spectroscopic survey called MaNGA (Mapping Nearby Galaxies at Apache Point Observatory), one of three core programs in the fourth-generation Sloan Digital Sky Survey (SDSS-IV) that began on 2014 July 1. MaNGA will investigate the internal kinematic structure and composition of gas and stars in an unprecedented sample of 10,000 nearby galaxies. We summarize essential characteristics of the instrument and survey design in the context of MaNGA's key science goals and present prototype observations to demonstrate MaNGA's scientific potential. MaNGA employs dithered observations with 17 fiber-bundle integral field units that vary in diameter from 12'' (19 fibers) to 32'' (127 fibers). Two dual-channel spectrographs provide simultaneous wavelength coverage over 3600-10300 Å at R ∼ 2000. With a typical integration time of 3 hr, MaNGA reaches a target r-band signal-to-noise ratio of 4-8 (Å{sup –1} per 2'' fiber) at 23 AB mag arcsec{sup –2}, which is typical for the outskirts of MaNGA galaxies. Targets are selected with M {sub *} ≳ 10{sup 9} M {sub ☉} using SDSS-I redshifts and i-band luminosity to achieve uniform radial coverage in terms of the effective radius, an approximately flat distribution in stellar mass, and a sample spanning a wide range of environments. Analysis of our prototype observations demonstrates MaNGA's ability to probe gas ionization, shed light on recent star formation and quenching, enable dynamical modeling, decompose constituent components, and map the composition of stellar populations. MaNGA's spatially resolved spectra will enable an unprecedented study of the astrophysics of nearby galaxies in the coming 6 yr.

  11. OVERVIEW OF THE SDSS-IV MaNGA SURVEY: MAPPING NEARBY GALAXIES AT APACHE POINT OBSERVATORY

    International Nuclear Information System (INIS)

    Bundy, Kevin; Bershady, Matthew A.; Wake, David A.; Tremonti, Christy; Diamond-Stanic, Aleksandar M.; Law, David R.; Cherinka, Brian; Yan, Renbin; Sánchez-Gallego, José R.; Drory, Niv; MacDonald, Nicholas; Weijmans, Anne-Marie; Thomas, Daniel; Masters, Karen; Coccato, Lodovico; Aragón-Salamanca, Alfonso; Avila-Reese, Vladimir; Badenes, Carles; Falcón-Barroso, Jésus; Belfiore, Francesco

    2015-01-01

    We present an overview of a new integral field spectroscopic survey called MaNGA (Mapping Nearby Galaxies at Apache Point Observatory), one of three core programs in the fourth-generation Sloan Digital Sky Survey (SDSS-IV) that began on 2014 July 1. MaNGA will investigate the internal kinematic structure and composition of gas and stars in an unprecedented sample of 10,000 nearby galaxies. We summarize essential characteristics of the instrument and survey design in the context of MaNGA's key science goals and present prototype observations to demonstrate MaNGA's scientific potential. MaNGA employs dithered observations with 17 fiber-bundle integral field units that vary in diameter from 12'' (19 fibers) to 32'' (127 fibers). Two dual-channel spectrographs provide simultaneous wavelength coverage over 3600-10300 Å at R ∼ 2000. With a typical integration time of 3 hr, MaNGA reaches a target r-band signal-to-noise ratio of 4-8 (Å –1 per 2'' fiber) at 23 AB mag arcsec –2 , which is typical for the outskirts of MaNGA galaxies. Targets are selected with M * ≳ 10 9 M ☉ using SDSS-I redshifts and i-band luminosity to achieve uniform radial coverage in terms of the effective radius, an approximately flat distribution in stellar mass, and a sample spanning a wide range of environments. Analysis of our prototype observations demonstrates MaNGA's ability to probe gas ionization, shed light on recent star formation and quenching, enable dynamical modeling, decompose constituent components, and map the composition of stellar populations. MaNGA's spatially resolved spectra will enable an unprecedented study of the astrophysics of nearby galaxies in the coming 6 yr

  12. The sources of trace element pollution of dry depositions nearby a drinking water source.

    Science.gov (United States)

    Guo, Xinyue; Ji, Hongbing; Li, Cai; Gao, Yang; Ding, Huaijian; Tang, Lei; Feng, Jinguo

    2017-02-01

    Miyun Reservoir is one of the most important drinking water sources for Beijing. Thirteen atmospheric PM sampling sites were established around this reservoir to analyze the mineral composition, morphological characteristics, element concentration, and sources of atmospheric PM pollution, using transmission electron microscope, X-ray diffraction, and inductively coupled plasma mass spectrometry analyses. The average monthly dry deposition flux of aerosols was 15.18 g/m 2 , with a range of 5.78-47.56 g/m 2 . The maximum flux season was winter, followed by summer, autumn, and spring. Zn and Pb pollution in this area was serious, and some of the sample sites had Cr, Co, Ni, and Cu pollution. Deposition fluxes of Zn/Pb in winter and summer reached 99.77/143.63 and 17.04/33.23 g/(hm 2 month), respectively. Principal component analysis showed two main components in the dry deposition; the first was Cr, Co, Ni, Cu, and Zn, and the other was Pb and Cd. Principal sources of the trace elements were iron mining and other anthropogenic activities in the surrounding areas and mountainous area north of the reservoir. Mineralogy analysis and microscopic conformation results showed many iron minerals and some unweathered minerals in dry deposition and atmospheric particulate matter, which came from an iron ore yard in the northern mountainous area of Miyun County. There was possible iron-rich dry deposition into Miyun Reservoir, affecting its water quality and harming the health of people living in areas around the reservoir and Beijing.

  13. Twin radio relics in the nearby low-mass galaxy cluster Abell 168

    Science.gov (United States)

    Dwarakanath, K. S.; Parekh, V.; Kale, R.; George, L. T.

    2018-06-01

    We report the discovery of twin radio relics in the outskirts of the low-mass merging galaxy cluster Abell 168 (redshift=0.045). One of the relics is elongated with a linear extent ˜800 kpc and projected width of ˜80 kpc and is located ˜900 kpc towards the north of the cluster centre, oriented roughly perpendicular to the major axis of the X-ray emission. The second relic is ring-shaped with a size ˜220 kpc and is located near the inner edge of the elongated relic at a distance of ˜600 kpc from the cluster centre. These radio sources were imaged at 323 and 608 MHz with the Giant Meterwave Radio Telescope and at 1520 MHz with the Karl G. Jansky Very Large Array (VLA). The elongated relic was detected at all frequencies, with a radio power of 1.38 ± 0.14 × 1023 W Hz-1 at 1.4 GHz and a power law in the frequency range 70-1500 MHz (S ∝ να, α = -1.1 ± 0.04). This radio power is in good agreement with that expected from the known empirical relation between the radio powers of relics and host cluster masses. This is the lowest mass (M500 = 1.24 × 1014 M⊙) cluster in which relics due to merger shocks are detected. The ring-shaped relic has a steeper spectral index (α) of -1.74 ± 0.29 in the frequency range 100-600 MHz. We propose this relic to be an old plasma, revived due to adiabatic compression by the outgoing shock that produced the elongated relic.

  14. Photochemical processing of organic aerosol at nearby continental sites: contrast between urban plumes and regional aerosol

    Science.gov (United States)

    Slowik, J. G.; Brook, J.; Chang, R. Y.-W.; Evans, G. J.; Hayden, K.; Jeong, C.-H.; Li, S.-M.; Liggio, J.; Liu, P. S. K.; McGuire, M.; Mihele, C.; Sjostedt, S.; Vlasenko, A.; Abbatt, J. P. D.

    2011-03-01

    As part of the BAQS-Met 2007 field campaign, Aerodyne time-of-flight aerosol mass spectrometers (ToF-AMS) were deployed at two sites in southwestern Ontario from 17 June to 11 July 2007. One instrument was located at Harrow, ON, a rural, agriculture-dominated area approximately 40 km southeast of the Detroit/Windsor/Windsor urban area and 5 km north of Lake Erie. The second instrument was located at Bear Creek, ON, a rural site approximately 70 km northeast of the Harrow site and 50 km east of Detroit/Windsor. Positive matrix factorization analysis of the combined organic mass spectral dataset yields factors related to secondary organic aerosol (SOA), direct emissions, and a factor tentatively attributed to the reactive uptake of isoprene and/or condensation of its early generation reaction products. This is the first application of PMF to simultaneous AMS measurements at different sites, an approach which allows for self-consistent, direct comparison of the datasets. Case studies are utilized to investigate processing of SOA from (1) fresh emissions from Detroit/Windsor and (2) regional aerosol during periods of inter-site flow. A strong correlation is observed between SOA/excess CO and photochemical age as represented by the NOx/NOy ratio for Detroit/Windsor outflow. Although this correlation is not evident for more aged air, measurements at the two sites during inter-site transport nevertheless show evidence of continued atmospheric processing by SOA production. However, the rate of SOA production decreases with airmass age from an initial value of ~10.1 μg m-3 ppmvCO-1 h-1 for the first ~10 h of plume processing to near-zero in an aged airmass (i.e. after several days). The initial SOA production rate is comparable to the observed rate in Mexico City over similar timescales.

  15. Radiation protection of workers from uranium mines and of the public living nearby uranium mining and milling facilities

    International Nuclear Information System (INIS)

    Kiselev, Mikhail; Romanov, Vladimir; Shandala, Nataliya; Gneusheva, Galina; Titov, Alex; Novikova, Natalia; Smith, Graham

    2008-01-01

    As part of the program of nuclear power development, the Russia Federation plans to increase uranium production and to improve supply from existing uranium mining and milling facilities. Moreover, development of new uranium ore deposits is also envisaged. A corollary of these developments is the placing of a high priority on environmental and human health protection Special attention should be paid to assurance of health protection both of workers and of the public living nearby such facilities. This paper reviews the status and development of understanding of facilities in the Russian Federation from a regulatory perspective. (author)

  16. Nanoscale quantum gyroscope using a single 13C nuclear spin coupled with a nearby NV center in diamond

    Science.gov (United States)

    Song, Xuerui; Wang, Liujun; Feng, Fupan; Lou, Liren; Diao, Wenting; Duan, Chongdi

    2018-03-01

    Developing gyroscopes based on quantum systems are important for inertial sensing applications, and its underlying physics is of fundamental interest. In this paper, we proposed a new type of gyroscope based on the Berry phase generated during rotation of the quantum system by using a single 13C nuclear spin coupled with a nearby nitrogen-vacancy center in diamond. Due to the atom-scale size of the quantum system, rotation information can be obtained with high spatial resolution. The gyroscope can be manipulated at room temperature and without the need for a strong magnetic field, which is also beneficial to its further applications.

  17. Determination of radon concentration in drinking water resources of villages nearby Lalehzar fault and evaluation the annual effective dose

    International Nuclear Information System (INIS)

    Mohammad Malakootian; Zahra Darabi Fard; Mojtaba Rahimi

    2015-01-01

    The radon concentration has been measured in 44 drinking water resources, in villages nearby Lalehzar fault in winter 2014. Some samples showed a higher concentration of radon surpassing limit set by EPA. Further, a sample was taken from water distribution networks for these sources of water. Soluble radon concentration was measured by RAD7 device. Range radon concentration was 26.88 and 0.74 BqL -1 respectively. The maximum and minimum annual effective dose for adults was estimated at 52.7 and 2.29 µSvY -1 , respectively. Reducing radon from water before use is recommended to improve public health. (author)

  18. A High-definition View Of The Circum-nuclear Regions In Nearby Seyferts With Chandra And HST

    Science.gov (United States)

    Wang, Junfeng; Fabbiano, G.; Elvis, M.; Risaliti, G.; Karovska, M.; Zezas, A.; Mundell, C. G.

    2011-09-01

    To improve our understanding of AGN feedback, it is crucial to evaluate the true role of outflows on galaxy evolution observationally. I will present new results from the CHandra survey of Extended Emission-line Regions in nearby Seyfert galaxies (CHEERS), which aims to examine feedback in action in much greater detail than at high redshift. Findings from Chandra studies of the circum-nuclear region in the archetypal Seyfert 1 galaxy NGC 4151 will be discussed in detail. Exploiting Chandra's highest possible resolution, we find evidence for X-ray emission from interaction between radio outflow and the optical narrow-line region clouds, in addition to the emission from photoionized gas.

  19. Enormous Disc of Cool Gas Surrounding the Nearby Powerful Radio Galaxy NGC 612 (PKS 0131-36)

    Science.gov (United States)

    2008-05-22

    galaxies in clus- ters appear to be much more devoid of H I gas, as sug- gested by a recent H I survey of the VIRGO cluster by di Serego Alighieri et...120th Street, New York, N.Y. 10027, USA 2Netherlands Foundation for Research in Astronomy, Postbus 2, 7990 AA Dwingeloo, the Netherlands 3Kapteyn...NGC 612. This paper is part of an ongoing study to map the large-scale neutral hydrogen properties of nearby radio galaxies and it presents the first

  20. Assessement of nonindigenous marine species in harbors and nearby coral reefs on Kauai, Molokai, Maui, and Hawaii, 2002-2003 (NODC Accession 0002270)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Collections and observations in 2002-2003 at harbor and nearby reef sites at Nawilwili and Port Allen, Kauai; Hale O Lono and Kaunakakai, Molokai; Kahului and...

  1. Assessment of nonindigenous marine species in harbors and nearby coral reefs on Kauai, Molokai, Maui, and Hawaii, 2002 - 2003 (NODC Accession 0002270)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Collections and observations in 2002-2003 at harbor and nearby reef sites at Nawilwili and Port Allen, Kauai; Hale O Lono and Kaunakakai, Molokai; Kahului and...

  2. The North Field Development

    International Nuclear Information System (INIS)

    1993-01-01

    The Qatar Europe LNG Company's activities include gas production, gathering, treatment, liquefaction, shipping and marketing of Liquefied Natural Gas (LNG) and by-products. The (LNG) project to be developed by the Company shall be initially capable of processing 1200 mmscfd of raw gas and associated quantities of condensate from the North Field. Hydrocarbons produced will be delivered to shore in the industrial area (Ras Laffan) via a sub sea pipeline system. Raw gas is used as a feedstock into the liquefaction plant which is initially capable of producing 6.1 Million Tonnes Per Annum (MTPA) of (LNG). The initial quantity of (LNG) will be exported from (Ras Laffan) loading terminal to a receiving terminal located on the North East coast of Italy via a dedicated fleet of (LNG) carriers. The whole project (Upstream, Downstream and Shipping) shall be executed on an integrated scheme basis under the the direct control of the Qatar Europe LNG Company and in accordance with the overall Master Schedule in order to ensure a delivery of first shipment of (LNG) in the 2 nd half of 1997. 3 figs

  3. Estimating North Dakota's Economic Base

    OpenAIRE

    Coon, Randal C.; Leistritz, F. Larry

    2009-01-01

    North Dakota’s economic base is comprised of those activities producing a product paid for by nonresidents, or products exported from the state. North Dakota’s economic base activities include agriculture, mining, manufacturing, tourism, and federal government payments for construction and to individuals. Development of the North Dakota economic base data is important because it provides the information to quantify the state’s economic growth, and it creates the final demand sectors for the N...

  4. Photochemical processing of organic aerosol at nearby continental sites: contrast between urban plumes and regional aerosol

    Directory of Open Access Journals (Sweden)

    J. G. Slowik

    2011-03-01

    Full Text Available As part of the BAQS-Met 2007 field campaign, Aerodyne time-of-flight aerosol mass spectrometers (ToF-AMS were deployed at two sites in southwestern Ontario from 17 June to 11 July 2007. One instrument was located at Harrow, ON, a rural, agriculture-dominated area approximately 40 km southeast of the Detroit/Windsor/Windsor urban area and 5 km north of Lake Erie. The second instrument was located at Bear Creek, ON, a rural site approximately 70 km northeast of the Harrow site and 50 km east of Detroit/Windsor. Positive matrix factorization analysis of the combined organic mass spectral dataset yields factors related to secondary organic aerosol (SOA, direct emissions, and a factor tentatively attributed to the reactive uptake of isoprene and/or condensation of its early generation reaction products. This is the first application of PMF to simultaneous AMS measurements at different sites, an approach which allows for self-consistent, direct comparison of the datasets. Case studies are utilized to investigate processing of SOA from (1 fresh emissions from Detroit/Windsor and (2 regional aerosol during periods of inter-site flow. A strong correlation is observed between SOA/excess CO and photochemical age as represented by the NOx/NOy ratio for Detroit/Windsor outflow. Although this correlation is not evident for more aged air, measurements at the two sites during inter-site transport nevertheless show evidence of continued atmospheric processing by SOA production. However, the rate of SOA production decreases with airmass age from an initial value of ~10.1 μg m−3 ppmvCO−1 h−1 for the first ~10 h of plume processing to near-zero in an aged airmass (i.e. after several days. The initial SOA production rate is comparable to the observed rate in Mexico City over similar timescales.

  5. Energy policy of North Korea

    International Nuclear Information System (INIS)

    Rueth, G.

    2006-01-01

    Since the year 1990, North Korea suffers internal-policy problems as well as foreign-political problems. The gross domestic investment decreased by 3.8% yearly between the years 1990 and 1998. Many actual problems of North Korea correspond with the energy crisis in this land affecting nearly all sectors of economy and society. This energy crisis was released by the fact, that the former Soviet Union has stopped the supply of primary energy in the year 1991. In the contribution under consideration, the author reports on the energy policy of North Korea. The main themes of this contribution are: (a) Development and characteristics of the energy sector; (b) Crisis of the energy sector; (c) Consequences of the energy crisis in North Korea; (d) Possibilities of the solution of the energy crisis. For the U.S.A. and the international community, the energy crisis offers the possibility to turn North Korea to negotiations by means of remedial measures in the energy sector. In response, North Korea should drop its nuclear energy program. Apart from such positive incentives, the threat of sanctions is conceivable. North Korea imports nearly 70 % of its oil demand from the People's Republic of China. Therefore, China has an great influence on North Korea. The energy crisis of North Korea shows the fatal consequences of a falsely performed energy policy with respect to the population of this land and with respect to the stability and disposing capacity of the political leadership

  6. Assessment of Heavy and Trace Metals in Surface Soil Nearby an Oil Refinery, Saudi Arabia, Using Geoaccumulation and Pollution Indices.

    Science.gov (United States)

    Alshahri, Fatimh; El-Taher, A

    2018-04-30

    The present study deals with the measurement of heavy and trace metals in the soils of Ras Tanura city nearby one of the oldest and largest oil refineries located on Arabian Gulf, eastern Saudi Arabia. Metals were analyzed in 34 surface soil samples using plasma atomic emission spectrometer (ICPE-9820). The result showed that the mean values of the metals concentrations were in the order: Cd > Mo > Tb > Ce > Hf > Eu > Yb > U > Sm > Rb > Cr > Ni > Pb > Sc > Cs > Zn > Lu > Co. The mean values of Cd (39.9 mg/kg), Mo (13.2 mg/kg), Eu (4.01 mg/kg), Hf (6.09 mg/kg), Tb (8.23 mg/kg), and Yb (3.88) in soil samples were higher than the background values in soil and the world average. The obtained results indicated to elevated levels of Cd and Mo in most samples, with mean concentrations exceeded the background levels by 113 times for Cd and 5 times for Mo. Pollution index (PI) and Geoaccumulation (I geo ) for each metal were calculated to assess the metal contamination level of surface soil in the study area. The assessment results of PI and I geo revealed a significant pollution by Cd, Mo, Eu, Hf, Tb, and Yb in most of sampling sites nearby Ras Tanura refinery.

  7. Spectro-photometric calibration of the SuperNova Integral Field Spectrograph in the Nearby Supernova Factory collaboration framework

    International Nuclear Information System (INIS)

    Buton, Clement

    2009-01-01

    Ten years ago, type Ia supernovae used as distances indicators led to the discovery of the accelerating expansion of the universe. Today, a second generation of surveys has significantly increased the high-redshift type Ia supernovae sample. The low-redshift sample was however still limiting the cosmological analysis using SNe. In this framework, the Nearby Supernova Factory has followed 200 nearby type Ia supernovae using the dedicated Supernovae Integral Field Spectrograph with spectro-photometric capacities. My PhD thesis has been carried out at the Institut de Physique Nucleaire de Lyon and at the Lawrence Berkeley National Laboratory in the framework of the international cosmological project SNfactory. In order to reach the design spectrophotometric accuracy, attention has been focused on several key aspects of the calibration procedure, including: determination of a dedicated point spread function for 3D point source extraction, estimating the nightly photometric quality, derivation of the nightly sky extinction over the extended optical domain, its modeling in terms of physical components and its variability within a given night. A full multi-standards calibration pipeline has been implemented using approximately 4000 observations of spectrophotometric standard stars taken throughout the night over nearly 500 individual nights. Preliminary scientific results of the whole SNfactory collaboration will be presented at the end of this thesis. (author)

  8. The influences of soil and nearby structures on dispersion characteristics of wave propagating along buried plastic pipes

    Science.gov (United States)

    Liu, Shuyong; Jiang, J.; Parr, Nicola

    2016-09-01

    Water loss in distribution systems is a global problem for the water industry and governments. According to the international water supply association (IWSA), as a result of leaks from distribution pipes, 20% to 30% of water is lost while in transit from treatment plants to consumers. Although governments have tried to push the water industry to reduce the water leaks, a lot of experts have pointed out that a wide use of plastic pipes instead of metal pipes in recent years has caused difficulties in the detection of leaks using current acoustic technology. Leaks from plastic pipes are much quieter than traditional metal pipes and comparing to metal pipes the plastic pipes have very different coupling characteristics with soil, water and surrounding structures, such as other pipes, road surface and building foundations. The dispersion characteristics of wave propagating along buried plastic pipes are investigated in this paper using finite element and boundary element based models. Both empty and water- filled pipes were considered. Influences from nearby pipes and building foundations were carefully studied. The results showed that soil condition and nearby structures have significant influences on the dispersion characteristics of wave propagating along buried plastic pipes.

  9. Population studies in groups and clusters of galaxies. III. A catalog of galaxies in five nearby groups

    International Nuclear Information System (INIS)

    Ferguson, H.C.; Sandage, A.

    1990-01-01

    Five nearby groups of galaxies have been surveyed using large-scale plates from the 2.5 m duPont Telescope at Las Campanas Observatory. Catalogs of galaxies brighter than B(T) = 20 are presented for the Leo, Dorado, NGC 1400, NGC 5044, and Antlia groups. A total of 1044 galaxies are included, from visual inspection of 14 plates, covering 31 deg square. Galaxies have been classified in the extended Hubble system, and group memberships have been assigned based on velocity (where available) and morphology. About half the galaxies listed are likely members of one of the nearby groups. The catalogs are complete to B(T) = 18, although the completeness limits vary slightly from group to group. Based on King model fits to the surface density profiles, the core radii of the groups range from 0.3 to 1 Mpc, and central densities range from 120 to 1900 galaxies Mpc exp-3 brighter than M(BT) = -12.5. Dynamical analysis indicates that all of the groups are likely to be gravitationally bound. 64 refs

  10. Evaluating the Effects of Air Pollution from a Plastic Recycling Facility on the Health of Nearby Residents.

    Science.gov (United States)

    Xin, Zhao; Tsuda, Toshihide; Doi, Hiroyuki

    2017-06-01

    We evaluated how exposure to airborne volatile organic compounds emitted from a plastic recycling facility affected nearby residents, in a cross-sectional study. Individuals>10 years old were randomly sampled from 50 households at five sites and given questionnaires to complete. We categorized the subjects by distance from the recycling facility and used this as a proxy measure for pollutant exposure. We sought to improve on a preceding study by generating new findings, improving methods for questionnaire distribution and collection, and refining site selection. We calculated the odds of residents living 500 or 900 m away from the facility reporting mucocutaneous and respiratory symptoms using a reference group of residents 2,800 m away. Self-reported nasal congestion (odds ratio=3.0, 95% confidence interval=1.02-8.8), eczema (5.1, 1.1-22.9), and sore throat (3.9, 1.1-14.1) were significantly higher among residents 500 m from the facility. Those 900 m away were also considerably more likely to report experiencing eczema (4.6, 1.4-14.9). Air pollution was found responsible for significantly increased reports of mucocutaneous and respiratory symptoms among nearby residents. Our findings confirm the effects of pollutants emitted from recycling facilities on residents' health and clarify that study design differences did not affect the results.

  11. Star Formation In Nearby Clouds (SFiNCs): X-Ray and Infrared Source Catalogs and Membership

    Energy Technology Data Exchange (ETDEWEB)

    Getman, Konstantin V.; Broos, Patrick S.; Feigelson, Eric D.; Richert, Alexander J. W.; Ota, Yosuke [Department of Astronomy and Astrophysics, 525 Davey Laboratory, Pennsylvania State University, University Park, PA 16802 (United States); Kuhn, Michael A. [Instituto de Fisica y Astronomia, Universidad de Valparaiso, Gran Bretana 1111, Playa Ancha, Valparaiso (Chile); Millennium Institute of Astrophysics, MAS (Chile); Bate, Matthew R. [Department of Physics and Astronomy, University of Exeter, Stocker Road, Exeter, Devon EX4 4SB (United Kingdom); Garmire, Gordon P. [Huntingdon Institute for X-Ray Astronomy, LLC, 10677 Franks Road, Huntingdon, PA 16652 (United States)

    2017-04-01

    The Star Formation in Nearby Clouds (SFiNCs) project is aimed at providing a detailed study of the young stellar populations and of star cluster formation in the nearby 22 star-forming regions (SFRs) for comparison with our earlier MYStIX survey of richer, more distant clusters. As a foundation for the SFiNCs science studies, here, homogeneous data analyses of the Chandra X-ray and Spitzer mid-infrared archival SFiNCs data are described, and the resulting catalogs of over 15,300 X-ray and over 1,630,000 mid-infrared point sources are presented. On the basis of their X-ray/infrared properties and spatial distributions, nearly 8500 point sources have been identified as probable young stellar members of the SFiNCs regions. Compared to the existing X-ray/mid-infrared publications, the SFiNCs member list increases the census of YSO members by 6%–200% for individual SFRs and by 40% for the merged sample of all 22 SFiNCs SFRs.

  12. Updated methods for assessing the impacts of nearby gas drilling and production on neighborhood air quality and human health.

    Science.gov (United States)

    Olaguer, Eduardo P; Erickson, Matthew; Wijesinghe, Asanga; Neish, Brad; Williams, Jeff; Colvin, John

    2016-02-01

    An explosive growth in natural gas production within the last decade has fueled concern over the public health impacts of air pollutant emissions from oil and gas sites in the Barnett and Eagle Ford shale regions of Texas. Commonly acknowledged sources of uncertainty are the lack of sustained monitoring of ambient concentrations of pollutants associated with gas mining, poor quantification of their emissions, and inability to correlate health symptoms with specific emission events. These uncertainties are best addressed not by conventional monitoring and modeling technology, but by increasingly available advanced techniques for real-time mobile monitoring, microscale modeling and source attribution, and real-time broadcasting of air quality and human health data over the World Wide Web. The combination of contemporary scientific and social media approaches can be used to develop a strategy to detect and quantify emission events from oil and gas facilities, alert nearby residents of these events, and collect associated human health data, all in real time or near-real time. The various technical elements of this strategy are demonstrated based on the results of past, current, and planned future monitoring studies in the Barnett and Eagle Ford shale regions. Resources should not be invested in expanding the conventional air quality monitoring network in the vicinity of oil and gas exploration and production sites. Rather, more contemporary monitoring and data analysis techniques should take the place of older methods to better protect the health of nearby residents and maintain the integrity of the surrounding environment.

  13. Propane: North American opportunities

    International Nuclear Information System (INIS)

    Dempsey, C.

    1992-01-01

    Opportunities for expanding the propane market in North America are discussed. The goal of change should be to enhance client satisfaction and loyalty. The current customer base is largely comprised of pick-up trucks, vans and buses in commercial fleet service, police and similar fleet service and privately owned vehicles. Opportunities for the expansion of propane exist due to: vehicles being kept and lasting longer, allowing a longer pay-back time; exhaust emission standards becoming more stringent; the possible introduction of emission standards for substances currently not controlled; and properly combusted CO 2 emissions that are at least 12% lower than gasoline. The continuing development of engine fuel management systems, application of extensive road/highway experience, matching supply and refuelling infrastructure to consumer demands, application in air quality non-attainment areas, and original equipment manufacturer, government and industry cooperation are discussed. 8 figs

  14. Forests of North Dakota, 2017

    Science.gov (United States)

    Charles S. Paulson

    2018-01-01

    This resource update provides an overview of forest resources in North Dakota based on an inventory conducted by the USDA Forest Service, Forest Inventory and Analysis (FIA) program within the Northern Research Station in cooperation with the North Dakota Forest Service. Estimates are based on field data collected using the FIA annualized sample design and are updated...

  15. Forests of North Dakota, 2015

    Science.gov (United States)

    David E. Haugen

    2016-01-01

    This resource update provides an overview of forest resources in North Dakota based on an inventory conducted by the U.S. Forest Service, Forest Inventory and Analysis (FIA) program at the Northern Research Station in cooperation with the North Dakota Forest Service. Estimates are based on field data collected using the FIA annualized sample design and are updated...

  16. Forests of North Dakota, 2013

    Science.gov (United States)

    David E. Haugen

    2014-01-01

    This resource update provides an overview of forest resources in North Dakota based on an inventory conducted by the U.S. Forest Service, Forest Inventory and Analysis (FIA) program at the Northern Research Station in cooperation with the North Dakota Forest Service. Estimates are based on field data collected using the FIA annualized sample design and are updated...

  17. Forests of North Carolina, 2013

    Science.gov (United States)

    Mark J. Brown

    2015-01-01

    This periodic resource update provides an overview of forest resources in North Carolina based on an inventory conducted by the U.S. Forest Service, Forest Inventory and Analysis (FIA) program at the Southern Research Station in cooperation with the North Carolina Forest Service. Data estimates are based on field data collected using the FIA annualized sample design...

  18. Forests of North Dakota, 2014

    Science.gov (United States)

    D.E. Haugen; S.A. Pugh

    2014-01-01

    This resource update provides an overview of forest resources in North Dakota based on an inventory conducted by the U.S. Forest Service, Forest Inventory and Analysis (FIA) program at the Northern Research Station in cooperation with the North Dakota Forest Service. Estimates are based on field data collected using the FIA annualized sample design and are updated...

  19. Forests of North Carolina, 2014

    Science.gov (United States)

    Mark Brown; Samuel Lambert

    2016-01-01

    This periodic resource update provides an overview of forest resources in North Carolina based on an inventory conducted by the U.S. Forest Service, Forest Inventory and Analysis (FIA) program at the Southern Research Station in cooperation with the North Carolina Forest Service. Data estimates are based on field data collected using the FIA annualized sample design...

  20. 36 CFR 7.43 - Natchez Trace Parkway.

    Science.gov (United States)

    2010-07-01

    ...) Trailers. Trailers are permitted when used non-commercially to transport baggage, camping equipment, horses... written permission when transporting people for special recreational or educational purposes. (7) Towed... exceed 55 feet in length. (d) Beer and alcoholic beverages. The possession of beer or any alcoholic...

  1. North Polar Cap

    Science.gov (United States)

    2004-01-01

    [figure removed for brevity, see original site] This week we will be looking at five examples of laminar wind flow on the north polar cap. On Earth, gravity-driven south polar cap winds are termed 'catabatic' winds. Catabatic winds begin over the smooth expanse of the cap interior due to temperature differences between the atmosphere and the surface. Once begun, the winds sweep outward along the surface of the polar cap toward the sea. As the polar surface slopes down toward sealevel, the wind speeds increase. Catabatic wind speeds in the Antartic can reach several hundreds of miles per hour. In the images of the Martian north polar cap we can see these same type of winds. Notice the streamers of dust moving downslope over the darker trough sides, these streamers show the laminar flow regime coming off the cap. Within the trough we see turbulent clouds of dust, kicked up at the trough base as the winds slow down and enter a chaotic flow regime. The horizontal lines in these images are due to framelet overlap and lighting conditions over the bright polar cap. Image information: VIS instrument. Latitude 86.5, Longitude 64.5 East (295.5 West). 40 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen

  2. The JHKs Magnitudes of the Red Giant Branch Tip and the Distance Moduli of Nearby Dwarf Galaxy NGC 205

    Directory of Open Access Journals (Sweden)

    M. Y. Jung

    2009-12-01

    Full Text Available We have used the near-infrared JHKS photometric data of resolved stars in a nearby dwarf elliptical galaxy NGC 205 to determine the magnitudes of the red giant branch tip (TRGB. By applying Savitzky-Golay filter to the observed luminosity functions (LFs in each band, we derived the second derivatives of the LFs so as to determine the magnitudes of the TRGB. Absolute magnitudes of the TRGB in JHKs bands were measured from the Yonsei-Yale isochrones. By comparing the determined apparent magnitudes and the theoretical absolute magnitudes of the TRGB, we estimated the distance moduli of NGC 205 to be (m-M = 24.10±0:08, 24.08±0.12 and 24.14±0.14 in J, H, and Ks bands, respectively.

  3. ASTEROSEISMOLOGY OF THE NEARBY SN-II PROGENITOR: RIGEL. I. THE MOST HIGH-PRECISION PHOTOMETRY AND RADIAL VELOCITY MONITORING

    International Nuclear Information System (INIS)

    Moravveji, Ehsan; Guinan, Edward F.; Shultz, Matt; Williamson, Michael H.; Moya, Andres

    2012-01-01

    Rigel (β Ori, B8 Ia) is a nearby blue supergiant displaying α Cyg type variability, and is one of the nearest Type II supernova progenitors. As such it is an excellent test bed to study the internal structure of pre-core-collapse stars. In this study, for the first time, we present 28 days of high-precision MOST photometry and over six years of spectroscopic monitoring. We report 19 significant pulsation modes of signal-to-noise ratio, S/N ∼> 4.6 from radial velocities, with variability timescales ranging from 1.21 to 74.7 days, which are associated with high-order low-degree gravity modes. While the radial velocity variations show a degree of correlation with the flux changes, there is no clear interplay between the equivalent widths of different metallic and Hα lines.

  4. SPICES: Spectro-Polarimetric Imaging and Characterization of Exoplanetary Systems - From Planetary Disks To Nearby Super Earths

    Science.gov (United States)

    Boccaletti, Anthony; Schneider, Jean; Traub, Wes; Lagage, Pierre-Olivier; Stam, Daphne; Gratton, Raffaele; Trauger, John; Cahoy, Kerri; Snik, Frans; Baudoz, Pierre; hide

    2012-01-01

    SPICES (Spectro-Polarimetric Imaging and Characterization of Exoplanetary Systems) is a five-year M-class mission proposed to ESA Cosmic Vision. Its purpose is to image and characterize long-period extrasolar planets and circumstellar disks in the visible (450-900 nm) at a spectral resolution of about 40 using both spectroscopy and polarimetry. By 2020/2022, present and near-term instruments will have found several tens of planets that SPICES will be able to observe and study in detail. Equipped with a 1.5 m telescope, SPICES can preferentially access exoplanets located at several AUs (0.5-10 AU) from nearby stars (less than 25 pc) with masses ranging from a few Jupiter masses to Super Earths (approximately 2 Earth radii, approximately 10 mass compared to Earth) as well as circumstellar disks as faint as a few times the zodiacal light in the Solar System.

  5. Excitation energy transfer in molecular complexes: transport processes, optical properties and effects of nearby placed metal nano-particles

    Science.gov (United States)

    May, Volkhard; Megow, Jörg; Zelinskyi, Iaroslav

    2012-04-01

    Excitation energy transfer (EET) in molecular systems is studied theoretically. Chromophore complexes are considered which are formed by a butanediamine dendrimer with four pheophorbide-a molecules. To achieve a description with an atomic resolution and to account for the effect of an ethanol solvent a mixed quantum classical methodology is utilized. Details of the EET and spectra of transient anisotropy showing signatures of EET are presented. A particular control of intermolecular EET is achieved by surface plasmons of nearby placed metal nanoparticles (MNP). To attain a quantum description of the molecule-MNP system a microscopic theory is introduced. As a particular application surface plasmon affected absorption spectra of molecular complexes placed in the proximity of a spherical MNP are discussed.

  6. Natural Radionuclides in Different plants, Together with Their Corresponding Soils in Egypt at Inshas Region and the Area Nearby

    International Nuclear Information System (INIS)

    Abu - Khadra, S.A.; Eissa, H.S.

    2009-01-01

    Six different locations :Inshas, Shebeen, Abu-Zaabal, Al-Oboor in addition to two sites in the Nuclear Research Centre (NRC), (Old reactor and Protection department sites), in Egypt at Inshas region and the area nearby (about 30 Km radius) were selected for collection of plant samples , together with their corresponding soils. Natural radionuclides concentration in different environmental samples of plants especially grasses ,)leaves of old trees) and soils, were determined using high resolution gamma- spectroscopy (Hyper Pure Germanium detector).Natural uranium-238 and thorium -232 together with their decay products were determined as well as K-40. Also, Cs-137 radiation level was determined as an indication of the contamination from the fallout. It is noticed that the obtained results for all plants and grasses in the present study are higher than those obtained for their corresponding soils (except for Shebeen), which has nearly the same average concentration value of K-40 in plants and their corresponding soils

  7. Groups of Galaxies in the Nearby Universe Proceedings of the ESO Workshop held at Santiago de Chile

    CERN Document Server

    Saviane, Ivo; Borissova, Jordanka

    2007-01-01

    For every galaxy in the field or in clusters, there are about three galaxies in groups. The Milky Way itself resides in a group, and groups can be found at high redshift. The current generation of 10-m class telescopes and space facilities allows the observation of the members of nearby groups with exquisite detail, and their properties can be correlated with the global properties of their host group. Groups in the local Universe offer us the chance to study galaxies in environments characterized by strong interactions. In the cosmological context, groups trace large-scale structures better than clusters, and the evolution of groups and clusters appears to be related. All these aspects of research on groups of galaxies are summarized in this book written by scientists working in various fields.

  8. ASTEROSEISMOLOGY OF THE NEARBY SN-II PROGENITOR: RIGEL. I. THE MOST HIGH-PRECISION PHOTOMETRY AND RADIAL VELOCITY MONITORING

    Energy Technology Data Exchange (ETDEWEB)

    Moravveji, Ehsan [Department of Physics, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731 (Iran, Islamic Republic of); Guinan, Edward F. [Department of Astronomy, Villanova University, 800 Lancaster Avenue, Villanova, PA 19085 (United States); Shultz, Matt [Royal Military College of Canada, PO Box 17000, Station Forces, Kingston, ON K7K 4B4 (Canada); Williamson, Michael H. [Center of Excellence in Information Systems, Tennessee State University, Nashville, TN (United States); Moya, Andres, E-mail: moravveji@iasbs.ac.ir [Departamento de Astrofisica, Centro de Astrobiologia (INTA-CSIC), PO BOX 78, 28691 Villanueva de la Canada, Madrid (Spain)

    2012-03-10

    Rigel ({beta} Ori, B8 Ia) is a nearby blue supergiant displaying {alpha} Cyg type variability, and is one of the nearest Type II supernova progenitors. As such it is an excellent test bed to study the internal structure of pre-core-collapse stars. In this study, for the first time, we present 28 days of high-precision MOST photometry and over six years of spectroscopic monitoring. We report 19 significant pulsation modes of signal-to-noise ratio, S/N {approx}> 4.6 from radial velocities, with variability timescales ranging from 1.21 to 74.7 days, which are associated with high-order low-degree gravity modes. While the radial velocity variations show a degree of correlation with the flux changes, there is no clear interplay between the equivalent widths of different metallic and H{alpha} lines.

  9. Artistic view of VAB

    Science.gov (United States)

    2000-01-01

    A bundle of flexible pipes arcing toward the Vehicle Assembly Building (left) and Operations Support Building (right) presents an artistic design to travelers on nearby Kennedy Parkway and Saturn Causeway.

  10. The 60 Month All-Sky Burst Alert Telescope Survey of Active Galactic Nucleus and the Anisotropy of Nearby AGNs

    Science.gov (United States)

    Ajello, M.; Alexander, D. M.; Greiner, J.; Madejeski, G. M.; Gehrels, N.; Burlon, D.

    2014-01-01

    Surveys above 10 keV represent one of the best resources to provide an unbiased census of the population of active galactic nuclei (AGNs). We present the results of 60 months of observation of the hard X-ray sky with Swift/Burst Alert Telescope (BAT). In this time frame, BAT-detected (in the 15-55 keV band) 720 sources in an all-sky survey of which 428 are associated with AGNs, most of which are nearby. Our sample has negligible incompleteness and statistics a factor of approx. 2 larger over similarly complete sets of AGNs. Our sample contains (at least) 15 bona fide Compton-thick AGNs and 3 likely candidates. Compton-thick AGNs represent approx. 5% of AGN samples detected above 15 keV. We use the BAT data set to refine the determination of the log N-log S of AGNs which is extremely important, now that NuSTAR prepares for launch, toward assessing the AGN contribution to the cosmic X-ray background. We show that the log N-log S of AGNs selected above 10 keV is now established to approx. 10% precision. We derive the luminosity function of Compton-thick AGNs and measure a space density of 7.9(+4.1/-2.9)× 10(exp -5)/cubic Mpc for objects with a de-absorbed luminosity larger than 2 × 10(exp 42) erg / s. As the BAT AGNs are all mostly local, they allow us to investigate the spatial distribution of AGNs in the nearby universe regardless of absorption. We find concentrations of AGNs that coincide spatially with the largest congregations of matter in the local (much < 85 Mpc) universe. There is some evidence that the fraction of Seyfert 2 objects is larger than average in the direction of these dense regions..

  11. SPIRITS 15c and SPIRITS 14buu: Two Obscured Supernovae in the Nearby Star-forming Galaxy IC 2163

    International Nuclear Information System (INIS)

    Jencson, Jacob E.; Kasliwal, Mansi M.; Cao, Yi; Johansson, Joel; Contreras, Carlos; Castellón, Sergio; Morrell, Nidia; Phillips, Mark; Bond, Howard E.; Monson, Andrew J.; Masci, Frank J.; Helou, George; Cody, Ann Marie; Andrews, Jennifer E.; Bally, John; Green, Wayne; Fox, Ori D.; Gburek, Timothy; Gehrz, Robert D.; Hsiao, Eric

    2017-01-01

    SPitzer InfraRed Intensive Transients Survey—SPIRITS—is an ongoing survey of nearby galaxies searching for infrared (IR) transients with Spitzer /IRAC. We present the discovery and follow-up observations of one of our most luminous ( M [4.5] = −17.1 ± 0.4 mag, Vega) and reddest ([3.6] − [4.5] = 3.0 ± 0.2 mag) transients, SPIRITS 15c. The transient was detected in a dusty spiral arm of IC 2163 ( D ≈ 35.5 Mpc). Pre-discovery ground-based imaging revealed an associated, shorter-duration transient in the optical and near-IR (NIR). NIR spectroscopy showed a broad (≈8400 km s −1 ), double-peaked emission line of He i at 1.083 μ m, indicating an explosive origin. The NIR spectrum of SPIRITS 15c is similar to that of the Type IIb SN 2011dh at a phase of ≈200 days. Assuming an A V = 2.2 mag of extinction in SPIRITS 15c provides a good match between their optical light curves. The NIR light curves, however, show some minor discrepancies when compared with SN 2011dh, and the extreme [3.6]–[4.5] color has not been previously observed for any SN IIb. Another luminous ( M 4.5 = −16.1 ± 0.4 mag) event, SPIRITS 14buu, was serendipitously discovered in the same galaxy. The source displays an optical plateau lasting ≳80 days, and we suggest a scenario similar to the low-luminosity Type IIP SN 2005cs obscured by A V ≈ 1.5 mag. Other classes of IR-luminous transients can likely be ruled out in both cases. If both events are indeed SNe, this may suggest that ≳18% of nearby core-collapse SNe are missed by currently operating optical surveys.

  12. NEAR-INFRARED SPECTROSCOPY OF NEARBY SEYFERT GALAXIES: IS THERE EVIDENCE FOR SHOCK EXCITATION IN NARROW-LINE REGIONS?

    Energy Technology Data Exchange (ETDEWEB)

    Terao, K. [Graduate School of Science and Engineering, Ehime University, Bunkyo-cho 2-5, Matsuyama, Ehime 790-8577 (Japan); Nagao, T.; Toba, Y. [Research Center for Space and Cosmic Evolution, Ehime University, Bunkyo-cho 2-5, Matsuyama, Ehime 790-8577 (Japan); Hashimoto, T. [National Tsing Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu, 30013, Taiwan (China); Yanagisawa, K. [Okayama Astrophysical Observatory, National Astronomical Observatory of Japan, Honjo 3037-5, Kamogata-cho, Asaguchi, Okayama 719-0232 (Japan); Matsuoka, K. [Department of Astronomy, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502 (Japan); Ikeda, H. [National Astronomical Observatory of Japan, Osawa 2-21-1, Mitaka, Tokyo, 181-8588 (Japan); Taniguchi, Y., E-mail: terao@cosmos.phys.sci.ehime-u.ac.jp [The Open University of Japan, Wakaba 2-11, Mihama-ku, Chiba 261-8586 (Japan)

    2016-12-20

    One of the important unsettled problems regarding active galactic nuclei (AGNs) is the major ionization mechanism of gas clouds in AGN narrow-line regions (NLRs). In order to investigate this issue, we present our J -band spectroscopic observations of a sample of 26 nearby Seyfert galaxies. In our study, we use the flux ratio of the following two forbidden emission lines, [Fe ii]1.257  μ m and [P ii]1.188  μ m, because it is known that this ratio is sensitive to the ionization mechanism. We obtain the [Fe ii]/[P ii] flux ratio or its lower limit for 19 objects. In addition to our data, we compile this flux ratio (or its lower limit) for 23 nearby Seyfert galaxies from the literature. Based on the collected data, we find that three Seyfert galaxies show very large lower limits of the [Fe ii]/[P ii] flux ratios (≳10): NGC 2782, NGC 5005, and Mrk 463. It is thus suggested that the contribution of the fast shock in the gas excitation is significantly large for them. However, more than half of the Seyfert galaxies in our sample show moderate [Fe ii]/[P ii] flux ratios (∼2), which is consistent with pure photoionization by power-law ionizing continuum emission. We also find that the [Fe ii]/[P ii] flux ratio shows no clear correlation with the radio loudness, suggesting that the radio jet is not the primary origin of shocks in NLRs of Seyfert galaxies.

  13. The diversity of neutron stars: Nearby thermally emitting neutron stars and the compact central objects in supernova remnants

    Science.gov (United States)

    Kaplan, David L.

    Neutron stars are invaluable tools for exploring stellar death, the physics of ultra-dense matter, and the effects of extremely strong magnetic fields. The observed population of neutron stars is dominated by the > 1000 radio pulsars, but there are distinct sub-populations that, while fewer in number, can have significant impact on our understanding of the issues mentioned above. These populations are the nearby isolated neutron stars discovered by ROSAT, and the central compact objects in supernova remnants. The studies of both of these populations have been greatly accelerated in recent years through observations with the Chandra X-ray Observatory and the XMM-Newton telescope. First, we discuss radio, optical, and X-ray observations of the nearby neutron stars aimed at determining their relation to the Galactic neutron star population and at unraveling their complex physical processes by determining the basic astronomical parameters that define the population -- instances, ages, and magnetic fields -- the uncertainties in which limit any attempt to derive basic physical parameters for these objects. We conclude that these sources are 10^6 year-old cooling neutron stars with magnetic fields above 10^13 G. Second, we describe the hollow supernova remnant problem: why many of the supernova remnants in the Galaxy have no indication central neutron stars. We have undertaken an X-ray census of neutron stars in a volume-limited sample of Galactic supernova remnants, and from it conclude that either many supernovae do not produce neutron stars contrary to expectation, or that neutron stars can have a wide range in cooling behavior that makes many sources disappear from the X-ray sky.

  14. SPIRITS 15c and SPIRITS 14buu: Two Obscured Supernovae in the Nearby Star-forming Galaxy IC 2163

    Energy Technology Data Exchange (ETDEWEB)

    Jencson, Jacob E.; Kasliwal, Mansi M.; Cao, Yi [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Johansson, Joel [Benoziyo Center for Astrophysics, Weizmann Institute of Science, 76100 Rehovot (Israel); Contreras, Carlos; Castellón, Sergio; Morrell, Nidia; Phillips, Mark [Las Campanas Observatory, Carnegie Observatories, Casilla 601, La Serena (Chile); Bond, Howard E.; Monson, Andrew J. [Dept. of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States); Masci, Frank J.; Helou, George [Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States); Cody, Ann Marie [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Andrews, Jennifer E. [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Bally, John; Green, Wayne [Center for Astrophysics and Space Astronomy, University of Colorado, 389 UCB, Boulder, CO 80309 (United States); Fox, Ori D. [Space Telescope Science Institute, 3700 San Martin Dr., Baltimore, MD 21218 (United States); Gburek, Timothy; Gehrz, Robert D. [Minnesota Institute for Astrophysics, School of Physics and Astronomy, 116 Church Street, S. E., University of Minnesota, Minneapolis, MN 55455 (United States); Hsiao, Eric, E-mail: jj@astro.caltech.edu [Department of Physics, Florida State University, 77 Chieftain Way, Tallahassee, FL, 32306 (United States); and others

    2017-03-10

    SPitzer InfraRed Intensive Transients Survey—SPIRITS—is an ongoing survey of nearby galaxies searching for infrared (IR) transients with Spitzer /IRAC. We present the discovery and follow-up observations of one of our most luminous ( M {sub [4.5]} = −17.1 ± 0.4 mag, Vega) and reddest ([3.6] − [4.5] = 3.0 ± 0.2 mag) transients, SPIRITS 15c. The transient was detected in a dusty spiral arm of IC 2163 ( D ≈ 35.5 Mpc). Pre-discovery ground-based imaging revealed an associated, shorter-duration transient in the optical and near-IR (NIR). NIR spectroscopy showed a broad (≈8400 km s{sup −1}), double-peaked emission line of He i at 1.083 μ m, indicating an explosive origin. The NIR spectrum of SPIRITS 15c is similar to that of the Type IIb SN 2011dh at a phase of ≈200 days. Assuming an A {sub V} = 2.2 mag of extinction in SPIRITS 15c provides a good match between their optical light curves. The NIR light curves, however, show some minor discrepancies when compared with SN 2011dh, and the extreme [3.6]–[4.5] color has not been previously observed for any SN IIb. Another luminous ( M {sub 4.5} = −16.1 ± 0.4 mag) event, SPIRITS 14buu, was serendipitously discovered in the same galaxy. The source displays an optical plateau lasting ≳80 days, and we suggest a scenario similar to the low-luminosity Type IIP SN 2005cs obscured by A{sub V} ≈ 1.5 mag. Other classes of IR-luminous transients can likely be ruled out in both cases. If both events are indeed SNe, this may suggest that ≳18% of nearby core-collapse SNe are missed by currently operating optical surveys.

  15. BANYAN. II. Very low mass and substellar candidate members to nearby, young kinematic groups with previously known signs of youth

    International Nuclear Information System (INIS)

    Gagné, Jonathan; Lafrenière, David; Doyon, René; Malo, Lison; Artigau, Étienne

    2014-01-01

    We present Bayesian Analysis for Nearby Young AssociatioNs II (BANYAN II), a modified Bayesian analysis for assessing the membership of later-than-M5 objects to any of several Nearby Young Associations (NYAs). In addition to using kinematic information (from sky position and proper motion), this analysis exploits 2MASS-WISE color-magnitude diagrams in which old and young objects follow distinct sequences. As an improvement over our earlier work, the spatial and kinematic distributions for each association are now modeled as ellipsoids whose axes need not be aligned with the Galactic coordinate axes, and we use prior probabilities matching the expected populations of the NYAs considered versus field stars. We present an extensive contamination analysis to characterize the performance of our new method. We find that Bayesian probabilities are generally representative of contamination rates, except when a parallax measurement is considered. In this case contamination rates become significantly smaller and hence Bayesian probabilities for NYA memberships are pessimistic. We apply this new algorithm to a sample of 158 objects from the literature that are either known to display spectroscopic signs of youth or have unusually red near-infrared colors for their spectral type. Based on our analysis, we identify 25 objects as new highly probable candidates to NYAs, including a new M7.5 bona fide member to Tucana-Horologium, making it the latest-type member. In addition, we reveal that a known L2γ dwarf is co-moving with a bright M5 dwarf, and we show for the first time that two of the currently known ultra red L dwarfs are strong candidates to the AB Doradus moving group. Several objects identified here as highly probable members to NYAs could be free-floating planetary-mass objects if their membership is confirmed.

  16. ALFALFA DISCOVERY OF THE NEARBY GAS-RICH DWARF GALAXY LEO P. III. AN EXTREMELY METAL DEFICIENT GALAXY

    Energy Technology Data Exchange (ETDEWEB)

    Skillman, Evan D.; Berg, Danielle A.; Olive, Keith A.; McQuinn, Kristen B. W., E-mail: skillman@astro.umn.edu, E-mail: berg@astro.umn.edu, E-mail: olive@physics.umn.edu, E-mail: kmcquinn@astro.umn.edu [Minnesota Institute for Astrophysics, School of Physics and Astronomy, University of Minnesota, 116 Church St. SE, Minneapolis, MN 55455 (United States); and others

    2013-07-01

    We present KPNO 4 m and LBT/MODS spectroscopic observations of an H II region in the nearby dwarf irregular galaxy Leo P discovered recently in the Arecibo ALFALFA survey. In both observations, we are able to accurately measure the temperature sensitive [O III] {lambda}4363 line and determine a ''direct'' oxygen abundance of 12 + log(O/H) = 7.17 {+-} 0.04. Thus, Leo P is an extremely metal deficient (XMD) galaxy, and, indeed, one of the most metal deficient star-forming galaxies ever observed. For its estimated luminosity, Leo P is consistent with the relationship between luminosity and oxygen abundance seen in nearby dwarf galaxies. Leo P shows normal {alpha} element abundance ratios (Ne/O, S/O, and Ar/O) when compared to other XMD galaxies, but elevated N/O, consistent with the ''delayed release'' hypothesis for N/O abundances. We derive a helium mass fraction of 0.2509{sup +0.0184}{sub -0.0123}, which compares well with the WMAP + BBN prediction of 0.2483 {+-} 0.0002 for the primordial helium abundance. We suggest that surveys of very low mass galaxies compete well with emission line galaxy surveys for finding XMD galaxies. It is possible that XMD galaxies may be divided into two classes: the relatively rare XMD emission line galaxies which are associated with starbursts triggered by infall of low-metallicity gas and the more common, relatively quiescent XMD galaxies like Leo P, with very low chemical abundances due to their intrinsically small masses.

  17. BANYAN. II. Very low mass and substellar candidate members to nearby, young kinematic groups with previously known signs of youth

    Energy Technology Data Exchange (ETDEWEB)

    Gagné, Jonathan; Lafrenière, David; Doyon, René; Malo, Lison; Artigau, Étienne [Département de Physique and Observatoire du Mont-Mégantic, Université de Montréal, C.P. 6128 Succ. Centre-ville, Montréal, Qc H3C 3J7 (Canada)

    2014-03-10

    We present Bayesian Analysis for Nearby Young AssociatioNs II (BANYAN II), a modified Bayesian analysis for assessing the membership of later-than-M5 objects to any of several Nearby Young Associations (NYAs). In addition to using kinematic information (from sky position and proper motion), this analysis exploits 2MASS-WISE color-magnitude diagrams in which old and young objects follow distinct sequences. As an improvement over our earlier work, the spatial and kinematic distributions for each association are now modeled as ellipsoids whose axes need not be aligned with the Galactic coordinate axes, and we use prior probabilities matching the expected populations of the NYAs considered versus field stars. We present an extensive contamination analysis to characterize the performance of our new method. We find that Bayesian probabilities are generally representative of contamination rates, except when a parallax measurement is considered. In this case contamination rates become significantly smaller and hence Bayesian probabilities for NYA memberships are pessimistic. We apply this new algorithm to a sample of 158 objects from the literature that are either known to display spectroscopic signs of youth or have unusually red near-infrared colors for their spectral type. Based on our analysis, we identify 25 objects as new highly probable candidates to NYAs, including a new M7.5 bona fide member to Tucana-Horologium, making it the latest-type member. In addition, we reveal that a known L2γ dwarf is co-moving with a bright M5 dwarf, and we show for the first time that two of the currently known ultra red L dwarfs are strong candidates to the AB Doradus moving group. Several objects identified here as highly probable members to NYAs could be free-floating planetary-mass objects if their membership is confirmed.

  18. HIGH IONIZATION SPECIES IN THE NEARBY INTERSTELLAR MEDIUM FROM AN EXHAUSTIVE ANALYSIS OF THE IUE INES DATABASE

    Energy Technology Data Exchange (ETDEWEB)

    Freire Ferrero, R.; Halbwachs, J.-L. [Observatoire Astronomique, Universite de Strasbourg, 11 rue de l' Universite, 67.000 Strasbourg (France); Morales Duran, C.; Cabo Cubeiro, A. M., E-mail: rubens.freire@astro.unistra.fr, E-mail: jean-louis.halbwachs@astro.unistra.fr, E-mail: morales@cab.inta-csic.es, E-mail: amcabo@cab.inta-csic.es [LAEX, Centro de Astrobiologia (CAB, CSIC-INTA), LAEFF, European Space Astronomy Centre, P.O. Box 78, 28691 Villanueva de la Canada, Madrid (Spain)

    2012-02-15

    Main-sequence (MS) and giant late-B and early-A type stars are the best targets for searching for nearby interstellar (IS) Si IV and C IV resonance lines because they are not able to produce them, either in atmospheric layers or in their circumstellar environment, and because many stars of these spectral types are nearby and located in the local interstellar medium (LISM). In addition, the use of certain stars hotter than B6 can lead to misinterpretations (e.g., alpha Arae). This work analyzes the reliable Short-Wavelength Prime high-resolution UV spectra of 558 B6-A9 type stars observed by the International Ultraviolet Explorer at distances lower than 400 pc from the Sun. For the first time, this work utilizes the entire INES database to extract stellar and IS information in a systematic way from homogeneous data. Stars were classified into seven groups: normal (MS and subgiant), giant, peculiar, emission line, Algols, pre-main sequence or Herbig Ae/Be, and shell stars. Only 10 normal stars, located beyond 90 pc, show weak Si IV and C IV absorptions and are clustered around the direction of Sco-Cen, while 85 located closer than 90 pc, as well as another 89 beyond 90 pc, do not show any absorptions at all. We conclude that these highly ionized species originate most probably in the LISM, at 90 pc from the Sun, corresponding to the warm interaction zone (IZ), where the expanding Loop I super-shell and the Local Bubble collide. We base our results on a robust statistical analysis of both spectral types and spatial distributions of the different stellar groups we defined. Our estimated column densities N of both ions are similar to those obtained by other authors for distant stars, suggesting that these absorptions concentrate fundamentally in the IZ. A logarithmic correlation between N and the distance D confirms these results.

  19. Effect of historical earthquakes on pre-stressed anchor tie back diaphragm wall and on near-by building

    Directory of Open Access Journals (Sweden)

    Kamal Mohamed Hafez Ismail Ibrahim

    2013-04-01

    Full Text Available Pre-stressed tie back anchored diaphragm walls are considered one of the safest lateral supports which help in overall stability when there is a significant difference in land level between back and front of these walls. Permanent lateral supports to these walls are frequently represented by supporting it laterally with foundation and floor slabs of the building. In this paper a special study of one raw anchor diaphragm wall subjected to different earthquake dynamic loads will be presented. The wall retains an excavation of 9.5 m and supports laterally a near-by 5 floor building. Five historical strong motions with different fundamental frequencies are subjected on the wall. The wall displacement, straining actions, anchor extreme force and the influence of variation of anchor stiffness are calculated using a dynamic Plaxis finite element program. The soil is considered as elasto-plastic material and represented using Mohr–Coulomb criteria, the wall and the anchor are considered to behave elastically. Prescribed displacement at the lower bottom boundary represents the earthquake motion. Far left and right absorbent boundaries are assumed to prevent dynamic wave reflection. Four static phases representing construction procedure and one dynamic loading phase are considered. It is found that the straining actions of different historical earthquakes match in shape with each other, the only change is in the amplitude which is affected by earthquake fundamental frequency and its intensity. The maximum dynamic lateral displacement of the wall is at its free top. The near-by building shows a differential settlement towards the wall which causes a change in the sign and amplitude of the straining actions. Increasing the stiffness of anchor was also studied and it was found that it reduces too much the maximum dynamic top wall lateral displacement.

  20. North Korea: a mercenary proliferator?

    International Nuclear Information System (INIS)

    Hemez, Remy

    2015-01-01

    After having recalled that North Korea possesses a rather advanced ballistic programme which has been started in the 1970 with the Chinese support, that North Korea is the fourth world producer of ballistic missiles, the author outlines that this country has become a major proliferator as it exports this production to different States and non-State actors. He recalls the long history of relationships between North Korea and terrorist organisations (even during the Cold War), comments the current and major support of North Korea to Hamas and Hezbollah in Gaza and in Lebanon. These relationships are then related with those these both organisations have with Syria and Iran who are in fact the relays between them and North Korea. The author explains why Hamas and Hezbollah must buy their weapons to such a far country: Iran is submitted to international sanctions, Iran and Syria want to avoid being banned from the international community for selling weapon to a terrorist (or so-said) organisation, and prices are rather competitive. If North Korea is also submitted to international sanctions, weapon smuggling seems to be institutional in this country. The author finally briefly evokes the issue of chemical weapons: North Korea possesses few thousand tonnes of these weapons, and could export them to non-state organisations

  1. North Atlantic Energy Structures

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, S. [North Atlantic Energy Structures Inc., St. John' s, NL (Canada); Derradji, A. [National Research Council of Canada, St. John' s, NL (Canada). Inst. for Ocean Technology

    2005-07-01

    North Atlantic Energy Structures Inc. is in the process of designing a tidal fence for a site near the Straits of Belle Isle. This presentation provided details of both the design and the location in which the wave energy plant will be installed. Design constraints included a short seasonal work window, and a harsh but pristine environment. Design specifications of the paddlewheels and caissons were presented. The paddlewheel is iceberg and slab ice resistant, and has portals below the wheel axis, a water-free upper chamber, and bi-directional power generation. The planned installation sequence was presented, as well as details of a hydrodynamic simulation examining torque on the turbines in the tidal energy chamber. Results of the study indicated that 20 paddlewheels per caisson provided the equivalent of 12 MW of energy. A tidal fence of 70 to 80 caissons provided the equivalent of 1.2 GW of energy. A slab ice simulation study was outlined, and details of the pumping station, inlet and hydro-generation station were provided. A map of the proposed siting of the tidal fence was presented. It was concluded that financing for the pilot project has been granted. However, further financing for research and development is required. refs., tabs., figs.

  2. The Zoogeography of North American freshwater fishes

    National Research Council Canada - National Science Library

    Hocutt, Charles H; Wiley, E. O

    1986-01-01

    ..., and Pleistoscene glaciation. The Zoogeography of North American Freshwater Fishes is a comprehensive treatment of the freshwater biogeography of North America, with implications for other disciplines...

  3. North American oil demand outlook

    International Nuclear Information System (INIS)

    Stewart, M.B.

    1995-01-01

    An understanding of the relationship of economic growth and potential petroleum product demand is needed to forecast the potential for North American oil demand growth as well as knowledge of world supply and price. The bullish expectations for economic growth in the US and Canada auger well for North American refiners and marketeers. The growth in world economic output forecast, however, means a larger oil demand and an increase in OPEC's pricing power. Such price increases could depress North American oil demand growth. (author)

  4. Changes in persistent contaminant concentration and CYP1A1 protein expression in biopsy samples from northern bottlenose whales, Hyperoodon ampullatus, following the onset of nearby oil and gas development

    Energy Technology Data Exchange (ETDEWEB)

    Hooker, Sascha K. [Department of Biology, Dalhousie University, Halifax, Nova Scotia B3H 4J1 (Canada); Sea Mammal Research Unit, University of St Andrews, FIFE KY16 8YG (United Kingdom)], E-mail: s.hooker@st-andrews.ac.uk; Metcalfe, Tracy L.; Metcalfe, Chris D. [Environmental and Resource Studies, Trent University, Peterborough, Ontario K9J 7B8 (Canada); Angell, Carolyn M.; Wilson, Joanna Y.; Moore, Michael J. [Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543 (United States); Whitehead, Hal [Department of Biology, Dalhousie University, Halifax, Nova Scotia B3H 4J1 (Canada)

    2008-03-15

    A small population of endangered northern bottlenose whales (Hyperoodon ampullatus) inhabits 'The Gully' a Marine Protected Area on the Scotian Shelf, eastern Canada. Amid concerns regarding nearby oil and gas development, we took 36 skin and blubber biopsy samples in 1996-1997 (prior to major development) and 2002-2003 (five years after development began), and three samples from a population in the Davis Strait, Labrador in 2003. These were analysed for cytochrome P4501A1 (CYP1A1) protein expression (n = 36), and for persistent contaminants (n = 23). CYP1A1 showed generally low expression in whales from The Gully, but higher levels during 2003, potentially coincident with recorded oil spills, and higher levels in Davis Strait whales. A range of PCB congeners and organochlorine compounds were detected, with concentrations similar to other North Atlantic odontocetes. Concentrations were higher in whales from The Gully than from the Davis Strait, with significant increases in 4,4'-DDE and trans-nonachlor in 2002-2003 relative to 1996-1997. - Whale contaminants highlight concerns from oil and gas development near a marine protected area.

  5. Changes in persistent contaminant concentration and CYP1A1 protein expression in biopsy samples from northern bottlenose whales, Hyperoodon ampullatus, following the onset of nearby oil and gas development

    International Nuclear Information System (INIS)

    Hooker, Sascha K.; Metcalfe, Tracy L.; Metcalfe, Chris D.; Angell, Carolyn M.; Wilson, Joanna Y.; Moore, Michael J.; Whitehead, Hal

    2008-01-01

    A small population of endangered northern bottlenose whales (Hyperoodon ampullatus) inhabits 'The Gully' a Marine Protected Area on the Scotian Shelf, eastern Canada. Amid concerns regarding nearby oil and gas development, we took 36 skin and blubber biopsy samples in 1996-1997 (prior to major development) and 2002-2003 (five years after development began), and three samples from a population in the Davis Strait, Labrador in 2003. These were analysed for cytochrome P4501A1 (CYP1A1) protein expression (n = 36), and for persistent contaminants (n = 23). CYP1A1 showed generally low expression in whales from The Gully, but higher levels during 2003, potentially coincident with recorded oil spills, and higher levels in Davis Strait whales. A range of PCB congeners and organochlorine compounds were detected, with concentrations similar to other North Atlantic odontocetes. Concentrations were higher in whales from The Gully than from the Davis Strait, with significant increases in 4,4'-DDE and trans-nonachlor in 2002-2003 relative to 1996-1997. - Whale contaminants highlight concerns from oil and gas development near a marine protected area

  6. Blogging from North Pond

    Science.gov (United States)

    Marziali, C. G.; Edwards, K. J.

    2009-12-01

    Sea going research expeditions provide an ideal opportunity for outreach through blogs: the finite duration limits the author's commitment; scientists are usually in a remote location with fewer distractions; and fieldwork is visual and interesting to describe. Over four weeks this winter, Katrina Edwards of USC authored a blog about her deep-sea drilling expedition to North Pond, a depression in the ocean crust in the mid-Atlantic. She emailed daily dispatches and photos to USC Media Relations, which maintained a (still accessible) blog. Written for the general public, the blog quickly attracted interest from lay readers as well as from media organizations. Scientific American carried the blog on its web site, and the National Science Foundation linked to it in its "Science 360" electronic news digest. The blog also led to a Q&A with Edwards in the widely-read "Behind the Scenes" feature of LiveScience. Interest from science bloggers and National Geographic towards the end suggests that the blog could have expanded its reach given more time: expeditions lasting between six weeks and three months, such as occur during ocean drilling expeditions, would appear to be ideal candidates for a blog. Most importantly, the blog educated readers about the importance to planetary life of what Edwards calls the "intraterrestrials": the countless microbes that inhabit the oceanic crust and influence major chemical and biological cycles. Considering that the subjects of the expedition were invisible critters in a pitch-dark place, the blog shows what can be accomplished by scientists and institutions committed to public outreach.

  7. Environmental Info for North Dakota

    Science.gov (United States)

    This page contains information about air and water in North Dakota, including state implementation programs (SIPs), air permitting, underground injection control (UIC) and National Pollution Discharge Elimination System (NPDES).

  8. Whither North Carolina furniture manufacturing?

    OpenAIRE

    Robert L. Lacy

    2004-01-01

    North Carolina's furniture manufacturing industry has contracted in recent years as imports have gained a greater share of the domestic furniture market. Rapid growth of the furniture industry in China and a surge in exports from that country to the United States in particular have contributed to plant closings and consolidation of operations in the state. North Carolina's furniture manufacturers are adapting to the emergence of global competition and are developing new corporate strategies t...

  9. Hubble Space Telescope Observations of Extended [O III]λ 5007 Emission in Nearby QSO2s: New Constraints on AGN Host Galaxy Interaction

    Science.gov (United States)

    Fischer, Travis C.; Kraemer, S. B.; Schmitt, H. R.; Longo Micchi, L. F.; Crenshaw, D. M.; Revalski, M.; Vestergaard, M.; Elvis, M.; Gaskell, C. M.; Hamann, F.; Ho, L. C.; Hutchings, J.; Mushotzky, R.; Netzer, H.; Storchi-Bergmann, T.; Straughn, A.; Turner, T. J.; Ward, M. J.

    2018-04-01

    We present a Hubble Space Telescope survey of extended [O III] λ5007 emission for a sample of 12 nearby (z continuing to be kinematically influenced by the central active galactic nucleus (AGN) out to an average radius of ∼1130 pc. These findings question the effectiveness of AGNs being capable of clearing material from their host bulge in the nearby universe and suggest that disruption of gas by AGN activity may prevent star formation without requiring evacuation. Additionally, we find a dichotomy in our targets when comparing [O III] radial extent and nuclear FWHM, where QSO2s with compact [O III] morphologies typically possess broader nuclear emission lines.

  10. Cosmic rays, gas and dust in nearby anticentre clouds. I. CO-to-H2 conversion factors and dust opacities

    Science.gov (United States)

    Remy, Q.; Grenier, I. A.; Marshall, D. J.; Casandjian, J. M.

    2017-05-01

    Aims: We aim to explore the capabilities of dust emission and γ rays for probing the properties of the interstellar medium in the nearby anti-centre region, using γ-ray observations with the Fermi Large Area Telescope (LAT), and the thermal dust optical depth inferred from Planck and IRAS observations. We also aim to study massive star-forming clouds including the well known Taurus, Auriga, Perseus, and California molecular clouds, as well as a more diffuse structure which we refer to as Cetus. In particular, we aim at quantifying potential variations in cosmic-ray density and dust properties per gas nucleon across the different gas phases and different clouds, and at measuring the CO-to-H2 conversion factor, XCO, in different environments. Methods: We have separated six nearby anti-centre clouds that are coherent in velocities and distances, from the Galactic-disc background in H I 21-cm and 12CO 2.6-mm line emission. We have jointly modelled the γ-ray intensity recorded between 0.4 and 100 GeV, and the dust optical depth τ353 at 353 GHz as a combination of H I-bright, CO-bright, and ionised gas components. The complementary information from dust emission and γ rays was used to reveal the gas not seen, or poorly traced, by H I, free-free, and 12CO emissions, namely (I) the opaque H iand diffuse H2 present in the Dark Neutral Medium at the atomic-molecular transition, and (II) the dense H2 to be added where 12CO lines saturate. Results: The measured interstellar γ-ray spectra support a uniform penetration of the cosmic rays with energies above a few GeV through the clouds, from the atomic envelopes to the 12CO-bright cores, and with a small ± 9% cloud-to-cloud dispersion in particle flux. We detect the ionised gas from the H iiregion NGC 1499 in the dust and γ-ray emissions and measure its mean electron density and temperature. We find a gradual increase in grain opacity as the gas (atomic or molecular) becomes more dense. The increase reaches a factor of

  11. THE ADVANCED CAMERA FOR SURVEYS NEARBY GALAXY SURVEY TREASURY. VI. THE ANCIENT STAR-FORMING DISK OF NGC 404

    International Nuclear Information System (INIS)

    Williams, Benjamin F.; Dalcanton, Julianne J.; Gilbert, Karoline M.; Stilp, Adrienne; Dolphin, Andrew; Seth, Anil C.; Weisz, Daniel; Skillman, Evan

    2010-01-01

    We present HST/WFPC2 observations across the disk of the nearby isolated dwarf S0 galaxy NGC 404, which hosts an extended gas disk. The locations of our fields contain a roughly equal mixture of bulge and disk stars. All of our resolved stellar photometry reaches m F814W = 26 (M F814W = -1.4), which covers 2.5 mag of the red giant branch and main-sequence stars with ages F814W = 27.2 (M F814W = -0.2), sufficient to resolve the red clump and main-sequence stars with ages 10 Gyr) population. Detailed modeling of the color-magnitude diagram suggests that ∼70% of the stellar mass in the NGC 404 disk formed by z ∼ 2 (10 Gyr ago) and at least ∼90% formed prior to z ∼ 1 (8 Gyr ago). These results indicate that the stellar populations of the NGC 404 disk are on average significantly older than those of other nearby disk galaxies, suggesting that early- and late-type disks may have different long-term evolutionary histories, not simply differences in their recent star formation rates. Comparisons of the spatial distribution of the young stellar mass and FUV emission in Galaxy Evolution Explorer images show that the brightest FUV regions contain the youngest stars, but that some young stars (<160 Myr) lie outside of these regions. FUV luminosity appears to be strongly affected by both age and stellar mass within individual regions. Finally, we use our measurements to infer the relationship between the star formation rate and the gas density of the disk at previous epochs. We find that most of the history of the NGC 404 disk is consistent with star formation that has decreased with the gas density according to the Schmidt law. However, ∼ 0.5-1 Gyr ago, the star formation rate was unusually low for the inferred gas density, consistent with the possibility that there was a gas accretion event that reignited star formation ∼0.5 Gyr ago. Such an event could explain why this S0 galaxy hosts an extended gas disk.

  12. The White-Dwarf Mass-Radius Relation from 40 Eridani B and Other Nearby Visual Binaries

    Science.gov (United States)

    Bond, Howard E.; Bergeron, P.; Bedard, A.

    2018-01-01

    The bright, nearby DA-type white dwarf (WD) 40 Eridani B is orbited by the M dwarf 40 Eri C, allowing determination of the WD's mass. Until recently, however, the mass depended on orbital elements determined four decades ago, and that mass was so low that it created several astrophysical puzzles. Using new astrometric measurements, the binary-star group at the U.S. Naval Observatory has revised the dynamical mass upward, to 0.573 ± 0.018 M⊙. We have used model-atmosphere analysis to update other parameters of the WD, including effective temperature, surface gravity, radius, and luminosity. We then comparethese results with WD interior models.Within the observational uncertainties, theoretical cooling tracks for CO-core WDs of its measured mass are consistent with the position of 40 Eri B in the H-R diagram; equivalently, the theoretical mass-radius relation (MRR) is consistent with the star's location in the mass-radius plane. This consistency is, however, achieved only if we assume a "thin'' outer hydrogen layer, with qH = MH/MWD ∼ 10–10.We discuss other evidence that a significant fraction of DA WDs have such thin H layers, in spite of expectation from canonical stellar-evolution theory of "thick'' H layers with qH ∼ 10–4 . The cooling age of 40 Eri B is ~122 Myr, and its total age is ~1.8 Gyr. We present the MRRs for 40 Eri B and three other nearby WDs in visual binaries with precise mass determinations, and show that the agreement of current theory with observation is excellent in all cases.However, astrophysical puzzles remain. The eccentricity of the BC orbit has remained high (0.43), even though the progenitor of B ought to have interacted tidally with C when it was an AGB star. This puzzle exists also for the Sirius and Procyon systems. If thin hydrogen layers are common among WDs, the mass scale will need to be shifted downwards by a few hundredths of a solar mass.

  13. THE CO-TO-H2 CONVERSION FACTOR AND DUST-TO-GAS RATIO ON KILOPARSEC SCALES IN NEARBY GALAXIES

    International Nuclear Information System (INIS)

    Sandstrom, K. M.; Walter, F.; Leroy, A. K.; Bolatto, A. D.; Wolfire, M.; Croxall, K. V.; Crocker, A.; Draine, B. T.; Aniano, G.; Wilson, C. D.; Calzetti, D.; Kennicutt, R. C.; Galametz, M.; Donovan Meyer, J.; Usero, A.; Bigiel, F.; Brinks, E.; De Blok, W. J. G.; Dale, D.; Engelbracht, C. W.

    2013-01-01

    We present ∼kiloparsec spatial resolution maps of the CO-to-H 2 conversion factor (α CO ) and dust-to-gas ratio (DGR) in 26 nearby, star-forming galaxies. We have simultaneously solved for α CO and the DGR by assuming that the DGR is approximately constant on kiloparsec scales. With this assumption, we can combine maps of dust mass surface density, CO-integrated intensity, and H I column density to solve for both α CO and the DGR with no assumptions about their value or dependence on metallicity or other parameters. Such a study has just become possible with the availability of high-resolution far-IR maps from the Herschel key program KINGFISH, 12 CO J = (2-1) maps from the IRAM 30 m large program HERACLES, and H I 21 cm line maps from THINGS. We use a fixed ratio between the (2-1) and (1-0) lines to present our α CO results on the more typically used 12 CO J = (1-0) scale and show using literature measurements that variations in the line ratio do not affect our results. In total, we derive 782 individual solutions for α CO and the DGR. On average, α CO = 3.1 M ☉ pc –2 (K km s –1 ) –1 for our sample with a standard deviation of 0.3 dex. Within galaxies, we observe a generally flat profile of α CO as a function of galactocentric radius. However, most galaxies exhibit a lower α CO value in the central kiloparsec—a factor of ∼2 below the galaxy mean, on average. In some cases, the central α CO value can be factors of 5-10 below the standard Milky Way (MW) value of α CO, M W = 4.4 M ☉ pc –2 (K km s –1 ) –1 . While for α CO we find only weak correlations with metallicity, the DGR is well-correlated with metallicity, with an approximately linear slope. Finally, we present several recommendations for choosing an appropriate α CO for studies of nearby galaxies

  14. Search for type Ia supernovae within the EROS2 collaboration. Photometric study of nearby SNIa and measurement of H_0

    International Nuclear Information System (INIS)

    Regnault, Nicolas

    2000-01-01

    Type Ia supernovae (SNIa) are powerful distance indicators. The comparison of nearby (z ∼ 0:1) and distant (z ∼ 1) SNIa apparent magnitudes leads to the determination of the large scale geometry of the universe. Cosmological parameters such as the Hubble constant H_0, the matter density Ω_m and the cosmological constant Ω_Λ can thus be determined. The EROS2 experiment devotes about 10% of its observing time to the detection of nearby SNIa. In the spring of 1999, EROS2 participated in a worldwide search conducted by the Supernova Cosmology Project. This campaign resulted in the discovery of 50 supernovae. Among these, 20 turned out to be SNIa discovered within 10 days from maximum. The thesis work is divided into 3 parts. First, we present a quick overview of the standard cosmological model and the main techniques used for measuring the cosmological parameters (SNIa, rich clusters properties, and anisotropies of the cosmological background radiation). We then describe the physics and observational properties of SNIa. In particular, we show that the peak absolute luminosity of these objects is uniform (within 30%), and correlates with other observables. Using these correlations, we can construct a corrected peak luminosity, which exhibits a lower dispersion (∼10%). The second part is devoted to the description of the EROS2 setup, and our SNe search techniques. In the last part, we present the analysis of the spring 1999 SNIa's photometric follow-up data. We describe the photometry software developed for this analysis as well as the complex intercalibration process of the follow-up images taken with 10 different telescopes. In the last chapter, we show how the peak luminosity and the decline rate of each SN can be reconstructed. Using these quantities, we study the correlations between the peak luminosity the decline rate and the color of SNIa, which leads to a value of H_0: H_0 = 67.4 ± 2(int)"+"5"."8_-_6_._4(ext.). (author) [fr

  15. North European Transect

    Science.gov (United States)

    Korja, Annakaisa; Heikkinen, Pekka J.; Roslov, Yuri; Ivanova, Nina; Verba, Marc; Sakoulina, Tamara

    2010-05-01

    A nearly continuous, 3600 km long, NE-running North European Transect (NET) is combined from the existing deep seismic reflection data sets in the Baltic Sea (BABEL, 1600 km), Northern Finland (FIRE 4-4A, 580 km) and Barents Sea (1-AR, 1440 km;). The reflective image of the deep crust is highly dependent on the thickness of the sedimentary cover. The cover is few hundred meters in the Baltic sea, few tens of meters in the land areas and few kilometers in the Barents Sea area. In the Barents Sea area, the seismic image is dominated by the layered structure of the sedimentary basins and the middle and lower crust are poorly imaged. Therefore the Moho boundary in the Barents Sea has been determined from wide-angle reflections. Geologically the transect covers the transition from Phanerozoic Europe to Precambrian Europe and back to the Phanerozoic Barents Sea Shelf. It displays how Northern Europe grew around Baltica in several tectonic episodes involving the formation and destruction of Columbia/Hudsonland, Rodinia and Pangea supercontinents. The paleo plateboundaries are traversed by subvertical transparent zones suggesting transpressional and trantensional environments. The BABEL lines image how the core of Baltica was formed by sequential accretion of microcontinents and arc terranes at the old continental margin during the Svecofennian Orogeny ~1.9-1.8 Ga .When Baltica joined the Columbia supercontinent, new terranes were added to its southern edge in the Sveocbaltic Orogeny (~1.8 Ga). During the dispersal of the Columbia, the Baltic Sea failed rift was formed, rapakivi granitoids were intruded and sedimentary basins were developed. An extended plate margin structure has been imposed on the Rodinian (Sveconorwegian) and Pangean additions (Variscan-Caledonian). Major crustal thinning takes place along a series of subvertical faults across the Trans-European Suture Zone marking the transition from Phanerozoic to Proterozoic Europe. The FIRE lines in Northen Finland

  16. Young Nearby Loose Associations

    Science.gov (United States)

    Torres, C. A. O.; Quast, G. R.; Melo, C. H. F.; Sterzik, M. F.

    2008-12-01

    A significant population of stars with ages younger than the Pleiades exists in the solar neighborhood. They are grouped in loose young associations, sharing similar kinematical and physical properties, but, due to their vicinity to the Sun, they are dispersed in the sky, and hard to identify. Their strong stellar coronal activity, causing enhanced X-ray emission, allows them to be identified as counterparts of X-ray sources. The analysis presented here is based mainly on the SACY project, aimed to survey in a systematic way counterparts of ROSAT all-sky X-ray sources in the Southern Hemisphere for which proper motions are known. We give the definition, main properties, and lists of high-probability members of nine confirmed loose young associations that do not belong directly to the well-known Oph-Sco-Cen complex. The youth and vicinity of many members of these new associations make them ideal targets for follow-up studies, specifically geared towards the understanding of planetary system formation. Searches for very low-mass and brown dwarf companions are ongoing, and it will be promising to search for planetary companions with next generation instruments.

  17. NEW OPTICAL/ULTRAVIOLET COUNTERPARTS AND THE SPECTRAL ENERGY DISTRIBUTIONS OF NEARBY, THERMALLY EMITTING, ISOLATED NEUTRON STARS

    International Nuclear Information System (INIS)

    Kaplan, D. L.; Kamble, A.; Van Kerkwijk, M. H.; Ho, W. C. G.

    2011-01-01

    We present Hubble Space Telescope optical and ultraviolet photometry for five nearby, thermally emitting neutron stars. With these measurements, all seven such objects have confirmed optical and ultraviolet counterparts. Combining our data with archival space-based photometry, we present spectral energy distributions for all sources and measure the 'optical excess': the factor by which the measured photometry exceeds that extrapolated from X-ray spectra. We find that the majority have optical and ultraviolet fluxes that are inconsistent with that expected from thermal (Rayleigh-Jeans) emission, exhibiting more flux at longer wavelengths. We also find that most objects have optical excesses between 5 and 12, but that one object (RX J2143.0+0654) exceeds the X-ray extrapolation by a factor of more than 50 at 5000 A, and that this is robust to uncertainties in the X-ray spectra and absorption. We consider explanations for this ranging from atmospheric effects, magnetospheric emission, and resonant scattering, but find that none is satisfactory.

  18. NEW M, L, AND T DWARF COMPANIONS TO NEARBY STARS FROM THE WIDE-FIELD INFRARED SURVEY EXPLORER

    Energy Technology Data Exchange (ETDEWEB)

    Luhman, Kevin L.; Loutrel, Nicholas P.; McCurdy, Nicholas S.; Melso, Nicole D.; Star, Kimberly M.; Terrien, Ryan C. [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States); Mace, Gregory N.; McLean, Ian S. [UCLA Division of Astronomy and Astrophysics, Los Angeles, CA 90095 (United States); Young, Michael D.; Rhode, Katherine L. [Department of Astronomy, Indiana University, Swain West 319, 727 East Third Street, Bloomington, IN 47405 (United States); Davy Kirkpatrick, J., E-mail: kluhman@astro.psu.edu [Infrared Processing and Analysis Center, MS 100-22, California Institute of Technology, Pasadena, CA 91125 (United States)

    2012-12-01

    We present 11 candidate late-type companions to nearby stars identified with data from the Wide-field Infrared Survey Explorer (WISE) and the Two Micron All Sky Survey (2MASS). Eight of the candidates are likely to be companions based on their common proper motions with the primaries. The remaining three objects are rejected as companions, one of which is a free-floating T7 dwarf. Spectral types are available for five of the companions, which consist of M2V, M8.5V, L5, T8, and T8. Based on their photometry, the unclassified companions are probably two mid-M dwarfs and one late-M/early-L dwarf. One of the T8 companions, WISE J142320.84+011638.0, has already been reported by Pinfield and coworkers. The other T8 companion, ULAS J095047.28+011734.3, was discovered by Burningham and coworkers through the United Kingdom Infrared Telescope Infrared Deep Sky Survey, but its companionship has not been previously recognized in the literature. The L5 companion, 2MASS J17430860+8526594, is a new member of a class of L dwarfs that exhibit unusually blue near-IR colors. Among the possible mechanisms that have been previously proposed for the peculiar colors of these L dwarfs, low metallicity does not appear to be a viable explanation for 2MASS J17430860+8526594 since our spectrum of the primary suggests that its metallicity is not significantly subsolar.

  19. NEW M, L, AND T DWARF COMPANIONS TO NEARBY STARS FROM THE WIDE-FIELD INFRARED SURVEY EXPLORER

    International Nuclear Information System (INIS)

    Luhman, Kevin L.; Loutrel, Nicholas P.; McCurdy, Nicholas S.; Melso, Nicole D.; Star, Kimberly M.; Terrien, Ryan C.; Mace, Gregory N.; McLean, Ian S.; Young, Michael D.; Rhode, Katherine L.; Davy Kirkpatrick, J.

    2012-01-01

    We present 11 candidate late-type companions to nearby stars identified with data from the Wide-field Infrared Survey Explorer (WISE) and the Two Micron All Sky Survey (2MASS). Eight of the candidates are likely to be companions based on their common proper motions with the primaries. The remaining three objects are rejected as companions, one of which is a free-floating T7 dwarf. Spectral types are available for five of the companions, which consist of M2V, M8.5V, L5, T8, and T8. Based on their photometry, the unclassified companions are probably two mid-M dwarfs and one late-M/early-L dwarf. One of the T8 companions, WISE J142320.84+011638.0, has already been reported by Pinfield and coworkers. The other T8 companion, ULAS J095047.28+011734.3, was discovered by Burningham and coworkers through the United Kingdom Infrared Telescope Infrared Deep Sky Survey, but its companionship has not been previously recognized in the literature. The L5 companion, 2MASS J17430860+8526594, is a new member of a class of L dwarfs that exhibit unusually blue near-IR colors. Among the possible mechanisms that have been previously proposed for the peculiar colors of these L dwarfs, low metallicity does not appear to be a viable explanation for 2MASS J17430860+8526594 since our spectrum of the primary suggests that its metallicity is not significantly subsolar.

  20. Daily Peak Load Forecasting of Next Day using Weather Distribution and Comparison Value of Each Nearby Date Data

    Science.gov (United States)

    Ito, Shigenobu; Yukita, Kazuto; Goto, Yasuyuki; Ichiyanagi, Katsuhiro; Nakano, Hiroyuki

    By the development of industry, in recent years; dependence to electric energy is growing year by year. Therefore, reliable electric power supply is in need. However, to stock a huge amount of electric energy is very difficult. Also, there is a necessity to keep balance between the demand and supply, which changes hour after hour. Consequently, to supply the high quality and highly dependable electric power supply, economically, and with high efficiency, there is a need to forecast the movement of the electric power demand carefully in advance. And using that forecast as the source, supply and demand management plan should be made. Thus load forecasting is said to be an important job among demand investment of electric power companies. So far, forecasting method using Fuzzy logic, Neural Net Work, Regression model has been suggested for the development of forecasting accuracy. Those forecasting accuracy is in a high level. But to invest electric power in higher accuracy more economically, a new forecasting method with higher accuracy is needed. In this paper, to develop the forecasting accuracy of the former methods, the daily peak load forecasting method using the weather distribution of highest and lowest temperatures, and comparison value of each nearby date data is suggested.

  1. The sub-energetic gamma-ray burst GRB 031203 as a cosmic analogue to the nearby GRB 980425.

    Science.gov (United States)

    Soderberg, A M; Kulkarni, S R; Berger, E; Fox, D W; Sako, M; Frail, D A; Gal-Yam, A; Moon, D S; Cenko, S B; Yost, S A; Phillips, M M; Persson, S E; Freedman, W L; Wyatt, P; Jayawardhana, R; Paulson, D

    2004-08-05

    Over the six years since the discovery of the gamma-ray burst GRB 980425, which was associated with the nearby (distance approximately 40 Mpc) supernova 1998bw, astronomers have debated fiercely the nature of this event. Relative to bursts located at cosmological distance (redshift z approximately 1), GRB 980425 was under-luminous in gamma-rays by three orders of magnitude. Radio calorimetry showed that the explosion was sub-energetic by a factor of 10. Here we report observations of the radio and X-ray afterglow of the recent GRB 031203 (refs 5-7), which has a redshift of z = 0.105. We demonstrate that it too is sub-energetic which, when taken together with the low gamma-ray luminosity, suggests that GRB 031203 is the first cosmic analogue to GRB 980425. We find no evidence that this event was a highly collimated explosion viewed off-axis. Like GRB 980425, GRB 031203 appears to be an intrinsically sub-energetic gamma-ray burst. Such sub-energetic events have faint afterglows. We expect intensive follow-up of faint bursts with smooth gamma-ray light curves (common to both GRB 031203 and 980425) to reveal a large population of such events.

  2. EARLY RADIO AND X-RAY OBSERVATIONS OF THE YOUNGEST NEARBY TYPE Ia SUPERNOVA PTF 11kly (SN 2011fe)

    International Nuclear Information System (INIS)

    Horesh, Assaf; Kulkarni, S. R.; Carpenter, John; Kasliwal, Mansi M.; Ofek, Eran O.; Fox, Derek B.; Quimby, Robert; Gal-Yam, Avishay; Cenko, S. Bradley; De Bruyn, A. G.; Kamble, Atish; Wijers, Ralph A. M. J.; Van der Horst, Alexander J.; Kouveliotou, Chryssa; Podsiadlowski, Philipp; Sullivan, Mark; Maguire, Kate; Howell, D. Andrew; Nugent, Peter E.; Gehrels, Neil

    2012-01-01

    On 2011 August 24 (UT) the Palomar Transient Factory (PTF) discovered PTF11kly (SN 2011fe), the youngest and most nearby Type Ia supernova (SN Ia) in decades. We followed this event up in the radio (centimeter and millimeter bands) and X-ray bands, starting about a day after the estimated explosion time. We present our analysis of the radio and X-ray observations, yielding the tightest constraints yet placed on the pre-explosion mass-loss rate from the progenitor system of this supernova. We find a robust limit of M-dot ∼ -8 (w/100 km s -1 ) M sun yr -1 from sensitive X-ray non-detections, as well as a similar limit from radio data, which depends, however, on assumptions about microphysical parameters. We discuss our results in the context of single-degenerate models for SNe Ia and find that our observations modestly disfavor symbiotic progenitor models involving a red giant donor, but cannot constrain systems accreting from main-sequence or sub-giant stars, including the popular supersoft channel. In view of the proximity of PTF11kly and the sensitivity of our prompt observations, we would have to wait for a long time (a decade or longer) in order to more meaningfully probe the circumstellar matter of SNe Ia.

  3. Phenology of spotted wing drosophila in the San Joaquin Valley varies by season, crop and nearby vegetation

    Directory of Open Access Journals (Sweden)

    David R. Haviland

    2016-01-01

    Full Text Available The spotted wing drosophila, first detected in California in 2008, has become a major insect pest in caneberries and sweet cherries, causing commercial crop losses. Managing it is challenging because it has many other hosts, including riparian and backyard fruit plantings, and it increases rapidly, with generations overlapping one another. In our study we monitored trap captures in two parts of the San Joaquin Valley, within sweet cherry orchards and in nearby locations. Captures of adult flies showed two main periods of activity — spring and fall — and low captures in the winter (except for citrus and evergreen riparian areas and summer. On many occasions during the year, trap captures were higher outside of the cherry orchards than within them. Additionally, early in the season, when decisions about control programs are being made, the sex ratio of captured flies in cherries was strongly female-biased. The results suggest that during the weeks leading up to harvest growers should experiment by placing traps in different environments surrounding their orchards to determine SWD activity and potential pest pressure locally, and monitor for both male and female flies.

  4. The activity of superoxide dismutase in animal liver and erythrocyte at Sea Area nearby Dayawan Nuclear Power Station

    International Nuclear Information System (INIS)

    Cheng, Ge; Cai, Yana; Chen, Huizhen

    1995-01-01

    Many tests, the effect of ionizing radiation on SOD in vivo and vitro, had proved that the irradiation can cause the SOD activity to decrease with the increase of irradiation dose, change some physicochemical properties and structure. This artical was to study the activity of SOD in Fish (Thearpon jorbua) and Toad(Bufo melanostictus) liver erythrocyte at sea area nearby Dayawan Nuclear Power Station (Nps). We found that the SOD activity in fish liver, after NPS revolved one year, was higher than that of before revoling (7.30 ± 1.35U/mg protein, 5.49 ±1.56 U/mg protein respectively). The SOD activity in the toad liver at NPS revolving one year after was decreased (4.54 ± 0.75 U/mg protein 5.68± 1.49U/mg protein P < 0.001) but in erythrocyte increased (2.32 ± 0.75 U/mg Hb, 0.70 ± 0.33 U/mg Hb P < 0.001). These results indicated that the SOD activity was changed in different with the animal variety. The effect of irradiation on fish at present was absent, on toad need to research in the future

  5. THE ACS NEARBY GALAXY SURVEY TREASURY. IX. CONSTRAINING ASYMPTOTIC GIANT BRANCH EVOLUTION WITH OLD METAL-POOR GALAXIES

    International Nuclear Information System (INIS)

    Girardi, Leo; Williams, Benjamin F.; Gilbert, Karoline M.; Rosenfield, Philip; Dalcanton, Julianne J.; Marigo, Paola; Boyer, Martha L.; Dolphin, Andrew; Weisz, Daniel R.; Skillman, Evan; Melbourne, Jason; Olsen, Knut A. G.; Seth, Anil C.

    2010-01-01

    In an attempt to constrain evolutionary models of the asymptotic giant branch (AGB) phase at the limit of low masses and low metallicities, we have examined the luminosity functions and number ratios between AGB and red giant branch (RGB) stars from a sample of resolved galaxies from the ACS Nearby Galaxy Survey Treasury. This database provides Hubble Space Telescope optical photometry together with maps of completeness, photometric errors, and star formation histories for dozens of galaxies within 4 Mpc. We select 12 galaxies characterized by predominantly metal-poor populations as indicated by a very steep and blue RGB, and which do not present any indication of recent star formation in their color-magnitude diagrams. Thousands of AGB stars brighter than the tip of the RGB (TRGB) are present in the sample (between 60 and 400 per galaxy), hence, the Poisson noise has little impact in our measurements of the AGB/RGB ratio. We model the photometric data with a few sets of thermally pulsing AGB (TP-AGB) evolutionary models with different prescriptions for the mass loss. This technique allows us to set stringent constraints on the TP-AGB models of low-mass, metal-poor stars (with M sun , [Fe/H]∼ sun . This is also in good agreement with recent observations of white dwarf masses in the M4 old globular cluster. These constraints can be added to those already derived from Magellanic Cloud star clusters as important mileposts in the arduous process of calibrating AGB evolutionary models.

  6. The Breakthrough Listen Search for Intelligent Life: 1.1-1.9 GHz Observations of 692 Nearby Stars

    Science.gov (United States)

    Enriquez, J. Emilio; Siemion, Andrew; Foster, Griffin; Gajjar, Vishal; Hellbourg, Greg; Hickish, Jack; Isaacson, Howard; Price, Danny C.; Croft, Steve; DeBoer, David; Lebofsky, Matt; MacMahon, David H. E.; Werthimer, Dan

    2017-11-01

    We report on a search for engineered signals from a sample of 692 nearby stars using the Robert C. Byrd Green Bank Telescope, undertaken as part of the Breakthrough Listen Initiative search for extraterrestrial intelligence. Observations were made over 1.1-1.9 GHz (L band), with three sets of five-minute observations of the 692 primary targets, interspersed with five-minute observations of secondary targets. By comparing the “ON” and “OFF” observations, we are able to identify terrestrial interference and place limits on the presence of engineered signals from putative extraterrestrial civilizations inhabiting the environs of the target stars. During the analysis, 11 events passed our thresholding algorithm, but a detailed analysis of their properties indicates that they are consistent with known examples of anthropogenic radio-frequency interference. We conclude that, at the time of our observations, none of the observed systems host high-duty-cycle radio transmitters emitting between 1.1 and 1.9 GHz with an Equivalent Isotropic Radiated Power of ˜1013 W, which is readily achievable by our own civilization. Our results suggest that fewer than ˜0.1% of the stellar systems within 50 pc possess the type of transmitters searched in this survey.

  7. "1"3CO/C"1"8O Gradients across the Disks of Nearby Spiral Galaxies

    International Nuclear Information System (INIS)

    Jiménez-Donaire, María J.; Cormier, Diane; Bigiel, Frank; Leroy, Adam K.; Gallagher, Molly; Krumholz, Mark R.; Usero, Antonio; Hughes, Annie; Kramer, Carsten; Meier, David; Murphy, Eric; Pety, Jérôme; Schuster, Karl; Schinnerer, Eva; Sliwa, Kazimierz; Tomicic, Neven; Schruba, Andreas

    2017-01-01

    We use the IRAM Large Program EMPIRE and new high-resolution ALMA data to measure "1"3CO(1-0)/C"1"8O(1-0) intensity ratios across nine nearby spiral galaxies. These isotopologues of "1"2CO are typically optically thin across most of the area in galaxy disks, and this ratio allows us to gauge their relative abundance due to chemistry or stellar nucleosynthesis effects. Resolved "1"3CO/C"1"8O gradients across normal galaxies have been rare due to the faintness of these lines. We find a mean "1"3CO/C"1"8O ratio of 6.0 ± 0.9 for the central regions of our galaxies. This agrees well with results in the Milky Way, but differs from results for starburst galaxies (3.4 ± 0.9) and ultraluminous infrared galaxies (1.1 ± 0.4). In our sample, the "1"3CO/C"1"8O ratio consistently increases with increasing galactocentric radius and decreases with increasing star formation rate surface density. These trends could be explained if the isotopic abundances are altered by fractionation; the sense of the trends also agrees with those expected for carbon and oxygen isotopic abundance variations due to selective enrichment by massive stars.

  8. SDSS-IV MaNGA: environmental dependence of stellar age and metallicity gradients in nearby galaxies

    Science.gov (United States)

    Zheng, Zheng; Wang, Huiyuan; Ge, Junqiang; Mao, Shude; Li, Cheng; Li, Ran; Mo, Houjun; Goddard, Daniel; Bundy, Kevin; Li, Hongyu; Nair, Preethi; Lin, Lihwai; Long, R. J.; Riffel, Rogério; Thomas, Daniel; Masters, Karen; Bizyaev, Dmitry; Brownstein, Joel R.; Zhang, Kai; Law, David R.; Drory, Niv; Roman Lopes, Alexandre; Malanushenko, Olena

    2017-03-01

    We present a study on the stellar age and metallicity distributions for 1105 galaxies using the STARLIGHT software on MaNGA (Mapping Nearby Galaxies at APO) integral field spectra. We derive age and metallicity gradients by fitting straight lines to the radial profiles, and explore their correlations with total stellar mass M*, NUV - r colour and environments, as identified by both the large-scale structure (LSS) type and the local density. We find that the mean age and metallicity gradients are close to zero but slightly negative, which is consistent with the inside-out formation scenario. Within our sample, we find that both the age and metallicity gradients show weak or no correlation with either the LSS type or local density environment. In addition, we also study the environmental dependence of age and metallicity values at the effective radii. The age and metallicity values are highly correlated with M* and NUV - r and are also dependent on LSS type as well as local density. Low-mass galaxies tend to be younger and have lower metallicity in low-density environments while high-mass galaxies are less affected by environment.

  9. An Extremely Red and Two Other Nearby L Dwarf Candidates Previously Overlooked in 2MASS, WISE, and Other Surveys

    Science.gov (United States)

    Scholz, Ralf-Dieter; Bell, Cameron P. M.

    2018-02-01

    We present three new nearby L dwarf candidates, found in a continued combined color/proper motion search using WISE, 2MASS, and other survey data, where we included extended WISE sources and looked closer to the Galactic plane region. Their spectral types and distances were estimated from photometric comparisons to well-known L dwarfs with trigonometric parallaxes. The first object, 2MASS J07555430-3259589, is an extremely red L7.5p dwarf candidate at a photometric distance of about 16 pc. Its position, proper motion and distance are consistent with membership in the Carina-Near young moving group. The second one, 2MASS J07414279-0506464, is resolved in Gaia DR1 as a close binary (separation 0.3 arcsec), and we classify it as a equal-mass binary candidate consisting of two L5 dwarfs at 19 pc. Our nearest new neighbor, 2MASS J19251275+0700362, is an L7 dwarf candidate at 10 pc.

  10. FRB 121102: A Repeatedly Combed Neutron Star by a Nearby Low-luminosity Accreting Supermassive Black Hole

    Science.gov (United States)

    Zhang, Bing

    2018-02-01

    The origin of fast radio bursts (FRBs) remains mysterious. Recently, the only repeating FRB source, FRB 121102, was reported to possess an extremely large and variable rotation measure (RM). The inferred magnetic field strength in the burst environment is comparable to that in the vicinity of the supermassive black hole Sagittarius A* of our Galaxy. Here, we show that all of the observational properties of FRB 121102 (including the high RM and its evolution, the high linear polarization degree, an invariant polarization angle across each burst and other properties previously known) can be interpreted within the “cosmic comb” model, which invokes a neutron star with typical spin and magnetic field parameters whose magnetosphere is repeatedly and marginally combed by a variable outflow from a nearby low-luminosity accreting supermassive black hole in the host galaxy. We propose three falsifiable predictions (periodic “on/off” states, and periodic/correlated variation of RM and polarization angle) of the model and discuss other FRBs within the context of the cosmic comb model as well as the challenges encountered by other repeating FRB models in light of the new observations.

  11. Type Ia Supernova Light Curve Inference: Hierarchical Models for Nearby SN Ia in the Optical and Near Infrared

    Science.gov (United States)

    Mandel, Kaisey; Kirshner, R. P.; Narayan, G.; Wood-Vasey, W. M.; Friedman, A. S.; Hicken, M.

    2010-01-01

    I have constructed a comprehensive statistical model for Type Ia supernova light curves spanning optical through near infrared data simultaneously. The near infrared light curves are found to be excellent standard candles (sigma(MH) = 0.11 +/- 0.03 mag) that are less vulnerable to systematic error from dust extinction, a major confounding factor for cosmological studies. A hierarchical statistical framework incorporates coherently multiple sources of randomness and uncertainty, including photometric error, intrinsic supernova light curve variations and correlations, dust extinction and reddening, peculiar velocity dispersion and distances, for probabilistic inference with Type Ia SN light curves. Inferences are drawn from the full probability density over individual supernovae and the SN Ia and dust populations, conditioned on a dataset of SN Ia light curves and redshifts. To compute probabilistic inferences with hierarchical models, I have developed BayeSN, a Markov Chain Monte Carlo algorithm based on Gibbs sampling. This code explores and samples the global probability density of parameters describing individual supernovae and the population. I have applied this hierarchical model to optical and near infrared data of over 100 nearby Type Ia SN from PAIRITEL, the CfA3 sample, and the literature. Using this statistical model, I find that SN with optical and NIR data have a smaller residual scatter in the Hubble diagram than SN with only optical data. The continued study of Type Ia SN in the near infrared will be important for improving their utility as precise and accurate cosmological distance indicators.

  12. Correlations of natural radionuclides in soil with those in sediment from the Danube and nearby irrigation channels

    International Nuclear Information System (INIS)

    Krmar, M.; Varga, E.; Slivka, J.

    2013-01-01

    The correlation between activity concentrations of some natural radionuclides ( 238 U, 226 Ra, 232 Th, 40 K) measured in soil and in sediment taken from the Danube River and nearby irrigation channels was studied. The soil samples were collected from the northern part of Serbia and the sediment from the Serbian part of the Danube River and from the surrounding irrigation channels. The correlation between 238 U and other natural radionuclides in irrigation channel sediments was not as good as in the Danube. One of the possible explanations for this weak correlation can be the different chemical dynamics of 238 U in the irrigation channel sediment or changes of the 238 U activity concentration in irrigation channel sediment due to some human activities. The evaluation of ratios of activity concentrations of some natural radionuclides could be a more sensitive method for the determination of contaminant, rather than the straightforward analysis of activity concentrations. -- Highlights: ► 238 U, 232 Th and 40 K were measured in soil, Danube and surrounding channel sediment. ► Correlation of activity concentrations were observed. ► In cannel sediment natural radionuclides are not well correlated as in Danube one. ► Ratios of 238 U, 232 Th and 40 K can be good indicator for TENORM monitoring

  13. [Distribution and origin of polycyclic aromatic hydrocarbons in suspended particulate matters from the Yangtze estuarine and nearby coastal areas].

    Science.gov (United States)

    Ou, Dong-ni; Liu, Min; Xu, Shi-yuan; Cheng, Shu-bo; Hou, Li-jun; Gao, Lei

    2008-09-01

    Parent PAHs have been quantified in suspended particulate matters from the Yangtze Estuarine and Coastal Areas. The results show that the concentrations of total PAHs ranged from 2278.79-14293.98 ng/g, and were characterized by greatest content near sewage discharge point with trend to decrease by increasing distance. As for PAHs composition, 4-6 rings PAHs were dominant while 2-3 rings PAHs were relative low. Cluster analysis found that except urban sewage discharge, the hydrodynamic force was influencing PAHs distribution patterns. Moreover, the content of suspended particulate matters, organic carbon and soot carbon of suspended particulate matters also play the important roles in PAHs distribution from the Yangtze estuarine and nearby coastal areas. Principal component analysis and PAH ratios demonstrated that uncompleted combustion of fossil fuels was the main source of PAHs in coastal areas, as well as a few anthropogenic releases of oil and oil products. Ecological risk assessment indicated that most of PAH compounds exceeded the effects range ER-L values and ISQV-L values, which might certain potential damage to the Yangtze Estuary ecosystem.

  14. Kinematics and physical conditions of H I in nearby radio sources. The last survey of the old Westerbork Synthesis Radio Telescope

    NARCIS (Netherlands)

    Maccagni, F. M.; Morganti, R.; Oosterloo, T. A.; Geréb, K.; Maddox, N.

    2017-01-01

    We present an analysis of the properties of neutral hydrogen (H I) in 248 nearby (0.02 30 mJy and for which optical spectroscopy is available. The observations were carried out with the Westerbork Synthesis Radio Telescope as the last large project before the

  15. Development of an Intervention Programme to Encourage High School Students to Stay in School for Lunch Instead of Eating at Nearby Fast-Food Restaurants

    Science.gov (United States)

    Beaulieu, Dominique; Godin, Gaston

    2012-01-01

    Many schools have recently adopted food policies and replaced unhealthy products by healthy foods. Consequently, adolescents are more likely to consume a healthy meal if they stay in school for lunch to eat a meal either prepared at home or purchased in school cafeterias. However, many continue to eat in nearby fast-food restaurants. The present…

  16. Contrasting responses to drought of forest floor CO2 efflux in a loblolly pine plantation and a nearby Oak-Hickory forest

    Science.gov (United States)

    S. Palmroth; Chris A. Maier; Heather R. McCarthy; A. C. Oishi; H. S. Kim; Kurt H. Johnsen; Gabrial G. Katul; Ram Oren

    2005-01-01

    Forest floor C02 efflux (Fff) depends on vegetation type, climate, and soil physical properties. We assessed the effects of biological factors on Fff by comparing a maturing pine plantation (PP) and a nearby mature Oak-Hickory-type hardwood forest (HW). Fff was measured...

  17. The North Dakota lignite partnership

    International Nuclear Information System (INIS)

    Porter, C.R.

    1998-01-01

    The State of North Dakota and the Lignite Energy Council have formed a government/industry partnership to promote the use of North Dakota lignite. The partnership provides funding and management for the Lignite Research, Development and Marketing Program. The program funds activities which preserve and enhance jobs and lignite production; ensure economic growth, stability and opportunity; and maintain a stable and competitive tax base. Funding is provided for activities in three areas: marketing feasibility studies, small research projects, and demonstration projects. Funding is derived from the state coal severance tax. Approximately $3,000,000 annually is appropriated from coal severance revenues for program activities. North Dakota is the ninth largest coal producing state, with lignite as the only rank of coal found in the state. Energy is the second largest economic sector in North Dakota, and it currently comprises over 12% of the state's total economic base. This paper reviews the North Dakota lignite industry and describes studies and projects which have received funding from the program

  18. The North Alabama Lightning Mapping Array (LMA): A Network Overview

    Science.gov (United States)

    Blakeslee, R. J.; Bailey, J.; Buechler, D.; Goodman, S. J.; McCaul, E. W., Jr.; Hall, J.

    2005-01-01

    The North Alabama Lightning Mapping Array (LMA) is s a 3-D VHF regional lightning detection system that provides on-orbit algorithm validation and instrument performance assessments for the NASA Lightning Imaging Sensor, as well as information on storm kinematics and updraft evolution that offers the potential to improve severe storm warning lead time by up t o 50% and decrease te false alarm r a t e ( for non-tornado producing storms). In support of this latter function, the LMA serves as a principal component of a severe weather test bed to infuse new science and technology into the short-term forecasting of severe and hazardous weather, principally within nearby National Weather Service forecast offices. The LMA, which became operational i n November 2001, consists of VHF receivers deployed across northern Alabama and a base station located at the National Space Science and Technology Center (NSSTC), which is on t h e campus of the University of Alabama in Huntsville. The LMA system locates the sources of impulsive VHF radio signals s from lightning by accurately measuring the time that the signals aririve at the different receiving stations. Each station's records the magnitude and time of the peak lightning radiation signal in successive 80 ms intervals within a local unused television channel (channel 5, 76-82 MHz in our case ) . Typically hundreds of sources per flash can be reconstructed, which i n t u r n produces accurate 3-dimensional lightning image maps (nominally network topology and the links have an effective data throughput rate ranging from 600 kbits s -1 t o 1.5 %its s -1. This presentation provides an overview of t h e North Alabama network, the data processing (both real-time and post processing) and network statistics.

  19. The effects of regional economic integration in Europe of the pattern north-north and north-south

    Directory of Open Access Journals (Sweden)

    Antevski Miroslav

    2007-01-01

    Full Text Available This paper examines the effects of regional economic integration in Europe, especially the North-North and North-South integration patterns, and how the benefits and costs of integration are divided between countries. Outcomes depend on: comparative advantages, factor endowments, factor intensities, competitive advantages, FDI flows, transfers of technology, knowledge spillovers, economies of scale, transport costs, industry/GDP ratios, and agglomeration forces. The North-North integration between high income countries tends to lead to convergence of country incomes. Contrary, the South-South integration between low income countries causes divergence. Low income countries are likely to be better served by the North-South integration.

  20. Energy, North Africa and Europe

    International Nuclear Information System (INIS)

    Boussena, S.

    1995-01-01

    The energy situation in the North African countries not only offers a multitude of opportunities for regional cooperation, but also for consolidating ties with the European Union. What are the medium-term chances of putting these possibilities to use ? This article reviews the energy issues in Algeria, Morocco, and Tunisia, all in the middle of a complete economic, political, and cultural mutations. It identifies the intra-regional cooperative projects and certain potential obstacles, and analyzes the energy relations between North Africa and Europe from the strategic viewpoint of both regions. (author). 7 tabs

  1. North Sea oil directory 1976

    Energy Technology Data Exchange (ETDEWEB)

    1976-01-01

    This edition of the North Sea Oil Directory has been revised to keep pace with the ever-changing North Sea industry. The information is grouped under the following topics: exploration and production; group licensees; Dutch and Norwegian licensees; UK Offshore Operators Association Committees; drilling contractors; offshore exploration and surveys; cement, drilling fluids, and related equipment; drilling equipment; prime mover, transmission equipment; production and process equipment; rig and platform equipment suppliers; rig builders, ship builders; rig and platform logistics; ports, supply bases; marine civil engineering; specialized equipment and services; classified index; and an alphabetical index. (MCW)

  2. The North Korean nuclear dilemma

    International Nuclear Information System (INIS)

    Hecker, Siegfried S.

    2004-01-01

    The current nuclear crisis, the second one in ten years, erupted when North Korea expelled international nuclear inspectors in December 2002, then withdrew from the Nuclear Nonproliferation Treaty (NPT), and claimed to be building more nuclear weapons with the plutonium extracted from the spent fuel rods heretofore stored under international inspection. These actions were triggered by a disagreement over U.S. assertions that North Korea had violated the Agreed Framework (which froze the plutonium path to nuclear weapons to end the first crisis in 1994) by clandestinely developing uranium enrichment capabilities providing an alternative path to nuclear weapons. With Stanford University Professor John Lewis and three other Americans, I was allowed to visit the Yongbyon Nuclear Center on Jan. 8, 2004. We toured the 5 MWe reactor, the 50 MWe reactor construction site, the spent fuel pool storage building, and the radiochemical laboratory. We concluded that North Korea has restarted its 5 MWe reactor (which produces roughly 6 kg of plutonium annually), it removed the 8000 spent fuel rods that were previously stored under IAEA safeguards from the spent fuel pool, and that it most likely extracted the 25 to 30 kg of plutonium contained in these fuel rods. Although North Korean officials showed us what they claimed was their plutonium metal product from this reprocessing campaign, we were not able to conclude definitively that it was in fact plutonium metal and that it came from the most recent reprocessing campaign. Nevertheless, our North Korean hosts demonstrated that they had the capability, the facility and requisite capacity, and the technical expertise to produce plutonium metal. On the basis of our visit, we were not able to address the issue of whether or not North Korea had a 'deterrent' as claimed - that is, we were not able to conclude that North Korea can build a nuclear device and that it can integrate nuclear devices into suitable delivery systems. However

  3. Jurassic domes in the North Sea - northern North Atlantic region

    Energy Technology Data Exchange (ETDEWEB)

    Surlyk, F. [Univ. of Copenhagen, Geological Inst., Copenhagen (Denmark)

    1996-12-31

    The stratigraphic and tectonic evolution of the Jurassic of East Greenland, the Norwegian Shelf and the North Sea is remarkably similar. A major Middle Jurassic unconformity occurs in all three areas. In the North Sea it is commonly termed the `Mid-Cimmerian Unconformity` and is characterized by progressive truncation of the underlying section towards a centre at the triple junction between the Central Graben, Viking Graben and Moray Firth. Strata above the unconformity show a progressive Late Aalenian-Early Kimmeridgian onlap in the same direction. These relations have been interpreted as caused by Early Jurassic uplift and of a major thermal dome in the central North Sea, followed by Medial and Late Jurassic rifting, erosion, deflation and transgression of the dome. The East Greenland unconformity shows progressive truncation of underlying strata from south to north, and Bajocian to Callovian onlap in the same direction. The same pattern seems to be developed on the conjugate Norwegian margin. This suggests the possibility that the three unconformities have similar causes for their development. It is proposed that major rift domes formed in the Central North Sea and in the Greenland-Norway seaway in Early Jurassic times. The domes were eroded and gradually deflated during Medial Jurassic times and were finally submerged by the Late Oxfordian-Kimmeridgian. They were associated with volcanism and rifting which was delayed with respect to dome initiation. Roughly contemperaneous domes were present west of Britain, north of the Porcupine Seabight, and in Scania, southern Sweden, as reflected by development of asymmetrical unconformities showing progressive truncation of underlying strata, onlap of overlying Jurassic strata, and associated intrusive and extrusive volcanism. The domes are related to impingement of the heads of transient mantle plumes at the base of the lithosphere. The associated unconformities are thus of non-eustatic nature. Domal uplift and

  4. Preliminary report on the geology of the Red River Valley drilling project, eastern North Dakota and northwestern Minnesota

    International Nuclear Information System (INIS)

    Moore, W.L.

    1979-01-01

    Thirty-two wells, 26 of which penetrated the Precambrian, were drilled along the eastern edge of the Williston Basin in the eastern tier of counties in North Dakota and in nearby counties in northwestern Minnesota. These tests, along the Red River Valley of the North, were drilled to study the stratigraphy and uranium potential of this area. The drilling program was unsuccessful in finding either significant amounts of uranium or apparently important shows of uranium. It did, however, demonstrate the occurrence of thick elastic sections in the Ordovician, Jurassic and Cretaceous Systems, within the Red River Valley, along the eastern margins of the Williston Basin which could serve as host rocks for uranium ore bodies

  5. Stable genetic structure and connectivity in pollution-adapted and nearby pollution-sensitive populations of Fundulus heteroclitus

    Science.gov (United States)

    Biancani, Leann M.; Flight, Patrick A.; Nacci, Diane E.; Rand, David M.; Crawford, Douglas L.; Oleksiak, Marjorie F.

    2018-01-01

    Populations of the non-migratory estuarine fish Fundulus heteroclitus inhabiting the heavily polluted New Bedford Harbour (NBH) estuary have shown inherited tolerance to local pollutants introduced to their habitats in the past 100 years. Here we examine two questions: (i) Is there pollution-driven selection on the mitochondrial genome across a fine geographical scale? and (ii) What is the pattern of migration among sites spanning a strong pollution gradient? Whole mitochondrial genomes were analysed for 133 F. heteroclitus from seven nearby collection sites: four sites along the NBH pollution cline (approx. 5 km distance), which had pollution-adapted fish, as well as one site adjacent to the pollution cline and two relatively unpolluted sites about 30 km away, which had pollution-sensitive fish. Additionally, we used microsatellite analyses to quantify genetic variation over three F. heteroclitus generations in both pollution-adapted and sensitive individuals collected from two sites at two different time points (1999/2000 and 2007/2008). Our results show no evidence for a selective sweep of mtDNA in the polluted sites. Moreover, mtDNA analyses revealed that both pollution-adapted and sensitive populations harbour similar levels of genetic diversity. We observed a high level of non-synonymous mutations in the most polluted site. This is probably associated with a reduction in Ne and concomitant weakening of purifying selection, a demographic expansion following a pollution-related bottleneck or increased mutation rates. Our demographic analyses suggest that isolation by distance influences the distribution of mtDNA genetic variation between the pollution cline and the clean populations at broad spatial scales. At finer scales, population structure is patchy, and neither spatial distance, pollution concentration or pollution tolerance is a good predictor of mtDNA variation. Lastly, microsatellite analyses revealed stable population structure over the last

  6. AN ACTIVITY–ROTATION RELATIONSHIP AND KINEMATIC ANALYSIS OF NEARBY MID-TO-LATE-TYPE M DWARFS

    International Nuclear Information System (INIS)

    West, Andrew A.; Weisenburger, Kolby L.; Irwin, Jonathan; Charbonneau, David; Dittmann, Jason; Berta-Thompson, Zachory K.; Pineda, J. Sebastian

    2015-01-01

    Using spectroscopic observations and photometric light curves of 238 nearby M dwarfs from the MEarth exoplanet transit survey, we examine the relationships between magnetic activity (quantified by Hα emission), rotation period, and stellar age. Previous attempts to investigate the relationship between magnetic activity and rotation in these stars were hampered by the limited number of M dwarfs with measured rotation periods (and the fact that v sin i measurements probe only rapid rotation). However, the photometric data from MEarth allows us to probe a wide range of rotation periods for hundreds of M dwarf stars (from shorter than one to longer than 100 days). Over all M spectral types that we probe, we find that the presence of magnetic activity is tied to rotation, including for late-type, fully convective M dwarfs. We also find evidence that the fraction of late-type M dwarfs that are active may be higher at longer rotation periods compared to their early-type counterparts, with several active, late-type, slowly rotating stars present in our sample. Additionally, we find that all M dwarfs with rotation periods shorter than 26 days (early-type; M1–M4) and 86 days (late-type; M5–M8) are magnetically active. This potential mismatch suggests that the physical mechanisms that connect stellar rotation to chromospheric heating may be different in fully convective stars. A kinematic analysis suggests that the magnetically active, rapidly rotating stars are consistent with a kinematically young population, while slow-rotators are less active or inactive and appear to belong to an older, dynamically heated stellar population

  7. THE ADVANCED CAMERA FOR SURVEYS NEARBY GALAXY SURVEY TREASURY. V. RADIAL STAR FORMATION HISTORY OF NGC 300

    International Nuclear Information System (INIS)

    Gogarten, Stephanie M.; Dalcanton, Julianne J.; Williams, Benjamin F.; Roskar, Rok; Gilbert, Karoline M.; Quinn, Thomas R.; Holtzman, Jon; Seth, Anil C.; Dolphin, Andrew; Weisz, Daniel; Skillman, Evan; Cole, Andrew; Debattista, Victor P.; Olsen, Knut; De Jong, Roelof S.; Karachentsev, Igor D.

    2010-01-01

    We present new Hubble Space Telescope (HST) observations of NGC 300 taken as part of the Advanced Camera for Surveys Nearby Galaxy Survey Treasury (ANGST). Individual stars are resolved in these images down to an absolute magnitude of M F814W = 1.0 (below the red clump). We determine the star formation history of the galaxy in six radial bins by comparing our observed color-magnitude diagrams (CMDs) with synthetic CMDs based on theoretical isochrones. We find that the stellar disk out to 5.4 kpc is primarily old, in contrast with the outwardly similar galaxy M33. We determine the scale length as a function of age and find evidence for inside-out growth of the stellar disk: the scale length has increased from 1.1 ± 0.1 kpc 10 Gyr ago to 1.3 ± 0.1 kpc at present, indicating a buildup in the fraction of young stars at larger radii. As the scale length of M33 has recently been shown to have increased much more dramatically with time, our results demonstrate that two galaxies with similar sizes and morphologies can have very different histories. With an N-body simulation of a galaxy designed to be similar to NGC 300, we determine that the effects of radial migration should be minimal. We trace the metallicity gradient as a function of time and find a present-day metallicity gradient consistent with that seen in previous studies. Consistent results are obtained from archival images covering the same radial extent but differing in placement and filter combination.

  8. Radiofrequency radiation from nearby base stations gives high levels in an apartment in Stockholm, Sweden: A case report

    Science.gov (United States)

    Hardell, Lennart; Carlberg, Michael; Hedendahl, Lena K.

    2018-01-01

    Exposure to radiofrequency (RF) radiation was classified in 2011 as a possible human carcinogen, Group 2B, by the International Agency for Research on Cancer of the World Health Organisation. Evidence of the risk of cancer risk has since strengthened. Exposure is changing due to the rapid development of technology resulting in increased ambient radiation. RF radiation of sufficient intensity heats tissues, but the energy is insufficient to cause ionization, hence it is called non-ionizing radiation. These non-thermal exposure levels have resulted in biological effects in humans, animals and cells, including an increased cancer risk. In the present study, the levels of RF radiation were measured in an apartment close to two groups of mobile phone base stations on the roof. A total of 74,531 measurements were made corresponding to ~83 h of recording. The total mean RF radiation level was 3,811 µW/m2 (range 15.2–112,318 µW/m2) for the measurement of the whole apartment, including balconies. Particularly high levels were measured on three balconies and 3 of 4 bedrooms. The total mean RF radiation level decreased by 98% when the measured down-links from the base stations for 2, 3 and 4 G were disregarded. The results are discussed in relation to the detrimental health effects of non-thermal RF radiation. Due to the current high RF radiation, the apartment is not suitable for long-term living, particularly for children who may be more sensitive than adults. For a definitive conclusion regarding the effect of RF radiation from nearby base stations, one option would be to turn them off and repeat the measurements. However, the simplest and safest solution would be to turn them off and dismantle them. PMID:29725476

  9. Spitzer Trigonometric Parallaxes of L, T, and Y Dwarfs: Complementing Gaia's Optically-selected Census of Nearby Stars

    Science.gov (United States)

    Kirkpatrick, J. Davy; Smart, Richard; Marocco, Federico; Martin, Emily; Faherty, Jacqueline; Tinney, Christopher; Cushing, Michael; Beichman, Charles; Gelino, Christopher; Schneider, Adam; Wright, Edward; Lowrance, Patrick; Ingalls, James

    2018-05-01

    We now find ourselves at a moment in history where a parallax-selected census of nearby objects from the hottest A stars to the coldest Y dwarfs is almost a reality. With the release of Gaia DR2 in April of this year, we will be able to extract a volume-limited sample of stars out to 20 pc down to a spectral type of L5. Extending the census to colder types is much more difficult but nonetheless possible and essential. Ground-based astrometric monitoring of some of these colder dwarfs can be done with deep infrared detections on moderate to large (4+ meter) telescopes, but given the amount of time needed, only a portion of the colder objects believed to lie within 20 pc has been monitored. Our prior Spitzer observations have already enabled direct distance measures for T6 through Y dwarfs, but many 20-pc objects with spectral types between L5 and T5.5 have still not been astrometrically monitored, leaving a hole in our knowledge of this important all-sky sample. Spitzer Cycle 14 observations of modest time expenditure can rectify this problem by providing parallaxes for the 150+ objects remaining. Analysis of the brown dwarfs targeted by Spitzer is particularly important because it will provide insight into the low-mass cutoff of star formation, the shape of the mass function as inferred from the observed temperature distribution, the binary fraction of near-equal mass doubles, and the prevalence of extremely young (low-gravity) and extremely old (low metallicity) objects within the sample - all of which can be used to test and further refine model predictions of the underlying mass function.

  10. Impacts of agricultural irrigation on nearby freshwater ecosystems: the seasonal influence of triazine herbicides in benthic algal communities.

    Science.gov (United States)

    Lorente, Carmen; Causapé, Jesús; Glud, Ronnie N; Hancke, Kasper; Merchán, Daniel; Muñiz, Selene; Val, Jonatan; Navarro, Enrique

    2015-01-15

    A small hydrological basin (Lerma, NE Spain), transformed from its natural state (steppe) to rain-fed agriculture and recently to irrigation agriculture, has been monitored across four seasons of an agricultural year. The goal of this study was to assess how and whether agricultural activities impacted the nearby freshwater ecosystems via runoff. Specifically, we assessed the toxicity of three triazine herbicides, terbuthylazine, atrazine and simazine on the photosynthetic efficiency and structure of algal benthic biofilms (i.e., phototropic periphyton) in the small creek draining the basin. It was expected that the seasonal runoff of the herbicides in the creek affected the sensitivity of the periphyton in accord with the rationale of the Pollution Induced Community Tolerance (PICT): the exposure of the community to pollutants result in the replacement of sensitive species by more tolerant ones. In this way, PICT can serve to establish causal linkages between pollutants and the observed biological impacts. The periphyton presented significantly different sensitivities against terbuthylazine through the year in accord with the seasonal application of this herbicide in the crops nowadays. The sensitivity of already banned herbicides, atrazine and simazine does not display a clear seasonality. The different sensitivities to herbicides were in agreement with the expected exposures scenarios, according to the agricultural calendar, but not with the concentrations measured in water, which altogether indicates that the use of PICT approach may serve for long-term monitoring purposes. That will provide not only causal links between the occurrence of chemicals and their impacts on natural communities, but also information about the occurrence of chemicals that may escape from traditional sampling methods (water analysis). In addition, the EC50 and EC10 of periphyton for terbuthylazine or simazine are the first to be published and can be used for impact assessments

  11. Quarry blasts assessment and their environmental impacts on the nearby oil pipelines, southeast of Helwan City, Egypt

    Directory of Open Access Journals (Sweden)

    Adel M.E. Mohamed

    2013-06-01

    Full Text Available Ground vibrations induced by blasting in the cement quarries are one of the fundamental problems in the quarrying industry and may cause severe damage to the nearby utilities and pipelines. Therefore, a vibration control study plays an important role in the minimization of environmental effects of blasting in quarries. The current paper presents the influence of the quarry blasts at the National Cement Company (NCC on the two oil pipelines of SUMED Company southeast of Helwan City, by measuring the ground vibrations in terms of Peak Particle Velocity (PPV. The seismic refraction for compressional waves deduced from the shallow seismic survey and the shear wave velocity obtained from the Multi channel Analysis of Surface Waves (MASW technique are used to evaluate the closest site of the two pipelines to the quarry blasts. The results demonstrate that, the closest site of the two pipelines is of class B, according to the National Earthquake Hazard Reduction Program (NEHRP classification and the safe distance to avoid any environmental effects is 650 m, following the deduced Peak Particle Velocity (PPV and scaled distance (SD relationship (PPV = 700.08 × SD−1.225 in mm/s and the Air over Pressure (air blast formula (air blast = 170.23 × SD−0.071 in dB. In the light of prediction analysis, the maximum allowable charge weight per delay was found to be 591 kg with damage criterion of 12.5 mm/s at the closest site of the SUMED pipelines.

  12. Lyman alpha emission in nearby star-forming galaxies with the lowest metallicities and the highest [OIII]/[OII] ratios

    Science.gov (United States)

    Izotov, Yuri

    2017-08-01

    The Lyman alpha line of hydrogen is the strongest emission line in galaxies and the tool of predilection for identifying and studying star-forming galaxies over a wide range of redshifts, especially in the early universe. However, it has become clear over the years that not all of the Lyman alpha radiation escapes, due to its resonant scattering on the interstellar and intergalactic medium, and absorption by dust. Although our knowledge of the high-z universe depends crucially on that line, we still do not have a complete understanding of the mechanisms behind the production, radiative transfer and escape of Lyman alpha in galaxies. We wish here to investigate these mechanisms by studying the properties of the ISM in a unique sample of 8 extreme star-forming galaxies (SFGs) that have the highest excitation in the SDSS spectral data base. These dwarf SFGs have considerably lower stellar masses and metallicities, and higher equivalent widths and [OIII]5007/[OII]3727 ratios compared to all nearby SFGs with Lyman alpha emission studied so far with COS. They are, however, very similar to the dwarf Lyman alpha emitters at redshifts 3-6, which are thought to be the main sources of reionization in the early Universe. By combining the HST/COS UV data with data in the optical range, and using photoionization and radiative transfer codes, we will be able to study the properties of the Lyman alpha in these unique objects, derive column densities of the neutral hydrogen N(HI) and compare them with N(HI) obtained from the HeI emission-line ratios in the optical spectra. We will derive Lyman alpha escape fractions and indirectly Lyman continuum escape fractions.

  13. Gemini NIFS survey of feeding and feedback processes in nearby active galaxies - II. The sample and surface mass density profiles

    Science.gov (United States)

    Riffel, R. A.; Storchi-Bergmann, T.; Riffel, R.; Davies, R.; Bianchin, M.; Diniz, M. R.; Schönell, A. J.; Burtscher, L.; Crenshaw, M.; Fischer, T. C.; Dahmer-Hahn, L. G.; Dametto, N. Z.; Rosario, D.

    2018-02-01

    We present and characterize a sample of 20 nearby Seyfert galaxies selected for having BAT 14-195 keV luminosities LX ≥ 1041.5 erg s-1, redshift z ≤ 0.015, being accessible for observations with the Gemini Near-Infrared Field Spectrograph (NIFS) and showing extended [O III]λ5007 emission. Our goal is to study Active Galactic Nucleus (AGN) feeding and feedback processes from near-infrared integral-field spectra, which include both ionized (H II) and hot molecular (H2) emission. This sample is complemented by other nine Seyfert galaxies previously observed with NIFS. We show that the host galaxy properties (absolute magnitudes MB, MH, central stellar velocity dispersion and axial ratio) show a similar distribution to those of the 69 BAT AGN. For the 20 galaxies already observed, we present surface mass density (Σ) profiles for H II and H2 in their inner ˜500 pc, showing that H II emission presents a steeper radial gradient than H2. This can be attributed to the different excitation mechanisms: ionization by AGN radiation for H II and heating by X-rays for H2. The mean surface mass densities are in the range (0.2 ≤ ΣH II ≤ 35.9) M⊙ pc-2, and (0.2 ≤ ΣH2 ≤ 13.9)× 10-3 M⊙ pc-2, while the ratios between the H II and H2 masses range between ˜200 and 8000. The sample presented here will be used in future papers to map AGN gas excitation and kinematics, providing a census of the mass inflow and outflow rates and power as well as their relation with the AGN luminosity.

  14. Partitioning behaviour of perfluorinated alkyl contaminants between water, sediment and fish in the Orge River (nearby Paris, France)

    International Nuclear Information System (INIS)

    Labadie, Pierre; Chevreuil, Marc

    2011-01-01

    This paper reports on the partitioning behaviour of 15 perfluorinated compounds (PFCs), including C 4 -C 10 sulfonates and C 5 -C 14 carboxylic acids, between water, sediment and fish (European chub, Leuciscus cephalus) in the Orge River (nearby Paris). Total PFC levels were 73.0 ± 3.0 ng L -1 in water and 8.4 ± 0.5 ng g -1 in sediment. They were in the range 43.1-4997.2 ng g -1 in fish, in which PFC tissue distribution followed the order plasma > liver > gills > gonads > muscle. Sediment-water distribution coefficients (log K d ) and bioaccumulation factors (log BAF) were in the range 0.8-4.3 and 0.9-6.7, respectively. Both distribution coefficients positively correlated with perfluoroalkyl chain length. Field-based biota-sediment accumulation factors (BSAFs) are also reported, for the first time for PFCs other than perfluorooctane sulfonate. log BSAF ranged between -1.3 and 1.5 and was negatively correlated with the perfluoroalkyl chain length in the case of carboxylic acids. - Research highlights: → PFC tissue distribution in European chub followed the order plasma > liver > gills > gonads > muscle. → K d and BAF correlated with PFC alkyl chain length. → BSAF negatively correlated with the perfluoroalkyl chain length in the case of carboxylic acids. → BSAF did not correlate with alkyl chain length of sulfonates. - Sediment-water, biota-water and biota-sediment partitioning coefficients were determined for perfluorinated acids and sulfonates and were generally correlated with alkyl chain length.

  15. CALIBRATION OF THE MEARTH PHOTOMETRIC SYSTEM: OPTICAL MAGNITUDES AND PHOTOMETRIC METALLICITY ESTIMATES FOR 1802 NEARBY M-DWARFS

    International Nuclear Information System (INIS)

    Dittmann, Jason A.; Irwin, Jonathan M.; Charbonneau, David; Newton, Elisabeth R.

    2016-01-01

    The MEarth Project is a photometric survey systematically searching the smallest stars near the Sun for transiting rocky planets. Since 2008, MEarth has taken approximately two million images of 1844 stars suspected to be mid-to-late M dwarfs. We have augmented this survey by taking nightly exposures of photometric standard stars and have utilized this data to photometrically calibrate the MEarth system, identify photometric nights, and obtain an optical magnitude with 1.5% precision for each M dwarf system. Each optical magnitude is an average over many years of data, and therefore should be largely immune to stellar variability and flaring. We combine this with trigonometric distance measurements, spectroscopic metallicity measurements, and 2MASS infrared magnitude measurements in order to derive a color–magnitude–metallicity relation across the mid-to-late M dwarf spectral sequence that can reproduce spectroscopic metallicity determinations to a precision of 0.1 dex. We release optical magnitudes and metallicity estimates for 1567 M dwarfs, many of which did not have an accurate determination of either prior to this work. For an additional 277 stars without a trigonometric parallax, we provide an estimate of the distance, assuming solar neighborhood metallicity. We find that the median metallicity for a volume-limited sample of stars within 20 pc of the Sun is [Fe/H] = −0.03 ± 0.008, and that 29/565 of these stars have a metallicity of [Fe/H] = −0.5 or lower, similar to the low-metallicity distribution of nearby G dwarfs. When combined with the results of ongoing and future planet surveys targeting these objects, the metallicity estimates presented here will be important for assessing the significance of any putative planet–metallicity correlation

  16. METAMORPHOSIS OF SN 2014C: DELAYED INTERACTION BETWEEN A HYDROGEN POOR CORE-COLLAPSE SUPERNOVA AND A NEARBY CIRCUMSTELLAR SHELL

    International Nuclear Information System (INIS)

    Milisavljevic, D.; Margutti, R.; Kamble, A.; Patnaude, D. J.; Raymond, J. C.; Challis, P.; Drout, M. R.; Grindlay, J. E.; Kirshner, R. P.; Lunnan, R.; Miller, G. F.; Parrent, J. T.; Sanders, N. E.; Eldridge, J. J.; Fong, W.; Bietenholz, M.; Chornock, R.; Fransson, C.; Fesen, R. A.; Mackey, J.

    2015-01-01

    We present optical observations of supernova SN 2014C, which underwent an unprecedented slow metamorphosis from H-poor type Ib to H-rich type IIn over the course of one year. The observed spectroscopic evolution is consistent with the supernova having exploded in a cavity before encountering a massive shell of the progenitor star’s stripped hydrogen envelope. Possible origins for the circumstellar shell include a brief Wolf–Rayet fast wind phase that overtook a slower red supergiant wind, eruptive ejection, or confinement of circumstellar material by external influences of neighboring stars. An extended high velocity Hα absorption feature seen in near-maximum light spectra implies that the progenitor star was not completely stripped of hydrogen at the time of core collapse. Archival pre-explosion Subaru Telescope Suprime-Cam and Hubble Space Telescope Wide Field Planetary Camera 2 images of the region obtained in 2009 show a coincident source that is most likely a compact massive star cluster in NGC 7331 that hosted the progenitor system. By comparing the emission properties of the source with stellar population models that incorporate interacting binary stars we estimate the age of the host cluster to be 30–300 Myr, and favor ages closer to 30 Myr in light of relatively strong Hα emission. SN 2014C is the best observed member of a class of core-collapse supernovae that fill the gap between events that interact strongly with dense, nearby environments immediately after explosion and those that never show signs of interaction. Better understanding of the frequency and nature of this intermediate population can contribute valuable information about the poorly understood final stages of stellar evolution

  17. Alfalfa discovery of the nearby gas-rich dwarf galaxy Leo P. IV. Distance measurement from LBT optical imaging

    Energy Technology Data Exchange (ETDEWEB)

    McQuinn, Kristen B. W.; Skillman, Evan D.; Berg, Danielle [Minnesota Institute for Astrophysics, School of Physics and Astronomy, 116 Church Street, S.E., University of Minnesota, Minneapolis, MN 55455 (United States); Cannon, John M. [Department of Physics and Astronomy, Macalester College, 1600 Grand Avenue, Saint Paul, MN 55105 (United States); Salzer, John J.; Rhode, Katherine L. [Department of Astronomy, Indiana University, 727 East 3rd Street, Bloomington, IN 47405 (United States); Adams, Elizabeth A. K.; Giovanelli, Riccardo; Haynes, Martha P. [Center for Radiophysics and Space Research, Space Sciences Building, Cornell University, Ithaca, NY 14853 (United States); Dolphin, Andrew, E-mail: kmcquinn@astro.umn.edu, E-mail: skillman@astro.umn.edu, E-mail: berg@astro.umn.edu, E-mail: jcannon@macalester.edu, E-mail: rhode@astro.indiana.edu, E-mail: slaz@astro.indiana.edu, E-mail: betsey@astro.cornell.edu, E-mail: riccardo@astro.cornell.edu, E-mail: haynes@astro.cornell.edu [Raytheon Company, 1151 E. Hermans Road, Tucson, AZ 85756 (United States)

    2013-12-01

    Leo P is a low-luminosity dwarf galaxy discovered through the blind H I Arecibo Legacy Fast ALFA survey. The H I and follow-up optical observations have shown that Leo P is a gas-rich dwarf galaxy with both active star formation and an underlying older population, as well as an extremely low oxygen abundance. Here, we measure the distance to Leo P by applying the tip of the red giant branch (TRGB) distance method to photometry of the resolved stellar population from new Large Binocular Telescope V and I band imaging. We measure a distance modulus of 26.19{sub −0.50}{sup +0.17} mag corresponding to a distance of 1.72{sub −0.40}{sup +0.14} Mpc. Although our photometry reaches 3 mag below the TRGB, the sparseness of the red giant branch yields higher uncertainties on the lower limit of the distance. Leo P is outside the Local Group with a distance and velocity consistent with the local Hubble flow. While located in a very low-density environment, Leo P lies within ∼0.5 Mpc of a loose association of dwarf galaxies which include NGC 3109, Antlia, Sextans A, and Sextans B, and 1.1 Mpc away from its next nearest neighbor, Leo A. Leo P is one of the lowest metallicity star-forming galaxies known in the nearby universe, comparable in metallicity to I Zw 18 and DDO 68, but with stellar characteristics similar to dwarf spheriodals (dSphs) in the Local Volume such as Carina, Sextans, and Leo II. Given its physical properties and isolation, Leo P may provide an evolutionary link between gas-rich dwarf irregular galaxies and dSphs that have fallen into a Local Group environment and been stripped of their gas.

  18. Radiofrequency radiation from nearby base stations gives high levels in an apartment in Stockholm, Sweden: A case report.

    Science.gov (United States)

    Hardell, Lennart; Carlberg, Michael; Hedendahl, Lena K

    2018-05-01

    Exposure to radiofrequency (RF) radiation was classified in 2011 as a possible human carcinogen, Group 2B, by the International Agency for Research on Cancer of the World Health Organisation. Evidence of the risk of cancer risk has since strengthened. Exposure is changing due to the rapid development of technology resulting in increased ambient radiation. RF radiation of sufficient intensity heats tissues, but the energy is insufficient to cause ionization, hence it is called non-ionizing radiation. These non-thermal exposure levels have resulted in biological effects in humans, animals and cells, including an increased cancer risk. In the present study, the levels of RF radiation were measured in an apartment close to two groups of mobile phone base stations on the roof. A total of 74,531 measurements were made corresponding to ~83 h of recording. The total mean RF radiation level was 3,811 µW/m 2 (range 15.2-112,318 µW/m 2 ) for the measurement of the whole apartment, including balconies. Particularly high levels were measured on three balconies and 3 of 4 bedrooms. The total mean RF radiation level decreased by 98% when the measured down-links from the base stations for 2, 3 and 4 G were disregarded. The results are discussed in relation to the detrimental health effects of non-thermal RF radiation. Due to the current high RF radiation, the apartment is not suitable for long-term living, particularly for children who may be more sensitive than adults. For a definitive conclusion regarding the effect of RF radiation from nearby base stations, one option would be to turn them off and repeat the measurements. However, the simplest and safest solution would be to turn them off and dismantle them.

  19. Spectral Analysis, Synthesis, & Energy Distributions of Nearby E+A Galaxies Using SDSS-IV MaNGA

    Science.gov (United States)

    Weaver, Olivia A.; Anderson, Miguel Ricardo; Wally, Muhammad; James, Olivia; Falcone, Julia; Liu, Allen; Wallack, Nicole; Liu, Charles; SDSS Collaboration

    2017-01-01

    Utilizing data from the Mapping Nearby Galaxies at APO (MaNGA) Survey (MaNGA Product Launch-4, or MPL-4), of the latest generation of the Sloan Digital Sky Survey (SDSS-IV), we identified nine post-starburst (E+A) systems that lie within the Green Valley transition zone. We identify the E+A galaxies by their SDSS single fiber spectrum and u-r color, then confirmed their classification as post-starburst by coding/plotting methods and spectral synthesis codes (FIREFLY and PIPE3D), as well as with their Spectral Energy Distributions (SEDs) from 0.15 µm to 22 µm, using GALEX, SDSS, 2MASS, and WISE data. We produced maps of gaussian-fitted fluxes, equivalent widths, stellar velocities, metallicities and age. We also produced spectral line ratio diagrams to classify regions of stellar populations of the galaxies. We found that our sample of E+As retain their post-starburst properties across the entire galaxy, not just at their center. We detected matching a trend line in the ultraviolet and optical bands, consistent with the expected SEDs for an E+A galaxy, and also through the J, H and Ks bands, except for one object. We classified one of the nine galaxies as a luminous infrared galaxy, unusual for a post-starburst object. Our group seeks to further study stellar population properties, spectral energy distributions and quenching properties in E+A galaxies, and investigate their role in galaxy evolution as a whole. This work was supported by the Alfred P. Sloan Foundation via the SDSS-IV Faculty and Student Team (FAST) initiative, ARC Agreement #SSP483 to the CUNY College of Staten Island. This work was also supported by grants to The American Museum of Natural History, and the CUNY College of Staten Island through from National Science Foundation.

  20. CALIBRATION OF THE MEARTH PHOTOMETRIC SYSTEM: OPTICAL MAGNITUDES AND PHOTOMETRIC METALLICITY ESTIMATES FOR 1802 NEARBY M-DWARFS

    Energy Technology Data Exchange (ETDEWEB)

    Dittmann, Jason A.; Irwin, Jonathan M.; Charbonneau, David; Newton, Elisabeth R. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States)

    2016-02-20

    The MEarth Project is a photometric survey systematically searching the smallest stars near the Sun for transiting rocky planets. Since 2008, MEarth has taken approximately two million images of 1844 stars suspected to be mid-to-late M dwarfs. We have augmented this survey by taking nightly exposures of photometric standard stars and have utilized this data to photometrically calibrate the MEarth system, identify photometric nights, and obtain an optical magnitude with 1.5% precision for each M dwarf system. Each optical magnitude is an average over many years of data, and therefore should be largely immune to stellar variability and flaring. We combine this with trigonometric distance measurements, spectroscopic metallicity measurements, and 2MASS infrared magnitude measurements in order to derive a color–magnitude–metallicity relation across the mid-to-late M dwarf spectral sequence that can reproduce spectroscopic metallicity determinations to a precision of 0.1 dex. We release optical magnitudes and metallicity estimates for 1567 M dwarfs, many of which did not have an accurate determination of either prior to this work. For an additional 277 stars without a trigonometric parallax, we provide an estimate of the distance, assuming solar neighborhood metallicity. We find that the median metallicity for a volume-limited sample of stars within 20 pc of the Sun is [Fe/H] = −0.03 ± 0.008, and that 29/565 of these stars have a metallicity of [Fe/H] = −0.5 or lower, similar to the low-metallicity distribution of nearby G dwarfs. When combined with the results of ongoing and future planet surveys targeting these objects, the metallicity estimates presented here will be important for assessing the significance of any putative planet–metallicity correlation.

  1. Herschel Observations of Protostellar and Young Stellar Objects in Nearby Molecular Clouds: The DIGIT Open Time Key Project

    Science.gov (United States)

    Green, Joel D.; DIGIT OTKP Team

    2010-01-01

    The DIGIT (Dust, Ice, and Gas In Time) Open Time Key Project utilizes the PACS spectrometer (57-210 um) onboard the Herschel Space Observatory to study the colder regions of young stellar objects and protostellar cores, complementary to recent observations from Spitzer and ground-based observatories. DIGIT focuses on 30 embedded sources and 64 disk sources, and includes supporting photometry from PACS and SPIRE, as well as spectroscopy from HIFI, selected from nearby molecular clouds. For the embedded sources, PACS spectroscopy will allow us to address the origin of [CI] and high-J CO lines observed with ISO-LWS. Our observations are sensitive to the presence of cold crystalline water ice, diopside, and carbonates. Additionally, PACS scans are 5x5 maps of the embedded sources and their outflows. Observations of more evolved disk sources will sample low and intermediate mass objects as well as a variety of spectral types from A to M. Many of these sources are extremely rich in mid-IR crystalline dust features, enabling us to test whether similar features can be detected at larger radii, via colder dust emission at longer wavelengths. If processed grains are present only in the inner disk (in the case of full disks) or from the emitting wall surface which marks the outer edge of the gap (in the case of transitional disks), there must be short timescales for dust processing; if processed grains are detected in the outer disk, radial transport must be rapid and efficient. Weak bands of forsterite and clino- and ortho-enstatite in the 60-75 um range provide information about the conditions under which these materials were formed. For the Science Demonstration Phase we are observing an embedded protostar (DK Cha) and a Herbig Ae/Be star (HD 100546), exemplars of the kind of science that DIGIT will achieve over the full program.

  2. THE VELOCITY DISTRIBUTION OF NEARBY STARS FROM HIPPARCOS DATA. II. THE NATURE OF THE LOW-VELOCITY MOVING GROUPS

    International Nuclear Information System (INIS)

    Bovy, Jo; Hogg, David W.

    2010-01-01

    The velocity distribution of nearby stars (∼<100 pc) contains many overdensities or 'moving groups', clumps of comoving stars, that are inconsistent with the standard assumption of an axisymmetric, time-independent, and steady-state Galaxy. We study the age and metallicity properties of the low-velocity moving groups based on the reconstruction of the local velocity distribution in Paper I of this series. We perform stringent, conservative hypothesis testing to establish for each of these moving groups whether it could conceivably consist of a coeval population of stars. We conclude that they do not: the moving groups are neither trivially associated with their eponymous open clusters nor with any other inhomogeneous star formation event. Concerning a possible dynamical origin of the moving groups, we test whether any of the moving groups has a higher or lower metallicity than the background population of thin disk stars, as would generically be the case if the moving groups are associated with resonances of the bar or spiral structure. We find clear evidence that the Hyades moving group has higher than average metallicity and weak evidence that the Sirius moving group has lower than average metallicity, which could indicate that these two groups are related to the inner Lindblad resonance of the spiral structure. Further, we find weak evidence that the Hercules moving group has higher than average metallicity, as would be the case if it is associated with the bar's outer Lindblad resonance. The Pleiades moving group shows no clear metallicity anomaly, arguing against a common dynamical origin for the Hyades and Pleiades groups. Overall, however, the moving groups are barely distinguishable from the background population of stars, raising the likelihood that the moving groups are associated with transient perturbations.

  3. AN ACTIVITY–ROTATION RELATIONSHIP AND KINEMATIC ANALYSIS OF NEARBY MID-TO-LATE-TYPE M DWARFS

    Energy Technology Data Exchange (ETDEWEB)

    West, Andrew A.; Weisenburger, Kolby L. [Department of Astronomy, Boston University, 725 Commonwealth Ave, Boston, MA 02215 (United States); Irwin, Jonathan; Charbonneau, David; Dittmann, Jason [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Berta-Thompson, Zachory K. [MIT, Kavli Institute for Astrophysics and Space Research, 77 Massachusetts Ave., Bldg. 37, Cambridge, MA 02139 (United States); Pineda, J. Sebastian, E-mail: aawest@bu.edu [California Institute of Technology, Department of Astronomy, 1200 E. California Ave, Pasadena, CA 91125 (United States)

    2015-10-10

    Using spectroscopic observations and photometric light curves of 238 nearby M dwarfs from the MEarth exoplanet transit survey, we examine the relationships between magnetic activity (quantified by Hα emission), rotation period, and stellar age. Previous attempts to investigate the relationship between magnetic activity and rotation in these stars were hampered by the limited number of M dwarfs with measured rotation periods (and the fact that v sin i measurements probe only rapid rotation). However, the photometric data from MEarth allows us to probe a wide range of rotation periods for hundreds of M dwarf stars (from shorter than one to longer than 100 days). Over all M spectral types that we probe, we find that the presence of magnetic activity is tied to rotation, including for late-type, fully convective M dwarfs. We also find evidence that the fraction of late-type M dwarfs that are active may be higher at longer rotation periods compared to their early-type counterparts, with several active, late-type, slowly rotating stars present in our sample. Additionally, we find that all M dwarfs with rotation periods shorter than 26 days (early-type; M1–M4) and 86 days (late-type; M5–M8) are magnetically active. This potential mismatch suggests that the physical mechanisms that connect stellar rotation to chromospheric heating may be different in fully convective stars. A kinematic analysis suggests that the magnetically active, rapidly rotating stars are consistent with a kinematically young population, while slow-rotators are less active or inactive and appear to belong to an older, dynamically heated stellar population.

  4. METAMORPHOSIS OF SN 2014C: DELAYED INTERACTION BETWEEN A HYDROGEN POOR CORE-COLLAPSE SUPERNOVA AND A NEARBY CIRCUMSTELLAR SHELL

    Energy Technology Data Exchange (ETDEWEB)

    Milisavljevic, D.; Margutti, R.; Kamble, A.; Patnaude, D. J.; Raymond, J. C.; Challis, P.; Drout, M. R.; Grindlay, J. E.; Kirshner, R. P.; Lunnan, R.; Miller, G. F.; Parrent, J. T.; Sanders, N. E. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA, 02138 (United States); Eldridge, J. J. [Department of Physics, University of Auckland, Private Bag 92019, Auckland (New Zealand); Fong, W. [Steward Observatory, University of Arizona, 933 N. Cherry Avenue, Tucson, AZ 85721 (United States); Bietenholz, M. [Hartebeesthoek Radio Observatory, P.O. Box 443, Krugersdorp 1740 (South Africa); Chornock, R. [Astrophysical Institute, Department of Physics and Astronomy, 251B Clippinger Lab, Ohio University, Athens, OH 45701 (United States); Fransson, C. [Oskar Klein Centre, Department of Astronomy, Stockholm University, AlbaNova, SE106 91 Stockholm (Sweden); Fesen, R. A. [Department of Physics and Astronomy, Dartmouth College, 6127 Wilder Lab, Hanover, NH 03755 (United States); Mackey, J., E-mail: dmilisav@cfa.harvard.edu [Argelander-Institut für Astronomie, Auf dem Hgel 71, D-53121 Bonn (Germany); and others

    2015-12-20

    We present optical observations of supernova SN 2014C, which underwent an unprecedented slow metamorphosis from H-poor type Ib to H-rich type IIn over the course of one year. The observed spectroscopic evolution is consistent with the supernova having exploded in a cavity before encountering a massive shell of the progenitor star’s stripped hydrogen envelope. Possible origins for the circumstellar shell include a brief Wolf–Rayet fast wind phase that overtook a slower red supergiant wind, eruptive ejection, or confinement of circumstellar material by external influences of neighboring stars. An extended high velocity Hα absorption feature seen in near-maximum light spectra implies that the progenitor star was not completely stripped of hydrogen at the time of core collapse. Archival pre-explosion Subaru Telescope Suprime-Cam and Hubble Space Telescope Wide Field Planetary Camera 2 images of the region obtained in 2009 show a coincident source that is most likely a compact massive star cluster in NGC 7331 that hosted the progenitor system. By comparing the emission properties of the source with stellar population models that incorporate interacting binary stars we estimate the age of the host cluster to be 30–300 Myr, and favor ages closer to 30 Myr in light of relatively strong Hα emission. SN 2014C is the best observed member of a class of core-collapse supernovae that fill the gap between events that interact strongly with dense, nearby environments immediately after explosion and those that never show signs of interaction. Better understanding of the frequency and nature of this intermediate population can contribute valuable information about the poorly understood final stages of stellar evolution.

  5. North Dakota's forest resources, 2010

    Science.gov (United States)

    D.E. Haugen; R.A. Harsel

    2011-01-01

    This publication provides an overview of forest resource attributes for North Dakota based on an annual inventory conducted by the Forest Inventory and Analysis (FIA) program at the Northern Research Station of the U.S. Forest Service. These estimates, along with web-posted core tables, will be updated annually. For more information, please refer to page 4 of this...

  6. North Dakota's forest resources, 2011

    Science.gov (United States)

    D.E. Haugen; R.A. Harsel

    2012-01-01

    This publication provides an overview of forest resource attributes for North Dakota based on an annual inventory conducted by the Forest Inventory and Analysis (FIA) program at the Northern Research Station of the U.S. Forest Service. These estimates, along with web-posted core tables, will be updated annually. For more information, please refer to page 4 of this...

  7. North Dakota's forest resources, 2012

    Science.gov (United States)

    D.E. Haugen

    2013-01-01

    This publication provides an overview of forest resource attributes for North Dakota based on an annual inventory conducted by the Forest Inventory and Analysis (FIA) program at the Northern Research Station of the U.S. Forest Service. These estimates, along with Web-posted core tables, will be updated annually. For more information, please refer to page 4 of this...

  8. North Dakota's forest resources, 2008

    Science.gov (United States)

    D.E. Haugen; A.J. Lister

    2010-01-01

    This publication provides an overview of forest resource attributes for North Dakota based on an annual inventory conducted by the Forest Inventory and Analysis (FIA) program at the Northern Research Station of the U.S. Forest Service. These estimates, along with web-posted core tables, will be updated annually. For more information, please refer to page 4 of this...

  9. North Dakota's forest resources, 2009

    Science.gov (United States)

    D.E. Haugen

    2010-01-01

    This publication provides an overview of forest resource attributes for North Dakota based on an annual inventory conducted by the Forest Inventory and Analysis (FIA) program at the Northern Research Station of the U.S. Forest Service