WorldWideScience

Sample records for ray latitude survey

  1. Neutron monitor latitude survey of cosmic ray intensity during the 1986/1987 solar minimum

    International Nuclear Information System (INIS)

    Moraal, H.; Potgieter, M.S.; Stoker, P.H.; van der Walt, A.J.

    1989-01-01

    A latitude survey of the cosmic ray intensity at sea level was conducted during the 1986/1987 solar minimum period on commercial vessels of the South African Marine Corporation (SAFMARINE). The results show that the differential response function for the 1986/1987 solar minimum agrees well with that measured in 1965. Both these response functions are significantly lower than those for 1976 and 1954. This result supports the 22-year modulation cycle as predicted, for example, by models including drift effects of the charged cosmic ray particles in the large-scale interplanetary magnetic field. A crossover of the spectra at rigidities of about 7 GV was also observed. Such a crossover is necessary to explain both the stationary neutron monitor counting rates and the lower-energy balloon and space observations in consecutive solar cycles. copyright American Geophysical Union 1989

  2. Latitude survey investigation of galactic cosmic ray solar modulation during 1994-2007

    Energy Technology Data Exchange (ETDEWEB)

    Nuntiyakul, W.; Ruffolo, D.; Sáiz, A. [Department of Physics, Faculty of Science, Mahidol University, Bangkok 10400 (Thailand); Evenson, P.; Bieber, J. W.; Clem, J.; Pyle, R. [Bartol Research Institute and Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States); Duldig, M. L.; Humble, J. E., E-mail: w.nuntiyakul@gmail.com, E-mail: david.ruf@mahidol.ac.th, E-mail: alejandro.sai@mahidol.ac.th, E-mail: evenson@udel.edu, E-mail: jwbieber@bartol.udel.edu, E-mail: clem@bartol.udel.edu, E-mail: pyle@bartol.udel.edu, E-mail: John.Humble@utas.edu.au, E-mail: Marc.Duldig@utas.edu.au [School of Physical Sciences, University of Tasmania, Hobart, Tasmania 7001 (Australia)

    2014-11-01

    The Galactic cosmic ray spectrum exhibits subtle variations over the 22 yr solar magnetic cycle in addition to the more dramatic variations over the 11 yr sunspot cycle. Neutron monitors are large ground-based detectors that provide accurate measurements of variations in the cosmic ray flux at the top of the atmosphere above the detector. At any given location the magnetic field of the Earth excludes particles below a well-defined rigidity (momentum per unit charge) known as the cutoff rigidity, which can be accurately calculated using detailed models of the geomagnetic field. By carrying a neutron monitor to different locations, e.g., on a ship, the Earth itself serves as a magnet spectrometer. By repeating such latitude surveys with identical equipment, a sensitive measurement of changes in the spectrum can be made. In this work, we analyze data from the 1994 through 2007 series of latitude surveys conducted by the Bartol Research Institute, the University of Tasmania, and the Australian Antarctic Division. We confirm the curious 'crossover' in spectra measured near solar minima during epochs of opposite solar magnetic polarity, and show that it is directly related to a sudden change in the spectral behavior of solar modulation at the time of the polarity reversal, as revealed from contemporaneous variations in the survey data and a fixed station. We suggest that the spectral change and crossover result from the interaction of effects due to gradient/curvature drifts with a systematic change in the interplanetary diffusion coefficient caused by turbulent magnetic helicity.

  3. Cosmic ray access at polar heliographic latitudes

    International Nuclear Information System (INIS)

    Voelk, H.J.

    1976-01-01

    Based on a modified WKB analysis of the interplanetary irregularity spectra, a discussion of the radial dependence of the radial cosmic ray diffusion coefficient at polar heliographic latitudes is presented. At l-AU radial distance the parameters are taken to equal those observed in the ecliptic. In the sense of a present best estimate it is argued that relativistic nuclei should have significantly easier access to 1 AU at the pole than in the ecliptic. The reverse may very well be true for the direct access of very low rigidity particles

  4. Profiles of gamma-ray and magnetic data for aerial surveys over parts of the Western United States from longitude 108 to 126 degrees W. and from latitude 34 to 49 degrees N.

    Science.gov (United States)

    Duval, Joseph S.

    1995-01-01

    This CD-ROM contains images generated from geophysical data, software for displaying and analyzing the images and software for displaying and examining profile data from aerial surveys flown as part of the National Uranium Resource Evaluation (NURE) Program of the U.S. Department of Energy. The images included are of gamma-ray data (uranium, thorium, and potassium channels), Bouguer gravity data, isostatic residual gravity data, aeromagnetic anomalies, topography, and topography with bathymetry. This publication contains image data for the conterminous United States and profile data for the conterminous United States within the area longitude 108 to 126 degrees W. and latitude 34 to 49 degrees N. The profile data include apparent surface concentrations of potassium, uranium, and thorium, the residual magnetic field, and the height above the ground. The images on this CD-ROM include graytone and color images of each data set, color shaded-relief images of the potential-field and topographic data, and color composite images of the gamma-ray data. The image display and analysis software can register images with geographic and geologic overlays. The profile display software permits the user to view the profiles as well as obtain data listings and export ASCII versions of data for selected flight lines.

  5. The influence of the observatory latitude on the study of ultra high energy cosmic rays

    Energy Technology Data Exchange (ETDEWEB)

    Anjos, Rita C. dos [Departamento de Engenharias e Exatas, Universidade Federal do Paraná (UFPR), Pioneiro, 2153, Palotina, PR, 85950-000 Brazil (Brazil); De Souza, Vitor [Instituto de Física de São Carlos, Universidade de São Paulo, CP 369, São Carlos, SP, 13560-970 Brazil (Brazil); De Almeida, Rogerio M. [EEIMVR, Universidade Federal Fluminense, Volta Redonda, RJ (Brazil); Santos, Edivaldo M., E-mail: ritacassia@ufpr.br, E-mail: vitor@ifsc.usp.br, E-mail: rmenezes@id.uff.br, E-mail: emoura@if.usp.br [Instituto de Física, Universidade de São Paulo, Rua do Matão trav. R 187, São Paulo, 05508-090 Brazil (Brazil)

    2017-07-01

    Recent precision measurements of the Ultra High Energy Cosmic Rays (UHECR) arrival directions, spectrum and parameters related to the mass of the primary particle have been done by the HiRes, Pierre Auger and Telescope Array (TA) Observatories. In this paper, distributions of arrival directions of events in the nearby Universe are assumed to correlate with sources in the 2MASS Redshift Survey (2MRS), IRAS 1.2 Jy Survey, Palermo Swift-BAT and Swift-BAT catalogs, and the effect of the latitude of the observatory on the measurement of the energy spectrum and on the capability of measuring anisotropy is studied. The differences between given latitudes on the northern and southern hemispheres are quantified. It is shown that the latitude of the observatory: a) has an influence on the total flux measured and b) imposes an important limitation on the capability of measuring an anisotropic sky.

  6. Cosmic rays linked to rapid mid-latitude cloud changes

    Directory of Open Access Journals (Sweden)

    B. A. Laken

    2010-11-01

    Full Text Available The effect of the Galactic Cosmic Ray (GCR flux on Earth's climate is highly uncertain. Using a novel sampling approach based around observing periods of significant cloud changes, a statistically robust relationship is identified between short-term GCR flux changes and the most rapid mid-latitude (60°–30° N/S cloud decreases operating over daily timescales; this signal is verified in surface level air temperature (SLAT reanalysis data. A General Circulation Model (GCM experiment is used to test the causal relationship of the observed cloud changes to the detected SLAT anomalies. Results indicate that the anomalous cloud changes were responsible for producing the observed SLAT changes, implying that if there is a causal relationship between significant decreases in the rate of GCR flux (~0.79 GU, where GU denotes a change of 1% of the 11-year solar cycle amplitude in four days and decreases in cloud cover (~1.9 CU, where CU denotes a change of 1% cloud cover in four days, an increase in SLAT (~0.05 KU, where KU denotes a temperature change of 1 K in four days can be expected. The influence of GCRs is clearly distinguishable from changes in solar irradiance and the interplanetary magnetic field. However, the results of the GCM experiment are found to be somewhat limited by the ability of the model to successfully reproduce observed cloud cover. These results provide perhaps the most compelling evidence presented thus far of a GCR-climate relationship. From this analysis we conclude that a GCR-climate relationship is governed by both short-term GCR changes and internal atmospheric precursor conditions.

  7. The latitude distribution of cosmic rays at sea level during 1976

    International Nuclear Information System (INIS)

    Potgieter, M.S.

    1978-12-01

    During the 1976 period of maximum intensity of cosmic rays a latitude survey was carried out at sea level with two neutron monitors and a neutron moderated detector on board the S.A. Huguenot of Safmarine. The survey lasted for eleven months from December 1975 to November 1976 and a cutoff rigidity range from 1,8 GV (New York) to 17 GV (Singapore) was covered. The second neutron monitor was designed to be more effective and less sensitive than the standard 1NM64 for the roll and pitch of a ship. A theoretical simulation model was used to compare the characteristics of the two neutron monitors and was finally compared with experimental results. The data recorded during visits to various harbours at specific cutoff rigidities were used to determine a attenuation coefficient for both monitors. The data were corrected for variations in the primary cosmic ray spectrum by using a modulations function characteristic of a period of normal modulation. The data were normalised to the relative counting rate of four reference monitor stations during October 1976. A polynomial regression analysis was used to find the best fit to the experimental data for both monitors. The differential response functions were there-upon calculated and compared. Finally the data were corrected for temperature dependence because of the constribution of muons to the counting rate of a neutron monitor. The long term correction coefficients which were used proved to be satisfactory. The difference between the temperature corrected and uncorrected response functions turned out to be less than 0,5% at 1 GV. A comparison of the 1965 and 1976 latitude distributions showed that the 1976 cosmic ray spectrum was softer compared to the previous maximum in 1965 and about the same as in 1954

  8. OSO-7 observations of high galactic latitude x-ray sources

    International Nuclear Information System (INIS)

    Markert, T.H.; Canizares, C.R.; Clark, G.W.; Li, F.K.; Northridge, P.L.; Sprott, G.F.; Wargo, G.F.

    1976-01-01

    Six hundred days of observations by the MIT X-ray detectors aboard OSO-7 have been analyzed. All-sky maps of X-ray intensity have been constructed from these data. A sample map is displayed. Seven sources with galactic latitude vertical-barb/subi//subi/vertical-bar>10degree, discovered during the mapping process, are reported, and upper limits are set on other high-latitude sources. The OSO-7 results are compared with those of Uhuru and an implication of this comparison, that many of the high-latitude sources may be variable, is discussed

  9. HIGH ECLIPTIC LATITUDE SURVEY FOR SMALL MAIN-BELT ASTEROIDS

    International Nuclear Information System (INIS)

    Terai, Tsuyoshi; Takahashi, Jun; Itoh, Yoichi

    2013-01-01

    Main-belt asteroids have been continuously colliding with one another since they were formed. Their size distribution is primarily determined by the size dependence of asteroid strength against catastrophic impacts. The strength scaling law as a function of body size could depend on collision velocity, but the relationship remains unknown, especially under hypervelocity collisions comparable to 10 km s –1 . We present a wide-field imaging survey at an ecliptic latitude of about 25° for investigating the size distribution of small main-belt asteroids that have highly inclined orbits. The analysis technique allowing for efficient asteroid detections and high-accuracy photometric measurements provides sufficient sample data to estimate the size distribution of sub-kilometer asteroids with inclinations larger than 14°. The best-fit power-law slopes of the cumulative size distribution are 1.25 ± 0.03 in the diameter range of 0.6-1.0 km and 1.84 ± 0.27 in 1.0-3.0 km. We provide a simple size distribution model that takes into consideration the oscillations of the power-law slope due to the transition from the gravity-scaled regime to the strength-scaled regime. We find that the high-inclination population has a shallow slope of the primary components of the size distribution compared to the low-inclination populations. The asteroid population exposed to hypervelocity impacts undergoes collisional processes where large bodies have a higher disruptive strength and longer lifespan relative to tiny bodies than the ecliptic asteroids

  10. Cosmic ray zenith angle distribution at low geomagnetic latitude

    Energy Technology Data Exchange (ETDEWEB)

    Aragon, G [Instituto de Astronomia y Fisica del Espacio, Buenos Aires, Argentina; Gagliardini, A; Ghielmetti, H S

    1977-12-01

    The intensity of secondary charged cosmic rays at different zenith angles was measured by narrow angle Geiger-Mueller telescopes up to an atmospheric depth of 2 g cm/sup -2/. The angular distribution observed at high altitudes is nearly flat at small angles around the vertical and suggests that the particle intensity peaks at large zenith angles, close to the horizon.

  11. Cosmic rays and total ozone at higher middle latitudes

    Czech Academy of Sciences Publication Activity Database

    Laštovička, Jan; Križan, Peter; Kudela, K.

    2003-01-01

    Roč. 31, č. 9 (2003), s. 2139-2144 ISSN 0273-1177 R&D Projects: GA AV ČR KSK3012103 Keywords : cosmic rays * ozone Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 0.483, year: 2003

  12. Ames collaborative study of cosmic-ray neutrons. II. Low- and mid-latitude flights

    International Nuclear Information System (INIS)

    Stephens, L.D.; McCaslin, J.B.; Smith, A.R.; Thomas, R.H.; Hewitt, J.E.; Hughes, L.

    1978-01-01

    The continuing progress of the Ames Collaborative Study of Cosmic Ray Neutrons is described. Data obtained aboard flights from Hawaii at altitudes of 41,000 and 45,000 feet, and in the range of geomagnetic latitude 17 0 N less than or equal to lambda less than or equal to 21 0 N are reported. Preliminary estimates of neutron spectra were made

  13. Chandra X-ray Observations of Jovian Low-latitude Emissions: Morphological, Temporal, and Spectral Characteristics

    Science.gov (United States)

    Bhardwaj, Anil; Elsner, Ronald F.; Gladstone, G. Randall; Cravens, Thomas E.; Waiate J. Hunter, Jr.; Branduardi-Raymont, Graziella; Ford, Peter

    2004-01-01

    Chandra observed X-rays from Jupiter during 24-26 February 2003 for about 40 hours with the ACIS-S and HRC-I instruments. The analysis of Jovian low-latitude "disk" Xray emissions are presented and compared with the high-latitude "auroral" emissions. We report the first Chandra ACIS-S measured X-ray spectrum (0.3-2 keV) of Jupiter's low-latitude disk The disk X-ray emission is harder and extends to higher energies than the auroral spectrum. The temporal variation in the Jovian disk X-rays is on an average consistent with those in the solar X-rays observed by GOES, and TIMED/SSE. Contrary to the auroral X-rays, the disk emissions are uniformly distributed over Jupiter; no indication of longitudinal dependence or correlation with surface magneh field strength is visible. Also, unlike the approx. 40 +/- 20 min periodic oscillations seen in the auroral X-ray emissions, the disk emissions do not show any periodic oscillations. The disk spectrum seems to be consistent with resonant and fluorescent scattering of solar X-rays by the Jovian upper atmosphere. Jupiter's disk is found to be about 50% dimmer in soft X-rays in February 2003 compared that in December 2000, which is consistent with the decrease in solar activity. No evidence of lightning-induced X-rays is seen in the Chandra X-ray data. The Jovian disk spectra observed with Chandra-ACIS is stronger than that observed with XMM-Newton two months later during April 28-29, 2003. The XMM-Newton Xray image of Jupiter shows evidence of limb darkening on the anti-sunward side as seen from Earth, as well as an asymmetry with respect to the subsolar point: suggesting a solar driven process.

  14. A search for pre-main sequence stars in the high-latitude molecular clouds. II - A survey of the Einstein database

    Science.gov (United States)

    Caillault, Jean-Pierre; Magnani, Loris

    1990-01-01

    The preliminary results are reported of a survey of every EINSTEIN image which overlaps any high-latitude molecular cloud in a search for X-ray emitting pre-main sequence stars. This survey, together with complementary KPNO and IRAS data, will allow the determination of how prevalent low mass star formation is in these clouds in general and, particularly, in the translucent molecular clouds.

  15. The γ-ray emissivity of the local interstellar medium from correlations with gas at intermediate latitudes

    International Nuclear Information System (INIS)

    Strong, A.W.; Wolfendale, A.W.

    1981-01-01

    A survey of recent studies of the correlation between γ-rays from latitudes b > 10 0 and gas tracers is presented. Results for the ranges 35-100 MeV and above 100 MeV from the SAS-2 satellite, and for energies between 70 and 5000 MeV from the COS-B satellite, are used to obtain an estimate of the γ-ray emissivity spectrum for all forms of gas. Good agreement between the two experiments is found. A comparison is made between this spectrum (which is an average for a region some few hundred parsecs around the Sun) and that expected for recent estimates of the low energy electron spectrum in the local interstellar medium. If the pion-decay component is as expected for the demodulated interplanetary proton spectrum, then the electron spectrum must have a steep slope (differential index 2.8) below 1 GeV. If the pion contribution is smaller than expected, however, a flatter electron spectrum is allowable. The presence of a component of γ-ray emission related to gas in molecular form is evident in both the SAS-2 and COS-B data. The correlation of the SAS-2 data with both components is discussed and it is shown that the emissivities of each component can be independently determined. The longitude dependence of the emission is also discussed. Finally, an examination of the γ-ray fluxes from specific dense clouds of molecular gas is made. (author)

  16. Interstellar extinction from photometric surveys: application to four high-latitude areas

    Science.gov (United States)

    Malkov, Oleg; Karpov, Sergey; Kilpio, Elena; Sichevsky, Sergey; Chulkov, Dmitry; Dluzhnevskaya, Olga; Kovaleva, Dana; Kniazev, Alexei; Mickaelian, Areg; Mironov, Alexey; Murthy, Jayant; Sytov, Alexey; Zhao, Gang; Zhukov, Aleksandr

    2018-04-01

    Information on interstellar extinction and dust properties may be obtained from modern large photometric surveys data. Virtual Observatory facilities allow users to make a fast and correct cross-identification of objects from various surveys. It yields a multicolor photometry data on detected objects and makes it possible to estimate stellar parameters and calculate interstellar extinction. A 3D extinction map then can be constructed. The method was applied to 2MASS, SDSS, GALEX and UKIDSS surveys. Results for several high-latitude areas are obtained, compared with independent sources and discussed here.

  17. Interstellar extinction from photometric surveys: application to four high-latitude areas

    Directory of Open Access Journals (Sweden)

    Malkov Oleg

    2018-04-01

    Full Text Available Information on interstellar extinction and dust properties may be obtained from modern large photometric surveys data. Virtual Observatory facilities allow users to make a fast and correct cross-identification of objects from various surveys. It yields a multicolor photometry data on detected objects and makes it possible to estimate stellar parameters and calculate interstellar extinction. A 3D extinction map then can be constructed. The method was applied to 2MASS, SDSS, GALEX and UKIDSS surveys. Results for several high-latitude areas are obtained, compared with independent sources and discussed here.

  18. Diffuse galactic gamma rays at intermediate and high latitudes. Pt. 1. Constraints on the ISM properties

    Energy Technology Data Exchange (ETDEWEB)

    Cholis, Ilias; Tavakoli, Maryam; Ullio, Piero [SISSA, Trieste (Italy); INFN, Trieste (Italy); Evoli, Carmelo [SISSA, Trieste (Italy); Chinese Academy of Sciences, Beijing (China). National Astronomical Observatories; Maccione, Luca [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2011-06-15

    We study the high latitude (vertical stroke b vertical stroke >10 ) diffuse {gamma}-ray emission in the Galaxy in light of the recently published data from the Fermi collaboration at energies between 100 MeV and 100 GeV. The unprecedented accuracy in these measurements allows to probe and constrain the properties of sources and propagation of cosmic rays (CRs) in the Galaxy, as well as confirming conventional assumptions made on the interstellar medium (ISM). Using the publicly available DRAGON code, that has been shown to reproduce local measurements of CRs, we study assumptions made in the literature on HI and H2 gas distributions in the ISM, and non spatially uniform models of diffusion in the Galaxy. By performing a combined analysis of CR and {gamma}-ray spectra, we derive constraints on the properties of the ISM gas distribution and the vertical scale height of galactic CR diffusion, which may have implications also on indirect Dark Matter detection. We also discuss some of the possible interpretations of the break at {proportional_to}230 GeV in CR protons and helium spectra, recently observed by PAMELA and their impact on {gamma}-rays. (orig.)

  19. Diffuse galactic gamma rays at intermediate and high latitudes. I. Constraints on the ISM properties

    International Nuclear Information System (INIS)

    Cholis, Ilias; Tavakoli, Maryam; Evoli, Carmelo; Ullio, Piero; Maccione, Luca

    2012-01-01

    We study the high latitude (|b| > 10°) diffuse γ-ray emission in the Galaxy in light of the recently published data from the Fermi collaboration at energies between 100 MeV and 100 GeV. The unprecedented accuracy in these measurements allows to probe and constrain the properties of sources and propagation of cosmic rays (CRs) in the Galaxy, as well as confirming conventional assumptions made on the interstellar medium (ISM). Using the publicly available DRAGON code, that has been shown to reproduce local measurements of CRs, we study assumptions made in the literature on atomic (HI) and molecular hydrogen (H2) gas distributions in the ISM, and non spatially uniform models of diffusion in the Galaxy. By performing a combined analysis of CR and γ-ray spectra, we derive constraints on the properties of the ISM gas distribution and the vertical scale height of galactic CR diffusion, which may have implications also on indirect Dark Matter detection. We also discuss some of the possible interpretations of the break at high rigidity in CR protons and helium spectra, recently observed by PAMELA and their impact on γ-rays

  20. Diffuse galactic gamma rays at intermediate and high latitudes. Pt. 1. Constraints on the ISM properties

    International Nuclear Information System (INIS)

    Cholis, Ilias; Tavakoli, Maryam; Ullio, Piero; Evoli, Carmelo

    2011-06-01

    We study the high latitude (vertical stroke b vertical stroke >10 ) diffuse γ-ray emission in the Galaxy in light of the recently published data from the Fermi collaboration at energies between 100 MeV and 100 GeV. The unprecedented accuracy in these measurements allows to probe and constrain the properties of sources and propagation of cosmic rays (CRs) in the Galaxy, as well as confirming conventional assumptions made on the interstellar medium (ISM). Using the publicly available DRAGON code, that has been shown to reproduce local measurements of CRs, we study assumptions made in the literature on HI and H2 gas distributions in the ISM, and non spatially uniform models of diffusion in the Galaxy. By performing a combined analysis of CR and γ-ray spectra, we derive constraints on the properties of the ISM gas distribution and the vertical scale height of galactic CR diffusion, which may have implications also on indirect Dark Matter detection. We also discuss some of the possible interpretations of the break at ∝230 GeV in CR protons and helium spectra, recently observed by PAMELA and their impact on γ-rays. (orig.)

  1. Airborne gamma ray spectrometer surveying

    International Nuclear Information System (INIS)

    1991-01-01

    The International Atomic Energy Agency (IAEA) in its role as collector and disseminator of information on nuclear techniques has long had an interest in gamma ray spectrometer methods and has published a number of Technical Reports on various aspects of the subject. At an Advisory Group Meeting held in Vienna in November 1986 to review appropriate activities the IAEA could take following the Chernobyl accident, it was recommended that preparation begin on a new Technical Report on airborne gamma ray spectrometer surveying, taking into account the use of the technique for environmental monitoring as well as for nuclear emergency response requirements. Shortly thereafter the IAEA became the lead organization in the Radioelement Geochemical Mapping section of the International Geological Correlation Programme/United Nations Educational, Scientific and Cultural Organization (UNESCO) Project on International Geochemical Mapping. These two factors led to the preparation of the present Technical Report. 18 figs, 4 tabs

  2. Latitude gradient influences the age of onset of rheumatoid arthritis: a worldwide survey.

    Science.gov (United States)

    2017-03-01

    The age of onset of rheumatoid arthritis (RA) is an important outcome predictor. Northern countries report an age of RA onset of around 50 years, but apparently, variability exists across different geographical regions. The objective of the present study is to assess whether the age of onset of RA varies across latitudes worldwide. In a proof-of-concept cross-sectional worldwide survey, rheumatologists from preselected cities interviewed 20 consecutive RA patients regarding the date of RA onset (RAO, when the patient first noted a swollen joint). Other studied variables included location of each city, rheumatologist settings, latitudes (10° increments, south to north), longitudes (three regions), intracountry consistency, and countries' Inequality-adjusted Human Development Index (IHDI). Data from 2481 patients (82% females) were obtained from 126 rheumatologists in 77 cities of 41 countries. Worldwide mean age of RAO was 44 ± 14 years (95% CI 44-45). In 28% of patients, RA began before age 36 years and before age 46 years in 50% of patients. RAO was 8 years earlier around the Tropic of Cancer when compared with northern latitudes (p worldwide. We postulate that countries' developmental status and their geographical and geomagnetic location influence the age of RAO.

  3. The Canada–France Ecliptic Plane Survey (CFEPS)—High-latitude Component

    Energy Technology Data Exchange (ETDEWEB)

    Petit, J-M. [Institut UTINAM, CNRS-UMR 6213, Observatoire de Besançon, BP 1615, F-25010 Besançon Cedex (France); Kavelaars, J. J. [Herzberg Institute of Astrophysics, National Research Council of Canada, Victoria, BC V9E 2E7 (Canada); Gladman, B. J.; Van Laerhoven, C.; Lawler, S. M. [Department of Physics and Astronomy, 6224 Agricultural Road, University of British Columbia, Vancouver, BC (Canada); Jones, R. L. [Department of Astronomy, University of Washington, Seattle, WA (United States); Parker, J. Wm.; Bieryla, A. [Planetary Science Directorate, Southwest Research Institute, 1050 Walnut Street, Suite 300, Boulder, CO 80302 (United States); Pike, R. E. [Department of Physics and Astronomy, University of Victoria, Victoria, BC (Canada); Nicholson, P. [Cornell University, Space Sciences Building, Ithaca, NY 14853 (United States); Ashby, M. L. N. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

    2017-05-01

    The High Ecliptic Latitude (HiLat) extension of the Canada–France Ecliptic Plane Survey (CFEPS), conducted from 2006 June to 2009 July, discovered a set of Trans-Neptunian objects (TNOs) that we report here. The HiLat component was designed to address one of the shortcomings of ecliptic surveys (like CFEPS), their low sensitivity to high-inclination objects. We searched 701 deg{sup 2} of sky ranging from 12° to 85° ecliptic latitude and discovered 24 TNOs, with inclinations between 15° and 104°. This survey places a very strong constraint on the inclination distribution of the hot component of the classical Kuiper Belt, ruling out any possibility of a large intrinsic fraction of highly inclined orbits. Using the parameterization of Brown, the HiLat sample combined with CFEPS imposes a width 14° ≤  σ  ≤ 15.°5, with a best match for σ  = 14.°5. HiLat discovered the first retrograde TNO, 2008 KV{sub 42}, with an almost polar orbit with inclination 104°, and (418993) = 2009 MS{sub 9}, a scattering object with perihelion in the region of Saturn’s influence, with a  ∼ 400 au and i  = 68°.

  4. On scaling cosmogenic nuclide production rates for altitude and latitude using cosmic-ray measurements

    Science.gov (United States)

    Desilets, Darin; Zreda, Marek

    2001-11-01

    The wide use of cosmogenic nuclides for dating terrestrial landforms has prompted a renewed interest in characterizing the spatial distribution of terrestrial cosmic rays. Cosmic-ray measurements from neutron monitors, nuclear emulsions and cloud chambers have played an important role in developing new models for scaling cosmic-ray neutron intensities and, indirectly, cosmogenic production rates. Unfortunately, current scaling models overlook or misinterpret many of these data. In this paper, we describe factors that must be considered when using neutron measurements to determine scaling formulations for production rates of cosmogenic nuclides. Over the past 50 years, the overwhelming majority of nucleon flux measurements have been taken with neutron monitors. However, in order to use these data for scaling spallation reactions, the following factors must be considered: (1) sensitivity of instruments to muons and to background, (2) instrumental biases in energy sensitivity, (3) solar activity, and (4) the way of ordering cosmic-ray data in the geomagnetic field. Failure to account for these factors can result in discrepancies of as much as 7% in neutron attenuation lengths measured at the same location. This magnitude of deviation can result in an error on the order of 20% in cosmogenic production rates scaled from 4300 m to sea level. The shapes of latitude curves of nucleon flux also depend on these factors to a measurable extent, thereby causing additional uncertainties in cosmogenic production rates. The corrections proposed herein significantly improve our ability to transfer scaling formulations based on neutron measurements to scaling formulations applicable to spallation reactions, and, therefore, constitute an important advance in cosmogenic dating methodology.

  5. Total ozone derived from UV spectrophotometer measurements on the NASA CV-990 aircraft for the fall 1976 latitude survey flights

    Science.gov (United States)

    Hanser, F. A.

    1977-01-01

    An ultraviolet interference filter spectrophotometer was modified to use a photodiode and was flown on latitude survey flights in the fall of 1976. Comparison with Dobson station total ozone values shows agreement between UVS and Dobson total ozone of + or - 2 percent. The procedure used to convert UVS measured ozone above the aircraft altitude to total ozone above ground level introduces an additional 2 percent deviation for very high altitude UVS ozone data. Under stable aircraft operating conditions, the UVS derived ozone values have a variability, or reproducibility, of better than + or -1 percent. The UVS data from the latitude survey flights yield a detailed latitude profile of total ozone over the Pacific Ocean during November 1976. Significant latitudinal structure in total ozone is found at the middle latitudes (30 deg to 40 deg N and S).

  6. Gamma-ray surveys in uranium exploration

    International Nuclear Information System (INIS)

    1979-01-01

    This report is intended to provide newcomers to uranium exploration with an up-to-date statement of the principal factors to be considered in planning and using gamma-ray surveys. Since the report incorporates the results of recent research, and since its preparation was influenced by the cumulative experience of its contributors, it should also be useful to those who already have some knowledge of radioactivity surveys and methods. The intention is that the information and explanations given in the report will make it possible for gamma-ray surveys to be used in the most efficient way for a given exploration task

  7. ROSAT: X ray survey of compact groups

    NARCIS (Netherlands)

    van Gorkom, Jacqueline

    1993-01-01

    This is the final technical report on grant NAG5-1954, which was awarded under the NASA ROSAT Guest Investigator Program to Columbia University. This grant was awarded for a number of projects on two rather different topics: (1) an x-ray survey of compact groups of galaxies; and (2) the fate of gas

  8. The Swift BAT Hard X-ray Survey - A New Window on the Local AGN Universe

    Science.gov (United States)

    Mushotzky, Richard

    2009-01-01

    The Swift Burst and Transient telescope (BAT) has surveyed the entire sky for the last 3.5 years obtaining the first sensitive all sky survey of the 14-195 keV sky. At high galactic latitudes the vast majority of the detected sources are AGN. Since hard x-rays penetrate all but Compton thick obscuring material (Column densities of 1.6E24 atms/cm2) this survey is unbiased with respect to obscuration, host galaxy type, optical , radio or IR properties. We will present results on the broad band x-ray properties, the nature of the host galaxies, the luminosity function and will discuss a few of the optical, IR and x-ray results in detail.

  9. Results of the first continuous meteor head echo survey at polar latitudes

    Science.gov (United States)

    Schult, Carsten; Stober, Gunter; Janches, Diego; Chau, Jorge L.

    2017-11-01

    We present the first quasi continuous meteor head echo measurements obtained during a period of over two years using the Middle Atmosphere ALOMAR Radar System (MAARSY). The measurements yield information on the altitude, trajectory, vector velocity, radar cross section, deceleration and dynamical mass of every single event. The large statistical amount of nearly one million meteor head detections provide an excellent overview of the elevation, altitude, velocity and daily count rate distributions during different times of the year at polar latitudes. Only 40% of the meteors were detected within the full width half maximum of the specific sporadic meteor sources. Our observation of the sporadic meteors are compared to the observations with other radar systems and a meteor input function (MIF). The best way to compare different radar systems is by comparing the radar cross section (RCS), which is the main detection criterion for each system. In this study we aim to compare our observations with a MIF, which provides information only about the meteoroid mass. Thus, we are using a statistical approach for the elevation and velocity dependent visibility and a specific mass selection. The predicted absolute count rates from the MIF are in a good agreement with the observation when it is assumed that the radar system is only sensitive to meteoroids with masses higher than one microgram. The analysis of the dynamic masses seems to be consistent with this assumption since the count rate of events with smaller masses are low and decrease even more by using events with relatively small errors.

  10. The Einstein Observatory Extended Medium-Sensitivity Survey. I - X-ray data and analysis

    Science.gov (United States)

    Gioia, I. M.; Maccacaro, T.; Schild, R. E.; Wolter, A.; Stocke, J. T.

    1990-01-01

    This paper presents the results of the analysis of the X-ray data and the optical identification for the Einstein Observatory Extended Medium-Sensitivity Survey (EMSS). The survey consists of 835 serendipitous sources detected at or above 4 times the rms level in 1435 imaging proportional counter fields with centers located away from the Galactic plane. Their limiting sensitivities are about (5-300) x 10 to the -14th ergs/sq cm sec in the 0.3-3.5-keV energy band. A total area of 778 square deg of the high-Galactic-latitude sky has been covered. The data have been analyzed using the REV1 processing system, which takes into account the nonuniformities of the detector. The resulting EMSS catalog of X-ray sources is a flux-limited and homogeneous sample of astronomical objects that can be used for statistical studies.

  11. Los Alamos Scientific Laboratory x-ray survey manual

    International Nuclear Information System (INIS)

    Olsher, R.H.

    1980-02-01

    A manual has been developed by the Health Physics Group to establish procedures for routine testing of industrial and analytical x-ray equipment for compliance with applicable LASL administrative requirements and technical bulletins. Radiation protection survey procedures were developed for the following types of equipment: x-ray diffraction and fluorescence analysis systems, industrial cabinet x-ray systems, industrial noncabinet x-ray systems, and electron microscopes

  12. A search for pre-main-sequence stars in high-latitude molecular clouds. 3: A survey of the Einstein database

    Science.gov (United States)

    Caillault, Jean-Pierre; Magnani, Loris; Fryer, Chris

    1995-01-01

    In order to discern whether the high-latitude molecular clouds are regions of ongoing star formation, we have used X-ray emission as a tracer of youthful stars. The entire Einstein database yields 18 images which overlap 10 of the clouds mapped partially or completely in the CO (1-0) transition, providing a total of approximately 6 deg squared of overlap. Five previously unidentified X-ray sources were detected: one has an optical counterpart which is a pre-main-sequence (PMS) star, and two have normal main-sequence stellar counterparts, while the other two are probably extragalactic sources. The PMS star is located in a high Galactic latitude Lynds dark cloud, so this result is not too suprising. The translucent clouds, though, have yet to reveal any evidence of star formation.

  13. X-ray survey of the Pleiades: dependence of X-ray luminosity on stellar age

    International Nuclear Information System (INIS)

    Micela, G.; Sciortino, S.; Serio, S.; Vaiana, G.S.; Golub, L.; Harnden, F.R.; Rosner, R.

    1984-01-01

    The study of X-ray emission of stellar clusters, allows to decouple the influence of some individual stellar parameters, as initial conditions, composition and age, on the stellar X-ray function. The authors report preliminary results from an Einstein X-ray survey of the Pleiades. (Auth.)

  14. A γ-ray survey along Hanaore fault

    International Nuclear Information System (INIS)

    Mino, Kazuo

    1978-01-01

    The γ-ray survey was carried out by a scintillation survey meter at O-hara area near around Hanaore Fault Zone in the northern part of Kyoto. The survey was done several times over along the same observational line. Static pattern of γ-ray intensity is revealed similar one in each other, even there is small difference. Strong intensity of γ-ray means subsistance of crushed rocks zone and a huge fault as Hanaore consists of the structure made by these weak zones. A pretty large earthquake among microearthquakes was occurred, fortunately for us, during survey period. The γ-ray survey was done just on January 6, 1978 when it was just one day before the earthquake. The observational results before the earthquake, did not give large variations of γ-ray intensity. But after 5 days from the earthquake, that is January 11, the intensity of γ-ray decreases into low value, over observational error, at almost all stations. The improvement of γ-ray was found after 2 weeks from the earthquake. Ordinarily the large fault as Hanaore is one of boundaries around block of crust, and fault zone is more sensitive to geophysical activity in the crust. Continuous observation of γ-ray will give the solution to corelation with earthquake or earthquake prediction. (author)

  15. Optical Design for a Survey X-Ray Telescope

    Science.gov (United States)

    Saha, Timo T.; Zhang, William W.; McClelland, Ryan S.

    2014-01-01

    Optical design trades are underway at the Goddard Space Flight Center to define a telescope for an x-ray survey mission. Top-level science objectives of the mission include the study of x-ray transients, surveying and long-term monitoring of compact objects in nearby galaxies, as well as both deep and wide-field x-ray surveys. In this paper we consider Wolter, Wolter-Schwarzschild, and modified Wolter-Schwarzschild telescope designs as basic building blocks for the tightly nested survey telescope. Design principles and dominating aberrations of individual telescopes and nested telescopes are discussed and we compare the off-axis optical performance at 1.0 KeV and 4.0 KeV across a 1.0-degree full field-of-view.

  16. Recent developments in airborne gamma ray surveying

    International Nuclear Information System (INIS)

    Grasty, Robert L.

    1999-01-01

    Standardized procedures have been developed for converting airborne gamma ray measurements to ground concentrations of potassium, uranium and thorium. These procedures make use of an airborne calibration range whose ground concentrations should be measured with a calibrated portable spectrometer rather than by taking geochemical samples. Airborne sensitivities and height attenuation coefficients are normally determined from flights over the calibration range but may not be applicable in mountainous areas. Mathematical techniques have been now developed to reduce statistical noise in the airborne measurements by utilizing up to 256 channels of spectral information. (author)

  17. X-ray stars observed in LAMOST spectral survey

    Science.gov (United States)

    Lu, Hong-peng; Zhang, Li-yun; Han, Xianming L.; Shi, Jianrong

    2018-05-01

    X-ray stars have been studied since the beginning of X-ray astronomy. Investigating and studying the chromospheric activity from X-ray stellar optical spectra is highly significant in providing insights into stellar magnetic activity. The big data of LAMOST survey provides an opportunity for researching stellar optical spectroscopic properties of X-ray stars. We inferred the physical properties of X-ray stellar sources from the analysis of LAMOST spectra. First, we cross-matched the X-ray stellar catalogue (12254 X-ray stars) from ARXA with LAMOST data release 3 (DR3), and obtained 984 good spectra from 713 X-ray sources. We then visually inspected and assigned spectral type to each spectrum and calculated the equivalent width (EW) of Hα line using the Hammer spectral typing facility. Based on the EW of Hα line, we found 203 spectra of 145 X-ray sources with Hα emission above the continuum. For these spectra we also measured the EWs of Hβ, Hγ, Hδ and Ca ii IRT lines of these spectra. After removing novae, planetary nebulae and OB-type stars, we found there are 127 X-ray late-type stars with Hα line emission. By using our spectra and results from the literature, we found 53 X-ray stars showing Hα variability; these objects are Classical T Tauri stars (CTTs), cataclysmic variables (CVs) or chromospheric activity stars. We also found 18 X-ray stars showing obvious emissions in the Ca ii IRT lines. Of the 18 X-ray stars, 16 are CTTs and 2 are CVs. Finally, we discussed the relationships between the EW of Hα line and X-ray flux.

  18. Development of carborne gamma-ray survey system

    International Nuclear Information System (INIS)

    Sakamoto, Ryuichi; Tsutsumi, Masahiro

    1999-01-01

    A carborne γ-ray survey system was developed aiming at implementation of environmental radiation investigation in and around Chernobyl area after the accident. This system consists of a dose rate meter, a GPS and a personal computer, and acquires γ-ray dose rates and positional data using two serial ports of the computer. It is indispensable to acquire these two kinds of data simultaneously for carborne γ-ray survey in a large area. A feature of the system is to be able to get these data continuously by means of a simple programming. This system has been used in and around Chernobyl area for a few years, and it has worked without any troubles. The outline of this survey system, which is applicable for configuration of environmental radiation data acquisition system is reported with some results in Chernobyl. (author)

  19. Cosmological analysis of galaxy clusters surveys in X-rays

    International Nuclear Information System (INIS)

    Clerc, N.

    2012-01-01

    Clusters of galaxies are the most massive objects in equilibrium in our Universe. Their study allows to test cosmological scenarios of structure formation with precision, bringing constraints complementary to those stemming from the cosmological background radiation, supernovae or galaxies. They are identified through the X-ray emission of their heated gas, thus facilitating their mapping at different epochs of the Universe. This report presents two surveys of galaxy clusters detected in X-rays and puts forward a method for their cosmological interpretation. Thanks to its multi-wavelength coverage extending over 10 sq. deg. and after one decade of expertise, the XMM-LSS allows a systematic census of clusters in a large volume of the Universe. In the framework of this survey, the first part of this report describes the techniques developed to the purpose of characterizing the detected objects. A particular emphasis is placed on the most distant ones (z ≥ 1) through the complementarity of observations in X-ray, optical and infrared bands. Then the X-CLASS survey is fully described. Based on XMM archival data, it provides a new catalogue of 800 clusters detected in X-rays. A cosmological analysis of this survey is performed thanks to 'CR-HR' diagrams. This new method self-consistently includes selection effects and scaling relations and provides a means to bypass the computation of individual cluster masses. Propositions are made for applying this method to future surveys as XMM-XXL and eRosita. (author) [fr

  20. Differential effects of decision latitude and control on the job demands-strain relationship: a cross-sectional survey study among elderly care nursing staff.

    Science.gov (United States)

    Schmidt, Klaus-Helmut; Diestel, Stefan

    2011-03-01

    According to the influential Job Demands-Control (JD-C) model developed by Karasek (1979; Karasek and Theorell, 1990), job strain is expected to result from high job demands and low job control as well as an interaction between both job characteristics. Previous research, however, has found such an interaction only rarely or inconsistently.It has been suggested that the conceptualization of the control variable (formerly referred to as decision latitude) may be particularly responsible for the lack of supportive findings. The present study aimed at clarifying this issue by contrasting a focused measure of control with a traditional measure of decision latitude in their relations to job strain of health care workers. The measure of decision latitude encompassed a wide range of job characteristics including control, task variety, and learning opportunities. A cross-sectional questionnaire survey was conducted with job satisfaction, psychosomatic complaints and emotional exhaustion as criterion measures of job strain. A supra-regional organization for residential elderly care with 11 nursing homes located in a federal state in Germany. Questionnaires were distributed to the whole nursing staff, of which 379 filled in the questionnaire during normal working hours (68% participation rate). In addition to confirmatory factor analyses, descriptive statistics, and bivariate correlations, hierarchical multiple regression analyses were performed for testing the corresponding interaction effects. Findings confirmed the assumption that the focused measure of control and the traditional measure of decision latitude represent distinct, yet correlated factors. Furthermore, findings revealed a significant interaction effect between job demands and control on all outcomes considered. By way of contrast, there was no equivalent interaction effect between job demands and decision latitude. In line with the JD-C model, the adverse influence of increasing demands on job satisfaction

  1. New High Proper Motion Stars from the Digitized Sky Survey. II. Northern Stars with 0.5" yr-1 < μ < 2.0" yr-1 at High Galactic Latitudes

    Science.gov (United States)

    Lépine, Sébastien; Shara, Michael M.; Rich, R. Michael

    2003-08-01

    In a continuation of our systematic search for high proper motion stars in the Digitized Sky Survey, we have completed the analysis of northern sky fields at Galactic latitudes above 25°. With the help of our SUPERBLINK software, a powerful automated blink comparator developed by us, we have identified 1146 stars in the magnitude range 8data mining of the Digitized Sky Survey, developed and operated by the Catalogs and Surveys Branch of the Space Telescope Science Institute, Baltimore.

  2. Surface gamma-ray survey of SX Tank Farm

    International Nuclear Information System (INIS)

    Stromswold, D.C.; Arthur, R.J.

    1996-08-01

    Measurements made over the surface of the SX Tank Farm at Hanford show Cs 137 to be the only significant gamma ray emitting contaminant. A high-purity germanium detector collected the data in the surface survey. Most of the detected radiation originated from specific above ground objects, such as pipes and vents. One area of increased radiation in the north section of the tank farm between tanks SX-102 and SX-105, was apparently due to contamination of the soil by Cs 137. An area of interest near tanks SX-108, SX-111, and SX-112, below which borehole logs has indicated deep Cs 137 contamination, also showed Cs 137 at the surface, but the signal originated mainly from surface objects rather than from contaminated soils. A significant result of the surface survey is the understanding that surface objects with contamination can affect the signal observed by borehole logging tools as they reach the ground surface

  3. Survey of diagnostic X-Ray units at Recife- Brazil

    International Nuclear Information System (INIS)

    Hazing, C.A.; Khoury, H.J.; Santos, R.S.; Antonino, P.D.

    1998-01-01

    This paper reports reports the result of a survey aiming to determine the working conditions of x-ray units operating in hospital and clinics in the city of Recife, Pernamburgo, Brazil. The study comprised 27 x-ray units from both public and private diagnostic services operating. The following parameters were evaluated: a) coincidence between the luminous and radiation fields; b) alignment of the radiation beam; c) agreement between the real and preset values of the kVp and exposure time. The result showed that the discrepancy between the luminous and radiation fields stayed in the recommended 1 to 2% interval in 78.2% of the equipment surveyed, all units passing the alignment test (deviation of less than 3%). The results also showed that there is only a fair accuracy regarding both preset kilovoltage and exposure time, with discrepancies of more than 10% between ''true'' irradiation times(in85% of the case), and between the present and applied kilovoltage (in 46% of the inspected units)

  4. A deep X-ray spectroscopic survey of the ESO imaging survey fields

    DEFF Research Database (Denmark)

    Nørgaard-Nielsen, Hans Ulrik; Jørgensen, H.E.; Hansen, Lene

    1998-01-01

    The deepest ROSAT surveys have shown, that, in the energy range 0.5-2.0 keV, QSO's can account for similar to 30 per cent of the Diffuse X-ray Background (DXRB), and Narrow Emission Line Galaxies (NELG) and clusters of galaxies for about 10 per cent each. But, by assuming characteristic spectral ...... provide new insight into the evolution of galaxies, clusters of galaxies and AGN's.......The deepest ROSAT surveys have shown, that, in the energy range 0.5-2.0 keV, QSO's can account for similar to 30 per cent of the Diffuse X-ray Background (DXRB), and Narrow Emission Line Galaxies (NELG) and clusters of galaxies for about 10 per cent each. But, by assuming characteristic spectral....... This spectroscopic X-ray survey will provide a large, statistically complete, sample of sources detected at high energies, more than an order of magnitude fainter than obtained by previous missions. The study of these sources will significantly improve our understanding not only of the origin of DXRB, but also...

  5. The Einstein soft X-ray survey of the Pleiades

    Science.gov (United States)

    Caillault, J.-P.; Helfand, D. J.

    1985-01-01

    The results of a 0.1-4.5-keV X-ray survey of a 2 x 2-deg area centered on the Pleiades open cluster, performed using the imaging proportional counter and high-resolution imager of the Einstein Observatory on four days in 1980-1981, are presented in extensive tables, graphs, maps, histograms, and finding charts and characterized. A total of 61 sources are detected, and 44 of these are identified with cluster members of spectral types B-M. Findings discussed include Lx/Lbol of 10 the -7th for early-type stars; F-star mean Lx like that of F stars in the Hyades and in the field (denying time evolution of Lx); mean G-star Lx = 3.7 x 10 to the 29th erg/sec; G-star activity decay more gradual than 1/sq rt t, with sharp fall for t greater than 1 Gyr; and no evidence for X-ray-emissivity/rotational-velocity correlation in a homogeneous sample of K dwarfs or a sample of K and M stars with established V sin i data.

  6. The Danish airborne gamma-ray surveying results

    Energy Technology Data Exchange (ETDEWEB)

    Hovgaard, J. [Danish Emergency Management Agency, Birkeroed (Denmark)

    1997-12-31

    The Danish Emergency Management Agency (DEMA) in co-operation with the Technical University of Denmark (TUD), Department of Automation, participated in the international exercise RESUME-95 arranged in Finland in August 1995. DEMA performed measurement with their airborne gamma-ray surveying system. Surveys were done in the three areas known as AREA I, II, III. Results from AREA II (3 km x 6 km) show that the apparent {sup 137}Cs deposition assuming a deposition profile equal to the profile in AREA I based on soil samples varies from a few 10th kBqm{sup -2} up to 110 kBqm{sup -2}. However, a detailed analysis using a new method, Noise Adjusted Singular Value Decomposition (NASVD), shows that the true variations probably are smaller and that the observed differences to some extend are due to major variations in the depth distribution of the cesium. For example agricultural areas appears to have cesium much deeper deposit than the undisturbed areas. Another interesting result is that the NASVD analysis shows that the ration of {sup 134}Cs to {sup 137}Cs is fixed and approximately 0.03 (August 1995) a number in good agreement with the expected ratio from the Chernobyl accident. No true real-time software for source detection is yet integrated in the Danish system. Results from AREA III, however, show that the implemented software for rapid post processing of data worked excellent for detection of radioactive sources. Post analysis using NASVD demonstrates that all sources except for a small {sup 137}Cs source can be localized. (au).

  7. The Danish airborne gamma-ray surveying results

    Energy Technology Data Exchange (ETDEWEB)

    Hovgaard, J [Danish Emergency Management Agency, Birkeroed (Denmark)

    1998-12-31

    The Danish Emergency Management Agency (DEMA) in co-operation with the Technical University of Denmark (TUD), Department of Automation, participated in the international exercise RESUME-95 arranged in Finland in August 1995. DEMA performed measurement with their airborne gamma-ray surveying system. Surveys were done in the three areas known as AREA I, II, III. Results from AREA II (3 km x 6 km) show that the apparent {sup 137}Cs deposition assuming a deposition profile equal to the profile in AREA I based on soil samples varies from a few 10th kBqm{sup -2} up to 110 kBqm{sup -2}. However, a detailed analysis using a new method, Noise Adjusted Singular Value Decomposition (NASVD), shows that the true variations probably are smaller and that the observed differences to some extend are due to major variations in the depth distribution of the cesium. For example agricultural areas appears to have cesium much deeper deposit than the undisturbed areas. Another interesting result is that the NASVD analysis shows that the ration of {sup 134}Cs to {sup 137}Cs is fixed and approximately 0.03 (August 1995) a number in good agreement with the expected ratio from the Chernobyl accident. No true real-time software for source detection is yet integrated in the Danish system. Results from AREA III, however, show that the implemented software for rapid post processing of data worked excellent for detection of radioactive sources. Post analysis using NASVD demonstrates that all sources except for a small {sup 137}Cs source can be localized. (au).

  8. Survey on the parameters influencing X-ray picture quality

    International Nuclear Information System (INIS)

    Stender, H.S.

    1985-01-01

    Survey on factors influencing X-ray picture quality: 1) identification of patient and imaged body part. 2) Object properties - thickness, density, built; spatial expansion and arrangement of anatomical parts; object parts in a homogenic and an inhomogenic environment; object movements. 3) Examination technique - matching to medical issue; positioning and adjustment; projection; picture format in keeping with the medical issue; object-related fade-in; distance ratios; contrast medium distribution or deposition; compression. 4) Technical factors of picture production - radiation quality tube voltage; reproducible mAs and mR/mAs; automatic exposure equipment; focal spot size; scattered radiation grid; image intensifier and indirect radiography system; exposure time, dose-to-exposure-time ratio; film-screen combination; cassette with uniform pressure contact; film processing system; radiation safety and light safety. 5) Physical imaging parameters - mean optical density; resolution capacity; contrast reproduction; noise; modulation transmission function. 6) Perceptible picture properties - luminance density; picture contrast; recognizability of details; impression of grain structure; blurred picture structure; visually conspicuous elements. 7) Requirements on picture viewing - viewing device with high luminance density and equalized illumination; possible modification of brilliance; possible fade-in operations and prevention of ambient glare; spot light with iris diaphragm; possible viewing by magnifying lens; selection of correct viewing distances; repeated picture viewing or evaluation by two or more viewers. (orig./HP) [de

  9. New gonad protector for public survey X-ray images

    Energy Technology Data Exchange (ETDEWEB)

    Joos, M.

    1976-01-01

    A new gonad shield intended to be used for pubic survey X-ray images is introduced. This protector is mounted on the light sight and produces a shadow free of central radiation on the patient's body. The shield provides such a shape that in women the area limited by the terminal line and in which 95% of the ovaria are situated, is covered, and that in men the region below the pubic angle is protected. The 2 mm thick lead shield has dimensions of 4.0 to 2.5 cm and is inserted into a plexiglass ruler which lies freely movable on a plexiglass plate under the light sight. This shield was tested on the water phantom and on 125 patients. With this protector it was possible to lower the surface dosages calculated by film dosimeters to 20% in women, and also to reduce the gonade dosages to 9% of the dosages without protection. The position of the new gonad protector at a distance from the body provides several advantages: the shield does not alter its position when the patient moves, the protector does not slip off the abdomen in adipose female patients, the radiation protected region has always the same extent, independent from the abdominal curvature of the female patient, the hygienic problems are eliminated, and the shield can be used for both sexes.

  10. Prospecting effect of the combined gamma-ray survey in the hydrochemical reconnaissance

    International Nuclear Information System (INIS)

    Hu Zheng'an.

    1991-01-01

    Gamma-ray survey is characterized by economies, rapidness, portability and continuous measurement in uranium reconnaissance. Combined gamma-ray survey can be conducted in hydrochemical reconnaissance with less investment and faster results, and prospects for detailed prospecting and exposing can be directly found by the survey. The arrangements in the field operation is suited to hydrochemical reconnaissance. By working for one time two sets of data with different characteristics could be obtained. In data interpretation and application, both data can be mutually complementary. It is a blank area for the non-water section in hydrochemical reconnaissance in which gamma-ray survey can be supplemented. Gamma-ray survey can provide data for the interpretation of hydrochemical anomalies and the size and concentration of hydrochemical anomalies are the basis for the inference of the mineralization at depth. The statistical results confirm that as compared with the conventional gamma-ray survey (at 1:10000 scale), the discovery rate of anomalies from the combined gamma-ray survey (at 1: 25000 scale) may reach 60%. It is thus that the data from the combined gamma-ray survey can be applied by lowering one grade in measurement accuracy which can meet the demand for accuracy

  11. X-RAY-EMITTING STARS IDENTIFIED FROM THE ROSAT ALL-SKY SURVEY AND THE SLOAN DIGITAL SKY SURVEY

    International Nuclear Information System (INIS)

    Agueeros, Marcel A.; Newsom, Emily R.; Anderson, Scott F.; Hawley, Suzanne L.; Silvestri, Nicole M.; Szkody, Paula; Covey, Kevin R.; Posselt, Bettina; Margon, Bruce; Voges, Wolfgang

    2009-01-01

    The ROSAT All-Sky Survey (RASS) was the first imaging X-ray survey of the entire sky. Combining the RASS Bright and Faint Source Catalogs yields an average of about three X-ray sources per square degree. However, while X-ray source counterparts are known to range from distant quasars to nearby M dwarfs, the RASS data alone are often insufficient to determine the nature of an X-ray source. As a result, large-scale follow-up programs are required to construct samples of known X-ray emitters. We use optical data produced by the Sloan Digital Sky Survey (SDSS) to identify 709 stellar X-ray emitters cataloged in the RASS and falling within the SDSS Data Release 1 footprint. Most of these are bright stars with coronal X-ray emission unsuitable for SDSS spectroscopy, which is designed for fainter objects (g > 15 [mag]). Instead, we use SDSS photometry, correlations with the Two Micron All Sky Survey and other catalogs, and spectroscopy from the Apache Point Observatory 3.5 m telescope to identify these stellar X-ray counterparts. Our sample of 707 X-ray-emitting F, G, K, and M stars is one of the largest X-ray-selected samples of such stars. We derive distances to these stars using photometric parallax relations appropriate for dwarfs on the main sequence, and use these distances to calculate L X . We also identify a previously unknown cataclysmic variable (CV) as a RASS counterpart. Separately, we use correlations of the RASS and the SDSS spectroscopic catalogs of CVs and white dwarfs (WDs) to study the properties of these rarer X-ray-emitting stars. We examine the relationship between (f X /f g ) and the equivalent width of the Hβ emission line for 46 X-ray-emitting CVs and discuss tentative classifications for a subset based on these quantities. We identify 17 new X-ray-emitting DA (hydrogen) WDs, of which three are newly identified WDs. We report on follow-up observations of three candidate cool X-ray-emitting WDs (one DA and two DB (helium) WDs); we have not

  12. Airborne Gamma-Ray Survey in Latvia 1995/96

    DEFF Research Database (Denmark)

    Bargholz, Kim

    1998-01-01

    Based on Airborne Gamma-Ray Spectrometry measurements performed with the Danish AGS equipment in 1995 and 1996 maps of the natural radioactivity have been produdced for selected areas in Latvia. The calibration of the quipment have been improved by comparisons with soil sample measurements....

  13. Detectability of rotation-powered pulsars in future hard X-ray surveys

    International Nuclear Information System (INIS)

    Wang Wei

    2009-01-01

    Recent INTEGRAL/IBIS hard X-ray surveys have detected about 10 young pulsars. We show hard X-ray properties of these 10 young pulsars, which have a luminosity of 10 33 -10 37 erg s -1 and a photon index of 1.6-2.1 in the energy range of 20-100 keV. The correlation between X-ray luminosity and spin-down power of L X ∝ L sd 1.31 suggests that the hard X-ray emission in rotation-powered pulsars is dominated by the pulsar wind nebula (PWN) component. Assuming spectral properties are similar in 20-100 keV and 2-10 keV for both the pulsar and PWN components, the hard X-ray luminosity and flux of 39 known young X-ray pulsars and 8 millisecond pulsars are obtained, and a correlation of L X ∝ L sd 1.5 is derived. About 20 known young X-ray pulsars and 1 millisecond pulsars could be detected with future INTEGRAL and HXMT surveys. We also carry out Monte Carlo simulations of hard X-ray pulsars in the Galaxy and the Gould Belt, assuming values for the pulsar birth rate, initial position, proper motion velocity, period, and magnetic field distribution and evolution based on observational statistics and the L X - L sd relations: L X ∝ L sd 1.31 and L X ∝ L sd 1.5 . More than 40 young pulsars (mostly in the Galactic plane) could be detected after ten years of INTEGRAL surveys and the launch of HXMT. So, the young pulsars would be a significant part of the hard X-ray source population in the sky, and will contribute to unidentified hard X-ray sources in present and future hard X-ray surveys by INTEGRAL and HXMT.

  14. AGN classification for X-ray sources in the 105 month Swift/BAT survey

    Science.gov (United States)

    Masetti, N.; Bassani, L.; Palazzi, E.; Malizia, A.; Stephen, J. B.; Ubertini, P.

    2018-03-01

    We here provide classifications for 8 hard X-ray sources listed as 'unknown AGN' in the 105 month Swift/BAT all-sky survey catalogue (Oh et al. 2018, ApJS, 235, 4). The corresponding optical spectra were extracted from the 6dF Galaxy Survey (Jones et al. 2009, MNRAS, 399, 683).

  15. AN XMM-NEWTON SURVEY OF THE SOFT X-RAY BACKGROUND. III. THE GALACTIC HALO X-RAY EMISSION

    International Nuclear Information System (INIS)

    Henley, David B.; Shelton, Robin L.

    2013-01-01

    We present measurements of the Galactic halo's X-ray emission for 110 XMM-Newton sight lines selected to minimize contamination from solar wind charge exchange emission. We detect emission from few million degree gas on ∼4/5 of our sight lines. The temperature is fairly uniform (median = 2.22 × 10 6 K, interquartile range = 0.63 × 10 6 K), while the emission measure and intrinsic 0.5-2.0 keV surface brightness vary by over an order of magnitude (∼(0.4-7) × 10 –3 cm –6 pc and ∼(0.5-7) × 10 –12 erg cm –2 s –1 deg –2 , respectively, with median detections of 1.9 × 10 –3 cm –6 pc and 1.5 × 10 –12 erg cm –2 s –1 deg –2 , respectively). The high-latitude sky contains a patchy distribution of few million degree gas. This gas exhibits a general increase in emission measure toward the inner Galaxy in the southern Galactic hemisphere. However, there is no tendency for our observed emission measures to decrease with increasing Galactic latitude, contrary to what is expected for a disk-like halo morphology. The measured temperatures, brightnesses, and spatial distributions of the gas can be used to place constraints on models for the dominant heating sources of the halo. We provide some discussion of such heating sources, but defer comparisons between the observations and detailed models to a later paper

  16. Extragalactic Hard X-ray Surveys: From INTEGRAL to Simbol-X

    Science.gov (United States)

    Paltani, S.; Dwelly, T.; Walter, R.; McHardy, I. M.; Courvoisier, T. J.-L.

    2009-05-01

    We present some results of the deepest extragalactic survey performed by the INTEGRAL satellite. The fraction of very absorbed AGN is quite large. The sharp decrease in the absorption fraction with X-ray luminosity observed at lower-energy X-rays is not observed. The current lack of truly Compton-thick objects, with an upper limit of 14% to the size of this population, is just compatible with recent modeling of the cosmic X-ray background. We also study the prospects for a future hard X-ray serendipitous survey with Simbol-X. We show that Simbol-X will easily detect a large number of serendipitous AGN, allowing us to study the evolution of AGN up to redshifts about 2, opening the door to the cosmological study of hard X-ray selected AGN, which is barely possible with existing satellites like Swift and INTEGRAL.

  17. A ROTSE-I/ROSAT Survey of X-ray Emission from Contact Binary Stars

    Science.gov (United States)

    Geske, M.; McKay, T.

    2005-05-01

    Using public data from the ROSAT All Sky Survey (RASS) and the ROTSE-I Sky Patrols, the incidence of strong x-ray emissions from contact binary systems was examined. The RASS data was matched to an expanded catalog of contact binary systems from the ROTSE-I data, using a 35 arc second radius. X-ray luminosities for matching objects were then determined. This information was then used to evaluate the total x-ray emissions from all such objects, in order to determine their contribution to the galactic x-ray background.

  18. A survey of chest medical X-ray doses

    International Nuclear Information System (INIS)

    Lomba, M.; Conha, P.G. da; Almeida, C.E. de

    1996-01-01

    The medical X-ray exposures due to radiological examinations are responsible for the largest contribution to the population collective dose as result of the normal use of artificial sources of radiation. The relative impact of the medical exposures to the total dose received by the population from all kinds of radiation sources varies from country to country and in some cases within the same country. The dose variations observed for a specific type of examination are in general associated to several factors i.e. the type of film-ecran combination, the choice of the appropriate physical parameters of the X-ray generator (Kvp, filament current, exposure time) and finally to the film processing conditions. At the present moment the data available in Brazil are scarce and scanty to allow a complete analyzis of this question so needed by the health authorities to justify the implementation of a quality assurance and dose reduction programs. In addition, it is desirable to establish a cost effective operation based on simple administrative concepts in order to reduce the number of films retake, then increasing the life expectancy of the equipment and the number of radiological procedures. The aim of this work was to assess the typical doses of an PA and LAT chest wall X-ray examinations in five different public hospitals (a University Hospital, a Cancer Hospital, a Navy Hospital, an Emergency Hospital and a State General Hospital), as representative of the city of Rio de Janeiro, and compare the results with the international data and recommendations available. (author)

  19. Automating X-ray Fluorescence Analysis for Rapid Astrobiology Surveys.

    Science.gov (United States)

    Thompson, David R; Flannery, David T; Lanka, Ravi; Allwood, Abigail C; Bue, Brian D; Clark, Benton C; Elam, W Timothy; Estlin, Tara A; Hodyss, Robert P; Hurowitz, Joel A; Liu, Yang; Wade, Lawrence A

    2015-11-01

    A new generation of planetary rover instruments, such as PIXL (Planetary Instrument for X-ray Lithochemistry) and SHERLOC (Scanning Habitable Environments with Raman Luminescence for Organics and Chemicals) selected for the Mars 2020 mission rover payload, aim to map mineralogical and elemental composition in situ at microscopic scales. These instruments will produce large spectral cubes with thousands of channels acquired over thousands of spatial locations, a large potential science yield limited mainly by the time required to acquire a measurement after placement. A secondary bottleneck also faces mission planners after downlink; analysts must interpret the complex data products quickly to inform tactical planning for the next command cycle. This study demonstrates operational approaches to overcome these bottlenecks by specialized early-stage science data processing. Onboard, simple real-time systems can perform a basic compositional assessment, recognizing specific features of interest and optimizing sensor integration time to characterize anomalies. On the ground, statistically motivated visualization can make raw uncalibrated data products more interpretable for tactical decision making. Techniques such as manifold dimensionality reduction can help operators comprehend large databases at a glance, identifying trends and anomalies in data. These onboard and ground-side analyses can complement a quantitative interpretation. We evaluate system performance for the case study of PIXL, an X-ray fluorescence spectrometer. Experiments on three representative samples demonstrate improved methods for onboard and ground-side automation and illustrate new astrobiological science capabilities unavailable in previous planetary instruments. Dimensionality reduction-Planetary science-Visualization.

  20. THE 70 MONTH SWIFT-BAT ALL-SKY HARD X-RAY SURVEY

    International Nuclear Information System (INIS)

    Baumgartner, W. H.; Tueller, J.; Markwardt, C. B.; Skinner, G. K.; Barthelmy, S.; Gehrels, N.; Mushotzky, R. F.; Evans, P. A.

    2013-01-01

    We present the catalog of sources detected in 70 months of observations with the Burst Alert Telescope (BAT) hard X-ray detector on the Swift gamma-ray burst observatory. The Swift-BAT 70 month survey has detected 1171 hard X-ray sources (more than twice as many sources as the previous 22 month survey) in the 14-195 keV band down to a significance level of 4.8σ, associated with 1210 counterparts. The 70 month Swift-BAT survey is the most sensitive and uniform hard X-ray all-sky survey and reaches a flux level of 1.03 × 10 –11 erg s –1 cm –2 over 50% of the sky and 1.34 × 10 –11 erg s –1 cm –2 over 90% of the sky. The majority of new sources in the 70 month survey continue to be active galactic nuclei, with over 700 in the catalog. As part of this new edition of the Swift-BAT catalog, we also make available eight-channel spectra and monthly sampled light curves for each object detected in the survey in the online journal and at the Swift-BAT 70 month Web site

  1. THE 70 MONTH SWIFT-BAT ALL-SKY HARD X-RAY SURVEY

    Energy Technology Data Exchange (ETDEWEB)

    Baumgartner, W. H.; Tueller, J.; Markwardt, C. B.; Skinner, G. K.; Barthelmy, S.; Gehrels, N. [NASA/Goddard Space Flight Center, Astrophysics Science Division, Greenbelt, MD 20771 (United States); Mushotzky, R. F. [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Evans, P. A., E-mail: whbaumga@alum.mit.edu [X-Ray and Observational Astronomy Group/Department of Physics and Astronomy, University of Leicester, Leicester, LE1 7RH (United Kingdom)

    2013-08-15

    We present the catalog of sources detected in 70 months of observations with the Burst Alert Telescope (BAT) hard X-ray detector on the Swift gamma-ray burst observatory. The Swift-BAT 70 month survey has detected 1171 hard X-ray sources (more than twice as many sources as the previous 22 month survey) in the 14-195 keV band down to a significance level of 4.8{sigma}, associated with 1210 counterparts. The 70 month Swift-BAT survey is the most sensitive and uniform hard X-ray all-sky survey and reaches a flux level of 1.03 Multiplication-Sign 10{sup -11} erg s{sup -1} cm{sup -2} over 50% of the sky and 1.34 Multiplication-Sign 10{sup -11} erg s{sup -1} cm{sup -2} over 90% of the sky. The majority of new sources in the 70 month survey continue to be active galactic nuclei, with over 700 in the catalog. As part of this new edition of the Swift-BAT catalog, we also make available eight-channel spectra and monthly sampled light curves for each object detected in the survey in the online journal and at the Swift-BAT 70 month Web site.

  2. Understanding the Relation between Attitude Involvement and Response Latitude Using Item Response Theory

    Science.gov (United States)

    Lake, Christopher J.; Withrow, Scott; Zickar, Michael J.; Wood, Nicole L.; Dalal, Dev K.; Bochinski, Joseph

    2013-01-01

    Adapting the original latitude of acceptance concept to Likert-type surveys, response latitudes are defined as the range of graded response options a person is willing to endorse. Response latitudes were expected to relate to attitude involvement such that high involvement was linked to narrow latitudes (the result of selective, careful…

  3. The energy spectrum of cosmic-ray induced neutrons measured on an airplane over a wide range of altitude and latitude

    International Nuclear Information System (INIS)

    Goldhagen, P.; Clem, J. M.; Wilson, J. W.

    2004-01-01

    Crews of high-altitude aircraft are exposed to radiation from galactic cosmic rays (GCRs). To help determine such exposures, the Atmospheric Ionizing Radiation Project, an international collaboration of 15 laboratories, made simultaneous radiation measurements with 14 instruments on a NASA ER-2 high-altitude airplane. The primary instrument was a sensitive extended-energy multisphere neutron spectrometer. Its detector responses were calculated for energies up to 100 GeV using the radiation transport code MCNPX 2.5.d with improved nuclear models and including the effects of the airplane structure. New calculations of GCR-induced particle spectra in the atmosphere were used to correct for spectrometer counts produced by protons, pions and light nuclear ions. Neutron spectra were unfolded from the corrected measured count rates using the deconvolution code MAXED 3.1. The results for the measured cosmic-ray neutron spectrum (thermal to >10 GeV), total neutron fluence rate, and neutron dose equivalent and effective dose rates, and their dependence on altitude and geomagnetic cut-off agree well with results from recent calculations of GCR-induced neutron spectra. (authors)

  4. An HST Survey of Intermediate Luminosity X-ray Objects

    Science.gov (United States)

    Roye, E. W.; Colbert, E. J. M.; Heckman, T.; Ptak, R. F.; van der Marel, R. P.

    2003-03-01

    We searched for optical counterparts to 54 Intermediate-luminosity X-ray Objects (IXOs, a.k.a. ULXs) using HST WFPC2 archive data, and have uncovered a high yield of intriguing possible correlations. A total of 124 IXOs were identified from searching all of the Chandra ACIS archival galaxy data as of July 17, 2002. Archival WFPC2 data were available for 54 of these IXOs. The optical data utilized in this study consisted of 121 HST WFPC2 associations (stacked images). We will discuss the various methods used to register the HST WFPC2 images with the Chandra X-ray images. Our preliminary analysis indicates that 37 ( ˜70%) of the 54 IXOs have at least one 4 sigma counterpart within 1" of the IXO position, and ˜25% have unique counterparts (mostly in elliptical galaxies). The detection limit of the counterparts was typically 24-25 magnitudes in B, V, and R. The absolute magnitudes of many of the found counterparts appeared to correspond roughly to either the expected magnitudes for globular clusters, or the expected magnitudes for the brightest stars. Initial results illustrate that of the 37 IXOs with counterparts, 25 ( ˜70%) were in spiral, irregular, and merger galaxies, where the counterparts were often diffuse or clump-like sources. The counterparts found in elliptical galaxies were primarily single luminous point-sources, most likely globular clusters. We will discuss the results of color analysis for fields where counterparts in multiple bands exist, particularly for cases where a single counterpart is found. A preliminary finding in elliptical galaxies is that globular clusters associated with IXOs tend to be red, suggesting that IXOs are not found in metal-poor globular clusters.

  5. An X-ray and infrared survey of the Lynds 1228 cloud core

    Energy Technology Data Exchange (ETDEWEB)

    Skinner, Stephen L. [CASA, University of Colorado, Boulder, CO 80309-0389 (United States); Rebull, Luisa [Spitzer Science Center/Caltech, M/S 220-6, 1200 East California Blvd., Pasadena, CA 91125 (United States); Güdel, Manuel, E-mail: stephen.skinner@colorado.edu, E-mail: rebull@ipac.caltech.edu, E-mail: manuel.guedel@univie.ac.at [Department of Astrophysics, University of Vienna, Türkenschanzstr. 17, A-1180 Vienna (Austria)

    2014-04-01

    The nearby Lynds 1228 (L1228) dark cloud at a distance of ∼200 pc is known to harbor several young stars including the driving sources of the giant HH 199 and HH 200 Herbig-Haro (HH) outflows. L1228 has previously been studied at optical, infrared, and radio wavelengths but not in X-rays. We present results of a sensitive 37 ks Chandra ACIS-I X-ray observation of the L1228 core region. Chandra detected 60 X-ray sources, most of which are faint (<40 counts) and non-variable. Infrared counterparts were identified for 53 of the 60 X-ray sources using archival data from the Two Micron All-Sky Survey, the Spitzer Space Telescope, and the Wide-field Infrared Survey Explorer. Object classes were assigned using mid-IR colors for those objects with complete photometry, most of which were found to have colors consistent with extragalactic background sources. Seven young stellar object candidates were identified including the class I protostar HH 200-IRS which was detected as a faint hard X-ray source. No X-ray emission was detected from the luminous protostar HH 199-IRS. We summarize the X-ray and infrared properties of the detected sources and provide IR spectral energy distribution modeling of high-interest objects including the protostars driving the HH outflows.

  6. The NuSTAR Hard X-Ray Survey of the Norma Arm Region

    DEFF Research Database (Denmark)

    Fornasini, Francesca M.; Tomsick, John A.; Hong, JaeSub

    2017-01-01

    We present a catalog of hard X-ray sources in a square-degree region surveyed by the Nuclear Spectroscopic Telescope Array (NuSTAR) in the direction of the Norma spiral arm. This survey has a total exposure time of 1.7 Ms, and the typical and maximum exposure depths are 50 ks and 1 Ms, respectively...... model with kT ≈ 15 keV, as observed for the CV candidates....

  7. Rays in the northern Gulf of Mexico: Aerial Survey and Satellite Telemetry 2008-2012 (NCEI Accession 0129495)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The dataset contains distribution and abundance data for rays in the Gulf of Mexico collected through aerial surveys and satellite telemetry. Aerial survey data...

  8. CHANDRA ACIS SURVEY OF X-RAY POINT SOURCES IN NEARBY GALAXIES. II. X-RAY LUMINOSITY FUNCTIONS AND ULTRALUMINOUS X-RAY SOURCES

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Song; Qiu, Yanli; Liu, Jifeng [Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China); Bregman, Joel N., E-mail: songw@bao.ac.cn, E-mail: jfliu@bao.ac.cn [University of Michigan, Ann Arbor, MI 48109 (United States)

    2016-09-20

    Based on the recently completed Chandra /ACIS survey of X-ray point sources in nearby galaxies, we study the X-ray luminosity functions (XLFs) for X-ray point sources in different types of galaxies and the statistical properties of ultraluminous X-ray sources (ULXs). Uniform procedures are developed to compute the detection threshold, to estimate the foreground/background contamination, and to calculate the XLFs for individual galaxies and groups of galaxies, resulting in an XLF library of 343 galaxies of different types. With the large number of surveyed galaxies, we have studied the XLFs and ULX properties across different host galaxy types, and confirm with good statistics that the XLF slope flattens from lenticular ( α ∼ 1.50 ± 0.07) to elliptical (∼1.21 ± 0.02), to spirals (∼0.80 ± 0.02), to peculiars (∼0.55 ± 0.30), and to irregulars (∼0.26 ± 0.10). The XLF break dividing the neutron star and black hole binaries is also confirmed, albeit at quite different break luminosities for different types of galaxies. A radial dependency is found for ellipticals, with a flatter XLF slope for sources located between D {sub 25} and 2 D {sub 25}, suggesting the XLF slopes in the outer region of early-type galaxies are dominated by low-mass X-ray binaries in globular clusters. This study shows that the ULX rate in early-type galaxies is 0.24 ± 0.05 ULXs per surveyed galaxy, on a 5 σ confidence level. The XLF for ULXs in late-type galaxies extends smoothly until it drops abruptly around 4 × 10{sup 40} erg s{sup −1}, and this break may suggest a mild boundary between the stellar black hole population possibly including 30 M {sub ⊙} black holes with super-Eddington radiation and intermediate mass black holes.

  9. SMSS J130522.47-293113.0: a high-latitude stellar X-ray source with pc-scale outflow relics?

    Science.gov (United States)

    Da Costa, G. S.; Soria, R.; Farrell, S. A.; Bayliss, D.; Bessell, M. S.; Vogt, F. P. A.; Zhou, G.; Points, S. D.; Beers, T. C.; López-Sánchez, Á. R.; Bannister, K. W.; Bell, M.; Hancock, P. J.; Burlon, D.; Gaensler, B. M.; Sadler, E. M.; Tingay, S.; Keller, S. C.; Schmidt, B. P.; Tisserand, P.

    2018-06-01

    We report the discovery of an unusual stellar system SMSS J130522.47-293113.0. The optical spectrum is dominated by a blue continuum together with emission lines of hydrogen, neutral, and ionized helium, and the N III, C III blend at ˜4640-4650 Å. The emission-line profiles vary in strength and position on time-scales as short as 1 d, while optical photometry reveals fluctuations of as much as ˜0.2 mag in g on time-scales as short as 10-15 min. The system is a weak X-ray source (f0.3-10 = (1.2 ± 0.1) × 10-13 ergs cm2 s-1 in the 0.3-10 keV band) but is not detected at radio wavelengths (3σ upper limit of 50 μJy at 5.5 GHz). The most intriguing property of the system, however, is the existence of two `blobs', a few arcsec in size, that are symmetrically located 3{^'.}8 (2.2 pc for our preferred system distance of ˜2 kpc) each side of the central object. The blobs are detected in optical and near-IR broad-band images but do not show any excess emission in H α images. We discuss the interpretation of the system, suggesting that the central object is most likely a nova-like CV, and that the blobs are relics of a pc-scale accretion-powered collimated outflow.

  10. THE POTENTIAL OF γ-RAY SPECTROSCOPY FOR SOIL PROXIMAL SURVEY IN CLAYEY SOILS

    Directory of Open Access Journals (Sweden)

    Simone Priori

    2014-01-01

    Full Text Available Gamma-ray spectroscopy surveys the intensity and distribution of γ-rays emitted from radionuclides of soils and bedrocks. The most important radionuclides of soils and rocks are: 40K, 232Th, 238U and 137Cs, the latter due to Chernobyl burst or radioactive pollution. Distribution and quantity of these radionuclides into the soil is strictly linked to parent material mineralogy and soil cation exchange capacity. The aim of this work is to show the makings of γ-ray spectroscopy proximal survey within experimental fields with clayey soils in western Sicily.The γ-ray spectrometer used for the fieldwork was “The Mole”, made by “The Soil Company”, “Medusa system” and the University of Groningen, from The Netherlands. During the survey of eight experimental fields, 55 soil samples were collected for laboratory analysis of particle size distribution, calcium carbonate, organic carbon and total nitrogen content. The results of the work showed the statistical correlations between soil features and γ-ray data. 

  11. The Chandra planetary nebula survey (CHANPLANS). II. X-ray emission from compact planetary nebulae

    Energy Technology Data Exchange (ETDEWEB)

    Freeman, M.; Kastner, J. H. [Center for Imaging Science and Laboratory for Multiwavelength Astrophysics, Rochester Institute of Technology, 54 Lomb Memorial Drive, Rochester, NY 14623 (United States); Montez, R. Jr. [Department of Physics and Astronomy, Vanderbilt University, Nashville, TN (United States); Balick, B. [Department of Astronomy, University of Washington, Seattle, WA (United States); Frew, D. J.; De Marco, O.; Parker, Q. A. [Department of Physics and Astronomy and Macquarie Research Centre for Astronomy, Astrophysics and Astrophotonics, Macquarie University, Sydney, NSW 2109 (Australia); Jones, D. [Departamento de Física, Universidad de Atacama, Copayapu 485, Copiapó (Chile); Miszalski, B. [South African Astronomical Observatory, P.O. Box 9, Observatory, 7935 (South Africa); Sahai, R. [Jet Propulsion Laboratory, MS 183-900, California Institute of Technology, Pasadena, CA 91109 (United States); Blackman, E.; Frank, A. [Department of Physics and Astronomy, University of Rochester, Rochester, NY (United States); Chu, Y.-H. [Department of Astronomy, University of Illinois at Urbana-Champaign, Urbana, IL (United States); Guerrero, M. A. [Instituto de Astrofísica de Andalucía, IAA-CSIC, Glorieta de la Astronomía s/n, Granada, E-18008 (Spain); Lopez, J. A. [Instituto de Astronomía, Universidad Nacional Autonoma de Mexico, Campus Ensenada, Apdo. Postal 22860, Ensenada, B. C. (Mexico); Zijlstra, A. [School of Physics and Astronomy, University of Manchester, Manchester M13 9PL (United Kingdom); Bujarrabal, V. [Instituto de Astrofísica de Canarias, E-38200 La Laguna, Tenerife (Spain); Corradi, R. L. M. [Departamento de Astrofísica, Universidad de La Laguna, E-38206 La Laguna, Tenerife (Spain); Nordhaus, J. [NSF Astronomy and Astrophysics Fellow, Center for Computational Relativity and Gravitation, Rochester Institute of Technology, Rochester, NY 14623 (United States); and others

    2014-10-20

    We present results from the most recent set of observations obtained as part of the Chandra X-ray observatory Planetary Nebula Survey (CHANPLANS), the first comprehensive X-ray survey of planetary nebulae (PNe) in the solar neighborhood (i.e., within ∼1.5 kpc of the Sun). The survey is designed to place constraints on the frequency of appearance and range of X-ray spectral characteristics of X-ray-emitting PN central stars and the evolutionary timescales of wind-shock-heated bubbles within PNe. CHANPLANS began with a combined Cycle 12 and archive Chandra survey of 35 PNe. CHANPLANS continued via a Chandra Cycle 14 Large Program which targeted all (24) remaining known compact (R {sub neb} ≲ 0.4 pc), young PNe that lie within ∼1.5 kpc. Results from these Cycle 14 observations include first-time X-ray detections of hot bubbles within NGC 1501, 3918, 6153, and 6369, and point sources in HbDs 1, NGC 6337, and Sp 1. The addition of the Cycle 14 results brings the overall CHANPLANS diffuse X-ray detection rate to ∼27% and the point source detection rate to ∼36%. It has become clearer that diffuse X-ray emission is associated with young (≲ 5 × 10{sup 3} yr), and likewise compact (R {sub neb} ≲ 0.15 pc), PNe with closed structures and high central electron densities (n{sub e} ≳ 1000 cm{sup –3}), and is rarely associated with PNe that show H{sub 2} emission and/or pronounced butterfly structures. Hb 5 is one such exception of a PN with a butterfly structure that hosts diffuse X-ray emission. Additionally, two of the five new diffuse X-ray detections (NGC 1501 and NGC 6369) host [WR]-type central stars, supporting the hypothesis that PNe with central stars of [WR]-type are likely to display diffuse X-ray emission.

  12. Characteristic tests of ionization chamber and GM counter survey meters for beta-rays, (2)

    International Nuclear Information System (INIS)

    Suga, Shin-ichi; Bingo, Kazuyoshi; Kajimoto, Yoichi

    1979-03-01

    To estimate a beta-ray absorbed dose rate of contaminated skin, measurements were done twice by a survey meter without and with a filter, keeping the distance from the contaminated skin surface to the survey meter at 10 mm. The absorbed dose rate was obtained multiplying a net reading (equals a reading of survey meter's indicator measured without the filter minus that measured with the filter) by a multiplying factor. Calibrations were made with reference plane sources of natural uranium, 198 Au and 204 Tl, varying their area. The five types of ionization chamber survey meters had nearly same multiplying factors when the diameter of source was larger than the diameter of the chamber cylinder. Estimation of the absorbed doses due to beta-emitting nuclides was possible when the measured value without filter was larger by 20% or more than that of with filter. In the case of small sources, the multiplying factor varied significantly with area of the source. The multiplying factors agreed within +-30% in the respective types i.e. manufacturers and in maximum beta-ray energies from 0.7 up to 2.5 MeV. In the source to detector distance of 1 cm +-0.2 cm, the multiplying factor varied within +-20%. The multiplying factor of a GM counter survey meter varied with beta-ray energy, the multiplying factor for uranium was 1/3 that of 204 Tl. (author)

  13. High Latitude Polygons

    Science.gov (United States)

    2005-01-01

    26 September 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows polygonal patterned ground on a south high-latitude plain. The outlines of the polygons, like the craters and hills in this region, are somewhat enhanced by the presence of bright frost left over from the previous winter. On Earth, polygons at high latitudes would usually be attributed to the seasonal freezing and thawing cycles of ground ice. The origin of similar polygons on Mars is less certain, but might also be an indicator of ground ice. Location near: 75.3oS, 113.2oW Image width: width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Spring

  14. THE 22 MONTH SWIFT-BAT ALL-SKY HARD X-RAY SURVEY

    International Nuclear Information System (INIS)

    Tueller, J.; Baumgartner, W. H.; Markwardt, C. B.; Skinner, G. K.; Mushotzky, R. F.; Barthelmy, S.; Cummings, J.; Gehrels, N.; Holland, S.; Ajello, M.; Beardmore, A.; Evans, P.; Godet, O.; Brandt, W. N.; Burrows, D.; Grupe, D.; Chincarini, G.; Campana, S.; Cusumano, G.; Fenimore, E.

    2010-01-01

    We present the catalog of sources detected in the first 22 months of data from the hard X-ray survey (14-195 keV) conducted with the Burst Alert Telescope (BAT) coded mask imager on the Swift satellite. The catalog contains 461 sources detected above the 4.8σ level with BAT. High angular resolution X-ray data for every source from Swift-XRT or archival data have allowed associations to be made with known counterparts in other wavelength bands for over 97% of the detections, including the discovery of ∼30 galaxies previously unknown as active galactic nuclei and several new Galactic sources. A total of 266 of the sources are associated with Seyfert galaxies (median redshift z ∼ 0.03) or blazars, with the majority of the remaining sources associated with X-ray binaries in our Galaxy. This ongoing survey is the first uniform all-sky hard X-ray survey since HEAO-1 in 1977. Since the publication of the nine-month BAT survey we have increased the number of energy channels from four to eight and have substantially increased the number of sources with accurate average spectra. The BAT 22 month catalog is the product of the most sensitive all-sky survey in the hard X-ray band, with a detection sensitivity (4.8σ) of 2.2 x 10 -11 erg cm -2 s -1 (1 mCrab) over most of the sky in the 14-195 keV band.

  15. β-ray scintillation survey meter for small-sized pipes

    International Nuclear Information System (INIS)

    Yamano, Toshiya; Suzuki, Toshikazu; Yoshida, Yoshiteru; Higashidate, Takamichi; Yonemura, Kenji; Fujita, Michio.

    1990-01-01

    The outer surface of the small-sized pipes used as scaffolding is measured by beta/gamma survey meter when they are carried out from the controlled area in nuclear facilities. But, the measurement of the radioactive contamination on the inner surface, when it is needed, is done indirectly using the smear method. To improve these vexatious works, Fuji Electric Co., Ltd. and Chubu Electric Power Co., Inc. jointly developed a beta-ray scintillation survey meter which, when inserted directly into pipes, can detect radioactive contamination on the inner surface. This detector is made of cylindrical plastic scintillator and it can measure low energy beta-ray by using the coincidence method which reduces random noise. A field test carried out with this prototype survey meter brought favorable results for designing its final version. (author)

  16. A PILOT DEEP SURVEY FOR X-RAY EMISSION FROM fuvAGB STARS

    Energy Technology Data Exchange (ETDEWEB)

    Sahai, R. [Jet Propulsion Laboratory, MS 183-900, California Institute of Technology, Pasadena, CA 91109 (United States); Sanz-Forcada, J.; Sánchez Contreras, C. [Astrobiology Center (CSIC-INTA), ESAC campus, E-28691 Villanueva de la Canada, Madrid (Spain); Stute, M. [Institute for Astronomy and Astrophysics, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 10, D-72076, Tübingen (Germany)

    2015-09-01

    We report the results of a pilot survey for X-ray emission from a newly discovered class of AGB stars with far-ultraviolet excesses (fuvAGB stars) using XMM-Newton and Chandra. We detected X-ray emission in three of six fuvAGB stars observed—the X-ray fluxes are found to vary in a stochastic or quasi-periodic manner on roughly hour-long timescales, and simultaneous UV observations using the Optical Monitor on XMM for these sources show similar variations in the UV flux. These data, together with previous studies, show that X-ray emission is found only in fuvAGB stars. From modeling the spectra, we find that the observed X-ray luminosities are ∼(0.002–0.2) L{sub ⊙} and the X-ray-emitting plasma temperatures are ∼(35–160) × 10{sup 6} K. The high X-ray temperatures argue against the emission arising in stellar coronae, or directly in an accretion shock, unless it occurs on a WD companion. However, none of the detected objects is a known WD-symbiotic star, suggesting that if WD companions are present, they are relatively cool (<20,000 K). In addition, the high X-ray luminosities specifically argue against emission originating in the coronae of main-sequence companions. We discuss several models for the X-ray emission and its variability and find that the most likely scenario for the origin of the X-ray (and FUV) emission involves accretion activity around a companion star, with confinement by strong magnetic fields associated with the companion and/or an accretion disk around it.

  17. Characteristics of Gamma-Ray Loud Blazars in the VLBA Imaging and Polarimetry Survey

    Science.gov (United States)

    Linford, J. D.; Taylor, G. B.; Romani, R. W.; Healey, S. E.; Helmboldt, J. F.; Readhead, A. C.; Reeves, R.; Richards, J. L.; Cotter, G.

    2010-01-01

    The radio properties of blazars detected by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope have been observed as part of the VLBA Imaging and Polarimetry Survey. This large, flux-limited sample of active galactic nuclei (AGNs) provides insights into the mechanism that produces strong gamma-ray emission. At lower flux levels, radio flux density does not directly correlate with gamma-ray flux. We find that the LAT-detected BL Lac objects tend to be similar to the non-LAT BL Lac objects, but that the LAT-detected FSRQs are often significantly different from the non-LAT FSRQs. The differences between the gamma-ray loud and quiet FSRQS can be explained by Doppler boosting; these objects appear to require larger Doppler factors than those of the BL Lac objects. It is possible that the gamma-ray loud FSRQs are fundamentally different from the gamma-ray quiet FSRQs. Strong polarization at the base of the jet appears to be a signature for gamma-ray loud AGNs.

  18. CHARACTERISTICS OF GAMMA-RAY LOUD BLAZARS IN THE VLBA IMAGING AND POLARIMETRY SURVEY

    International Nuclear Information System (INIS)

    Linford, J. D.; Taylor, G. B.; Romani, R. W.; Healey, S. E.; Helmboldt, J. F.; Readhead, A. C. S.; Reeves, R.; Richards, J. L.; Cotter, G.

    2011-01-01

    The radio properties of blazars detected by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope have been observed as part of the VLBA Imaging and Polarimetry Survey. This large, flux-limited sample of active galactic nuclei (AGNs) provides insights into the mechanism that produces strong γ-ray emission. At lower flux levels, radio flux density does not directly correlate with γ-ray flux. We find that the LAT-detected BL Lac objects tend to be similar to the non-LAT BL Lac objects, but that the LAT-detected FSRQs are often significantly different from the non-LAT FSRQs. The differences between the γ-ray loud and quiet FSRQs can be explained by Doppler boosting; these objects appear to require larger Doppler factors than those of the BL Lac objects. It is possible that the γ-ray loud FSRQs are fundamentally different from the γ-ray quiet FSRQs. Strong polarization at the base of the jet appears to be a signature for γ-ray loud AGNs.

  19. Characteristics of Gamma-ray Loud Blazars in the VLBA Imaging and Polarimetry Survey

    Science.gov (United States)

    Linford, J. D.; Taylor, G. B.; Romani, R. W.; Healey, S. E.; Helmboldt, J. F.; Readhead, A. C. S.; Reeves, R.; Richards, J. L.; Cotter, G.

    2011-01-01

    The radio properties of blazars detected by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope have been observed as part of the VLBA Imaging and Polarimetry Survey. This large, flux-limited sample of active galactic nuclei (AGNs) provides insights into the mechanism that produces strong γ-ray emission. At lower flux levels, radio flux density does not directly correlate with γ-ray flux. We find that the LAT-detected BL Lac objects tend to be similar to the non-LAT BL Lac objects, but that the LAT-detected FSRQs are often significantly different from the non-LAT FSRQs. The differences between the γ-ray loud and quiet FSRQs can be explained by Doppler boosting; these objects appear to require larger Doppler factors than those of the BL Lac objects. It is possible that the γ-ray loud FSRQs are fundamentally different from the γ-ray quiet FSRQs. Strong polarization at the base of the jet appears to be a signature for γ-ray loud AGNs.

  20. An Einstein survey of the 1 keV soft X-ray background in the Galactic plane

    Science.gov (United States)

    Stanford, John M.; Caillault, Jean-Pierre

    1994-01-01

    We have analyzed 56 Einstein Observatory Imaging Proportional Counter (IPC) observations within +/- 3 deg of the Galactic plane in order to determine the low-latitude soft X-ray background flux in the 0.56-1.73 keV band. Any detected X-ray point source which fell within our regions of study was removed from the image, enabling us to present maps of the background flux as a function of Galactic latitude along 18 meridians. These maps reveal considerable structure to the background in the Galactic plane on an angular scale of approximately 1 deg. Our results are compared with those of an earlier study of the 1 keV X-ray background along l = 25 deg by Kahn & Caillault. The double-peaked structure they found is not discernible in our results, possibly because of the presence of solar backscattered flux in their data. A model which takes into account contributions to the background by extragalactic and stellar sources, the distribution of both atomic and molecular absorbing material with the Galaxy, the energy dependence of the cross section for absorption of X-rays, and the energy dependence of the detector has been constructed and fitted to these new data to derive constraints on the scale height, temperature, and volume emissivity of the unaccounted-for X-ray-emitting material. The results of this model along l = 25 deg are roughly similar to those of the model of Kahn & Caillault along the same meridian.

  1. The 105-Month Swift-BAT All-Sky Hard X-Ray Survey

    Science.gov (United States)

    Oh, Kyuseok; Koss, Michael; Markwardt, Craig B.; Schawinski, Kevin; Baumgartner, Wayne H.; Barthelmy, Scott D.; Cenko, S. Bradley; Gehrels, Neil; Mushotzky, Richard; Petulante, Abigail; hide

    2018-01-01

    We present a catalog of hard X-ray sources detected in the first 105 months of observations with the Burst Alert Telescope (BAT) coded-mask imager on board the Swift observatory. The 105-month Swift-BAT survey is a uniform hard X-ray all-sky survey with a sensitivity of 8.40 x 10(exp -12) erg s(exp -1) cm(exp -2) over 90% of the sky and 7.24 x 10(exp -12) erg s(exp -1) cm(exp -2) over 50% of the sky in the 14-195 keV band. The Swift-BAT 105-month catalog provides 1632 (422 new detections) hard X-ray sources in the 14-195 keV band above the 4.8 sigma significance level. Adding to the previously known hard X-ray sources, 34% (144/422) of the new detections are identified as Seyfert active galactic nuclei (AGNs) in nearby galaxies (z < 0.2). The majority of the remaining identified sources are X-ray binaries (7%, 31) and blazars/BL Lac objects (10%, 43). As part of this new edition of the Swift-BAT catalog, we release eight-channel spectra and monthly sampled light curves for each object in the online journal and at the Swift-BAT 105-month website.

  2. Uncovering extreme AGN variability in serendipitous X-ray source surveys

    Science.gov (United States)

    Moran, Edward C.; Garcia Soto, Aylin; LaMassa, Stephanie; Urry, Meg

    2018-01-01

    Constraints on the duty cycle and duration of accretion episodes in active galactic nuclei (AGNs) are vital for establishing how most AGNs are fueled, which is essential for a complete picture of black hole/galaxy co-evolution. Perhaps the best handle we have on these activity parameters is provided by AGNs that have displayed dramatic changes in their bolometric luminosities and, in some cases, spectroscopic classifications. Given that X-ray emission is directly linked to black-hole accretion, X-ray surveys should provide a straightforward means of identifying AGNs that have undergone dramatic changes in their accretion states. However, it appears that such events are very rare, so wide-area surveys separated in time by many years are needed to maximize discovery rates. We have cross-correlated the Einstein IPC Two-Sigma Catalog with the ROSAT All-Sky Survey Faint Source Catalog to identify a sample of soft X-ray sources that varied by factors ranging from 7 to more than 100 over a ten year timescale. When possible, we have constructed long-term X-ray light curves for the sources by combining the Einstein and RASS fluxes with those obtained from serendipitous pointed observations by ROSAT, Chandra,XMM, and Swift. Optical follow-up observations indicate that many of the extremely variable sources in our sample are indeed radio-quiet AGNs. Interestingly, the majority of objects that dimmed between ~1980 and ~1990 are still (or are again) broad-line AGNs rather than“changing-look” candidates that have more subtle AGN signatures in their spectra — despite the fact that none of the sources examined thus far has returned to its highest observed luminosity. Future X-ray observations will provide the opportunity to characterize the X-ray behavior of these anonymous, extreme AGNs over a four decade span.

  3. Simulating deep surveys of the Galactic Plane with the Advanced Gamma-ray Imaging System (AGIS)

    Science.gov (United States)

    Funk, Stefan; Digel, Seth

    2009-05-01

    The pioneering survey of the Galactic plane by H.E.S.S., together with the northern complement now underway with VERITAS, has shown the inner Milky Way to be rich in TeV-emitting sources; new source classes have been found among the H.E.S.S. detections and unidentified sources remain. In order to explore optimizations of the design of an Advanced Gamma-ray Imaging System (AGIS)-like instrument for survey science, we constructed a model of the flux and size distributions of Galactic TeV sources, normalized to the H.E.S.S. sources but extrapolated to lower flux levels. We investigated potential outcomes from a survey with the order of magnitude improvement in sensitivity and attendant improvement in angular resolution planned for AGIS. Studies of individual sources and populations found with such a sensitivity survey will advance understanding of astrophysical particle acceleration, source populations, and even high-energy cosmic rays via detection of the low-level TeV diffuse emission in regions of high cosmic-ray densitiy.

  4. Improving fault image by determination of optimum seismic survey parameters using ray-based modeling

    Science.gov (United States)

    Saffarzadeh, Sadegh; Javaherian, Abdolrahim; Hasani, Hossein; Talebi, Mohammad Ali

    2018-06-01

    In complex structures such as faults, salt domes and reefs, specifying the survey parameters is more challenging and critical owing to the complicated wave field behavior involved in such structures. In the petroleum industry, detecting faults has become crucial for reservoir potential where faults can act as traps for hydrocarbon. In this regard, seismic survey modeling is employed to construct a model close to the real structure, and obtain very realistic synthetic seismic data. Seismic modeling software, the velocity model and parameters pre-determined by conventional methods enable a seismic survey designer to run a shot-by-shot virtual survey operation. A reliable velocity model of structures can be constructed by integrating the 2D seismic data, geological reports and the well information. The effects of various survey designs can be investigated by the analysis of illumination maps and flower plots. Also, seismic processing of the synthetic data output can describe the target image using different survey parameters. Therefore, seismic modeling is one of the most economical ways to establish and test the optimum acquisition parameters to obtain the best image when dealing with complex geological structures. The primary objective of this study is to design a proper 3D seismic survey orientation to achieve fault zone structures through ray-tracing seismic modeling. The results prove that a seismic survey designer can enhance the image of fault planes in a seismic section by utilizing the proposed modeling and processing approach.

  5. Survey on ground water by gamma-ray measurement in civil engineering works

    Energy Technology Data Exchange (ETDEWEB)

    Ochiai, T [Nihon Norin Helicopter Co., Ltd., Tokyo

    1982-01-01

    In the fractured zones where ground water exists, the water permeability is generally large, so that the radioactive elements in the depths of the earth rise relatively easily. The high intensity of the gamma-ray from such elements is thus exhibited in the air. A survey on ground water made possible in this way by the aerial method using a helicopter is described. The method has various advantages including the free setting of courses of traverse, low-speed flying at low altitude, which raises the survey accuracy, communication with those on the ground by easy landing, and reduction in survey time. As actual instances, the following surveys are given: mountainous tunnel and water gushing, the permeability of a dam foundation, fractured zones such as collapse and landslide, and mountainous water sources.

  6. A survey on ground water by gamma-ray measurement in civil engineering works

    International Nuclear Information System (INIS)

    Ochiai, Toshio

    1982-01-01

    In the fractured zones where ground water exists, the water permeability is generally large, so that the radioactive elements in the depths of the earth rise relatively easily. The high intensity of the gamma-ray from such elements is thus exhibited in the air. A survey on ground water made possible in this way by the aerial method using a helicopter is described. The method has various advantages including the free setting of courses of traverse, low-speed flying at low altitude, which raises the survey accuracy, communication with those on the ground by easy landing, and reduction in survey time. As actual instances, the following surveys are given: mountainous tunnel and water gushing, the permeability of a dam foundation, fractured zones such as colapse and landslide, and mountainous water sources. (J.P.N.)

  7. The use of car-borne gamma-ray spectrometric survey in a basin

    International Nuclear Information System (INIS)

    Liu Tengyao; Lu Shili; Luo Zongquan.

    1985-01-01

    This paper describes the geological results in a basin in the Inner Mongolia which were obtained by using our newly-developed and assembled car-borne gamma-ray spectrometric system. Combined with the work of regional geology and remote sensing, five relatively favourable uranium zones were located within the working area. The field procedures of car-borne gamma-ray spectrometry for less rigid regions is discussed. The gamma-ray spectrometric profiling is mainly used for regional reconnaissance. In the case of enhanced anomalious radioactivity the profiling with varying directions is adopted and the data are plotted on scale 1:50000 topographic map. It is suggested that the car-borne gamma-ray spectrometric system can be calibrated both by the pads specified for portable spectrometers and by testing site when the calibration facility for the car-borne gamma-ray spectrometric system is not available. The effect of rainfall on car-borne gamma-ray spectrometric survey and the simplified field qualitative determination of U-Ra disequilibrium are also briefly discussed

  8. The one square meter hard X-ray (15-200 KeV) sky survey

    International Nuclear Information System (INIS)

    Ubertini, P.; Bazzano, A.; La Padula, C.D.; Polcaro, V.F.

    1981-01-01

    A long term program was started at I.A.S. since 1979 to perform a survey of the hard X-ray sky using multiwire high pressure Xenon filled Spectroscopic Proportional Counters (SPC). The first payload consisting of two very large area SPC (2,700 cm 2 each) was flown during summer 1980 from the Milo Base (Sicily, Italy). The instrument duplicated to reach 10,800 cm 2 geometric area is expected to fly from northern (1981), southern (1982) and equatorial (1983) bases to perform a deep sky survey

  9. ULTRAVIOLET EXTINCTION AT HIGH GALACTIC LATITUDES

    Energy Technology Data Exchange (ETDEWEB)

    Peek, J. E. G.; Schiminovich, David, E-mail: jegpeek@gmail.com [Department of Astronomy, Columbia University, New York, NY (United States)

    2013-07-01

    In order to study the properties and effects of high Galactic latitude dust, we present an analysis of 373,303 galaxies selected from the Galaxy Evolution Explorer All-Sky Survey and Wide-field Infrared Explorer All-Sky Data Release. By examining the variation in aggregate ultraviolet colors and number density of these galaxies, we measure the extinction curve at high latitude. We additionally consider a population of spectroscopically selected galaxies from the Sloan Digital Sky Survey to measure extinction in the optical. We find that dust at high latitude is neither quantitatively nor qualitatively consistent with standard reddening laws. Extinction in the FUV and NUV is {approx}10% and {approx}35% higher than expected, with significant variation across the sky. We find that no single R{sub V} parameter fits both the optical and ultraviolet extinction at high latitude, and that while both show detectable variation across the sky, these variations are not related. We propose that the overall trends we detect likely stem from an increase in very small silicate grains in the interstellar medium.

  10. ULTRAVIOLET EXTINCTION AT HIGH GALACTIC LATITUDES

    International Nuclear Information System (INIS)

    Peek, J. E. G.; Schiminovich, David

    2013-01-01

    In order to study the properties and effects of high Galactic latitude dust, we present an analysis of 373,303 galaxies selected from the Galaxy Evolution Explorer All-Sky Survey and Wide-field Infrared Explorer All-Sky Data Release. By examining the variation in aggregate ultraviolet colors and number density of these galaxies, we measure the extinction curve at high latitude. We additionally consider a population of spectroscopically selected galaxies from the Sloan Digital Sky Survey to measure extinction in the optical. We find that dust at high latitude is neither quantitatively nor qualitatively consistent with standard reddening laws. Extinction in the FUV and NUV is ∼10% and ∼35% higher than expected, with significant variation across the sky. We find that no single R V parameter fits both the optical and ultraviolet extinction at high latitude, and that while both show detectable variation across the sky, these variations are not related. We propose that the overall trends we detect likely stem from an increase in very small silicate grains in the interstellar medium.

  11. Trends in x-ray photography and patient exposure dose. Questionnaire survey results compared with those in 1973. [questionnaire survey in 1979

    Energy Technology Data Exchange (ETDEWEB)

    Orito, T; Sanada, S; Maekawa, R; Koshida, K; Hiraki, T [Kanazawa Univ. (Japan). School of Paramedicine

    1980-04-01

    The exposure doses of patients in X-ray photography are influenced by such technological factors as X-ray tube voltage, filter, sensitizing screen, film and grid. Survey by questionnnaire was made previously in 1973 on the above factors. The trends five years after were surveyed similarly, in connection with the exposure doses of patients. Questionnaires were sent to 200 radiation technicians, and 121 (60.5%) answered the survey in March, 1979. The results in the cases of simple X-ray photography and obstetric, infant and breast X-ray photographings are described. X-ray tube voltage is generally on the increase. In the sensitizing screens, exposure doses are fairly decreased due to the use of improved intensifying screen (LT-II). In the grid, the ratio 8 : 1 is used more than 5 : 1. In the usage of additional filters and in the distance of photography, improvements are desired.

  12. Deep Chandra Survey of the Small Magellanic Cloud. II. Timing Analysis of X-Ray Pulsars

    Energy Technology Data Exchange (ETDEWEB)

    Hong, JaeSub; Antoniou, Vallia; Zezas, Andreas; Drake, Jeremy J.; Plucinsky, Paul P. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Haberl, Frank [Max-Planck-Institut für extraterrestrische Physik, Giessenbach straße, D-85748 Garching (Germany); Sasaki, Manami [Friedrich-Alexander-Universität Erlangen-Nürnberg, Sternwartstrasse 7, 96049 Bamberg (Germany); Laycock, Silas, E-mail: jaesub@head.cfa.harvard.edu [Department of Physics, University of Massachusetts Lowell, MA 01854 (United States)

    2017-09-20

    We report the timing analysis results of X-ray pulsars from a recent deep Chandra survey of the Small Magellanic Cloud (SMC). We analyzed a total exposure of 1.4 Ms from 31 observations over a 1.2 deg{sup 2} region in the SMC under a Chandra X-ray Visionary Program. Using the Lomb–Scargle and epoch-folding techniques, we detected periodic modulations from 20 pulsars and a new candidate pulsar. The survey also covered 11 other pulsars with no clear sign of periodic modulation. The 0.5–8 keV X-ray luminosity ( L {sub X} ) of the pulsars ranges from 10{sup 34} to 10{sup 37} erg s{sup −1} at 60 kpc. All of the Chandra sources with L {sub X} ≳ 4 × 10{sup 35} erg s{sup −1} exhibit X-ray pulsations. The X-ray spectra of the SMC pulsars (and high-mass X-ray binaries) are in general harder than those of the SMC field population. All but SXP 8.02 can be fitted by an absorbed power-law model with a photon index of Γ ≲ 1.5. The X-ray spectrum of the known magnetar SXP 8.02 is better fitted with a two-temperature blackbody model. Newly measured pulsation periods of SXP 51.0, SXP 214, and SXP 701, are significantly different from the previous XMM-Newton and RXTE measurements. This survey provides a rich data set for energy-dependent pulse profile modeling. Six pulsars show an almost eclipse-like dip in the pulse profile. Phase-resolved spectral analysis reveals diverse spectral variations during pulsation cycles: e.g., for an absorbed power-law model, some exhibit an (anti)-correlation between absorption and X-ray flux, while others show more intrinsic spectral variation (i.e., changes in photon indices).

  13. Characterization of leveling problems of Patagonia gamma-ray spectrometry survey, Chubut province (Argentina)

    International Nuclear Information System (INIS)

    Ford, Kenneth L.; Lopez, Luis E.

    1998-01-01

    Measuring the radioelement concentrations of the soils along traverses perpendicular to the flight line direction was performed in order to gather useful information in support of the leveling of the airborne gamma-ray spectrometer survey of Patagonia. Two sites were selected as test areas which ground and airborne spectrometric data were systematically compared to asses the nature of the leveling problems. It is suspected that variations in soil moisture may play a significant roll in the leveling variations. (author)

  14. Airborne gamma-ray spectrometer and magnetometer survey, Sagavanirktok Quadrangle, Alaska. Volume I. Final report

    International Nuclear Information System (INIS)

    1981-03-01

    The results obtained from an airborne high sensitivity gamma-ray spectrometer and magnetometer survey over the Sagavanirktok map area of Alaska are presented. Based on the criteria outlined in the general section on interpretation, a total of eight uranium anomalies have been outlined on the interpretation map. However, all of these zones are only weakly to moderately anomalous. None are thought to be indicative of local enrichment of uranium to economically significant levels. No follow-up work is recommended

  15. The 105-Month Swift-BAT All-sky Hard X-Ray Survey

    Science.gov (United States)

    Oh, Kyuseok; Koss, Michael; Markwardt, Craig B.; Schawinski, Kevin; Baumgartner, Wayne H.; Barthelmy, Scott D.; Cenko, S. Bradley; Gehrels, Neil; Mushotzky, Richard; Petulante, Abigail; Ricci, Claudio; Lien, Amy; Trakhtenbrot, Benny

    2018-03-01

    We present a catalog of hard X-ray sources detected in the first 105 months of observations with the Burst Alert Telescope (BAT) coded-mask imager on board the Swift observatory. The 105-month Swift-BAT survey is a uniform hard X-ray all-sky survey with a sensitivity of 8.40× {10}-12 {erg} {{{s}}}-1 {cm}}-2 over 90% of the sky and 7.24× {10}-12 {erg} {{{s}}}-1 {cm}}-2 over 50% of the sky in the 14–195 keV band. The Swift-BAT 105-month catalog provides 1632 (422 new detections) hard X-ray sources in the 14–195 keV band above the 4.8σ significance level. Adding to the previously known hard X-ray sources, 34% (144/422) of the new detections are identified as Seyfert active galactic nuclei (AGNs) in nearby galaxies (zBAT catalog, we release eight-channel spectra and monthly sampled light curves for each object in the online journal and at the Swift-BAT 105-month website.

  16. Research on 3-D terrain correction methods of airborne gamma-ray spectrometry survey

    International Nuclear Information System (INIS)

    Liu Yanyang; Liu Qingcheng; Zhang Zhiyong

    2008-01-01

    The general method of height correction is not effectual in complex terrain during the process of explaining airborne gamma-ray spectrometry data, and the 2-D terrain correction method researched in recent years is just available for correction of section measured. A new method of 3-D sector terrain correction is studied. The ground radiator is divided into many small sector radiators by the method, then the irradiation rate is calculated in certain survey distance, and the total value of all small radiate sources is regarded as the irradiation rate of the ground radiator at certain point of aero- survey, and the correction coefficients of every point are calculated which then applied to correct to airborne gamma-ray spectrometry data. The method can achieve the forward calculation, inversion calculation and terrain correction for airborne gamma-ray spectrometry survey in complex topography by dividing the ground radiator into many small sectors. Other factors are considered such as the un- saturated degree of measure scope, uneven-radiator content on ground, and so on. The results of for- ward model and an example analysis show that the 3-D terrain correction method is proper and effectual. (authors)

  17. Optical and x-ray survey of s-type Markarian galaxies

    International Nuclear Information System (INIS)

    Hutter, D.J.; Mufson, S.L.

    1981-01-01

    We report here the results of a study of 23 compact, lineless Markarian galaxies using broadband optical photometry and x-ray satellite observations. Our photometry shows that the sample can be broken into four groups. In one group (Mrk 180, 421, and 501) are composite objects in which a BL Lacertae object is embedded in an elliptical galaxy. For this group, we present the results of multiepoch x-ray observations using the HEAO-1 and -2 satellites. In addition, we use our photometry to decompose the optical emission into nonthermal and galactic components. In the second group are objects showing a small ultraviolet excess relative to normal galaxies. The x-ray survey indicates that the x-ray luminosity of objects in group 2 is much lower than those in group 1. This suggests that there is an intrinsic difference between objects in groups 1 and 2. The third and fourth groups are objects whose colors are indistinguishable from those of normal field galaxies and those of galactic stars, respectively. No x-ray emission was detected from objects in either of these groups

  18. High latitude ionospheric structure

    International Nuclear Information System (INIS)

    1984-06-01

    The Earth's ionosphere is an important element in solar-terrestrial energy transfer processes. As a major terrestrial sink for many solar and magnetospheric events, the ionosphere has characteristic features that are traced to such seemingly remote phenomena as solar flares, radiation belt wave-particle interactions and magnetospheric substorms. In considering the multiple of solar-terrestrial plasma interactions, it is important to recognize that the high-latitude ionosphere is not altogether a simple receptor of various energy deposition processes. The high-altitude ionosphere plays an active feedback role by controlling the conductivity at the base of far-reaching magnetic field lines and by providing a plasma source for the magnetosphere. Indeed, the role of the ionosphere during magnetospheric substorms is emerging as a topic for meaningful study in the overall picture of magnetospheric-ionospheric coupling

  19. The CfA Einstein Observatory extended deep X-ray survey

    Science.gov (United States)

    Primini, F. A.; Murray, S. S.; Huchra, J.; Schild, R.; Burg, R.

    1991-01-01

    All IPC exposures in the Einstein Extended Deep X-ray Survey program have been reanalyzed. The current survey covers about 2.3 sq deg with a typical limiting sensitivity of about 5 x 10 to the -14th ergs/sq cm/s in the energy range from 0.8-3.5 keV. A total of 25 IPC sources are detected above a threshold of 4.5 sigma. A total of 18 are detected independently in the HRI, leading to the identification of six with stars and 11 with extragalactic objects. The remaining sources are classified as extragalactic. The population of identified extragalactic objects is dominated by QSOs, with one or two possible clusters. The basic conclusions of the original survey remain unchanged.

  20. Survey of radiation doses and health effects in medical diagnostic X-ray workers in China

    International Nuclear Information System (INIS)

    Wang Jixian; Zhang Liangan; Liu Jinzhong; Zhang Jingyuan

    1984-01-01

    The results of a nationwide survey of radiation doses and health effects in 26983 medical diagnostic X-ray workers in 28 provinces of China were reported. The control group was composed of 25785 non-X-ray medical workers in the same hospitals where the investigated X-ray workers worked. Of the radiological workers surveyed 75.3% received cumulative radiation doses below 50 mGy, only 2.7% received doses greater than 500 mGy, the average cumulative dose being 45.0 mGy. The average length of service was 11 years. The main radiation effects relating to radiation doses were the increase of frequencies of both chromosomal aberrations and micronuclei in peripheral blood lymphocytes, which were 0.362% and 0.0358% in the irradiated group, and 0.122% and 0.0138% in the control group, respectively. The incidence and mortality rate of leukemias increased significantly in the irradiated group. The incidence and standardized incidence of leukemias were 9.61 . 10 -5 and 9.67 . 10 -5 in the irradiated group and 2.74 . 10 -5 and 2.77 . 10 -5 in the control group. The leukemia mortality rates in the two groups were 8.60 . 10 -5 and 1.24 . 10 -5 respectively, and the standardized mortality rates were 8.60 . 10 -5 and 1.27 . 10 -5 respectively. (Author)

  1. Report based on fiscal 2000 diagnostic X-ray equipment questionnaire survey. Conditions of radiography

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, Mitsuo [Kitasato Univ., Sagamihara, Kanagawa (Japan). School of Allied Health Sciences; Matsuura, Takatoshi [Sekishinkai Sayama Hospital, Saitama (Japan); Okuaki, Tomoyuki; Imai, Yoshio; Tsukamoto, Atsuko [Kanto Medical Center NTT EC, Tokyo (Japan); Ide, Toshinori [Kajima Corp., Tokyo (Japan). Kajima Clinic; Shinohara, Fuminori [Nippon Medical School, Kawasaki, Kanagawa (Japan). Second Hospital; Miyazaki, Shigeru [Toho Univ., Tokyo (Japan). Ohashi Hospital

    2002-08-01

    X-ray equipment has seen advances in inverters and the digitalization of reception systems. The X-ray Systems Study Group, in order to examine changes in the conditions of radiography, including pediatric radiography, variations in shortest irradiation time, and standardization of the conditions of radiography, carried out investigative research using a questionnaire survey that was sent to 400 facilities. The recovery rate was 33%. In terms of the reception system, half of the general radiography systems were using computed radiography (CR). Seventy percent of respondents used an intensifying screen and film (SEF) in stomach double-contrast radiography. About 80% used digital radiography (DR) and digital subtraction angiography (DSA) in aorta abdominalis angiography. At least 70% of high-voltage generators were of the inverter type. The conditions of radiography were not greatly influenced by changes in reception systems and X-ray equipment. Many pediatric radiographies were carried out by radiological technologists. We consider it useful to conduct such survey investigations. (author)

  2. [Report based on fiscal 2000 diagnostic x-ray equipment questionnaire survey(conditions of radiography)].

    Science.gov (United States)

    Ishikawa, Mitsuo; Matsuura, Takatoshi; Okuaki, Tomiyuki; Imai, Yoshio; Tsukamoto, Atsuko; Ide, Toshinori; Shinohara, Fuminori; Miyazaki, Shigeru

    2002-08-01

    X-ray equipment has seen advances in inverters and the digitalization of reception systems. The X-ray Systems Study Group, in order to examine changes in the conditions of radiography, including pediatric radiography, variations in shortest irradiation time, and standardization of the conditions of radiography, carried out investigative research using a questionnaire survey that was sent to 400 facilities. The recovery rate was 33%. In terms of the reception system, half of the general radiography systems were using computed radiography (CR). Seventy percent of respondents used an intensifying screen and film(S EF)in stomach double-contrast radiography. About 80% used digital radiography (DR) and digital subtraction angiography (DSA) in aorta abdominalis angiography. At least 70% of high-voltage generators were of the inverter type. The conditions of radiography were not greatly influenced by changes in reception systems and X-ray equipment. Many pediatric radiographies were carried out by radiological technologists. We consider it useful to conduct such survey investigations.

  3. The Global Survey Method Applied to Ground-level Cosmic Ray Measurements

    Science.gov (United States)

    Belov, A.; Eroshenko, E.; Yanke, V.; Oleneva, V.; Abunin, A.; Abunina, M.; Papaioannou, A.; Mavromichalaki, H.

    2018-04-01

    The global survey method (GSM) technique unites simultaneous ground-level observations of cosmic rays in different locations and allows us to obtain the main characteristics of cosmic-ray variations outside of the atmosphere and magnetosphere of Earth. This technique has been developed and applied in numerous studies over many years by the Institute of Terrestrial Magnetism, Ionosphere and Radiowave Propagation (IZMIRAN). We here describe the IZMIRAN version of the GSM in detail. With this technique, the hourly data of the world-wide neutron-monitor network from July 1957 until December 2016 were processed, and further processing is enabled upon the receipt of new data. The result is a database of homogeneous and continuous hourly characteristics of the density variations (an isotropic part of the intensity) and the 3D vector of the cosmic-ray anisotropy. It includes all of the effects that could be identified in galactic cosmic-ray variations that were caused by large-scale disturbances of the interplanetary medium in more than 50 years. These results in turn became the basis for a database on Forbush effects and interplanetary disturbances. This database allows correlating various space-environment parameters (the characteristics of the Sun, the solar wind, et cetera) with cosmic-ray parameters and studying their interrelations. We also present features of the coupling coefficients for different neutron monitors that enable us to make a connection from ground-level measurements to primary cosmic-ray variations outside the atmosphere and the magnetosphere. We discuss the strengths and weaknesses of the current version of the GSM as well as further possible developments and improvements. The method developed allows us to minimize the problems of the neutron-monitor network, which are typical for experimental physics, and to considerably enhance its advantages.

  4. X-ray and optical substructures of the DAFT/FADA survey clusters

    Science.gov (United States)

    Guennou, L.; Durret, F.; Adami, C.; Lima Neto, G. B.

    2013-04-01

    We have undertaken the DAFT/FADA survey with the double aim of setting constraints on dark energy based on weak lensing tomography and of obtaining homogeneous and high quality data for a sample of 91 massive clusters in the redshift range 0.4-0.9 for which there were HST archive data. We have analysed the XMM-Newton data available for 42 of these clusters to derive their X-ray temperatures and luminosities and search for substructures. Out of these, a spatial analysis was possible for 30 clusters, but only 23 had deep enough X-ray data for a really robust analysis. This study was coupled with a dynamical analysis for the 26 clusters having at least 30 spectroscopic galaxy redshifts in the cluster range. Altogether, the X-ray sample of 23 clusters and the optical sample of 26 clusters have 14 clusters in common. We present preliminary results on the coupled X-ray and dynamical analyses of these 14 clusters.

  5. Reconstructing the Gamma-Ray Photon Optical Depth of the Universe To Z Approx. 4 from Multiwavelength Galaxy Survey Data

    Science.gov (United States)

    Helgason, Kari; Kashlinsky, Alexander

    2012-01-01

    Reconstructing the Gamma-Ray Photon Optical Depth of the Universe To Z Approx. 4fFrom Multiwavelength Galaxy Survey Data We reconstruct the gamma-ray opacity of the universe out to z approx. photons already at z approx. < 0.2 and reaching tau approx 10 at z = 1. Comparing with the currently available Fermi/LAT gamma-ray burst and blazar data shows that there is room for significant emissions originating in the first stars era.

  6. The third IBIS/ISGRI soft gamma-ray survey catalog

    International Nuclear Information System (INIS)

    Bird, A.J.; Barlow, E.J.; Hill, A.B.; Clark, D.J.; Dean, A.J.; Molina, M.; Sguera, V.; Malizia, A.; Bassani, L.; Capitanio, F.; Stephen, J.B.; Bazzano, A.; Fiocchi, M.; Ubertini, P.; Belanger, G.; Gotz, D.; Lebrun, F.; Renaud, M.; Zurita, J.; Produit, N.; Produit, N.; Walter, R.; Terrier, R.; Walter, R.; Winkler, C.

    2007-01-01

    In this paper we report on the third soft gamma-ray source catalog obtained with the IBIS/ISGRI gamma-ray imager on board the INTEGRAL satellite. The scientific data set is based on more than 40 Ms of high-quality observations performed during the first 3.5 yr of Core Program and public IBIS/ISGRI observations. Compared to previous IBIS/ISGRI surveys, this catalog includes a substantially increased coverage of extragalactic fields, and comprises more than 400 high-energy sources detected in the energy range 17-100 keV, including both transients and faint persistent objects that can only be revealed with longer exposure times. (authors)

  7. AGN Populations in Large-volume X-Ray Surveys: Photometric Redshifts and Population Types Found in the Stripe 82X Survey

    Science.gov (United States)

    Ananna, Tonima Tasnin; Salvato, Mara; LaMassa, Stephanie; Urry, C. Megan; Cappelluti, Nico; Cardamone, Carolin; Civano, Francesca; Farrah, Duncan; Gilfanov, Marat; Glikman, Eilat; Hamilton, Mark; Kirkpatrick, Allison; Lanzuisi, Giorgio; Marchesi, Stefano; Merloni, Andrea; Nandra, Kirpal; Natarajan, Priyamvada; Richards, Gordon T.; Timlin, John

    2017-11-01

    Multiwavelength surveys covering large sky volumes are necessary to obtain an accurate census of rare objects such as high-luminosity and/or high-redshift active galactic nuclei (AGNs). Stripe 82X is a 31.3 X-ray survey with Chandra and XMM-Newton observations overlapping the legacy Sloan Digital Sky Survey Stripe 82 field, which has a rich investment of multiwavelength coverage from the ultraviolet to the radio. The wide-area nature of this survey presents new challenges for photometric redshifts for AGNs compared to previous work on narrow-deep fields because it probes different populations of objects that need to be identified and represented in the library of templates. Here we present an updated X-ray plus multiwavelength matched catalog, including Spitzer counterparts, and estimated photometric redshifts for 5961 (96% of a total of 6181) X-ray sources that have a normalized median absolute deviation, σnmad=0.06, and an outlier fraction, η = 13.7%. The populations found in this survey and the template libraries used for photometric redshifts provide important guiding principles for upcoming large-area surveys such as eROSITA and 3XMM (in X-ray) and the Large Synoptic Survey Telescope (optical).

  8. Airborne gamma-ray spectrometer and magnetometer survey: Harrison Bay Quadrangle, Alaska. Final report, Volume 1

    International Nuclear Information System (INIS)

    1981-02-01

    During the months of July and August of 1980, Aero Service Division Western Geophysical Company of America conducted an airborne high sensitivity gamma-ray spectrometer and magnetometer survey over eleven (11) 3 0 x 1 0 and one (1) 4 0 x 1 0 NTMS quadrangles of the Alaska North Slope. These include the Barrow, Wainwright, Meade River, Teshekpuk, Harrison Bay, Beechey Point, Point Lay, Utukok River, Lookout Ridge, Ikpikpuk River, Umiat, and Sagavanirktok quadrangles. This report discusses the results obtained over the Harrison Bay map area

  9. Airborne gamma-ray spectrometer and magnetometer survey: Aberdeen quadrangle, South Dakota. Final report

    International Nuclear Information System (INIS)

    1981-04-01

    During the months of June through October, 1980, Aero Service Division Western Geophysical Company of America conducted an airborne high sensitivity gamma-ray spectrometer and magnetometer survey over eleven (11) 2 0 x 1 0 NTMS quadrangles located in the states of Minnesota and Wisconsin and seven (7) 2 0 x 1 0 NTMS quadrangles in North and South Dakota. This report discusses the results obtained over the Aberdeen, South Dakota map area. The final data are presented in four different forms: on magnetic tape; on microfiche; in graphic form as profiles and histograms; and in map form as anomaly maps, flight path maps, and computer printer maps

  10. Airborne gamma-ray spectrometer and magnetometer survey: north/south tieline. Final report

    International Nuclear Information System (INIS)

    1981-05-01

    An airborne high sensitivity gamma-ray spectrometer and magnetometer survey was conducted along the 99 0 longitude meridian from the Canadian border southward to the Mexican border. A total of 1555 line miles of geophysical data were acquired and, subsequently, compiled. The north-south tieline was flown as part of the National Uranium Resources Evaluation. NURE is a program of the US Department of Energy's Grand Junction, Colorado, office to acquire and compile geologic and other information with which to assess the magnitude and distribution of uranium resources and to determine areas favorable for the occurrence of uranium in the United States

  11. Airborne gamma-ray spectrometer and magnetometer survey, Point Lay Quadrangle, Alaska. Volume I. Final report

    International Nuclear Information System (INIS)

    1981-02-01

    The results obtained from an airborne high sensitivity gamma-ray spectrometer and magnetometer survey over the Point Lay map area of Alaska are presented. Based on the criteria outlined in the general section on interpretation, a total of six uranium anomalies have been indicated on the interpretation map. All six are only weakly to moderately anomalous in either uranium or the uranium ratios. None of these are thought to be of any economic significance. No follow-up work is recommended for the Point Lay Quadrangle

  12. Survey of Antibiotic-producing Bacteria Associated with the Epidermal Mucus Layers of Rays and Skates

    Directory of Open Access Journals (Sweden)

    Kim B. Ritchie

    2017-07-01

    Full Text Available Elasmobranchs represent a distinct group of cartilaginous fishes that harbor a remarkable ability to heal wounds rapidly and without infection. To date very little work has addressed this phenomenon although it is suggested that antibiotic capabilities associated with epidermal surfaces may be a factor. The study of benefits derived from mutualistic interactions between unicellular and multicellular organisms is a rapidly growing area of research. Here we survey and identify bacterial associates of three ray and one skate species in order to assess the potential for antibiotic production from elasmobranch associated bacteria as a novel source for new antibiotics.

  13. Airborne gamma-ray spectrometer and magnetometer survey, Wainwright Quadrangle, Alaska. Final report

    International Nuclear Information System (INIS)

    1981-03-01

    The results obtained from a gamma-ray spectrometer and magnetometer survey over the Wainwright map area of Alaska are presented. Based on the criteria outlined in the general section of interpretation, a total of seven uranium anomalies have been outlined on the interpretation map. With the exception of Anomaly 1, all are located over the higher terrain of the foothills in the southern portion of the quadrangle. All seven anomalies are only weakly to moderately anomalous. There are no indications anywhere within the area of any significant preferential accumulations of uranium. None of the anomalies are thought to be of any economic importance. No follow-up work is recommended

  14. Airborne gamma-ray spectrometer and magnetometer survey, Meade River Quadrangle, Alaska. Final report

    International Nuclear Information System (INIS)

    1981-02-01

    The results obtained from an airborne high sensitivity gamma-ray spectrometer and magnetometer survey over the Meade River map area of Alaska are presented. Based on the criteria outlined in the general section on interpretation, a total of eight uranium anomalies have been outlined on the interpretation map. Most of these are only weakly to moderately anomalous. Zones 3 and 7 are relatively better than the others though none of the anomalies are thought to be of any economic significance. No follow-up work is recommended

  15. Airborne gamma-ray spectrometer and magnetometer survey, Devils Lake quadrangle, North Dakota. Final report

    International Nuclear Information System (INIS)

    1981-05-01

    During the months of June through October, 1980, Aero Service Division Western Geophysical Company of America conducted an airborne high sensitivity gamma-ray spectrometer and magnetometer survey over eleven (11) 2 0 x 1 0 NTMS quadrangles located in the states of Minnesota and Wisconsin and seven (7) 2 0 x 1 0 NTMS quadrangles in North and South Dakota. This report discusses the results obtained over the Devil's Lake map area of North Dakota. The final data are presented in four different forms: on magnetic tape; on microfiche; in graphic form as profiles and histograms; and in map form as anomaly maps, flight path maps, and computer printer maps

  16. Two survey meters for measuring low γ-ray dose rates

    International Nuclear Information System (INIS)

    Jones, A.R.

    1979-01-01

    Two low-level survey meters have been developed which have numerical displays. The first is of the light-emitting diode (LED) type. The second is a liquid crystal display (LCD). The design of both instruments is described and results of measurements of performance are presented. They measure γ dose rates from background up to 2 mrad/h (20 μGy/h) for γ-rays in the energy range 0.05-1.25 MeV. They can be used at temperatures between -20 deg C and +50 deg C. Statistical accuracy and battery life both depend upon a number of factors and this dependence is shown. A later section describes the intended application of the survey meters. An appendix describes the circuit adjustments which are necessary and when they must be made. (author)

  17. The Swift Gamma-Ray Burst Host Galaxy Legacy Survey. I. Sample Selection and Redshift Distribution

    Science.gov (United States)

    Perley, D. A.; Kruhler, T.; Schulze, S.; Postigo, A. De Ugarte; Hjorth, J.; Berger, E.; Cenko, S. B.; Chary, R.; Cucchiara, A.; Ellis, R.; hide

    2016-01-01

    We introduce the Swift Gamma-Ray Burst Host Galaxy Legacy Survey (SHOALS), a multi-observatory high redshift galaxy survey targeting the largest unbiased sample of long-duration gamma-ray burst (GRB) hosts yet assembled (119 in total). We describe the motivations of the survey and the development of our selection criteria, including an assessment of the impact of various observability metrics on the success rate of afterglow-based redshift measurement. We briefly outline our host galaxy observational program, consisting of deep Spitzer/IRAC imaging of every field supplemented by similarly deep, multicolor optical/near-IR photometry, plus spectroscopy of events without preexisting redshifts. Our optimized selection cuts combined with host galaxy follow-up have so far enabled redshift measurements for 110 targets (92%) and placed upper limits on all but one of the remainder. About 20% of GRBs in the sample are heavily dust obscured, and at most 2% originate from z > 5.5. Using this sample, we estimate the redshift-dependent GRB rate density, showing it to peak at z approx. 2.5 and fall by at least an order of magnitude toward low (z = 0) redshift, while declining more gradually toward high (z approx. 7) redshift. This behavior is consistent with a progenitor whose formation efficiency varies modestly over cosmic history. Our survey will permit the most detailed examination to date of the connection between the GRB host population and general star-forming galaxies, directly measure evolution in the host population over cosmic time and discern its causes, and provide new constraints on the fraction of cosmic star formation occurring in undetectable galaxies at all redshifts.

  18. Interpretation of aerial gamma-ray surveys - adding the geochemical factors

    International Nuclear Information System (INIS)

    Dickson, B.L.; Scott, K.M.

    1997-01-01

    Aerial gamma-ray surveying reflects the geochemical variations of potassium, uranium and thorium in the upper 30 cm of the Earth's surface. This thin layer is subject to the effects of weathering, which leads to loss of K in all rock types and, for felsic rocks, loss of U and Th as well. The extent of the loss depends on many factors, but is typically 20-30 per cent for all three radioelements. Intermediate and basic rocks show little change in radioelement concentrations during initial weathering, but pedogenesis can result in soils with 2-3 times the U and Th content of the parent rock. However, wide ranges in radioelement compositions occur for a given rock type and its weathered products. Mineralizing processes can also affect radioelement contents. For example, K is increased in altered rocks at the Copper Hill and Goonumbla porphyry Cu deposits in central NSW. Thorium concentration shows both depletion and enrichment during hydrothermal alteration, as illustrated by the Au prospects at Bimurra, in northeast Queensland. Uranium is even more erratically affected by alteration and is generally not a useful indicator of alteration. Regolith processes can affect these alteration signatures. Highly weathered deposits may lose their K, particularly if hosted by K-feldspar, as at Goonumbla. Transported soils may disguise or change rock signatures often in unexpected ways. The Mt Leyshon gold deposit, in north Queensland, is seen in the aerial survey as a K-rich area because its signature is not contaminated by material weathered from late-Silurian dolerites. Detailed interpretation of aerial gamma-ray surveys for exploration purposes requires the delineation of the major geological units of the survey area, then examination of the subtle variations within the most prospective units, aided by other data sets and field checking of the anomalous areas identified. 42 refs.,2 tabs., 13 figs

  19. Determining the nature of faint X-ray sources from the ASCA Galactic center survey

    Science.gov (United States)

    Lutovinov, A. A.; Revnivtsev, M. G.; Karasev, D. I.; Shimansky, V. V.; Burenin, R. A.; Bikmaev, I. F.; Vorob'ev, V. S.; Tsygankov, S. S.; Pavlinsky, M. N.

    2015-05-01

    We present the results of the the identification of six objects from the ASCA Galactic center and Galactic plane surveys: AX J173548-3207, AX J173628-3141, AX J1739.5-2910, AX J1740.4-2856, AX J1740.5-2937, and AX J1743.9-2846. Chandra, XMM-Newton, and XRT/Swift X-ray data have been used to improve the positions of the optical counterparts to these sources. Thereafter, we have carried out a series of spectroscopic observations of the established optical counterparts at the RTT-150 telescope. Analysis of X-ray and optical spectra as well as photometric measurements in a wide wavelength range based on optical and infrared catalogs has allowed the nature of the program sources to be determined. Two X-ray objects have been detected in the error circle of AX J173628-3141: one is a coronally active G star and the other may be a symbiotic star, a red giant with an accreting white dwarf. Three sources (AX J1739.5-2910, AX J1740.5-2937, AX J1743.9-2846) have turned out to be active G-K stars, presumably RS CVn objects, one (AX J1740.4-2856) is an M dwarf, and another one (AX J173548-3207) most likely a low-mass X-ray binary in its low state. The distances and corresponding luminosities of the sources in the soft X-ray band (0.5-10 keV) have been estimated; analysis of deep INTEGRAL Galactic center observations has not revealed a statistically significant flux at energies >20 keV from any of them.

  20. ABCC-JNIH adult health study Hiroshima and Nagasaki 1961 exposure to medical x-ray. Preliminary survey

    Energy Technology Data Exchange (ETDEWEB)

    Ishimaru, Toranosuke; Russell, W J

    1962-05-16

    A survey was conducted for three months among subjects seen in the medical clinics of ABCC, Hiroshima and Nagasaki, to determine the extent of medical x-ray received in ABCC and other hospitals and clinics. Emphasis was chiefly methodological to prepare for later studies designed to evaluate the contribution of medical x-ray to total radiation dose received by survivors of the atomic bombings and controls. The frequency, the institution in which the subject received x-ray, as well as the types of exposure were the prime considerations in the survey. The data were analyzed for each city by sex, age, and exposure status. 2 references, 5 figures, 11 tables.

  1. Airborne gamma-ray spectrometer and magnetometer survey. Volume I. Final report

    International Nuclear Information System (INIS)

    An airborne combined radiometric and magnetic survey was performed for the Department of Energy (DOE) over the area covered by the Mariposa, California and Nevada; Fresno, California; and Bakersfield, Caifornia 1:250,000 National Topographic Map Series (NTMS) 1 0 x 2 0 quadrangle maps. The survey was a part of DOE's National Aerial Radiometric Reconnaissance (ARR) program, which in turn is a part of the National Uranium Resource Evaluation (NURE) program. Data were collected by a helicopter equipped with a gamma-ray spectrometer having a large crystal volume, and a high sensitivity proton precession magnetometer. The radiometric system was calibrated at the Walker Field Calibration pads and the Lake Mead Dynamic Test range. Data quality was ensured throughout the survey by daily test flights and equipment checks. Radiometric data were corrected for live time, aircraft and equipment background, cosmic background, atmospheric radon, Compton scatter, and altitude dependence. The corrected data were statistically evaluated, plotted, and contoured to produce anomaly maps based on the radiometric response of individual geological units. These maps were interpreted and an anomaly interpretation map produced. Volume I contains a description of the systems used in the survey, a discussion of the calibration of the systems, the data processing procedures, the data display format, the interpretation rationale, and the interpretation methodology. A separate Volume II for each quadrangle contains the data displays and the interpretation results

  2. Airborne gamma-ray spectrometer and magnetometer survey: Peoria, Decater, Belleville Quadrangles, (IL). Final report

    International Nuclear Information System (INIS)

    1981-01-01

    An airborne combined radiometric and magnetic survey was performed for the Department of Energy (DOE) over the area covered by the Peoria, Decatur, and Belleville, 1:250,000 National Topographic Map Series (NTMS), quadrangle maps. The survey was part of DOE's National Uranium Resource Evaluation (NURE) program. Data were collected by a helicopter equipped with a gamma-ray spectrometer with a large crystal volume, and with a high sensitivity proton procession magnetometer. The radiometric system was calibrated at the Walker Field Calibration pads and the Lake Mead Dynamic Test Range. Data quality was ensured during the survey by daily test flights and equipment checks. Radiometric data were corrected for live time, aircraft and equipment background, cosmic background, atmospheric radon, Compton scatter, and altitude dependence. The corrected data were statistically evaluated, plotted, and contoured to produce anomaly maps based on the radiometric response of individual geological units. The anomalies were interpreted and an interpretation map produced. Volume I contains a description of the systems used in the survey, a discussion of the calibration of the systems, the data collection procedures, the data processing procedures, the data presentation, the interpretation rationale, and the interpretation methodology. A separate Volume II for each quadrangle contains the data displays and the interpretation results

  3. The Ulysses fast latitude scans: COSPIN/KET results

    Directory of Open Access Journals (Sweden)

    B. Heber

    2003-06-01

    Full Text Available Ulysses, launched in October 1990, began its second out-of-ecliptic orbit in December 1997, and its second fast latitude scan in September 2000. In contrast to the first fast latitude scan in 1994/1995, during the second fast latitude scan solar activity was close to maximum. The solar magnetic field reversed its polarity around July 2000. While the first latitude scan mainly gave a snapshot of the spatial distribution of galactic cosmic rays, the second one is dominated by temporal variations. Solar particle increases are observed at all heliographic latitudes, including events that produce >250 MeV protons and 50 MeV electrons. Using observations from the University of Chicago’s instrument on board IMP8 at Earth, we find that most solar particle events are observed at both high and low latitudes, indicating either acceleration of these particles over a broad latitude range or an efficient latitudinal transport. The latter is supported by "quiet time" variations in the MeV electron background, if interpreted as Jovian electrons. No latitudinal gradient was found for >106 MeV galactic cosmic ray protons, during the solar maximum fast latitude scan. The electron to proton ratio remains constant and has practically the same value as in the previous solar maximum. Both results indicate that drift is of minor importance. It was expected that, with the reversal of the solar magnetic field and in the declining phase of the solar cycle, this ratio should increase. This was, however, not observed, probably because the transition to the new magnetic cycle was not completely terminated within the heliosphere, as indicated by the Ulysses magnetic field and solar wind measurements. We argue that the new A<0-solar magnetic modulation epoch will establish itself once both polar coronal holes have developed.Key words. Interplanetary physics (cosmic rays; energetic particles; interplanetary magnetic fields

  4. CHANDRA ACIS SURVEY OF X-RAY POINT SOURCES: THE SOURCE CATALOG

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Song; Liu, Jifeng; Qiu, Yanli; Bai, Yu; Yang, Huiqin; Guo, Jincheng; Zhang, Peng, E-mail: jfliu@bao.ac.cn, E-mail: songw@bao.ac.cn [Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)

    2016-06-01

    categorize these SSSs and pinpoint their properties. In addition, this survey can enable a wide range of statistical studies, such as X-ray activity in different types of stars, X-ray luminosity functions in different types of galaxies, and multi-wavelength identification and classification of different X-ray populations.

  5. The Einstein@Home Gamma-ray Pulsar Survey. II. Source Selection, Spectral Analysis, and Multiwavelength Follow-up

    Science.gov (United States)

    Wu, J.; Clark, C. J.; Pletsch, H. J.; Guillemot, L.; Johnson, T. J.; Torne, P.; Champion, D. J.; Deneva, J.; Ray, P. S.; Salvetti, D.; Kramer, M.; Aulbert, C.; Beer, C.; Bhattacharyya, B.; Bock, O.; Camilo, F.; Cognard, I.; Cuéllar, A.; Eggenstein, H. B.; Fehrmann, H.; Ferrara, E. C.; Kerr, M.; Machenschalk, B.; Ransom, S. M.; Sanpa-Arsa, S.; Wood, K.

    2018-02-01

    We report on the analysis of 13 gamma-ray pulsars discovered in the Einstein@Home blind search survey using Fermi Large Area Telescope (LAT) Pass 8 data. The 13 new gamma-ray pulsars were discovered by searching 118 unassociated LAT sources from the third LAT source catalog (3FGL), selected using the Gaussian Mixture Model machine-learning algorithm on the basis of their gamma-ray emission properties being suggestive of pulsar magnetospheric emission. The new gamma-ray pulsars have pulse profiles and spectral properties similar to those of previously detected young gamma-ray pulsars. Follow-up radio observations have revealed faint radio pulsations from two of the newly discovered pulsars and enabled us to derive upper limits on the radio emission from the others, demonstrating that they are likely radio-quiet gamma-ray pulsars. We also present results from modeling the gamma-ray pulse profiles and radio profiles, if available, using different geometric emission models of pulsars. The high discovery rate of this survey, despite the increasing difficulty of blind pulsar searches in gamma rays, suggests that new systematic surveys such as presented in this article should be continued when new LAT source catalogs become available.

  6. A survey of medical exposure during X-ray diagnosis in Aomori

    International Nuclear Information System (INIS)

    Kon, Masanori; Fukushi, Shouji; Oota, Fumio; Kawamura, Kouji; Shinohe, Tetsuo; Suwa, Kouki; Fujii, Kiyosuke; Yamagami, Hirofumi

    2000-01-01

    The purpose of this project was to survey medical exposure doses in Aomori Prefecture and compare them with guidance levels for X-ray diagnosis. A questionnaire survey on X-ray diagnosis was conducted at the main medical institutions in the prefecture. The questionnaire asked about technical conditions, and replies were obtained from 72.2% of the 79 institutions. The medical exposure doses (entrance surface doses) were calculated from the results of the questionnaires by the modified numerical dose determination (NDD) method. The distribution of the entrance surface doses at each site was calculated as the 1st quartile, median, 3rd quartile, average, standard deviation, maximum value and minimum value, by the quartile method. The distribution of exposed doses at each site showed a similar pattern with that of the national distribution. Some institutions used higher doses than the Japanese proposed guidance levels and International Atomic Energy Agency (IAEA) guidance levels. Re-assessment of radiographic conditions and photosensitive materials is needed to reduce exposure doses. (K.H.)

  7. SPIDERS: selection of spectroscopic targets using AGN candidates detected in all-sky X-ray surveys

    Science.gov (United States)

    Dwelly, T.; Salvato, M.; Merloni, A.; Brusa, M.; Buchner, J.; Anderson, S. F.; Boller, Th.; Brandt, W. N.; Budavári, T.; Clerc, N.; Coffey, D.; Del Moro, A.; Georgakakis, A.; Green, P. J.; Jin, C.; Menzel, M.-L.; Myers, A. D.; Nandra, K.; Nichol, R. C.; Ridl, J.; Schwope, A. D.; Simm, T.

    2017-07-01

    SPIDERS (SPectroscopic IDentification of eROSITA Sources) is a Sloan Digital Sky Survey IV (SDSS-IV) survey running in parallel to the Extended Baryon Oscillation Spectroscopic Survey (eBOSS) cosmology project. SPIDERS will obtain optical spectroscopy for large numbers of X-ray-selected active galactic nuclei (AGN) and galaxy cluster members detected in wide-area eROSITA, XMM-Newton and ROSAT surveys. We describe the methods used to choose spectroscopic targets for two sub-programmes of SPIDERS X-ray selected AGN candidates detected in the ROSAT All Sky and the XMM-Newton Slew surveys. We have exploited a Bayesian cross-matching algorithm, guided by priors based on mid-IR colour-magnitude information from the Wide-field Infrared Survey Explorer survey, to select the most probable optical counterpart to each X-ray detection. We empirically demonstrate the high fidelity of our counterpart selection method using a reference sample of bright well-localized X-ray sources collated from XMM-Newton, Chandra and Swift-XRT serendipitous catalogues, and also by examining blank-sky locations. We describe the down-selection steps which resulted in the final set of SPIDERS-AGN targets put forward for spectroscopy within the eBOSS/TDSS/SPIDERS survey, and present catalogues of these targets. We also present catalogues of ˜12 000 ROSAT and ˜1500 XMM-Newton Slew survey sources that have existing optical spectroscopy from SDSS-DR12, including the results of our visual inspections. On completion of the SPIDERS programme, we expect to have collected homogeneous spectroscopic redshift information over a footprint of ˜7500 deg2 for >85 per cent of the ROSAT and XMM-Newton Slew survey sources having optical counterparts in the magnitude range 17 < r < 22.5, producing a large and highly complete sample of bright X-ray-selected AGN suitable for statistical studies of AGN evolution and clustering.

  8. Hospital and clinic survey estimates of medical x-ray exposures in Hiroshima and Nagasaki, (1)

    International Nuclear Information System (INIS)

    Sawada, Shozo; Land, C.E.; Otake, Masanori; Russell, W.J.; Takeshita, Kenji.

    1980-11-01

    All large hospitals and 40% of the small hospitals and clinics in Hiroshima and Nagasaki cities were surveyed for the X-ray examinations they performed during a 2-week period in 1974. The frequency and type of X-ray examinations received by members of the RERF Adult Health Study (AHS) and the RERF Life Span Study (LSS) extended, excluding AHS (Non-AHS), were compared with the general population in each city. Radiologic exposures of patients at hospitals and clinics were most frequent among the general populations. The number of patients, examinations, and exposures per caput per year in each population were estimated. Since the age distribution differed among the three populations, comparisons were made only after correcting for age. On a per caput per year basis exposure frequency was relatively high in the AHS and low in the general populations, a reflection of the greater number of patients in the AHS than in the general populations. Non-AHS males in Nagasaki had a higher X-ray examination rate than did the AHS subjects. The others in the Non-AHS did not differ appreciably from the general populations. There was no difference among these groups according to body sites examined. (author)

  9. The NuSTAR Hard X-Ray Survey of the Norma Arm Region

    Energy Technology Data Exchange (ETDEWEB)

    Fornasini, Francesca M. [Astronomy Department, University of California, 601 Campbell Hall, Berkeley, CA 94720 (United States); Tomsick, John A.; Chiu, Jeng-Lun; Clavel, Maïca; Krivonos, Roman A.; Boggs, Steven E.; Craig, William W. [Space Sciences Laboratory, 7 Gauss Way, University of California, Berkeley, CA 94720 (United States); Hong, JaeSub [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Gotthelf, Eric V.; Hailey, Charles J.; Mori, Kaya [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Bauer, Franz; Corral-Santana, Jesús [Instituto de Astrofísica and Centro de Astroingeniería, Facultad de Física, Pontificia Universidad Católica de Chile, Casilla 306, Santiago 22 (Chile); Rahoui, Farid [European Southern Observatory, K. Schwarzschild-Strasse 2, D-85748 Garching bei München (Germany); Stern, Daniel [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Bodaghee, Arash [Georgia College, 231 W. Hancock Street, Milledgeville, GA 31061 (United States); Alexander, David M. [Centre for Extragalactic Astronomy, Department of Physics, Durham University, Durham, DH1 3LE (United Kingdom); Barret, Didier [Université de Toulouse, UPS-OMP, IRAP, Toulouse (France); CNRS, Institut de Recherche en Astrophysique et Planétologie, 9 Av. colonel Roche, BP 44346, F-31028 Toulouse cedex 4 (France); Christensen, Finn E., E-mail: f.fornasini@berkeley.edu [DTU Space—National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby (Denmark); and others

    2017-04-01

    We present a catalog of hard X-ray sources in a square-degree region surveyed by the Nuclear Spectroscopic Telescope Array ( NuSTAR ) in the direction of the Norma spiral arm. This survey has a total exposure time of 1.7 Ms, and the typical and maximum exposure depths are 50 ks and 1 Ms, respectively. In the area of deepest coverage, sensitivity limits of 5 × 10{sup −14} and 4 × 10{sup −14} erg s{sup −1} cm{sup −2} in the 3–10 and 10–20 keV bands, respectively, are reached. Twenty-eight sources are firmly detected, and 10 are detected with low significance; 8 of the 38 sources are expected to be active galactic nuclei. The three brightest sources were previously identified as a low-mass X-ray binary, high-mass X-ray binary, and pulsar wind nebula. Based on their X-ray properties and multiwavelength counterparts, we identify the likely nature of the other sources as two colliding wind binaries, three pulsar wind nebulae, a black hole binary, and a plurality of cataclysmic variables (CVs). The CV candidates in the Norma region have plasma temperatures of ≈10–20 keV, consistent with the Galactic ridge X-ray emission spectrum but lower than the temperatures of CVs near the Galactic center. This temperature difference may indicate that the Norma region has a lower fraction of intermediate polars relative to other types of CVs compared to the Galactic center. The NuSTAR log N –log S distribution in the 10–20 keV band is consistent with the distribution measured by Chandra at 2–10 keV if the average source spectrum is assumed to be a thermal model with kT  ≈ 15 keV, as observed for the CV candidates.

  10. Surface gamma-ray survey of the Barre West quadrangle, Washington and Orange Counties, Vermont

    Science.gov (United States)

    Walsh, Gregory J.; Satkoski, Aaron M.

    2005-01-01

    This study was designed to determine the levels of naturally occurring radioactivity in bedrock from surface measurements at outcrops during the course of 1:24,000-scale geologic mapping and to determine which rock types were potential sources of radionuclides. Elevated levels of total alpha particle radiation (gross alpha) occur in a public water system in Montpelier, Vermont. Measured gross alpha levels in the Murray Hill water system (Vermont Dept. of Environmental Conservation, unpub. data, 2005) have exceeded the maximum contaminant level of 15 picocuries per liter (pCi/l) set by the Environmental Protection Agency (EPA) (EPA, 2000). The Murray Hill system began treatment for radium in 1999. Although this treatment was successful, annual monitoring for gross alpha, radium, and uranium continues as required (Jon Kim, written communication, 2005). The water system utilizes a drilled bedrock well located in the Silurian-Devonian Waits River Formation. Kim (2002) summarized radioactivity data for Vermont, and aside from a statewide assessment of radon in public water systems (Manning and Ladue, 1986) and a single flight line from the National Uranium Resource Evaluation (NURE) (Texas Instruments, 1976) (fig. 1), no data are available to identify the potential sources of naturally occurring radioactivity in the local bedrock. Airborne gamma-ray surveys are typically used for large areas (Duval, 2001, 2002), and ground-based surveys are more commonly used for local site assessments. For example, ground-based surveys have been used for fault mapping (Iwata and others, 2001), soil mapping (Roberts and others, 2003), environmental assessments (Stromswold and Arthur, 1996), and mineral exploration (Jubeli and others, 1998). Duval (1980) summarized the methods and applications of gamma- ray spectrometry. In this study, we present the results from a ground-based gamma-ray survey of bedrock outcrops in the 7.5-minute Barre West quadrangle, Vermont. Other related and

  11. An airborne gamma ray survey of parts of SW Scotland in February 1993. Final Report

    International Nuclear Information System (INIS)

    Sanderson, D.C.W.; Allyson, J.D.; Tyler, A.N.; Ni Riain, S.; Murphy, S.

    1994-01-01

    An airborne gamma ray survey was conducted for the Scottish Office Environment Department of coastal and inland parts of SW Scotland to define existing background levels, to locate features worthy of further attention, and to demonstrate the emergency response capabilities of radiometric methods. Coastal areas were surveyed with 500 m line spacing. Inland areas were specified to 2 km line spacing, however it was possible to achieve 1 km line spacing in the majority of the inland zone. The radiometric maps show clearly the distributions of each individual nuclide and indicate the contribution which individual localised features make to the overall gamma ray dose rate. Naturally occurring nuclides reflect the underlying geological and geomorphological contexts of the landscapes. The main granite intrusions, most notably at Cairnsmore of Fleet, the Loch Doon Granodiorite, Glencairn of Carsphairn, the Dalbeattie granite, and Criffel Pluton are readily visible in 40 K, 214 Bi and 208 Tl maps, and control their local radiation environments. A number of areas of enhanced 214 Bi, which may reflect radon potential, were noted. A transient radon associated 214 Bi signal was observed on the west of the Wigtown peninsular during the survey. Examination of spectral data in the vicinity Dundrennan has confirmed that there is no evidence of widespread terrestrial contamination arising from the use of depleted uranium projectiles on the range. The 137 Cs map indicates the environmental distribution of this nuclide in considerable detail. Levels of 137 Cs range from approximately 2 kBq m -2 , a level consistent with global weapons' testing fallout, from 2-40 kBq m -2 on terrestrial sites affected by deposition from the Chernobyl accident, and from 40 kBq m -2 to over 200 kBq m -2 on tide washed pastures which have accumulated marine sediments from the Irish sea. (author)

  12. Airborne gamma-ray spectrometer and magnetometer survey, Mitchell Quadrangle, South Dakota. Final report

    International Nuclear Information System (INIS)

    1981-04-01

    An airborne high sensitivity gamma-ray spectrometer and magnetometer survey was conducted over eleven (11) 2 0 x 1 0 NTMS quadrangles located in the states of Minnesota and Wisconsin and seven (7) 2 0 x 1 0 NTMS quadrangles in North and South Dakota. The quadrangles located within the North and South Dakota survey area include Devil's Lake, New Rockford, Jamestown, Aberdeen, Huron, Mitchell, and Sioux Falls. This report discusses the results obtained over the Mitchell map area. The purpose of this program is to acquire and compile geologic and other information with which to assess the magnitude and distribution of uranium resources and to determine areas favorable for the occurrence of uranium in the United States. Traverse lines were flown in an east-west direction at a line spacing of six (6) miles. Tie lines were flown north-south approximately twenty-four (24) miles apart. A total of 21,481 line miles of geophysical data were acquired, compiled, and interpreted during the survey, of which 1479 line miles are in this quadrangle

  13. Airborne gamma-ray spectrometer and magnetometer survey, New Rockford Quadrangle, North Dakota. Final report

    International Nuclear Information System (INIS)

    1981-04-01

    An airborne high sensitivity gamma-ray spectrometer and magnetometer survey was conducted over eleven (11) 2 0 x 1 0 NTMS quadrangles located in the states of Minnesota and Wisconsin and seven (7) 2 0 x 1 0 NTMS quadrangles in North and South Dakota. The quadrangles located within the North and South Dakota survey area include Devil's Lake, New Rockford, Jamestown, Aberdeen, Huron, Mitchell, and Sioux Falls. This report discusses the results obtained over the New Rockford map area. Traverse lines were flown in an east-west direction at a line spacing of six (6) miles. Tie lines were flown north-south approximately twenty-four (24) miles apart. A total of 21,481 line miles of geophysical data were acquired, compiled, and interpreted during the survey, of which 1397 line miles are in this quadrangle. The purpose of this study is to acquire and compile geologic and other information with which to assess the magnitude and distribution of uranium resources and to determine areas favorable for the occurrence of uranium in the United States

  14. Airborne gamma-ray spectrometer and magnetometer survey: Huron quadrangle, South Dakota. Final report

    International Nuclear Information System (INIS)

    1981-04-01

    An airborne high sensitivity gamma-ray spectrometer and magnetometer survey was conducted over eleven (11) 2 0 x 1 0 NTMS quadrangles located in the states of Minnesota and Wisconsin and seven (7) 2 0 x 1 0 NTMS quadrangles in North and South Dakota. The quadrangles located within the North and South Dakota survey area include Devil's Lake, New Rockford, Jamestown, Aberdeen, Huron, Mitchell, and Sioux Falls. This report discusses the results obtained over the Huron map area. Traverse lines were flown in an east-west direction at a line spacing of six (6) miles. Tie lines were flown north-south approximately twenty-four (24) miles apart. A total of 21,481 line miles of geophysical data were acquired, compiled, and interpreted during the survey, of which 1459 line miles are in this quadrangle. The purpose of this study is to acquire and compile geologic and other information with which to assess the magnitude and distribution of uranium resources and to determine areas favorable for the occurrence of uranium in the United States

  15. AN ABSENCE OF FAST RADIO BURSTS AT INTERMEDIATE GALACTIC LATITUDES

    Energy Technology Data Exchange (ETDEWEB)

    Petroff, E.; Van Straten, W.; Bailes, M.; Barr, E. D.; Coster, P.; Flynn, C.; Keane, E. F. [Centre for Astrophysics and Supercomputing, Swinburne University of Technology, P.O. Box 218, Hawthorn, VIC 3122 (Australia); Johnston, S. [CSIRO Astronomy and Space Science, Australia Telescope National Facility, P.O. Box 76, Epping, NSW 1710 (Australia); Bates, S. D.; Keith, M. J.; Kramer, M.; Stappers, B. W. [Jodrell Bank Centre for Astrophysics, University of Manchester, Alan Turing Building, Oxford Road, Manchester M13 9PL (United Kingdom); Bhat, N. D. R. [ARC Centre of Excellence for All-sky Astrophysics (CAASTRO), 44 Rosehill Street, Redfern, NSW 2016 (Australia); Burgay, M.; Possenti, A.; Tiburzi, C. [INAF—Osservatorio Astronomico di Cagliari, Via della Scienza, I-09047 Selargius (Italy); Burke-Spolaor, S. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91104 (United States); Champion, D.; Ng, C. [Max Planck Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany); Levin, L., E-mail: epetroff@astro.swin.edu.au [Department of Physics, West Virginia University, Morgantown, WV 26506 (United States); and others

    2014-07-10

    Fast radio bursts (FRBs) are an emerging class of bright, highly dispersed radio pulses. Recent work by Thornton et al. has revealed a population of FRBs in the High Time Resolution Universe (HTRU) survey at high Galactic latitudes. A variety of progenitors have been proposed, including cataclysmic events at cosmological distances, Galactic flare stars, and terrestrial radio frequency interference. Here we report on a search for FRBs at intermediate Galactic latitudes (–15° survey. No FRBs were discovered in this region. Several effects such as dispersion, scattering, sky temperature, and scintillation decrease the sensitivity by more than 3σ in ∼20% of survey pointings. Including all of these effects, we exclude the hypothesis that FRBs are uniformly distributed on the sky with 99% confidence. This low probability implies that additional factors—not accounted for by standard Galactic models—must be included to ease the discrepancy between the detection rates at high and low Galactic latitudes. A revised rate estimate or another strong and heretofore unknown selection effect in Galactic latitude would provide closer agreement between the surveys' detection rates. The dearth of detections at low Galactic latitude disfavors a Galactic origin for these bursts.

  16. AN ABSENCE OF FAST RADIO BURSTS AT INTERMEDIATE GALACTIC LATITUDES

    International Nuclear Information System (INIS)

    Petroff, E.; Van Straten, W.; Bailes, M.; Barr, E. D.; Coster, P.; Flynn, C.; Keane, E. F.; Johnston, S.; Bates, S. D.; Keith, M. J.; Kramer, M.; Stappers, B. W.; Bhat, N. D. R.; Burgay, M.; Possenti, A.; Tiburzi, C.; Burke-Spolaor, S.; Champion, D.; Ng, C.; Levin, L.

    2014-01-01

    Fast radio bursts (FRBs) are an emerging class of bright, highly dispersed radio pulses. Recent work by Thornton et al. has revealed a population of FRBs in the High Time Resolution Universe (HTRU) survey at high Galactic latitudes. A variety of progenitors have been proposed, including cataclysmic events at cosmological distances, Galactic flare stars, and terrestrial radio frequency interference. Here we report on a search for FRBs at intermediate Galactic latitudes (–15° survey. No FRBs were discovered in this region. Several effects such as dispersion, scattering, sky temperature, and scintillation decrease the sensitivity by more than 3σ in ∼20% of survey pointings. Including all of these effects, we exclude the hypothesis that FRBs are uniformly distributed on the sky with 99% confidence. This low probability implies that additional factors—not accounted for by standard Galactic models—must be included to ease the discrepancy between the detection rates at high and low Galactic latitudes. A revised rate estimate or another strong and heretofore unknown selection effect in Galactic latitude would provide closer agreement between the surveys' detection rates. The dearth of detections at low Galactic latitude disfavors a Galactic origin for these bursts

  17. The X-ray properties of five galactic supernova remnants detected by the Spitzer glimpse survey

    International Nuclear Information System (INIS)

    Pannuti, Thomas G.; Moffitt, William P.; Rho, Jeonghee; Heinke, Craig O.

    2014-01-01

    We present a study of the X-ray properties of five Galactic supernova remnants (SNRs)—Kes 17 (G304.6+0.1), G311.5–0.3, G346.6–0.2, CTB 37A (G348.5+0.1), and G348.5–0.0—that were detected in the infrared by Reach et al. in an analysis of data from the Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE) that was conducted by the Spitzer Space Telescope. We present and analyze archival ASCA observations of Kes 17, G311.5–0.3, and G346.6–0.2, archival XMM-Newton observations of Kes 17, CTB 37A, and G348.5–0.0, and an archival Chandra observation of CTB 37A. All of the SNRs are clearly detected in the X-ray except possibly G348.5–0.0. Our study reveals that the four detected SNRs all feature center-filled X-ray morphologies and that the observed emission from these sources is thermal in all cases. We argue that these SNRs should be classified as mixed-morphology SNRs (MM SNRs); our study strengthens the correlation between MM SNRs and SNRs interacting with molecular clouds and suggests that the origin of MM SNRs may be due to the interactions between these SNRs and adjacent clouds. Our ASCA analysis of G311.5–0.3 reveals for the first time X-ray emission from this SNR: the X-ray emission is center-filled within the radio and infrared shells and thermal in nature (kT ∼ 0.98 keV), thus motivating its classification as an MM SNR. We find considerable spectral variations in the properties associated with the plasmas of the other X-ray-detected SNRs, such as a possible overabundance of magnesium in the plasma of Kes 17. Our new results also include the first detailed spatially resolved spectroscopic study of CTB 37A using Chandra as well as a spectroscopic study of the discrete X-ray source CXOU J171428.5–383601, which may be a neutron star associated with CTB 37A. Finally, we also estimate such properties as electron density n e , radiative age t rad and swept-up mass M X for each of the four X-ray-detected SNRs. Each of these values

  18. NURE aerial gamma ray and magnetic reconnaissance survey, Thorpe area, Newark NK18-11 Quadrangle. Volume I. Narrative report

    International Nuclear Information System (INIS)

    1977-11-01

    During the flying seasons of 1976 and 1977 LKB Resources, Inc. conducted a rotary wing combined airborne high sensitivity gamma-ray and magnetic survey of four 1:250,000 quadrangles covering portions of Pennsylvania, New Jersey, and New York. The airborne system, field operations, data reduction, gamma-ray and magnetic data presentation, geology and uranium deposits of the Thorpe Area, photogeologic enhancement study of the Thorpe Area, and data interpretation are discussed

  19. A survey on respiratory diseases of atomic bomb survivors using chest X-ray examination

    International Nuclear Information System (INIS)

    Komatsubara, Naoka; Isobe, Takeshi; Nakamura, Kenji

    1994-01-01

    Chest X-ray films, taken from 48,160 A-bomb survivors aged 40 years or more during a 5-year period 1988-1992, were reviewed. Abnormal X-ray findings were obtained in 26.7% for men and 18.2% for women. The incidence of necessary detailed examination was 2.6%. Of these A-bomb survivors, 93.7% participated in it. Pulmonary fibrosis, chronic emphysema, and pulmonary cyst yielded higher prevalence per population of 100,000 in men, irrespective of exposure distance. In comparing with the results obtained during a 5-year period 1981-1985, the detection rate of primary lung cancer was not different from that in the present 5-year survey. For active pulmonary tuberculosis, pulmonary fibrosis, and chronic emphysema, however, the prevalence tended to decrease. Primary lung cancer and pulmonary fibrosis were more frequently detected with aging in both men and women. This was independent of exposure distance. (N.K.)

  20. First demonstration of aerial gamma-ray imaging using drone for prompt radiation survey in Fukushima

    Science.gov (United States)

    Mochizuki, S.; Kataoka, J.; Tagawa, L.; Iwamoto, Y.; Okochi, H.; Katsumi, N.; Kinno, S.; Arimoto, M.; Maruhashi, T.; Fujieda, K.; Kurihara, T.; Ohsuka, S.

    2017-11-01

    Considerable amounts of radioactive substances (mainly 137Cs and 134Cs) were released into the environment after the Japanese nuclear disaster in 2011. Some restrictions on residence areas were lifted in April 2017, owing to the successive and effective decontamination operations. However, the distribution of radioactive substances in vast areas of mountain, forest and satoyama close to the city is still unknown; thus, decontamination operations in such areas are being hampered. In this paper, we report on the first aerial gamma-ray imaging of a schoolyard in Fukushima using a drone that carries a high sensitivity Compton camera. We show that the distribution of 137Cs in regions with a diameter of several tens to a hundred meters can be imaged with a typical resolution of 2-5 m within a 10-20 min flights duration. The aerial gamma-ray images taken 10 m and 20 m above the ground are qualitatively consistent with a dose map reconstructed from the ground-based measurements using a survey meter. Although further quantification is needed for the distance and air-absorption corrections to derive in situ dose map, such an aerial drone system can reduce measurement time by a factor of ten and is suitable for place where ground-based measurement are difficult.

  1. Airborne gamma-ray spectrometer and magnetometer survey Coos Bay, Oregon. Final report

    International Nuclear Information System (INIS)

    1981-05-01

    During the months of August, September, and October of 1980, Aero Service Division Western Geophysical Company of America conducted an airborne high sensitivity gamma-ray spectrometer and magnetometer survey over ten (10) areas over northern California and southwestern Oregon. These include the 2 0 x 1 0 NTMS quadrangles of Roseburg, Medford, Weed, Alturas, Redding, Susanville, Ukiah, and Chico along with the 1 0 x 2 0 areas of the Coos Bay quadrangle and the Crescent City/Eureka areas combined. This report discusses the results obtained over the Coos Bay, Oregon, map area. Line spacing was generally six miles for east/west traverses and eighteen miles for north/south tie lines over the northern one-half of the area. Traverses and tie lines were flown at three miles and twelve miles respectively over the southern one-half of the area. A total of 16,880.5 line miles of geophysical data were acquired, compiled, and interpreted during the survey, of which 863.8 line miles are in this quadrangle

  2. Airborne gamma-ray spectrometer and magnetometer survey: Alturas quadrangle, California. Final report

    International Nuclear Information System (INIS)

    1981-05-01

    An airborne high sensitivity gamma-ray spectrometer and magnetometer survey was conducted over ten (10) areas over northern California and southwestern Oregon. These include the 2 0 x 1 0 NTMS quadrangles of Roseburg, Medford, Weed, Alturas, Redding, Susanville, Ukiah, and Chico along with the 1 0 x 2 0 areas of the Coos Bay quadrangle and the Crescent City/Eureka areas combined. This report discusses the results obtained over the Alturas, California, map area. Traverse lines were flown in an east-west direction at a line spacing of six (6) miles. Tie lines were flown north-south approximately eighteen (18) miles apart. A total of 16,880.5 line miles of geophysical data were acquired, compiled, and interpreted during the survey, of which 1631.6 line miles are in this quadrangle. The purpose of this study is to acquire and compile geologic and other information with which to assess the magnitude and distribution of uranium resources and to determine areas favorable for the occurrence of uranium in the United States

  3. Airborne gamma-ray spectrometer and magnetometer survey: Susanville quadrangle, California. Final report

    International Nuclear Information System (INIS)

    1981-05-01

    An airborne high sensitivity gamma-ray spectrometer and magnetometer survey was conducted over ten (10) areas over northern California and southwestern Oregon. These include the 2 0 x 1 0 NTMS quadrangles of Roseburg, Medford, Weed, Alturas, Redding, Susanville, Ukiah, and Chico along with the 1 0 x 2 0 areas of the Coos Bay quadrangle and the Crescent City/Eureka areas combined. This report discusses the results obtained over the Susanville, California, map area. Traverse lines were flown in an east-west direction at a line spacing of six (6) miles. Tie lines were flown north-south approximately eighteen (18) miles apart. A total of 16,880.5 line miles of geophysical data were acquired, compiled, and interpreted during the survey, of which 1642.8 line miles are in this quadrangle. The purpose of this study is to acquire and compile geologic and other information with which to assess the magnitude and distribution of uranium resources and to determine areas favorable for the occurrence of uranium in the United States

  4. The X-Ray Surveyor Mission Concept Study: Forging the Path to NASA Astrophysics 2020 Decadal Survey Prioritization

    Science.gov (United States)

    Gaskin, Jessica; Ozel, Feryal; Vikhlinin, Alexey

    2016-01-01

    The X-Ray Surveyor mission concept is unique among those being studied for prioritization in the NASA Astrophysics 2020 Decadal Survey. The X-Ray Surveyor mission will explore the high-energy Universe; providing essential and complimentary observations to the Astronomy Community. The NASA Astrophysics Roadmap (Enduring Quests, Daring Visions) describes the need for an X-Ray Observatory that is capable of addressing topics such as the origin and growth of the first supermassive black holes, galaxy evolution and growth of the cosmic structure, and the origin and evolution of the stars that make up our Universe. To address these scientifically compelling topics and more, an Observatory that exhibits leaps in capability over that of previous X-Ray Observatories in needed. This paper describes the current status of the X-Ray Surveyor Mission Concept Study and the path forward, which includes scientific investigations, technology development, and community participation.

  5. The X-Ray Surveyor mission concept study: forging the path to NASA astrophysics 2020 decadal survey prioritization

    Science.gov (United States)

    Gaskin, Jessica; Özel, Feryal; Vikhlinin, Alexey

    2016-07-01

    The X-Ray Surveyor mission concept is unique among those being studied for prioritization in the NASA Astrophysics 2020 Decadal Survey. The X-Ray Surveyor mission will explore the high-energy Universe; providing essential and complimentary observations to the Astronomy Community. The NASA Astrophysics Roadmap (Enduring Quests, Daring Visions) describes the need for an X-Ray Observatory that is capable of addressing topics such as the origin and growth of the first supermassive black holes, galaxy evolution and growth of the cosmic structure, and the origin and evolution of the stars that make up our Universe. To address these scientifically compelling topics and more, an Observatory that exhibits leaps in capability over that of previous X-Ray Observatories in needed. This paper describes the current status of the X-Ray Surveyor Mission Concept Study and the path forward, which includes scientific investigations, technology development, and community participation.

  6. Einstein Observatory magnitude-limited X-ray survey of late-type giant and supergiant stars

    Science.gov (United States)

    Maggio, A.; Vaiana, G. S.; Haisch, B. M.; Stern, R. A.; Bookbinder, J.

    1990-01-01

    Results are presented of an extensive X-ray survey of 380 giant and supergiant stars of spectral types from F to M, carried out with the Einstein Observatory. It was found that the observed F giants or subgiants (slightly evolved stars with a mass M less than about 2 solar masses) are X-ray emitters at the same level of main-sequence stars of similar spectral type. The G giants show a range of emissions more than 3 orders of magnitude wide; some single G giants exist with X-ray luminosities comparable to RS CVn systems, while some nearby large G giants have upper limits on the X-ray emission below typical solar values. The K giants have an observed X-ray emission level significantly lower than F and F giants. None of the 29 M giants were detected, except for one spectroscopic binary.

  7. Modulation of cosmic rays with particular reference to the Hermanus neutron monitor

    International Nuclear Information System (INIS)

    Stoker, P.H.

    1982-01-01

    Investigations at Potchefstroom has directed interest to the interaction between cosmic rays and the interplanetary magnetic field. In this paper the period of increasing modulation of cosmic rays from 1976 is discussed. The geomagnetic field as spectrometer for primary cosmic rays will be discussed and applied to the latitude surveys of 1975 and 1976. Features of the coronal magnetic field, the solar wind with interplanetary magnetic field and the transport of cosmic rays in the interplanetary magnetic field are outlined in order to relate cosmic ray recordings of fixed groundlevel stations to observations made in outerspace by space crafts and satellites and to explain these recordings in terms of cosmic ray modulation processes

  8. OTELO SURVEY: DEEP BVRI BROADBAND PHOTOMETRY OF THE GROTH STRIP. II. OPTICAL PROPERTIES OF X-RAY EMITTERS

    International Nuclear Information System (INIS)

    Povic, M.; Perez GarcIa, A. M.; Bongiovanni, A.; Castaneda, H.; Lorenzo, M. Fernandez; Lara-Lopez, M. A.; Sanchez-Portal, M.; Cepa, J.; Alfaro, E.; Gallego, J.; Gonzalez-Serrano, J. I.; Gonzalez, J. J.

    2009-01-01

    The Groth field is one of the sky regions that will be targeted by the OSIRIS Tunable Filter Emission Line Object survey in the optical 820 nm and 920 nm atmospheric windows. In the present paper, public Chandra X-ray data with total exposure time of 200 ks are analyzed and combined with optical broadband data of the Groth field, in order to study a set of optical structural parameters of the X-ray emitters and its relation with X-ray properties. To this aim, we processed the raw, public X-ray data using the Chandra Interactive Analysis of Observations, and determined and analyzed different structural parameters, in order to produce a morphological classification of X-ray sources. We present the morphology of 340 X-ray emitters with optical counterpart detected. Objects have been classified by X-ray type using a diagnostic diagram relating X-ray-to-optical ratio (X/O) to hardness ratio. We did not find any clear correlation between X-ray and morphological types. We analyzed the angular clustering of X-ray sources with optical counterpart using two-point correlation functions. A significant positive angular clustering was obtained from a preliminary analysis of four subsamples of the X-ray sources catalog. The clustering signal of the optically extended counterparts is similar to that of strongly clustered populations like red and very red galaxies, suggesting that the environment plays an important role in active galactic nuclei phenomena. Finally, we combined optical structural parameters with other X-ray and optical properties, and we confirmed an anticorrelation between the X/O ratio and the Abraham concentration index, which might suggest that early-type galaxies have lower Eddington rates than those of late-type galaxies.

  9. High Latitude Corals Tolerate Severe Cold Spell

    Directory of Open Access Journals (Sweden)

    Chenae A. Tuckett

    2018-01-01

    Full Text Available Climatically extreme weather events often drive long-term ecological responses of ecosystems. By disrupting the important symbiosis with zooxanthellae, Marine Cold Spells (MCS can cause bleaching and mortality in tropical and subtropical scleractinian corals. Here we report on the effects of a severe MCS on high latitude corals, where we expected to find bleaching and mortality. The MCS took place off the coast of Perth (32°S, Western Australia in 2016. Bleaching was assessed before (2014 and after (2017 the MCS from surveys of permanent plots, and with timed bleaching searches. Temperature data was recorded with in situ loggers. During the MCS temperatures dipped to the coldest recorded in ten years (15.3°C and periods of <17°C lasted for up to 19 days. Only 4.3% of the surveyed coral colonies showed signs of bleaching. Bleaching was observed in 8 species where those most affected were Plesiastrea versipora and Montipora mollis. These findings suggest that high latitude corals in this area are tolerant of cold stress and are not persisting near a lethal temperature minimum. It has not been established whether other environmental conditions are limiting these species, and if so, what the implications are for coral performance on these reefs in a warmer future.

  10. THE CHANDRA X-RAY SURVEY OF PLANETARY NEBULAE (CHANPLANS): PROBING BINARITY, MAGNETIC FIELDS, AND WIND COLLISIONS

    Energy Technology Data Exchange (ETDEWEB)

    Kastner, J. H.; Montez, R. Jr.; Rapson, V. [Center for Imaging Science and Laboratory for Multiwavelength Astrophysics, Rochester Institute of Technology, 54 Lomb Memorial Drive, Rochester, NY 14623 (United States); Balick, B. [Department of Astronomy, University of Washington, Seattle, WA (United States); Frew, D. J.; De Marco, O.; Parker, Q. A. [Department of Physics and Astronomy and Macquarie Research Centre for Astronomy, Astrophysics and Astrophotonics, Macquarie University, Sydney, NSW 2109 (Australia); Miszalski, B. [South African Astronomical Observatory, P.O. Box 9, Observatory, 7935 (South Africa); Sahai, R. [Jet Propulsion Laboratory, California Institute of Technology, MS 183-900, Pasadena, CA 91109 (United States); Blackman, E.; Frank, A. [Department of Physics and Astronomy, University of Rochester, Rochester, NY (United States); Chu, Y.-H. [Department of Astronomy, University of Illinois, Champagne-Urbana, IL (United States); Guerrero, M. A. [Instituto de Astrofisica de Astronomia, Glorieta de la Astronomia s/n, Granada 18008 (Spain); Lopez, J. A. [Instituto de Astronomia, Universidad Nacional Autonoma de Mexico, Campus Ensenada, Apdo. Postal 22860, Ensenada, B. C. (Mexico); Zijlstra, A. [School of Physics and Astronomy, University of Manchester, Manchester M13 9PL (United Kingdom); Behar, E. [Department of Physics, Technion (Israel); Bujarrabal, V. [Observatorio Astronomico Nacional, Apartado 112, E-28803, Alcala de Henares (Spain); Corradi, R. L. M. [Instituto de Astrofisica de Canarias, E-38200 La Laguna, Tenerife (Spain); Nordhaus, J. [Center for Computational Relativity and Gravitation, Rochester Institute of Technology, Rochester, NY 14623 (United States); Sandin, C., E-mail: jhk@cis.rit.edu, E-mail: soker@physics.technion.ac.il, E-mail: eva.villaver@uam.es [Leibniz Institute for Astrophysics Potsdam (AIP), An der Sternwarte 16, D-14482 Potsdam (Germany); and others

    2012-08-15

    We present an overview of the initial results from the Chandra Planetary Nebula Survey (CHANPLANS), the first systematic (volume-limited) Chandra X-Ray Observatory survey of planetary nebulae (PNe) in the solar neighborhood. The first phase of CHANPLANS targeted 21 mostly high-excitation PNe within {approx}1.5 kpc of Earth, yielding four detections of diffuse X-ray emission and nine detections of X-ray-luminous point sources at the central stars (CSPNe) of these objects. Combining these results with those obtained from Chandra archival data for all (14) other PNe within {approx}1.5 kpc that have been observed to date, we find an overall X-ray detection rate of {approx}70% for the 35 sample objects. Roughly 50% of the PNe observed by Chandra harbor X-ray-luminous CSPNe, while soft, diffuse X-ray emission tracing shocks-in most cases, 'hot bubbles'-formed by energetic wind collisions is detected in {approx}30%; five objects display both diffuse and point-like emission components. The presence (or absence) of X-ray sources appears correlated with PN density structure, in that molecule-poor, elliptical nebulae are more likely to display X-ray emission (either point-like or diffuse) than molecule-rich, bipolar, or Ring-like nebulae. All but one of the point-like CSPNe X-ray sources display X-ray spectra that are harder than expected from hot ({approx}100 kK) central stars emitting as simple blackbodies; the lone apparent exception is the central star of the Dumbbell nebula, NGC 6853. These hard X-ray excesses may suggest a high frequency of binary companions to CSPNe. Other potential explanations include self-shocking winds or PN mass fallback. Most PNe detected as diffuse X-ray sources are elliptical nebulae that display a nested shell/halo structure and bright ansae; the diffuse X-ray emission regions are confined within inner, sharp-rimmed shells. All sample PNe that display diffuse X-ray emission have inner shell dynamical ages {approx}< 5 Multiplication

  11. Einstein X-ray survey of the Pleiades - The dependence of X-ray emission on stellar age

    Science.gov (United States)

    Micela, G.; Sciortino, S.; Serio, S.; Vaiana, G. S.; Bookbinder, J.; Golub, L.; Harnden, F. R., Jr.; Rosner, R.

    1985-01-01

    The data obtained with two pointed observations of 1 deg by 1 deg fields of the Pleiades region have been analyzed, and the results are presented. The maximum-likelihood X-ray luminosity functions for the Pleiades G and K stars in the cluster are derived, and it is shown that, for the G stars, the Pleiades X-ray luminosity function is significantly brighter than the corresponding function for Hyades G dwarf stars. This finding indicates a dependence of X-ray luminosity on stellar age, which is confirmed by comparison of the same data with median X-ray luminosities of pre-main sequence and local disk population dwarf G stars. It is suggested that the significantly larger number of bright X-ray sources associated with G stars than with K stars, the lack of detection of M stars, and the relatively rapid rotation of the Pleiades K stars can be explained in terms of the onset of internal differential rotation near the convective envelope-radidative core interface after the spin-up phase during evolution to the main sequence.

  12. A CFH12k lensing survey of X-ray luminous galaxy clusters - II. Weak lensing analysis and global correlations

    NARCIS (Netherlands)

    Bardeau, S.; Soucail, G.; Kneib, J.-P.; Czoske, O.; Ebeling, H.; Hudelot, P.; Smail, I.; Smith, G. P.

    Aims. We present a wide-field multi-color survey of a homogeneous sample of eleven clusters of galaxies for which we measure total masses and mass distributions from weak lensing. This sample, spanning a small range in both X-ray luminosity and redshift, is ideally suited to determining the

  13. Inspection surveys of x-ray inspection systems: results of five years and implications on future management of radiation risks

    International Nuclear Information System (INIS)

    Maharaj, H.P.

    1999-01-01

    Until the mid-1980s, federal inspectors performed radiation surveys annually on individual x-ray inspection systems which were operated for security screening purposes in federal facilities nationwide, and problems identified were corrected. The surveys were undertaken because of perceived high radiation risks and a need to ensure worker and public external exposures were minimized. The x-ray inspection systems are federally regulated under the Radiation Emitting Devices (RED) Act and, initially they were assessed by model type against the design, construction and performance criteria specified in the applicable RED regulations (Schedule II, Part IV) and were found compliant. A subsequent study not only demonstrated a much lower radiation risk attributed to a combination of technological advances in x-ray system design with narrow primary beams, high efficiency detectors and image processing capability, but also stressed the need for proper equipment maintenance and continued education of operators and maintenance personnel. Survey frequency was thus reduced to once every 2-3 years in accordance with a 1993 federal operational standard (Safety Code 29). The radiation protection principles in Safety Code 29 are similar to those of the 1996 International Atomic Energy Agency (IAEA) Basic Safety Standards for the protection against ionizing radiation and the safety of radiation sources. The purpose of this study was to assess inspection-survey data from 1993 through 1997 to elicit guidance toward the future management of radiation risks associated with the operation of such x-ray systems. (author)

  14. NURE aerial gamma ray and magnetic reconnaissance survey, Thorpe area, Scranton NK18-8 Quadrangle. Volume I. Narrative report

    International Nuclear Information System (INIS)

    1978-02-01

    A rotary wing combined airborne high sensitivity gamma-ray and magnetic survey of four 1:250,000 quadrangles covering portions of Pennsylvania, New Jersey, and New York was made. The results are given for the Scranton NK18-8 quadrangle

  15. A model to survey diagnostic x-ray installations for licensing purpose

    International Nuclear Information System (INIS)

    Dias K, S.; Lassance, A.; Almeida, C.E. de; Cunha G, P.; Oliveira, S.V.; Motta, H.

    1996-01-01

    The process of diagnostic X-ray installations licensing in Rio de Janeiro requires several documents including an inspection report on radiation protection conditions. All the clinics have to renew their license annually. Because of the large amount of such installations, the state authority is unable to accomplish this process adequately. To overcome this problem, a postal system has been proposed to evaluate the radiological protection conditions by appropriate quality and risk indicators. A sample of 195 institutions of diagnostic radiology was chosen randomly. On this voluntary program, only 95 institutions answered the questionnaire sent in the first phase. Those clinics went to the second phase and received a thermoluminescent dosimeter (TLD) kit to be exposed in a lateral chest examination. Only 25% of the examinations were performed using kilo voltages in the range recommended by European Union for quality criteria (100-150 k Vp). Regarding to focus-film distance, about 15% of examination was performed at a distance smaller than 140 cm. High speed film-screen combinations were used in approximately 55% of the institutions. In this survey, patient doses ranged from 0.06 to 4.31 mGy. The third phase included a local inspection of 50 out 95 clinics to compose and test the risk indicators scoring system. These indicators include data on the qualification of the staff, individual monitoring, installation dimensions and layout, conditions of the equipment, maintenance, technique parameters for exams, dose to the patient, and x-ray output. (authors). 2 refs., 3 figs., 1 tab

  16. Latitudes: new Indian transnational cinema.

    Science.gov (United States)

    Villarejo, Amy

    2014-01-01

    This article examines films and video art that speak to conditions of exile and displacement, including the work of Mona Hatoum, Sonali Gulati, and Onir. It proposes the term "latitude" to interrogate the aesthetic and formal properties of these artworks, seeking to understand how lesbian and same-sex eroticism and identities are central to their efficacy.

  17. An Expanded Rossi X-Ray Timing Explorer Survey of X-Ray Variability in Seyfert 1 Galaxies

    Science.gov (United States)

    Markowitz, A.; Edelson, R.

    2004-12-01

    The first seven years of RXTE monitoring of Seyfert 1 active galactic nuclei have been systematically analyzed to yield five homogeneous samples of 2-12 keV light curves, probing hard X-ray variability on successively longer durations from ~1 day to ~3.5 yr. The 2-10 keV variability on timescales of ~1 day, as probed by ASCA, is included. All sources exhibit stronger X-ray variability toward longer timescales, but the increase is greater for relatively higher luminosity sources. Variability amplitudes are anticorrelated with X-ray luminosity and black hole mass, but amplitudes saturate and become independent of luminosity or black hole mass toward the longest timescales. The data are consistent with the models of power spectral density (PSD) movement described by Markowitz and coworkers and McHardy and coworkers, whereby Seyfert 1 galaxies' variability can be described by a single, universal PSD shape whose break frequency scales with black hole mass. The best-fitting scaling relations between variability timescale, black hole mass, and X-ray luminosity imply an average accretion rate of ~5% of the Eddington limit for the sample. Nearly all sources exhibit stronger variability in the relatively soft 2-4 keV band compared to the 7-12 keV band on all timescales. There are indications that relatively less luminous or less massive sources exhibit a greater degree of spectral variability for a given increase in overall flux.

  18. Hook whistlers observed at low latitude ground station Varanasi

    International Nuclear Information System (INIS)

    Khosa, P.N.; Lalmani; Ahmed, M.M.; Singh, B.D.

    1983-01-01

    Employing the Haselgrove ray tracing equations and a diffusive equilibrium model of the ionosphere, the propagation characteristics of hook whistlers recorded at low-latitude ground station Varanasi (geomag. lat., 16 0 6'N) are discussed. It is shown that the two traces of the hook whistlers are caused by the VLF waves radiated from the return stroke of a lightning discharge which after penetrating the ionosphere at two different entry points, propagated to the opposite hemisphere in the whistler mode and were received at 16 geomagnetic latitude. Further the crossing of ray paths for the same frequency leads to the explanation of the hook whistler. The lower and higher cut-off frequencies are explained in terms of their deviating away from the bunch of the recorded whistler waves and crossing of ray paths for the same frequency. (Auth.)

  19. The use of diagnostic x-ray among veterinarians. Results from a survey et guidance to regulations for veterinarian's use of diagnostic x-ray

    International Nuclear Information System (INIS)

    Solberg, M.

    2010-12-01

    The use of diagnostic X-ray equipment by veterinarians in Norway is regulated by the Radiation Protection Act (Stralevernloven) as well as the Regulation for Radiation Protection and Use of Radiation (Stralevernforskriften). A revised regulation was accepted by the Norwegian government 29/10/2010; revisions relevant to veterinarians will come to force 01/01/2011. Many X-ray machines are used in veterinary clinics in Norway, and the Norwegian Radiation Protection Authority (NRPA) has therefore undertaken a study to assess their use of X-ray equipment. The main objective has been to study occupational exposure to ionizing radiation. This report summarizes data collected during a web-based survey as well as data collected from 13 inspections at veterinary clinics, including in situ measurements of scattered radiation and measurements of compliance between light field and irradiation field at a selection of veterinary clinics. The report also includes guidance to regulations that are specific for the practice of radiology in veterinary medicine. The Norwegian organization for veterinarians (Den Norske Veterinarforening) is gratefully acknowledged for distributing the web-based survey among their members and thereby enabling a large number of responses to be collected. Of 441 completed surveys, 276 (63 %) confirmed that X-ray equipment was used in their clinic. The results from the survey and inspections generally show a good approach and satisfactory daily routines with regard to the use of X-ray machines, especially concerning occupational health aspects. However, nearly 50 % of the respondents were not familiar with the regulations. During the inspection round, certain regulatory requirements were found to be less than satisfactory in most clinics. Such requirements included reporting the use of X-ray machines to the NRPA and the proper use of radiation warning symbols in rooms where X-ray equipment was situated. About 50 % of the veterinary surgeons who used X -ray

  20. The applications of vehicle borne and ground gamma ray spectrometry in environmental radioactivity survey and monitoring: examples from the Philippines

    International Nuclear Information System (INIS)

    Reyes, R.Y.; Petrache, C.A.; Garcia, N.Q.; Tabora, E.U.; Juson, J.G.

    2002-01-01

    In the light of the nuclear development all over the world, there is an increasing global awareness on matters related to radioactivity and radioactive accidents. As such, the Philippine Nuclear Research Institute (PNRI) acquired through a technical cooperation project with the International Atomic Energy Agency the vehicle borne (car borne) and portable (ground) gamma ray, spectrometers. The objectives of this project were to establish environmental baseline information on the natural radioactivity of the entire country and to generate radioelement maps for geological mapping and mineral resource assessment. The purpose of this paper is to present the results of the different surveys including the methodologies and techniques conducted in the country using both spectrometers in effectively mapping natural and man-made sources of radiation. A pilot survey was successfully carried out over the small island of Marinduque (989 km 2 ) using the combined car borne and ground gamma ray spectrometric survey techniques. This was in preparation of the planned nationwide survey using this approach. Highlight of this study was the production of the first natural radioactivity maps within the country. Interestingly, these maps closely reflect the local geology of Marinduque Island. Car borne gamma ray spectrometric surveys were likewise undertaken at the former US naval base in Subic and US airforce base in Clark. This was due to mounting public concern over the presence of possible radioactive contamination or materials left behind by the US military forces in these bases. Results using the gamma-ray spectrum ratio technique indicated the absence of man-made sources of radiation in areas monitored within the two bases. A sizeable part of Metro Manila, the capital of the Philippines, has also been covered by the car borne survey. Results discovered an area with high measurements of thorium. The radiation source is coming from an establishment that uses thorium nitrate in

  1. A survey on coordinate metrology using dimensional X-ray CT

    International Nuclear Information System (INIS)

    Matsuzaki, Kazuya

    2016-01-01

    X-ray computed tomography (X-ray CT) has been occupying indispensable position in geometrical and dimensional measurements in industry, which is capable of measuring both external and internal dimensions of industrial products. Since dimensional X-ray CT has problems about ensuring traceability and estimating uncertainty, requirement of developing measurement standard for dimensional X-ray CT is increasing. Some of national metrology institutes (NMIs) including NMIJ have been working on developing measurement standard. In this report, the background of coordinate metrology using dimensional X-ray CT is reviewed. Then, measurement error sources are discussed. Finally, the plan to develop high accuracy dimensional X-ray CT is presented. (author)

  2. Airborne gamma-ray spectrometer and magnetometer survey: Barrow Quadrangle, Alaska. Final report. Volume I

    International Nuclear Information System (INIS)

    1981-03-01

    During the months of July-August 1980, Aero Service Division Western Geophysical Company of America conducted an airborne high sensitivity gamma-ray spectrometer and magnetometer survey over eleven (11) 3 0 x 1 0 and one (1) 4 0 x 1 0 NTMS quadrangles of the Alaskan North Slope. This report discusses the results obtained over the Barrow map area. The final data are presented in four different forms: on magnetic tape; on microfiche; in graphic form as profiles and histograms; and in map form as anomaly maps, flight path maps, and computer printer maps. The histograms and the multiparameter profiles are presented with the anomaly maps and flight path map in a separate bound volume. Complete data listings of both the reduced single record and the reduced averaged record data are found in the back of this report. The format of the printout of the microfiches and the format of the data files delivered on magnetic tape are in accordance with the specifications of the BFEC 1200-C and are described in appendices F through L of this report

  3. A Detailed Gamma-ray Survey for Estimating the Radiogenic Power of Sardinian Variscan Crust

    International Nuclear Information System (INIS)

    Xhixha, M.; Baldoncini, M.; Bezzon, G.P.; Buso, G.P.; Carmignani, L.; Casini, L.; Callegari, I.; Colonna, T.; Cuccuru, S.; Guastaldi, E.; Fiorentini, G.; Mantovani, F.; Massa, G.; Mou, L.; Oggiano, G.; Puccini, A.; Rossi Alvarez, C.; Strati, V.; Xhixha, G.; Zanon, A.

    2014-01-01

    The N-E Sardinia batholith is part of the European Variscan belt which is generally considered an example for hot collisional orogens. After a period of crustal thickening characterized by lower gradients, during Late Carboniferous and Early Permian times, higher geothermal gradients were diffusively established. The sources which contributed to the thermal budget of late Variscan high-temperature events are still debated. One of the hypothesis(1) considers an extra contribution by radioactive heating of felsic crust tectonically emplaced at the bottom of a Palaeozoic orogenic root. It is apparent that a detailed characterization of heat-producing elements (K, U and Th) of Sardinian Variscan crust are needed by the Earth Science community. This study focus on this goal reporting the results of an extensive survey on the base of gamma-ray measurements performed in the laboratory and in situ. The K, U and Th abundances obtained for the main lithotypes of Sardinia batholiths will be used as input for modeling the geodynamic and thermal evolution of the South Variscan Belt

  4. A new gonad protector for public survey X-ray images

    International Nuclear Information System (INIS)

    Joos, M.

    1976-01-01

    A new gonad shield intended to be used for pubic survey X-ray images is introduced. This protector is mounted on the light sight and produces a shadow free of central radiation on the patient's body. The shield provides such a shape that in women the area limited by the terminal line and in which 95% of the ovaria are situated, is covered, and that in men the region below the pubic angle is protected. The 2 mm thick lead shield has dimensions of 4.0 to 2.5 cm and is inserted into a plexiglass ruler which lies freely movable on a plexiglass plate under the light sight. This shield was tested on the water phantom and on 125 patients. With this protector it was possible to lower the surface dosages calculated by film dosimeters to 20% in women, and also to reduce the gonade dosages to 9% of the dosages without protection. The position of the new gonad protector at a distance from the body provides several advantages: the shield does not alter its position when the patient moves, the protector does not slip off the abdomen in adipose female patients, the radiation protected region has always the same extent, independent from the abdominal curvature of the female patient, the hygienic problems are eliminated, and the shield can be used for both sexes. (orig./HP) [de

  5. Error Analysis Of Clock Time (T), Declination (*) And Latitude ...

    African Journals Online (AJOL)

    ), latitude (Φ), longitude (λ) and azimuth (A); which are aimed at establishing fixed positions and orientations of survey points and lines on the earth surface. The paper attempts the analysis of the individual and combined effects of error in time ...

  6. Einstein Observatory survey of X-ray emission from solar-type stars - the late F and G dwarf stars

    Energy Technology Data Exchange (ETDEWEB)

    Maggio, A.; Sciortino, S.; Vaiana, G.S.; Majer, P.; Bookbinder, J.

    1987-04-01

    Results of a volume-limited X-ray survey of stars of luminosity classes IV and V in the spectral range F7-G9 observed with the Einstein Observatory are presented. Using survival analysis techniques, the stellar X-ray luminosity function in the 0.15-4.0 keV energy band for both single and multiple sources. It is shown that the difference in X-ray luminosity between these two classes of sources is consistent with the superposition of individual components in multiple-component systems, whose X-ray properties are similar to those of the single-component sources. The X-ray emission of the stars in our sample is well correlated with their chromospheric CA II H-K line emission and with their projected equatorial rotational velocity. Comparison of the X-ray luminosity function constructed for the sample of the dG stars of the local population with the corresponding functions derived elsewhere for the Hyades, the Pleiades, and the Orion Ic open cluster confirms that the level of X-ray emission decreases with stellar age. 62 references.

  7. Einstein Observatory survey of X-ray emission from solar-type stars - The late F and G dwarf stars

    Science.gov (United States)

    Maggio, A.; Sciortino, S.; Vaiana, G. S.; Majer, P.; Bookbinder, J.

    1987-01-01

    Results of a volume-limited X-ray survey of stars of luminosity classes IV and V in the spectral range F7-G9 observed with the Einstein Observatory are presented. Using survival analysis techniques, the stellar X-ray luminosity function in the 0.15-4.0 keV energy band for both single and multiple sources. It is shown that the difference in X-ray luminosity between these two classes of sources is consistent with the superposition of individual components in multiple-component systems, whose X-ray properties are similar to those of the single-component sources. The X-ray emission of the stars in our sample is well correlated with their chromospheric CA II H-K line emission and with their projected equatorial rotational velocity. Comparison of the X-ray luminosity function constructed for the sample of the dG stars of the local population with the corresponding functions derived elsewhere for the Hyades, the Pleiades, and the Orion Ic open cluster confirms that the level of X-ray emission decreases with stellar age.

  8. The high latitude heliosphere. Proceedings. 28. ESLAB Symposium, Friedrichshafen (Germany), 19 - 21 Apr 1994.

    Science.gov (United States)

    Marsden, R. G.

    1995-04-01

    The following topics were dealt with: high latitude heliosphere, Ulysses mission, corona, spectra, coronal holes, composition, solar wind, He, plasma, streams, interplanetary magnetic field, plasma waves, radio bursts, energetic particles, cosmic rays, and interstellar gas.

  9. Centre-excised X-ray luminosity as an efficient mass proxy for future galaxy cluster surveys

    Science.gov (United States)

    Mantz, Adam B.; Allen, Steven W.; Morris, R. Glenn; von der Linden, Anja

    2018-01-01

    The cosmological constraining power of modern galaxy cluster catalogues can be improved by obtaining low-scatter mass proxy measurements for even a small fraction of sources. In the context of large upcoming surveys that will reveal the cluster population down to the group scale and out to high redshifts, efficient strategies for obtaining such mass proxies will be valuable. In this work, we use high-quality weak-lensing and X-ray mass estimates for massive clusters in current X-ray-selected catalogues to revisit the scaling relations of the projected, centre-excised X-ray luminosity (Lce), which previous work suggests correlates tightly with total mass. Our data confirm that this is the case with Lce having an intrinsic scatter at fixed mass comparable to that of gas mass, temperature or YX. Compared to the other proxies, however, Lce is less susceptible to systematic uncertainties due to background modelling, and can be measured precisely with shorter exposures. This opens up the possibility of using Lce to estimate masses for large numbers of clusters discovered by new X-ray surveys (e.g. eROSITA) directly from the survey data, as well as for clusters discovered at other wavelengths with relatively short follow-up observations. We describe a simple procedure for making such estimates from X-ray surface brightness data, and comment on the spatial resolution required to apply this method as a function of cluster mass and redshift. We also explore the potential impact of Chandra and XMM-Newton follow-up observations over the next decade on dark energy constraints from new cluster surveys.

  10. Nightside High Latitude Magnetic Impulse Events

    Science.gov (United States)

    Engebretson, M. J.; Connors, M. G.; Braun, D.; Posch, J. L.; Kaur, M.; Guillon, S.; Hartinger, M.; Kim, H.; Behlke, R.; Reiter, K.; Jackel, B. J.; Russell, C. T.

    2017-12-01

    High latitude Magnetic Impulse Events (MIEs), isolated pulses with periods 5-10 min, were first noted in ground-based magnetometer data near local noon, and are now understood to be signatures of transient pressure increases in the solar wind (sudden impulses - SIs) and/or in the ion foreshock (traveling convection vortex events - TCVs). However, solitary pulses with considerably larger amplitude (ΔB up to 1500 nT) have often been observed in the night sector at these same latitudes. These events are not directly associated with transient external pressure increases, and are often large enough to produce significant ground induced currents. Although many night sector MIEs occur in association with substorm signatures, others appear to be very isolated. We present here a survey of intense MIE events identified in magnetometer data from the AUTUMNX and MACCS arrays in eastern Arctic Canada at all local times between July 1, 2014 and June 30, 2017. We also show maps of horizontal and vertical perturbations and maximum dB/dt values, as well as sample magnetograms, for several example events using data from these and other arrays in Arctic Canada, as well as in West Greenland and Antarctica, the latter to show the conjugate nature of these events. A basic relation to GIC data in the Hydro-Québec electrical transmission network in eastern Canada has been determined and will be discussed.

  11. Airborne gamma-ray spectrometer and magnetometer survey: Norton Bay Quadrangle (Alaska). Final report

    International Nuclear Information System (INIS)

    1980-01-01

    During the months of July, August, and September 1979, an airborne high sensitivity gamma-ray spectrometer and magnetometer survey was conducted over ten 3 0 x 1 0 NTMS quadrangles of West-Central Alaska. The results obtained over the Norton Bay Map area are discussed. The final data are presented in four different forms: on magnetic tape; on microfiche; in graphic form as profiles and histograms; and in map form as anomaly maps and flight path maps. The histograms and the multiparameter are presented with the anomaly maps and flight path map in a separate volume. A total of twenty (20) uranium anomalies have been indicated on the interpretation map. No thorium anomalies were found. The uranium anomalies are all weak and generally have only U/K or U/T expression. Often the uranium concentration within the zone is low, and generally is less than 2.5 ppM. Only zones 9, with an average of 3.0 ppM eU, and 14, with 2.6 ppm have above average uranium content. Zone 14 is also the only uranium anomaly with combined U/K and U/T ratio anomalies. No single uranium anomaly is believed to represent an economic follow-up target. The most prospective area appears to be the elongate zone of generally high uranium content, formed by the deposits of the Shaktolik group, to the east of the Ungalik conglomerate. This zone flanks an elongate area of relatively strong shallow magnetic sources, interpreted to be related to a monozonitic intrusive of which the Christmas mountain forms part. This intrusive rock contains in other neighboring areas often high thorium and uranium concentrations and may here as well served as a possible source of uranium deposits

  12. Neoplasms in persons treated with x-rays in infancy: fourth survey in 20 years

    International Nuclear Information System (INIS)

    Hempelmann, L.H.; Hall, W.J.; Phillips, M.; Cooper, R.A.; Ames, W.R.

    1975-01-01

    The incidence of neoplastic disease was determined by a mail survey of 2,872 young adults given x-ray treatments in infancy and of their 5,005 nonirradiated siblings. Newly diagnosed benign and malignant neoplasms appeared more frequently in the irradiated subjects than in their siblings or the age- and sex-matched general population of upstate New York. Only thyroid neoplasms occurred in sufficient numbers to permit statistical analysis for the effects on incidence of sex, age, and dose, and of being in a high-risk group (sub-group C). Thyroid cancers developed earlier in life than did benign neoplasms, especially in boys; benign goiters occurred after smaller doses, predominantly in females. Females had a greater risk of developing thyroid cancer than males--2.3 times for females of all ages and 5 times for young adults. Except for young adult females, there was no definite age effect. The risk of cancer (but not of benign goiter) was proportional to the thyroid dose, with a linear risk coefficient of 2.5/year/million people exposed to 1 rad for the entire irradiated population and 4.0 for subgroup C. The high risk of thyroid cancer in subgroup C may be the result of the high percentage of Jews, who had a 3.4-fold greater risk than non-Jews. Young adult Jewish females had a 17-fold increased risk. An incidental observation was an apparent increased incidence of asthma and rare diseases with abnormal immunologic features in the irradiated population. (auth)

  13. The cosmological analysis of X-ray cluster surveys - I. A new method for interpreting number counts

    Science.gov (United States)

    Clerc, N.; Pierre, M.; Pacaud, F.; Sadibekova, T.

    2012-07-01

    We present a new method aimed at simplifying the cosmological analysis of X-ray cluster surveys. It is based on purely instrumental observable quantities considered in a two-dimensional X-ray colour-magnitude diagram (hardness ratio versus count rate). The basic principle is that even in rather shallow surveys, substantial information on cluster redshift and temperature is present in the raw X-ray data and can be statistically extracted; in parallel, such diagrams can be readily predicted from an ab initio cosmological modelling. We illustrate the methodology for the case of a 100-deg2XMM survey having a sensitivity of ˜10-14 erg s-1 cm-2 and fit at the same time, the survey selection function, the cluster evolutionary scaling relations and the cosmology; our sole assumption - driven by the limited size of the sample considered in the case study - is that the local cluster scaling relations are known. We devote special attention to the realistic modelling of the count-rate measurement uncertainties and evaluate the potential of the method via a Fisher analysis. In the absence of individual cluster redshifts, the count rate and hardness ratio (CR-HR) method appears to be much more efficient than the traditional approach based on cluster counts (i.e. dn/dz, requiring redshifts). In the case where redshifts are available, our method performs similar to the traditional mass function (dn/dM/dz) for the purely cosmological parameters, but constrains better parameters defining the cluster scaling relations and their evolution. A further practical advantage of the CR-HR method is its simplicity: this fully top-down approach totally bypasses the tedious steps consisting in deriving cluster masses from X-ray temperature measurements.

  14. A Chandra Survey of Milky Way Globular Clusters. I. Emissivity and Abundance of Weak X-Ray Sources

    Science.gov (United States)

    Cheng, Zhongqun; Li, Zhiyuan; Xu, Xiaojie; Li, Xiangdong

    2018-05-01

    Based on archival Chandra data, we have carried out an X-ray survey of 69, or nearly half the known population of, Milky Way globular clusters (GCs), focusing on weak X-ray sources, mainly cataclysmic variables (CVs) and coronally active binaries (ABs). Using the cumulative X-ray luminosity per unit stellar mass (i.e., X-ray emissivity) as a proxy of the source abundance, we demonstrate a paucity (lower by 41% ± 27% on average) of weak X-ray sources in most GCs relative to the field, which is represented by the Solar Neighborhood and Local Group dwarf elliptical galaxies. We also revisit the mutual correlations among the cumulative X-ray luminosity (L X), cluster mass (M), and stellar encounter rate (Γ), finding {L}{{X}}\\propto {M}0.74+/- 0.13, {L}{{X}}\\propto {{{Γ }}}0.67+/- 0.07 and {{Γ }}\\propto {M}1.28+/- 0.17. The three quantities can further be expressed as {L}{{X}}\\propto {M}0.64+/- 0.12 {{{Γ }}}0.19+/- 0.07, which indicates that the dynamical formation of CVs and ABs through stellar encounters in GCs is less dominant than previously suggested, and that the primordial formation channel has a substantial contribution. Taking these aspects together, we suggest that a large fraction of primordial, soft binaries have been disrupted in binary–single or binary–binary stellar interactions before they could otherwise evolve into X-ray-emitting close binaries, whereas the same interactions also have led to the formation of new close binaries. No significant correlations between {L}{{X}}/{L}K and cluster properties, including dynamical age, metallicity, and structural parameters, are found.

  15. Large-area Soil Moisture Surveys Using a Cosmic-ray Rover: Approaches and Results from Australia

    Science.gov (United States)

    Hawdon, A. A.; McJannet, D. L.; Renzullo, L. J.; Baker, B.; Searle, R.

    2017-12-01

    Recent improvements in satellite instrumentation has increased the resolution and frequency of soil moisture observations, and this in turn has supported the development of higher resolution land surface process models. Calibration and validation of these products is restricted by the mismatch of scales between remotely sensed and contemporary ground based observations. Although the cosmic ray neutron soil moisture probe can provide estimates soil moisture at a scale useful for the calibration and validation purposes, it is spatially limited to a single, fixed location. This scaling issue has been addressed with the development of mobile soil moisture monitoring systems that utilizes the cosmic ray neutron method, typically referred to as a `rover'. This manuscript describes a project designed to develop approaches for undertaking rover surveys to produce soil moisture estimates at scales comparable to satellite observations and land surface process models. A custom designed, trailer-mounted rover was used to conduct repeat surveys at two scales in the Mallee region of Victoria, Australia. A broad scale survey was conducted at 36 x 36 km covering an area of a standard SMAP pixel and an intensive scale survey was conducted over a 10 x 10 km portion of the broad scale survey, which is at a scale equivalent to that used for national water balance modelling. We will describe the design of the rover, the methods used for converting neutron counts into soil moisture and discuss factors controlling soil moisture variability. We found that the intensive scale rover surveys produced reliable soil moisture estimates at 1 km resolution and the broad scale at 9 km resolution. We conclude that these products are well suited for future analysis of satellite soil moisture retrievals and finer scale soil moisture models.

  16. AN X-RAY SURVEY OF THE YOUNG STELLAR POPULATION OF THE LYNDS 1641 AND IOTA ORIONIS REGIONS

    Energy Technology Data Exchange (ETDEWEB)

    Pillitteri, I.; Wolk, S. J.; Myers, P.; Walter, F. [SAO-Harvard Center for Astrophysics, Cambridge, MA 02138 (United States); Megeath, S. T. [Department of Physics and Astronomy, University of Toledo, Toledo, OH 43606 (United States); Allen, L. [National Optical Astronomy Observatory, Tucson, AZ 85719 (United States); Bally, J. [University of Colorado, Boulder, CO 80309 (United States); Gagne, M. [Department of Geology and Astronomy, West Chester University, West Chester, PA 19383 (United States); Gutermuth, R. A. [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); Hartman, L. [University of Michigan, Ann Arbor, MI 48109 (United States); Micela, G.; Sciortino, S. [INAF-Osservatorio Astronomico di Palermo, I-90134 Palermo (Italy); Oliveira, J. M. [School of Physical and Geographical Sciences, Lennard-Jones Laboratories, Keele University, Staffordshire ST5 5BG (United Kingdom); Rebull, L.; Stauffer, J., E-mail: ipillitteri@cfa.harvard.edu [CALTECH, Pasadena, CA 91125 (United States)

    2013-05-10

    We present an XMM-Newton survey of the part of the Orion A cloud south of the Orion Nebula. This survey includes the Lynds 1641 (L1641) dark cloud, a region of the Orion A cloud with very few massive stars and hence a relatively low ambient UV flux, and the region around the O9 III star {iota} Orionis. In addition to proprietary data, we used archival XMM data of the Orion Nebula Cluster (ONC) to extend our analysis to a major fraction of the Orion A cloud. We have detected 1060 X-ray sources in L1641 and the {iota} Ori region. About 94% of the sources have Two Micron All Sky Survey and Spitzer counterparts, 204 and 23 being Class II and Class I or protostar objects, respectively. In addition, we have identified 489 X-ray sources as counterparts to Class III candidates, given they are bright in X-rays and appear as normal photospheres at mid-IR wavelengths. The remaining 205 X-ray sources are likely distant active galactic nuclei or other galactic sources not related to Orion A. We find that Class III candidates appear more concentrated in two main clusters in L1641. The first cluster of Class III stars is found toward the northern part of L1641, concentrated around {iota} Ori. The stars in this cluster are more evolved than those in the Orion Nebula. We estimate a distance of 300-320 pc for this cluster showing that it is in the foreground of the Orion A cloud. Another cluster rich in Class III stars is located in L1641 South and appears to be a slightly older cluster embedded in the Orion A cloud. Furthermore, other evolved Class III stars are found north of the ONC toward NGC 1977.

  17. AN X-RAY SURVEY OF THE YOUNG STELLAR POPULATION OF THE LYNDS 1641 AND IOTA ORIONIS REGIONS

    International Nuclear Information System (INIS)

    Pillitteri, I.; Wolk, S. J.; Myers, P.; Walter, F.; Megeath, S. T.; Allen, L.; Bally, J.; Gagné, M.; Gutermuth, R. A.; Hartman, L.; Micela, G.; Sciortino, S.; Oliveira, J. M.; Rebull, L.; Stauffer, J.

    2013-01-01

    We present an XMM-Newton survey of the part of the Orion A cloud south of the Orion Nebula. This survey includes the Lynds 1641 (L1641) dark cloud, a region of the Orion A cloud with very few massive stars and hence a relatively low ambient UV flux, and the region around the O9 III star ι Orionis. In addition to proprietary data, we used archival XMM data of the Orion Nebula Cluster (ONC) to extend our analysis to a major fraction of the Orion A cloud. We have detected 1060 X-ray sources in L1641 and the ι Ori region. About 94% of the sources have Two Micron All Sky Survey and Spitzer counterparts, 204 and 23 being Class II and Class I or protostar objects, respectively. In addition, we have identified 489 X-ray sources as counterparts to Class III candidates, given they are bright in X-rays and appear as normal photospheres at mid-IR wavelengths. The remaining 205 X-ray sources are likely distant active galactic nuclei or other galactic sources not related to Orion A. We find that Class III candidates appear more concentrated in two main clusters in L1641. The first cluster of Class III stars is found toward the northern part of L1641, concentrated around ι Ori. The stars in this cluster are more evolved than those in the Orion Nebula. We estimate a distance of 300-320 pc for this cluster showing that it is in the foreground of the Orion A cloud. Another cluster rich in Class III stars is located in L1641 South and appears to be a slightly older cluster embedded in the Orion A cloud. Furthermore, other evolved Class III stars are found north of the ONC toward NGC 1977.

  18. The complete Einstein Observatory X-ray survey of the Orion Nebula region.

    Science.gov (United States)

    Gagne, Marc; Caillault, Jean-Pierre

    1994-01-01

    We have analyzed archival Einstein Observatory images of a roughly 4.5 square degree region centered on the Orion Nebula. In all, 245 distinct X-ray sources have been detected in six High Resolution Imager (HRI) and 17 Imaging Proportional Counter (IPC) observations. An optical database of over 2700 stars has been assembled to search for candidate counterparts to the X-ray sources. Roughly half the X-ray sources are identified with a single Orion Nebula cluster member. The 10 main-sequence O6-B5 cluster stars detected in Orion have X-ray activity levels comparable to field O and B stars. X-ray emission has also been detected in the direction of four main-sequence late-B and early-A type stars. Since the mechanisms producing X-rays in late-type coronae and early-type winds cannot operate in the late-B and early-A type atmospheres, we argue that the observed X-rays, with L(sub X) approximately = 3 x 10(exp 30) ergs/s, are probably produced in the coronae of unseen late-type binary companions. Over 100 X-ray sources have been associated with late-type pre-main sequence stars. The upper envelope of X-ray activity rises sharply from mid-F to late-G, with L(sub x)/L(sub bol) in the range 10(exp -4) to 2 x 10(exp -3) for stars later than approximately G7. We have looked for variability of the late-type cluster members on timescales of a day to a year and find that 1/4 of the stars show significantly variable X-ray emission. A handful of the late-type stars have published rotational periods and spectroscopic rotational velocities; however, we see no correlation between X-ray activity and rotation. Thus, for this sample of pre-main-sequence stars, the large dispersion in X-ray activity does not appear to be caused by the dispersion in rotation, in contrast with results obtained for low-mass main-sequence stars in the Pleiades and pre-main-sequence stars in Taurus-Auriga.

  19. Production of secondary Deuterium in the atmosphere at various latitudes

    Energy Technology Data Exchange (ETDEWEB)

    Papini, P. [Florence Univ. (Italy)]|[INFN, Florence (Italy); Grimani, C. [Perugia Univ. (Italy)]|[INFN, Perugia (Italy); Stephens, S.A. [Tata Institute of Fundamental Research, Bombay (International Commission on Radiation Units and Measurements)

    1995-09-01

    Secondary deuterium in the atmosphere are produced in interactions by primary cosmic rays. The shape of their energy spectrum depends on the primary cosmic ray spectrum incident at the top of the atmosphere. At high energies, the spectral shape depends on the primary spectrum of helium and heavy nuclei. However, at very low energies, specially below the geomagnetic cut-off, the spectral shape depends on the evaporation and recoil processes and hence almost independent of the spectral shape of the primary radiation. It is undertaken a calculation of the secondary deuterium spectrum at small atmospheric depths at various latitudes and the results will be presented.

  20. THE 31 DEG{sup 2} RELEASE OF THE STRIPE 82 X-RAY SURVEY: THE POINT SOURCE CATALOG

    Energy Technology Data Exchange (ETDEWEB)

    LaMassa, Stephanie M.; Urry, C. Megan; Ananna, Tonima; Civano, Francesca; Marchesi, Stefano; Pecoraro, Robert [Yale Center for Astronomy and Astrophysics, Physics Department, P.O. Box 208120, New Haven, CT 06520 (United States); Cappelluti, Nico; Comastri, Andrea; Brusa, Marcella [INAF-Osservatorio Astronomico di Bologna, via Ranzani 1, I-40127 Bologna (Italy); Böhringer, Hans; Chon, Gayoung [Max-Planck-Institut für extraterrestrische Physik, D-85748 Garching (Germany); Glikman, Eilat [Department of Physics, Middlebury College, Middlebury, VT 05753 (United States); Richards, Gordon [Department of Physics, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 (United States); Cardamone, Carie [Department of Math and Science, Wheelock College, 200 Riverway, Boston, MA 02215 (United States); Farrah, Duncan [Department of Physics MC 0435, Virginia Polytechnic Institute and State University, 850 West Campus Drive, Blacksburg, VA 24061 (United States); Gilfanov, Marat [Max-Planck Institut für Astrophysik, Karl-Schwarzschild-Str. 1, Postfach 1317, D-85741 Garching (Germany); Green, Paul [Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States); Komossa, S. [Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany); Lira, Paulina [Departamento de Astronomia, Universidad de Chile, Camino del Observatorio 1515, Santiago (Chile); Makler, Martin [Centro Brasileiro de Pesquisas Fisicas, Rua Dr Xavier Sigaud 150, Rio de Janeiro, RJ 22290-180 (Brazil); and others

    2016-02-01

    We release the next installment of the Stripe 82 X-ray survey point-source catalog, which currently covers 31.3 deg{sup 2} of the Sloan Digital Sky Survey (SDSS) Stripe 82 Legacy field. In total, 6181 unique X-ray sources are significantly detected with XMM-Newton (>5σ) and Chandra (>4.5σ). This catalog release includes data from XMM-Newton cycle AO 13, which approximately doubled the Stripe 82X survey area. The flux limits of the Stripe 82X survey are 8.7 × 10{sup −16} erg s{sup −1} cm{sup −2}, 4.7 × 10{sup −15} erg s{sup −1} cm{sup −2}, and 2.1 × 10{sup −15} erg s{sup −1} cm{sup −2} in the soft (0.5–2 keV), hard (2–10 keV), and full bands (0.5–10 keV), respectively, with approximate half-area survey flux limits of 5.4 × 10{sup −15} erg s{sup −1} cm{sup −2}, 2.9 × 10{sup −14} erg s{sup −1} cm{sup −2}, and 1.7 × 10{sup −14} erg s{sup −1} cm{sup −2}. We matched the X-ray source lists to available multi-wavelength catalogs, including updated matches to the previous release of the Stripe 82X survey; 88% of the sample is matched to a multi-wavelength counterpart. Due to the wide area of Stripe 82X and rich ancillary multi-wavelength data, including coadded SDSS photometry, mid-infrared WISE coverage, near-infrared coverage from UKIDSS and VISTA Hemisphere Survey, ultraviolet coverage from GALEX, radio coverage from FIRST, and far-infrared coverage from Herschel, as well as existing ∼30% optical spectroscopic completeness, we are beginning to uncover rare objects, such as obscured high-luminosity active galactic nuclei at high-redshift. The Stripe 82X point source catalog is a valuable data set for constraining how this population grows and evolves, as well as for studying how they interact with the galaxies in which they live.

  1. Regional radiometric study over the east of Homs City depending on carborne gamma-ray spectrometry survey

    International Nuclear Information System (INIS)

    Aissa, Mosa

    1994-03-01

    The purpose of regional carborne gamma-ray survey over the east of Homs city is to determine the ground concentration of potassium, uranium and thorium. In the other hand, collecting essential information for future monitoring of any suspected leakage or contamination. In the presented study, we used four channel gamma-ray spectrometer with a 1.8 liter NaI(TI) detector, supplied by the IAEA 1988. About 1205 records of data was accomplished over the area, the car was run at 15-25 km/hr. Potassium, uranium, thorium, and total gamma-ray counts were recorded every 100 m and stored on HD with fiducial. Diurnal variations in the content of atmospheric radon in area were indicated by base station. The background counting-rate variations was obtained from the counts recorded over the Al-Furat river. Stripping ratios and window sensitivities are determined experimentally before the survey operations. The processing of the raw data was done with Pc-computer at SAEC software had written using Fortran, for date validation, editing, corrections, and gridding. The contour maps of seven parameters of Ur, U, Th (ppm), %K, and U/Th, U/K, Th/K ratios had drawn with the help of Surfer program, in which these maps showed without high concentration, They, infect, reflect the natural concentrations of radioactive elements in the concerned area. (Author). 14 refs., 12 figs., 10 tabs

  2. A CHANDRA SURVEY OF THE X-RAY PROPERTIES OF BROAD ABSORPTION LINE RADIO-LOUD QUASARS

    International Nuclear Information System (INIS)

    Miller, B. P.; Brandt, W. N.; Garmire, G. P.; Gibson, R. R.; Shemmer, O.

    2009-01-01

    This work presents the results of a Chandra study of 21 broad absorption line (BAL) radio-loud quasars (RLQs). We conducted a Chandra snapshot survey of 12 bright BAL RLQs selected from Sloan Digital Sky Survey Data/Faint Images of the Radio Sky data and possessing a wide range of radio and C IV absorption properties. Optical spectra were obtained nearly contemporaneously with the Hobby-Eberly Telescope; no strong flux or BAL variability was seen between epochs. In addition to the snapshot targets, we include in our sample nine additional BAL RLQs possessing archival Chandra coverage. We compare the properties of (predominantly high-ionization) BAL RLQs to those of non-BAL RLQs as well as to BAL radio-quiet quasars (RQQs) and non-BAL RQQs for context. All 12 snapshots and 8/9 archival BAL RLQs are detected, with observed X-ray luminosities less than those of non-BAL RLQs having comparable optical/UV luminosities by typical factors of 4.1-8.5. (BAL RLQs are also X-ray weak by typical factors of 2.0-4.5 relative to non-BAL RLQs having both comparable optical/UV and radio luminosities.) However, BAL RLQs are not as X-ray weak relative to non-BAL RLQs as are BAL RQQs relative to non-BAL RQQs. While some BAL RLQs have harder X-ray spectra than typical non-BAL RLQs, some have hardness ratios consistent with those of non-BAL RLQs, and there does not appear to be a correlation between X-ray weakness and spectral hardness, in contrast to the situation for BAL RQQs. RLQs are expected to have X-ray continuum contributions from both accretion-disk corona and small-scale jet emission. While the entire X-ray continuum in BAL RLQs cannot be obscured to the same degree as in BAL RQQs, we calculate that the jet is likely partially covered in many BAL RLQs. We comment briefly on implications for geometries and source ages in BAL RLQs.

  3. Assessment of survey radiography and comparison with x-ray computed tomography for detection of hyperfunctioning adrenocortical tumors in dogs

    International Nuclear Information System (INIS)

    Voorhout, G.; Stolp, R.; Rijnberk, A.; Waes, P.F.G.M. van

    1990-01-01

    Results of abdominal survey radiography and x-ray computed tomography (CT) were compared in 13 dogs with hyperadrenocorticism histologically attributed to adrenocortical tumors. X-ray computed tomography enabled accurate localization of the tumor in all 13 dogs. Apart from 2 poorly demarcated irregular-shaped and mineralized carcinomas, there were no differences between adenoma (n = 3) and carcinoma (n = 10) on CT images. In 1 dog, invasion of the caudal vena cava by the tumor was suggested on CT images and was confirmed during surgery. Suspicion of adhesions between tumors of the right adrenal gland and the caudal vena cava on the basis of CT images was confirmed during surgery in only 2 of 6 dogs. Survey radiography allowed accurate localization of the tumor in 7 dogs (4 on the right side and 3 on the left). In 6 of these dogs, the tumor was visible as a well-demarcated soft tissue mass and, in the other dog, as a poorly demarcated mineralized mass. The smallest tumor visualized on survey radiographs had a diameter of 20 mm on CT images. Six tumors with diameter less than or equal to 20 mm were not visualized on survey radiographs. In 1 of these dogs, a mineralized nodule was found in the left adrenal region, without evidence of a mass. In a considerable number of cases, survey radiography can provide presurgical localization of adrenocortical tumors in dogs with hyperadrenocorticism; CT is redundant in these instances. In the absence of positive radiographic findings, CT is valuable for localization of adrenocortical tumors

  4. Determination of data correction coefficients and the sensitivities of the KIER air-borne gamma-ray spectrometer survey system

    International Nuclear Information System (INIS)

    Koo, J.H.; Cho, D.H.; Park, Y.S.

    1982-01-01

    In air-borne gamma-ray spectrometer survey, the observed data must be corrected for the background, Compton scattering and flight altitude. And the corrected data are usually converted into the radiometric elements equivalents of the ground, using the sensitivities of the survey system. Accordingly, the correction coefficients and the sensitivities are determined as follows for the KIER air-borne survey system. The stripping or Compton scattering coefficients α, β and γ at the ground level were first determined on the basis of the gamma-ray count rates due to the 5 concrete calibration pads of the Soosaek Airbase, together with the radiometric elements concentrations of the core samples taken from the pads. As for the determination of the exponential altitude coefficients anti μ(K), anti μ(U), anti μ(Th) and anti μ(Tc), the count rates observed over the Hongseong Test Strip of about 3 km length were used after they had been corrected for the background and Compton scattering. The background count rates mainly caused by the air-craft as well as cosmic radiations were determined with the data taken over the West Sea near Anmyon Island, Chung-cheongnam-do. And the corrected count rates observed over the Strip, combined with the average radiometric elements concentrations of the Strip, yielded the sensitivities k(K), k(U) and k(Th) at the 400 feet flight altitude. (author)

  5. A Deep X-ray Survey of the Globular Cluster Omega Centauri

    Science.gov (United States)

    Henleywillis, Simon; Cool, Adrienne M.; Haggard, Daryl; Heinke, Craig; Callanan, Paul; Zhao, Yue

    2018-03-01

    We identify 233 X-ray sources, of which 95 are new, in a 222 ks exposure of Omega Centauri with the Chandra X-ray Observatory's ACIS-I detector. The limiting unabsorbed flux in the core is fX(0.5-6.0 keV) ≃ 3×10-16 erg s-1 cm-2 (Lx ≃ 1×1030 erg s-1 at 5.2 kpc). We estimate that ˜60 ± 20 of these are cluster members, of which ˜30 lie within the core (rc = 155 arcsec), and another ˜30 between 1-2 core radii. We identify four new optical counterparts, for a total of 45 likely identifications. Probable cluster members include 18 cataclysmic variables (CVs) and CV candidates, one quiescent low-mass X-ray binary, four variable stars, and five stars that are either associated with ω Cen's anomalous red giant branch, or are sub-subgiants. We estimate that the cluster contains 40 ± 10 CVs with Lx > 1031 erg s-1, confirming that CVs are underabundant in ω Cen relative to the field. Intrinsic absorption is required to fit X-ray spectra of six of the nine brightest CVs, suggesting magnetic CVs, or high-inclination systems. Though no radio millisecond pulsars (MSPs) are currently known in ω Cen, more than 30 unidentified sources have luminosities and X-ray colours like those of MSPs found in other globular clusters; these could be responsible for the Fermi-detected gamma-ray emission from the cluster. Finally, we identify a CH star as the counterpart to the second-brightest X-ray source in the cluster and argue that it is a symbiotic star. This is the first such giant/white dwarf binary to be identified in a globular cluster.

  6. Optical spectroscopic observations of blazars and γ-ray blazar candidates in the sloan digital sky survey data release nine

    Energy Technology Data Exchange (ETDEWEB)

    Massaro, F.; Masetti, N.; D' Abrusco, R.; Paggi, A.; Funk, S.

    2014-09-09

    We present an analysis of the optical spectra available in the Sloan Digital Sky Survey data release nine (SDSS DR9) for the blazars listed in the ROMA-BZCAT and for the γ-ray blazar candidates selected according to their IR colors. First, we adopt a statistical approach based on Monte Carlo simulations to find the optical counterparts of the blazars listed in the ROMA-BZCAT catalog. Then, we crossmatched the SDSS spectroscopic catalog with our selected samples of blazars and γ-ray blazar candidates, searching for those with optical spectra available to classify our blazar-like sources and, whenever possible, to confirm their redshifts. Our main objectives are to determine the classification of uncertain blazars listed in the ROMA-BZCAT and to discover new gamma-ray blazars. For the ROMA-BZCAT sources, we investigated a sample of 84 blazars, confirming the classification for 20 of them and obtaining 18 new redshift estimates. For the γ-ray blazars, indicated as potential counterparts of unassociated Fermi sources or with uncertain nature, we established the blazar-like nature of 8 out of the 27 sources analyzed and confirmed 14 classifications.

  7. Diagnostic x-ray equipment compliance and facility survey. Recommended procedures for equipment and facility testing

    International Nuclear Information System (INIS)

    1994-01-01

    The Radiation Protection Bureau has set out guidelines for the testing of diagnostic x-ray equipment and facilities. This guide provides information for the x-ray inspector, test engineer, technologist, medical physicist and any other person responsible for verifying the regulatory compliance or safety of diagnostic x-ray equipment and facilities. Diagnostic x-radiation is an essential part of present day medical practice. The largest contributor of irradiation to the general population comes from diagnostic x-radiation. Although individual irradiations are usually small, there is a concern of possible excess cancer risk when large populations are irradiated. Unnecessary irradiations to patients from radiological procedures can be significantly reduced with little or no decrease in the value of medical diagnostic information. This can be achieved by using well designed x-ray equipment which is installed, used and maintained by trained personnel, and by the adoption of standardized procedures. In general, when patient surface dose is reduced, there is a corresponding decrease in dose to x-ray equipment operators and other health care personnel. 2 tabs., 4 figs

  8. Diagnostic x-ray equipment compliance and facility survey. Recommended procedures for equipment and facility testing

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-31

    The Radiation Protection Bureau has set out guidelines for the testing of diagnostic x-ray equipment and facilities. This guide provides information for the x-ray inspector, test engineer, technologist, medical physicist and any other person responsible for verifying the regulatory compliance or safety of diagnostic x-ray equipment and facilities. Diagnostic x-radiation is an essential part of present day medical practice. The largest contributor of irradiation to the general population comes from diagnostic x-radiation. Although individual irradiations are usually small, there is a concern of possible excess cancer risk when large populations are irradiated. Unnecessary irradiations to patients from radiological procedures can be significantly reduced with little or no decrease in the value of medical diagnostic information. This can be achieved by using well designed x-ray equipment which is installed, used and maintained by trained personnel, and by the adoption of standardized procedures. In general, when patient surface dose is reduced, there is a corresponding decrease in dose to x-ray equipment operators and other health care personnel. 2 tabs., 4 figs.

  9. Clinical evaluation of wide-latitude HR-C film for chest radiography

    International Nuclear Information System (INIS)

    Kim, Young Sung; Hwang, Nam Sun; Yeo, Young Bok; Lee, In Ja; Huh, Joon

    1990-01-01

    In application of wide latitude HR-C film to chest x-ray examination, former x-ray diagnosis area is larger and diagnostic information has great deal of promotion. HR-C film is compare to former x-ray film is larger latitude and density level is small, reading is very easily. Especially, high estimate that is in characteristic curve linearity of toe part is good, contrast of low density made good shape and not good describe to overlap is diagnostic information increase mediastinum portion etc

  10. THE X-RAY PROPERTIES OF THE OPTICALLY BRIGHTEST MINI-BAL QUASARS FROM THE SLOAN DIGITAL SKY SURVEY

    International Nuclear Information System (INIS)

    Wu Jianfeng; Brandt, W. N.; Comins, M. L.; Garmire, Gordon P.; Schneider, Donald P.; Gibson, Robert R.; Shemmer, Ohad

    2010-01-01

    We have compiled a sample of 14 of the optically brightest radio-quiet quasars (m i ≤ 17.5 and z ≥ 1.9) in the Sloan Digital Sky Survey Data Release 5 quasar catalog that have C IV mini-broad absorption lines (mini-BALs) present in their spectra. X-ray data for 12 of the objects were obtained via a Chandra snapshot survey using ACIS-S, while data for the other two quasars were obtained from archival XMM-Newton observations. Joint X-ray spectral analysis shows that the mini-BAL quasars have a similar average power-law photon index (Γ ∼ 1.9) and level of intrinsic absorption (N H ∼ 21 cm -2 ) as non-BMB (neither BAL nor mini-BAL) quasars. Mini-BAL quasars are more similar to non-BMB quasars than to BAL quasars in their distribution of relative X-ray brightness (assessed with Δα ox ). Relative colors indicate mild dust reddening in the optical spectra of mini-BAL quasars. Significant correlations between Δα ox and UV absorption properties are confirmed for a sample of 56 sources combining mini-BAL and BAL quasars with high signal-to-noise ratio rest-frame UV spectra, which generally supports models in which X-ray absorption is important in enabling driving of the UV absorption-line wind. We also propose alternative parameterizations of the UV absorption properties of mini-BAL and BAL quasars, which may better describe the broad absorption troughs in some respects.

  11. Distribution of gamma-ray dose rate in Fukushima prefecture by a car-borne survey method

    International Nuclear Information System (INIS)

    Sugihara, Shinji; Momoshima, Noriyuki; Maekawa, Akihiro; Ichikawa, Ryohei; Kawamura, Hidehisa

    2013-01-01

    The Tohoku Pacific Earthquake and Tsunami on March 11, 2011, caused severe damage to the TEPCO Fukushima Dai-ichi NPP. This was followed by a nuclear accident at an unprecedented scale, and huge amounts of radioactive material were released into the environment. The distributions of the gamma-ray dose rate in Fukushima prefecture were measured using a NaI(Tl) scintillation survey meter as part of a car-borne survey method on April 18-21, June 20-22, October 18-21, 2011, and on April 9-11 and July 30 - August 1, 2012. The dose rate near TEPCO Fukushima Dai-ichi NPP and at Iitate-mura, Fukushima-city was high (1 to >30 μSv/h). (author)

  12. Machine learning from hard x-ray surveys: applications to magnetic cataclysmic variable studies

    Science.gov (United States)

    Scaringi, Simone

    2009-11-01

    Within this thesis are discussed two main topics of contemporary astrophysics. The first is that of machine learning algorithms for astronomy whilst the second is that of magnetic cataclysmic variables (mCVs). To begin, an overview is given of ISINA: INTEGRAL Scouce Identifiction Network Algorithm. This machine learning algorithm, using random forests, is applied to the IBIS/ISGRI data set in order to ease the production of unbiased future soft gamma-ray source catalogues. The feature extraction process on an initial candidate list is described together with feature merging. Three trainng and testing sets are created in order to deal with the diverse time-scales encountered when dealing with the gamma-ray sky: one dealing with faint persistent source recognition, one dealing with strong persistent sources and a final one dealing with transients. For the latter, a new transient detection technique is introduced and described: the transient matrix. Finally the performance of the network is assessed and discussed using the testing set and some illustrative source examples. ISINA is also compared to the more conventional approach of visual inspection. Next mCVs are discussed, and in particular the properties arising from a hard X-ray selected sample which has proven remarkably efficient in detecting intermediate polars and asynchronous polars, two of the rarest type of cataclysmic variables (CVs). This thesis focuses particularly on the link between hard X-ray properties and spin/orbital periods. To this end, a new sample of these objects is constructed by cross-corelating candidate sources detected in INTEGRAL/IBIS observations against catalogues of known CVs. Also included in the analysis are hard X-ray Observations from Swift/BAT and SUZAKU/HXD in order to make the study more complete. It is found that most hard X-ray detected mCVs have Pspin/Porb<0.1 above the period gap. In this respect, attention is given to the very low number of detected systems in any ban

  13. Cosmic Rays in Magnetospheres of the Earth and other Planets

    CERN Document Server

    Dorman, Lev

    2009-01-01

    This monograph describes the behaviour of cosmic rays in the magnetosphere of the Earth and of some other planets. Recently this has become an important topic both theoretically, because it is closely connected with the physics of the Earth’s magnetosphere, and practically, since cosmic rays determine a significant part of space weather effects on satellites and aircraft. The book contains eight chapters, dealing with – The history of the discovery of geomagnetic effects caused by cosmic rays and their importance for the determination of the nature of cosmic rays or gamma rays – The first explanations of geomagnetic effects within the framework of the dipole approximation of the Earth’s magnetic field – Trajectory computations of cutoff rigidities, transmittance functions, asymptotic directions, and acceptance cones in the real geomagnetic field taking into account higher harmonics – Cosmic ray latitude-longitude surveys on ships, trains, tracks, planes, balloons and satellites for determining the...

  14. Airborne gamma-ray spectrometer and magnetometer survey: Lund quadrangle, Ely quadrangle, Nevada. Volume I. Final report

    International Nuclear Information System (INIS)

    1980-01-01

    An airborne combined radiometric and magnetic survey was performed for the Department of Energy (DOE) over the area covered by the Ely and Lund 1:250,000 National Topographic Map Series (NTMS quadrangle maps). The survey was part of DOE's National Uranium Resource Evaluation (NURE) Aerial Radiometric Reconnaissance program. Data were collected by a helicopter equipped with a gamma-ray spectrometer having a large crystal volume, and a high sensitivity proton precession magnetometer. The radiometric system was calibrated at the Walker Field Calibration pads and the Lake Mead Dynamic Test range. Data quality was ensured during the survey by daily test flights and equipment checks. Radiometric data were corrected for live time, aircraft and equipment background, cosmic background, atmospheric radon, Compton scatter, and altitude dependence. The corrected data were statistically evaluated, plotted, and contoured to produce anomaly maps based on the radiometric response of individual geological units. The maps were interpreted and an anomaly interpretation map produced. Volume I contains a description of the systems used in the survey, a discussion of the calibration of the systems, the data processing procedures, the data display format, the interpretation rationale, and interpretation methodology. Volume II contains the data displays for a quadrangle and the interpretation results

  15. Energetic Particles at High Latitudes of the Heliosphere

    International Nuclear Information System (INIS)

    Zhang Ming

    2004-01-01

    Ulysses has by now made two complete out-of-ecliptic orbits around the sun. The first encounter of the solar poles occurred in 1994-1995, when the sun was near the minimum of its activity cycle, while the second one was in 2000-2001, when the sun was at solar maximum. To our surprise, energetic particles of all origins at high latitude are not much different from those we observe near the ecliptic for at least these two phases of solar cycle. The latitude gradients of galactic and anomalous cosmic rays are positive but small at the 1994-1995 solar minimum and almost zero at the 2000-2001 solar maximum, while temporal solar cycle variation dominates their flux variation at all latitudes. Solar energetic particles from all large gradual events can be seen at both Ulysses and Earth no matter how large their spatial separations from the solar event are, and the particle flux often reaches a uniform level in the entire inner heliosphere within a few days after event onset and remains so throughout the decay phase that can sometimes last over a month. Energetic particles accelerated by low-latitude CIRs can appear at high latitudes, far beyond the latitudinal range of CIRs. All these observations suggest that latitudinal transport of energetic particles is quite easy. In addition, because the average magnetic field is radial at the pole, The Ulysses observations indicate that parallel diffusion and drift in the radial direction need to be reduced at the poles relative to their equatorial values. To achieve such behaviors of particle transport, the heliospheric magnetic field needs a significant latitudinal component at the poles. A non-zero latitudinal magnetic field component can be produced by latitudinal motion of the magnetic field line in solar corona, which can be in form of either random walk suggested by Jokipii or large scale systematic motion suggested by Fisk

  16. Geological interpretation of an airborne gamma-ray spectrometer survey of the Hearne Lake area, Northwest Territories

    International Nuclear Information System (INIS)

    Newton, A.R.; Slaney, V.R.

    1978-01-01

    This study shows how large volumes of airborne data can be displayed in a simple format which provides both mapping and exploration geologists with information not easily obtained from the original data. Eleven lines or part-lines from a gamma-ray survey of the Hearne Lake area were chosen as test lines, and airphotos were used to identify outcrops of each rock type and the distribution of overburden, swamp and water along each line. Geological maps were used to locate the test lines and to provide a listing of the rock types in the area. With this information, it was possible to calculate the average radioelement characteristics of each rock type and to group the rock signatures into a number of rock classes. The techniques described are most usefully applied to those areas where the outcrop is extensive, where some form of geological map already exists, where there are airphotos at scales of 1:30,000 or larger, and where the gamma-ray survey lines are less than 2.5 km apart

  17. The Hunt for Red Quasars: Luminous Obscured Black Hole Growth Unveiled in the Stripe 82 X-Ray Survey

    Science.gov (United States)

    LaMassa, Stephanie M.; Glikman, Eilat; Brusa, Marcella; Rigby, Jane R.; Tasnim Ananna, Tonima; Stern, Daniel; Lira, Paulina; Urry, C. Megan; Salvato, Mara; Alexandroff, Rachael; Allevato, Viola; Cardamone, Carolin; Civano, Francesca; Coppi, Paolo; Farrah, Duncan; Komossa, S.; Lanzuisi, Giorgio; Marchesi, Stefano; Richards, Gordon; Trakhtenbrot, Benny; Treister, Ezequiel

    2017-10-01

    We present results of a ground-based near-infrared campaign with Palomar TripleSpec, Keck NIRSPEC, and Gemini GNIRS to target two samples of reddened active galactic nucleus (AGN) candidates from the 31 deg2 Stripe 82 X-ray survey. One sample, which is ˜89% complete to Kprogram, and is selected to have red R - K colors (> 4, Vega). The fainter sample (K> 17, Vega) represents a pilot program to follow-up four sources from a parent sample of 34 that are not detected in the single-epoch SDSS catalog and have WISE quasar colors. All 12 sources are broad-line AGNs (at least one permitted emission line has an FWHM exceeding 1300 km s-1) and span a redshift range 0.59 0.5), and a greater percentage have high X-ray luminosities ({L}{{X},{full}}> {10}44 erg s-1). Such outflows and high luminosities may be consistent with the paradigm that reddened broad-line AGNs represent a transitory phase in AGN evolution as described by the major merger model for black hole growth. Results from our pilot program demonstrate proof of concept that our selection technique is successful in discovering reddened quasars at z> 1 missed by optical surveys.

  18. X-ray microanalytical surveys of minor element concentrations in unsectioned biological samples

    Science.gov (United States)

    Schofield, R. M. S.; Lefevre, H. W.; Overley, J. C.; Macdonald, J. D.

    1988-03-01

    Approximate concentration maps of small unsectioned biological samples are made using the pixel by pixel ratio of PIXE images to areal density images. Areal density images are derived from scanning transmission ion microscopy (STIM) proton energy-loss images. Corrections for X-ray production cross section variations, X-ray attenuation, and depth averaging are approximated or ignored. Estimates of the magnitude of the resulting error are made. Approximate calcium concentrations within the head of a fruit fly are reported. Concentrations in the retinula cell region of the eye average about 1 mg/g dry weight. Concentrations of zinc in the mandible of several ant species average about 40 mg/g. Zinc concentrations in the stomachs of these ants are at least 1 mg/g.

  19. The Einstein objective grating spectrometer survey of galactic binary X-ray sources

    Science.gov (United States)

    Vrtilek, S. D.; Mcclintock, J. E.; Seward, F. D.; Kahn, S. M.; Wargelin, B. J.

    1991-01-01

    The results of observations of 22 bright Galactic X-ray point sources are presented, and the most reliable measurements to date of X-ray column densities to these sources are derived. The results are consistent with the idea that some of the objects have a component of column density intrinsic to the source in addition to an interstellar component. The K-edge absorption due to oxygen is clearly detected in 10 of the sources and the Fe L and Ne K edges are detected in a few. The spectra probably reflect emission originating in a collisionally excited region combined with emission from a photoionized region excited directly by the central source.

  20. Finding X-ray counterparts for unidentified sources in the 105 months BAT survey - 1

    Science.gov (United States)

    Stephen, J. B.; Bassani, L.; Malizia, A.; Masetti, N.; Ubertini, P.

    2018-02-01

    We provide X-ray counterparts for the unidentified Swift/BAT sources listed in the 105 month catalogue (Oh et al. 2018, ApJS in press). These associations were found by cross-correlating the list of U1,U2 and U3 sources with the ROSAT Bright (RASSBSC, Voges et al. 1999, A & A, 349, 389) and the XMM-Newton Slew (XMMSlew, Saxton et al. 2008, A & A, 480, 611) catalogues.

  1. Finding X-ray counterparts for unidentified sources in the 105 months BAT survey - 2

    Science.gov (United States)

    Stephen, J. B.; Bassani, L.; Malizia, A.; Masetti, N.; Ubertini, P.

    2018-02-01

    We provide X-ray counterparts for unidentified Swift/BAT sources in the 105 month catalogue (Oh et al. 2018, ApJS in press). They were found by cross-correlating the list of U1,U2 and U3 sources with the ROSAT Bright (RASSBSC, Voges et al. 1999, A & A, 349, 389) and XMM-Newton Slew (XMMSlew, Saxton et al. 2008, A & A, 480, 611) catalogues and optically identified as reported in Atel #11340.

  2. An indoor radon survey of the X-ray rooms of Mexico City hospitals

    Energy Technology Data Exchange (ETDEWEB)

    Juarez, Faustino [Facultad de Ciencias, Universidad Autonoma del Estado de Mexico, Instituto Literario No. 100. Estado de Mexico, 50000, Mexico. Instituto de Geofisica, Universidad Nacional Autonoma de Mexico, Circuito (Mexico); Reyes, Pedro G. [Facultad de Ciencias, Universidad Autonoma del Estado de Mexico, Instituto Literario No. 100. Estado de Mexico, 50000 (Mexico); Espinosa, Guillermo [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Circuito Exterior Ciudad Universitaria, Mexico D.F. Cp.04510 (Mexico)

    2013-07-03

    This paper presents the results of measurements of indoor radon concentrations in the X-ray rooms of a selection of hospitals in the metropolitan area of Mexico City. The metropolitan area of Mexico City is Mexico's largest metropolitan area by population; the number of patients requiring the use of X-rays is also the highest. An understanding of indoor radon concentrations in X-ray rooms is necessary for the estimation of the radiological risk to which patients, radiologists and medical technicians are exposed. The indoor radon concentrations were monitored for a period of six months using nuclear track detectors (NTD) consisting of a closed-end cup system with CR-39 (Lantrack Registered-Sign ) polycarbonate as detector material. The indoor radon concentrations were found to be between 75 and 170 Bq m{sup -3}, below the USEPA-recommended indoor radon action level for working places of 400 Bq m{sup -3}. It is hoped that the results of this study will contribute to the establishment of recommended action levels by the Mexican regulatory authorities responsible for nuclear safety.

  3. The survey of the surface doses of the dental x-ray machines

    International Nuclear Information System (INIS)

    Lee, Jae Seo; Kang, Byung Cheol; Yoon, Suk Ja

    2005-01-01

    The purpose of this study was to investigate variability of doses with same exposure parameters and evaluate radiographic density according to the variability of doses. Twenty-eight MAX-GLS (Shinhung Co, Seoul, Korea), twenty-one D-60-S (DongSeo Med, Seoul, Korea), and eleven REX-601 (Yoshida Dental MFG, Tokyo, Japan) dental x-ray machines were selected for this study. Surface doses were measured under selected combinations of tube voltage, tube current, exposure time, and constant distance 42 cm from the focal spot to the surface of the Multi-O-meter (Unfors Instrument, Billdal, Sweden). Radiographic densities were measured on the films at maximum, minimum and mean surface doses of each brand of x-ray units. With MAX-GLS, the maximum surface doses were thirteen to fourteen times as much as the minimum surfaces doses. With D-60-S, the maximum surface doses were three to eight times as much as the minimum surface doses. With REX-601, the maximum surface doses were six to ten times as much as the minimum surface doses. The differences in radiographic densities among maximum, mean, and minimum doses were significant (p<0.01). The surface exposure doses of each x-ray machine at the same exposure parameters were different within the same manufacturer's machines.

  4. Active galactic nucleus X-ray variability in the XMM-COSMOS survey

    Energy Technology Data Exchange (ETDEWEB)

    Lanzuisi, G.; Ponti, G.; Salvato, M.; Brusa, M.; Nandra, P. K.; Merloni, A.; Rosario, D. [Max-Planck-Institut für extraterrestrische Physik, Giessenbachstrasse, D-85748 Garching (Germany); Hasinger, G.; Sanders, D. [Institute for Astronomy, 2680 Woodlawn Drive, Honolulu, HI 96822-1839 (United States); Cappelluti, N.; Comastri, A.; Gilli, R. [INAF-Osservatorio Astronomico di Bologna, via Ranzani 1, I-40127 Bologna (Italy); Bongiorno, A. [Istituto Nazionale di Astrofisica-Osservatorio Astronomico di Roma Via Frascati 33, I-00040, Monte Porzio Catone (Italy); Lusso, E.; Steinhardt, C. [Max Planck Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany); Silverman, J.; Schramm, M. [Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU) 5-1-5 Kashiwanoha Kashiwa, Chiba 277-8583 (Japan); Trump, J. [University of California Observatories/Lick Observatory and Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Vignali, C. [Dipartimento di Fisica e Astronomia, Universitá di Bologna, viale Berti Pichat 6/2, I-40127 Bologna (Italy); Kartaltepe, J., E-mail: lanzuisi@noa.gr [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); and others

    2014-02-01

    We used the observations carried out by XMM in the COSMOS field over 3.5 yr to study the long term variability of a large sample of active galactic nuclei (AGNs) (638 sources) in a wide range of redshifts (0.1 < z < 3.5) and X-ray luminosities (10{sup 41} < L {sub 0.5-10} <10{sup 45.5}). Both a simple statistical method to assess the significance of variability and the Normalized Excess Variance (σ{sub rms}{sup 2}) parameter were used to obtain a quantitative measurement of the variability. Variability is found to be prevalent in most AGNs, whenever we have good statistics to measure it, and no significant differences between type 1 and type 2 AGNs were found. A flat (slope –0.23 ± 0.03) anti-correlation between σ{sub rms}{sup 2} and X-ray luminosity is found when all significantly variable sources are considered together. When divided into three redshift bins, the anti-correlation becomes stronger and evolving with z, with higher redshift AGNs being more variable. We prove, however, that this effect is due to the pre-selection of variable sources: when considering all of the sources with an available σ{sub rms}{sup 2} measurement, the evolution in redshift disappears. For the first time, we were also able to study long term X-ray variability as a function of M {sub BH} and Eddington ratio for a large sample of AGNs spanning a wide range of redshifts. An anti-correlation between σ{sub rms}{sup 2} and M {sub BH} is found, with the same slope of anti-correlation between σ{sub rms}{sup 2} and X-ray luminosity, suggesting that the latter may be a by-product of the former. No clear correlation is found between σ{sub rms}{sup 2} and the Eddington ratio in our sample. Finally, no correlation is found between the X-ray σ{sub rms}{sup 2} and optical variability.

  5. AN XMM-NEWTON SURVEY OF THE SOFT X-RAY BACKGROUND. II. AN ALL-SKY CATALOG OF DIFFUSE O VII AND O VIII EMISSION INTENSITIES

    International Nuclear Information System (INIS)

    Henley, David B.; Shelton, Robin L.

    2012-01-01

    We present an all-sky catalog of diffuse O VII and O VIII line intensities, extracted from archival XMM-Newton observations. This catalog supersedes our previous catalog, which covered the sky between l = 120° and l = 240°. We attempted to reduce the contamination from near-Earth solar wind charge exchange (SWCX) emission by excluding times of high solar wind proton flux from the data. Without this filtering, we were able to extract measurements from 1868 observations. With this filtering, nearly half of the observations became unusable, and only 1003 observations yielded measurements. The O VII and O VIII intensities are typically ∼2-11 and ∼ –2 s –1 sr –1 (line unit, L.U.), respectively, although much brighter intensities were also recorded. Our data set includes 217 directions that have been observed multiple times by XMM-Newton. The time variation of the intensities from such directions may be used to constrain SWCX models. The O VII and O VIII intensities typically vary by ∼ 10 L.U. were observed. We compared our measurements with models of the heliospheric and geocoronal SWCX. The heliospheric SWCX intensity is expected to vary with ecliptic latitude and solar cycle. We found that the observed oxygen intensities generally decrease from solar maximum to solar minimum, both at high ecliptic latitudes (which is as expected) and at low ecliptic latitudes (which is not as expected). The geocoronal SWCX intensity is expected to depend on the solar wind proton flux incident on the Earth and on the sightline's path through the magnetosheath. The intensity variations seen in directions that have been observed multiple times are in poor agreement with the predictions of a geocoronal SWCX model. We found that the oxygen lines account for ∼40%-50% of the 3/4 keV X-ray background that is not due to unresolved active galactic nuclei, in good agreement with a previous measurement. However, we found that this fraction is not easily explainable by a

  6. Survey on th incidence of homeless pulmonary tuberculosis infection rate through chest x-ray examination

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Mi Young; Shin, Sung Rae [Dept. of Nursing, Sahmyook University, Seoul (Korea, Republic of); Ryu, Young Hwan [Dept. of Radiology, Seoul Medical Center, Seoul (Korea, Republic of); Lim, Hwan Yeal [Dept. of Medical Business Administration, U1 University, Yeongdong (Korea, Republic of)

    2017-02-15

    This study, Seoul City shelter, you are trying to seek medical cooperation and cure rate increase proposal Yu fndings’s current situation and tuberculosis of homeless tuberculosis. Inspector, and has a total 591 people is targeted to implement an interview after acquiring utilization agreement in studies conducted chest X-ray photography. Of the interview questions, three or more protons, it is determined that the TB symptomatic conducted sputum examination, chest X-ray examination confrms the physician radiology, when sputum examination primarily chromatic fndings the double implemented and conducted by requesting the ship inspection also said inspection sputum acid-fast bacteria if it is true one, respectively. confrmed case result of checking whether there is a difference due to risk factors (Jb) at the chi square black, it was found that there is no statistically significant difference at 95% confidence level. (χ{sup 2}=0.276, p>0.05), suspected case (Ac, Ae) results of examining whether there is a difference due to risk factors in chi square black, that there is a statistically significant difference at 99% confidence level is I found (χ{sup 2}=9.414, p<0.01). The nature of the homeless tuberculosis screening and directed to the distance homeless specifc location are likely to evaluate the actual incidence low and aggressive or management needs, the rationale is allowed insufficient reality is. Through this research, future, for tuberculosis high risk tuberculosis patient, such as homeless to expand the tuberculosis screening of infectious tuberculosis patients in private medical institutions, and one-stop service that chest X-ray examination and sputum examination is carried out at the same time introduced immediately to prevent the inspection and examination, cure, and should establish a foundation that can be up to post administration.

  7. Survey on th incidence of homeless pulmonary tuberculosis infection rate through chest x-ray examination

    International Nuclear Information System (INIS)

    Kim, Mi Young; Shin, Sung Rae; Ryu, Young Hwan; Lim, Hwan Yeal

    2017-01-01

    This study, Seoul City shelter, you are trying to seek medical cooperation and cure rate increase proposal Yu fndings’s current situation and tuberculosis of homeless tuberculosis. Inspector, and has a total 591 people is targeted to implement an interview after acquiring utilization agreement in studies conducted chest X-ray photography. Of the interview questions, three or more protons, it is determined that the TB symptomatic conducted sputum examination, chest X-ray examination confrms the physician radiology, when sputum examination primarily chromatic fndings the double implemented and conducted by requesting the ship inspection also said inspection sputum acid-fast bacteria if it is true one, respectively. confrmed case result of checking whether there is a difference due to risk factors (Jb) at the chi square black, it was found that there is no statistically significant difference at 95% confidence level. (χ 2 =0.276, p>0.05), suspected case (Ac, Ae) results of examining whether there is a difference due to risk factors in chi square black, that there is a statistically significant difference at 99% confidence level is I found (χ 2 =9.414, p<0.01). The nature of the homeless tuberculosis screening and directed to the distance homeless specifc location are likely to evaluate the actual incidence low and aggressive or management needs, the rationale is allowed insufficient reality is. Through this research, future, for tuberculosis high risk tuberculosis patient, such as homeless to expand the tuberculosis screening of infectious tuberculosis patients in private medical institutions, and one-stop service that chest X-ray examination and sputum examination is carried out at the same time introduced immediately to prevent the inspection and examination, cure, and should establish a foundation that can be up to post administration

  8. A radio monitoring survey of ultra-luminous X-ray sources

    Science.gov (United States)

    Körding, E.; Colbert, E.; Falcke, H.

    2005-06-01

    We present the results of a radio monitoring campaign to search for radio emission from nearby ultra-luminous X-ray sources (ULXs). These sources are bright off-nuclear X-ray point sources with luminosities exceeding LX > 1039 erg s-1. A well-defined sample of the 9 nearest ULXs has been monitored eight times over 5 months with the Very Large Array in A and B configuration. Our limiting sensitivity is ≈0.15 mJy (4σ) for radio flares and ≈60 μJy for continuous emission. In M 82 two ULXs seem to have coincident compact radio sources, which are probably supernova remnants. No continuous or flaring radio emission has been detected from any other ULX. Thus, ULXs do not generally emit steady-state radio emission above radio powers of 1.5 × 1017 W/Hz. The non-detections of the continuous emission are consistent with beamed or unbeamed radio emission from accreting black holes of ≤ 103 M⊙ based on the radio/X-ray correlation. Other published radio detections (M 82, NGC 5408) are also discussed in this context. Both detections are significantly above our detection limit. If ULXs have flaring radio emission above 4 × 1017 W/Hz we can give an upper limit on the duty cycle of the flares of 6%. This upper limit is in agreement with the observed number of flares in Galactic radio transients. Additionally we present a yet unreported radio double structure in the nearby low-luminosity AGN NGC 4736.

  9. Forward to all-around survey of environmental neutrons from cosmic ray secondary neutron measurements. History and prospects

    International Nuclear Information System (INIS)

    Aratani, M.

    2000-01-01

    At the present stage of our civilization, environmental neutrons come from not only cosmic ray but also the various kinds of nuclear facilities where uranium, plutonium, californium-252, and other transuranium elements are treated in a large scale. To be regret, those neutron-emitting elements have already been released into the environment by experiments with the military purpose, and been distributed among atmosphere, hydrosphere and geosphere in further larger scale than the peaceful use of nuclear energy. Now environmental neutrons should be surveyed against the horizontal component from the nuclear facilities, upward component from soil, and downward component as secondary neutron from cosmic ray, which is to be regarded as background neutron in the environment. The third category of neutrons have long been surveyed by Y. Nishina and his group of the Institute of Physical and Chemical Research (IPCR) since 1970 at the Itabashi Branch (Itabashi, Tokyo) of IPCR. The BF 3 gas-filled monitors (20 cm in diameter x 200 cm) of 28 (36 at maximum) vessels were used for neutrons till Sept. of 1998, and were transferred to Yanpahchin, Tibet, China for the primary neutrons that might be preferred to secondary ones by researchers of the cosmic ray. A critical accident happened at the Tokai facilities of JCO (Japan Conversion Organization) on Sept. 30 1999, and was discussed in various contexts at home and in a severe tone abroad. A background survey of the environmental neutrons has not been made at any nuclear site or facilities concerning fission in this country. The neutron monitor which detected and recorded the neutrons from the JCO critical accidents was what had been equipped for the fusion research, but not for fission application. Radiation education on neutron has not been made in both school and social education. Basic scientists also may be responsible for the critical accident through making light of these fundamental aspects of nuclear technology. In this

  10. A survey on respiratory diseases of atomic bomb survivors using chest X-ray examination

    International Nuclear Information System (INIS)

    Sasaki, Hideo; Noma, Koji; Ito, Chikako; Mitsuyama, Toyofumi; Kamitsuna, Akimitsu; Nishimoto, Yukio; Katsuta, Shizutomo.

    1986-01-01

    From April 1981 through March 1986, 39,363 A-bomb survivors older than 50 years of age underwent chest X-ray examination. The incidence of abnormal findings was higher in men (28 %) than in women (13 %). The most common disease was old pulmonary tuberculosis in both men and women. The incidence of pulmonary fibrosis was remarkably high in survivors exposed directly to A-bomb radiation, when compared with controls. There was no data suggesting the relationship between the incidence of respiratory disease and exposure status such as the distance from ground zero. (Namekawa, K.)

  11. An airborne gamma ray snow survey of a forest covered area with a deep snowpack

    International Nuclear Information System (INIS)

    Glynn, J.E.; Carroll, T.R.; Holman, P.B.; Grasty, R.L.

    1988-01-01

    Problems arising from the airborne gamma ray measurement of snow water equivalent over a forest covered deep snowpack are examined. The principal sources of error are believed to be due to the radioactivity in the biomass and to variability in the snow cover. A theoretical model is developed to correct the airborne measurements for these sources of error. The application of the theory to data collected over the St. John River Basin, located in the eastern part of Canada and the United States, is found to significantly improve the airborne results

  12. Survey of natural radioactivity levels in Ilex paraguariensis (St. Hil.) by gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Scheibel, Viviane; Appoloni, Carlos Roberto

    2007-01-01

    The mate tea (Ilex paraguariensis - St. Hil.) is a beverage broadly cultivated and consumed in Brazil. The radioactive traces present in three trademarks of toasted mate tea produced at the south of Brazil were analyzed. Measurements were carried out by gamma-ray spectrometry. The average value for the 40 K activity measured for marks A, B and C was 1216 ± 8, 1047 ± 14 and 666 ± 13 Bq.kg -1 , respectively. The 137 Cs activity was lower than the limit of detection. (author)

  13. Evolution of cluster X-ray luminosities and radii: Results from the 160 square degree rosat survey

    DEFF Research Database (Denmark)

    Vikhlinin, A.; McNamara, B.R.; Forman, W.

    1998-01-01

    We searched for cluster X-ray luminosity and radius evolution using our sample of 203 galaxy clusters detected in the 160 deg(2) survey with the ROSAT PSPC (Vikhlinin et al.). With such a large area survey, it is possible, for the first time with ROSAT, to test the evolution of luminous clusters, L......-X > 3 x 10(44) ergs s(-1) in the 0.5-2 keV band. We detect a factor of 3-4 deficit of such luminous clusters at z > 0.3 compared with the present. The evolution is much weaker or absent at modestly lower luminosities, (1-3) x 10(44) ergs s(-1). At still lower luminosities, we find no evolution from...... the analysis of the log N-log S relation. The results in the two upper L, bins are in agreement with the Einstein Extended Medium-Sensitivity Survey evolution result (Gioia et al.; Henry ct al.), which was obtained using a completely independent cluster sample. The low-L-X results are in agreement with other...

  14. The Archaeology and History of Lake Ray Roberts. Volume 1. Cultural Resources Survey.

    Science.gov (United States)

    1982-03-01

    the survey have rendered the information they contain through the recording process and should be determined ineligible for further study. Fifty-five...clay features were actually human hearths ( Heizer and Brooks 1965), and the possibility that the Clovis point was planted ( Heizer 1974). Recent research...15:157-172. Hart, John Fraser 1976 The look of the land. Prentice-Hall, Englewood Cliffs, New Jersey. * 9-5 Heizer , R.F. 1974 Some thoughts on hoaxes

  15. CO observations of southern high-latitude clouds

    International Nuclear Information System (INIS)

    Keto, E.R.; Myers, P.C.

    1986-01-01

    Results from a survey of 2.6 mm emission in the J = 1 to 0 transition of CO of clouds are reported for 15 high Galactic latitude clouds and three clouds located on the fringe of a large molecular cloud in the Chameleon dark cloud complex. The line widths, excitation temperatures, sizes, and n(CO)/N(H2) ratio of these clouds are similar to those seen in dark clouds. The densities, extinctions, and masses of the high-latitude clouds are one order of magnitude less than those found in dark clouds. For its size and velocity dispersion, the typical cloud has a mass of at least 10 times less than that needed to bind the cloud by self-gravity alone. External pressures are needed to maintain the typical cloud in equilibrium, and these values are consistent with several estimates of the intercloud pressure. 32 references

  16. Gamma-ray and surface organic results of the robotic survey of Pit 9 at INEL

    International Nuclear Information System (INIS)

    Clegg, B.; Rowland, M.; Pence, J.

    1991-09-01

    The Buried Waste Robotics Program demonstrated and evaluated robotic techniques to non-invasively characterize a representative radiological burial area at the Idaho National Engineering Laboratory (ML). Lawrence Livermore National Laboratory (LLNL) contributed a large, NaI gamma-ray detector system and a photo-ionization organics detector to this program. This Program mounted multiple geophysics, nucleonic, and chemical sensor systems on the Solder Robot Interface Program (SRIP) remotely operated vehicle. These sensors simultaneously collected radiological waste-site, surface characterization data on Pit 9 radiological burial area, and the Cold Test Pit (CTP), off-site control area. LLNL sensors found no radiological waste at the CTP control area, however, we easily detected the natural thorium series, the potassium radionuclides and trace worldwide fallout cesium. Earlier manual measurements indicated no significant data error invoked by the vehicle on our gamma-ray and organic sensor systems. Thick soil overburden at the Subsurface Disposal Area (SDA), Pit 9, permitted radiological, but no isotopic determinations. A flood of scattered photons from the buried waste allows a surface, spatial radiological dose assessment. We found no evidence of surface-evolving organics, sensitive to photo-ionization detection. The observed signals can safely guide a remediation excavation. The vehicle-supported multiple measurements enhanced the data collection efficiency. Data provided site-surface characterization, quickly and safely in potentially hazardous areas. However, a large, buried-waste site will require subsurface access for detailed characterization

  17. Sickness presence, sick leave and adjustment latitude

    Directory of Open Access Journals (Sweden)

    Joachim Gerich

    2014-10-01

    Full Text Available Objectives: Previous research on the association between adjustment latitude (defined as the opportunity to adjust work efforts in case of illness and sickness absence and sickness presence has produced inconsistent results. In particular, low adjustment latitude has been identified as both a risk factor and a deterrent of sick leave. The present study uses an alternative analytical strategy with the aim of joining these results together. Material and Methods: Using a cross-sectional design, a random sample of employees covered by the Upper Austrian Sickness Fund (N = 930 was analyzed. Logistic and ordinary least square (OLS regression models were used to examine the association between adjustment latitude and days of sickness absence, sickness presence, and an estimator for the individual sickness absence and sickness presence propensity. Results: A high level of adjustment latitude was found to be associated with a reduced number of days of sickness absence and sickness presence, but an elevated propensity for sickness absence. Conclusions: Employees with high adjustment latitude experience fewer days of health complaints associated with lower rates of sick leave and sickness presence compared to those with low adjustment latitude. In case of illness, however, high adjustment latitude is associated with a higher pro­bability of taking sick leave rather than sickness presence.

  18. THE 37 MONTH MAXI/GSC SOURCE CATALOG OF THE HIGH GALACTIC-LATITUDE SKY

    Energy Technology Data Exchange (ETDEWEB)

    Hiroi, Kazuo; Ueda, Yoshihiro; Hayashida, Masaaki; Shidatsu, Megumi; Sato, Ryosuke; Kawamuro, Taiki [Department of Astronomy, Kyoto University, Oiwake-cho, Sakyo-ku, Kyoto 606-8502 (Japan); Sugizaki, Mutsumi; Serino, Motoko; Matsuoka, Masaru; Mihara, Tatehiro [Institute of Physical and Chemical Research (RIKEN), 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Nakahira, Satoshi; Tomida, Hiroshi; Ueno, Shiro [ISS Science Project Office, Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), 2-1-1 Sengen, Tsukuba, Ibaraki 305-8505 (Japan); Kawai, Nobuyuki; Morii, Mikio [Department of Physics, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8551 (Japan); Nakajima, Motoki [School of Dentistry at Matsudo, Nihon University, 2-870-1 Sakaecho-nishi, Matsudo, Chiba 101-8308 (Japan); Negoro, Hitoshi [Department of Physics, Nihon University, 1-8-14 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8308 (Japan); Sakamoto, Takanori [Department of Physics and Mathematics, Aoyama Gakuin University, 5-10-1 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5258 (Japan); Tsuboi, Yohko [Department of Physics, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo 112-8551 (Japan); Tsunemi, Hiroshi, E-mail: hiroi@kusastro.kyoto-u.ac.jp [Department of Earth and Space Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043 (Japan); and others

    2013-08-15

    We present a catalog of high Galactic-latitude (|b| > 10 Degree-Sign ) X-ray sources detected in the first 37 months of data of the Monitor of All-sky X-ray Image/Gas Slit Camera (MAXI/GSC). To achieve the best sensitivity, we develop a background model of the GSC that well reproduces the data based on the detailed on-board calibration. Source detection is performed through image fits with a Poisson likelihood algorithm. The catalog contains 500 objects detected with significances of s{sub D,4-10keV} {>=} 7 in the 4-10 keV band. The limiting sensitivity is Almost-Equal-To 7.5 Multiplication-Sign 10{sup -12} erg cm{sup -2} s{sup -1} ( Almost-Equal-To 0.6 mCrab) in the 4-10 keV band for 50% of the survey area, which is the highest ever achieved in an all-sky survey mission covering this energy band. We summarize the statistical properties of the catalog and results from cross matching with the Swift/BAT 70 month catalog, the meta-catalog of X-ray detected clusters of galaxies, and the MAXI/GSC 7 month catalog. Our catalog lists the source name (2MAXI), position and its error, detection significances and fluxes in the 4-10 keV and 3-4 keV bands, the hardness ratio, and the basic information of the likely counterpart available for 296 sources.

  19. A survey in Portuguese X-ray fluoroscopy equipment: dose rates and image quality

    International Nuclear Information System (INIS)

    Teixeira, Nuno G.; Cunha, Gilda R.; Coutinho, Guilherme M.; Trindade, Hugo R.; Carvoeiras, Pedro P.

    2015-01-01

    X-ray fluoroscopy is essential in both diagnosis and medical intervention, although it may contribute to significant radiation doses to patients that have to be optimised and justified. Therefore, it is crucial to the patient to be exposed to the lowest achievable dose without compromising the image quality. The purpose of this study was to perform an analysis of the quality control measurements, particularly dose rates, contrast and spatial resolution of Portuguese fluoroscopy equipment and also to provide a contribution to the establishment of reference levels for the equipment performance parameters. Measurements carried out between 2007 and 2013 on 143 fluoroscopy equipment distributed by 34 nationwide health units were analysed. The measurements suggest that image quality and dose rates of Portuguese equipment are congruent with other studies, and in general, they are as per the Portuguese law. However, there is still a possibility of improvements intending optimisation at a national level. (authors)

  20. A neutron survey of a 25 MV x-ray clinical linac treatment room

    International Nuclear Information System (INIS)

    Price, Kenneth W.; Holeman, George R.; Nath, Ravinder

    1978-01-01

    Neutron production in high energy x-ray radiotherapy machines results in unnecessary dose to patients and has been of recent interest to private and Federal agencies. An activation technique has been used to measure fast and thermal neutron fluxes in the high energy x-ray beam, and at radial distances of 1 and 2 meters from the beam axis of the 25 MV Sagittaire Linear Accelerator located at the Yale-New Haven Hospital's Cancer Therapy Center. Phosphorous pentoxide activation detectors were used to monitor the thermal flux and the fast neutron flux above 0.7 MeV neutron energy. Unlike other techniques for measuring neutrons, this detector has been shown to be insensitive to high energy photon interference at the photon dose rates present in the beam. Neutron spectra at various distances from the accelerator target were computed for the treatment room geometry using the Morse Monte Carlo Code (R.C. McCall, SLAC, Personal Communication). Normalization of these spectra provided the means by which the activation products measured in the phosphorous were converted to fast neutron fluxes. Dose equivalent conversion factors were applied to each energy of the calculated neutron spectra and integrated, resulting in fast neutron flux to dose equivalent conversion factors at various locations in the treatment room. Fast neutron dose equivalent was found to maximize in the photon beam, (0.005 - .007 neutron Rem/photon Rad) and decrease with distance thereafter. Thermal neutron dose equivalent was found to be essentially constant through- out the treatment room (∼ 3.35x10 -5 neutron Rem/ photon Rad). (author)

  1. Aerial gamma ray and magnetic survey: Green Bay Quadrangle, Wisconsin. Final report

    International Nuclear Information System (INIS)

    1978-04-01

    Data obtained from a high sensitivity airborne radiometric and magnetic survey of Green Bay Quadrangle in Wisconsin are presented. All data are presented as corrected profiles of all radiometric variables, magnetic data, radar and barometric altimeter data, air temperature and airborne Bismuth contributions. Radiometric data presented are corrected for Compton Scatter, altitude dependence and atmospheric Bismuth. These data are also presented on microfiche, and digital magnetic tapes. In addition, anomaly maps and interpretation maps are presented relating known geology or soil distribution to the corrected radiometric/magnetic data

  2. Aerial gamma ray and magnetic survey: Iron Mountain Quadrangle, Wisconsin/Michigan. Final report

    International Nuclear Information System (INIS)

    1978-04-01

    Data obtained from a high sensitivity airborne radiometric and magnetic survey of Iron Mountain Quadrangle in Wisconsin/Michigan are presented. All data are presented as corrected profiles of all radiometric variables, magnetic data, radar and barometric altimeter data, air temperature and airborne Bismuch contributions. Radiometric data presented are corrected for Compton Scatter, altitude dependence and atmospheric Bismuth. These data are also presented on microfiche, and digital magnetic tapes. In addition, anomaly maps and interpretation maps are presented relating known geology or soil distribution to the corrected radiometric/magnetic data

  3. Aerial gamma ray and magnetic survey: Rice Lake Quadrangle, Wisconsin. Final report

    International Nuclear Information System (INIS)

    1978-04-01

    Data obtained from a high sensitivity airborne radiometric and magnetic survey of the Rice Lake Quadrangle in Wisconsin are presented. All data are presented as corrected profiles of all radiometric variables, magnetic data, radar and barometric altimeter data, air temperature and airborne Bismuth contributions. Radiometric data presented are corrected for Compton Scatter, altitude dependence and atmospheric Bismuth. These data are also presented on microfiche, and digital magnetic tapes. In addition, anomaly maps and interpretation maps are presented relating known geology or soil distribution to the corrected radiometric/magnetic data

  4. NURE aerial gamma ray and magnetic detail survey of portions of northeast Washington. Final report

    International Nuclear Information System (INIS)

    1981-11-01

    The Northeast Washington Survey was performed under the United States Department of Energy's National Uranium Resource Evaluation (NURE) Program, which is designed to provide radioelement distribution information to assist in assessing the uraniferous material potential of the United States. The radiometric and ancilliary data were digitally recorded and processed. The results are presented in the form of stacked profiles, contour maps, flight path maps, statistical tables and frequency distribution histograms. These graphical outputs are presented at a scale of 1:62,500 and are contained in the individual Volume 2 reports

  5. Aerial gamma ray and magnetic survey: Eau Claire Quadrangle, Wisconsin/Minnesota. Final report

    International Nuclear Information System (INIS)

    1978-04-01

    Data obtained from a high sensitivity airborne radiometric and magnetic survey of the Eau Claire Quadrangle in Wisconsin/Minnesota are presented. All data are presented as corrected profiles of all radiometric variables, magnetic data, radar and barometric altimeter data, air temperature and airborne Bismuth contributions. Radiometric data presented are corrected for Compton Scatter, altitude dependence and atmospheric Bismuth. These data are also presented on microfiche, and digital magnetic tapes. In addition, anomaly maps and interpretation maps are presented relating known geology or soil distribution to the corrected radiometric/magnetic data

  6. Study on the optimization of the water Cherenkov detector array of the LHAASO project for surveying VHE gamma ray sources

    Science.gov (United States)

    Li, Hui-Cai; Chen, Ming-Jun; Jia, Huan-Yu; Gao, Bo; Wu, Han-Rong; Yao, Zhi-Guo; Yuo, Xiao-Hao; Zhou, Bin; Zhu, Feng-Rong

    2014-01-01

    It is prpopsed that a water Cherenkov detector array, LHAASO-WCDA, is to be built at Shangri-la, Yunnan Province, China. As one of the major components of the LHAASO project, the main purpose of it is to survey the northern sky for gamma ray sources in the energy range of 100 GeV-30 TeV. In order to design the water Cherenkov array efficiently to economize the budget, a Monte Carlo simulation is carried out. With the help of the simulation, the cost performance of different configurations of the array are obtained and compared with each other, serving as a guide for the more detailed design of the experiment in the next step.

  7. Study on the optimization of the water Cherenkov detector array of the LHAASO project for surveying VHE gamma ray sources

    International Nuclear Information System (INIS)

    Li Huicai; Chen Mingjun; Gao Bo; Wu Hanrong; Yao Zhiguo; Zhou Bin; Jia Huanyu; Zhu Fengrong; You Xiaohao

    2014-01-01

    It is proposed that a water Cherenkov detector array, LHAASO-WCDA, is to be built at Shangri-la, Yunnan Province, China. As one of the major components of the LHAASO project, the main purpose of it is to survey the northern sky for gamma ray sources in the energy range of 100 GeV-30 TeV. In order to design the water Cherenkov array efficiently to economize the budget, a Monte Carlo simulation is carried out. With the help of the simulation, the cost performance of different configurations of the array are obtained and compared with each other, serving as a guide for the more detailed design of the experiment in the next step. (authors)

  8. A Survey of Students from the National School on Neutron and X-ray Scattering: Communication Habits and Preferences

    Energy Technology Data Exchange (ETDEWEB)

    Bryant, Rebecca [Bryant Research, LLC

    2010-12-01

    Oak Ridge National Laboratory (ORNL) offers the scientific community unique access to two types of world-class neutron sources at a single site - the Spallation Neutron Source (SNS) and the High Flux Isotope Reactor (HFIR). The 85-MW HFIR provides one of the highest steady-state neutron fluxes of any research reactor in the world. And the SNS is one of the world's most intense pulse neutron beams. Management of these resources is the responsibility of the Neutron Sciences Directorate (NScD). NScD started conducting the National School on Neutron and X-ray Scattering (NXS) in conjunction with the Advanced Photon Source (APS) at Argonne National Laboratory in 2007. This survey was conducted to determine the most effective ways to reach students with information about what SNS and HFIR offer the scientific community, including content and communication vehicles. The emphasis is on gaining insights into compelling messages and the most effective channels, e.g., Web sites and social media, for communicating with students about neutron science The survey was conducted in two phases using a classic qualitative investigation to confirm language and content followed by a survey designed to quantify issues, assumptions, and working hypotheses. Phase I consisted of a focus group in late June 2010 with students attending NXS. The primary intent of the group was to inform development of an online survey. Phase two consisted of an online survey that was developed and pre-tested in July 2010 and launched on August 9, 2010 and remained in the field until September 9, 2010. The survey achieved an overall response rate of 48% for a total of 157 completions. The objective of this study is to determine the most effective ways to reach students with information about what SNS and HFIR offer the scientific community, including content and communication vehicles. The emphasis is on gaining insights into compelling messages and the most effective channels, e.g., Web sites, social

  9. A Survey of Students from the National School on Neutron and X-ray Scattering: Communication Habits and Preferences

    International Nuclear Information System (INIS)

    Bryant, Rebecca

    2010-01-01

    Oak Ridge National Laboratory (ORNL) offers the scientific community unique access to two types of world-class neutron sources at a single site - the Spallation Neutron Source (SNS) and the High Flux Isotope Reactor (HFIR). The 85-MW HFIR provides one of the highest steady-state neutron fluxes of any research reactor in the world. And the SNS is one of the world's most intense pulse neutron beams. Management of these resources is the responsibility of the Neutron Sciences Directorate (NScD). NScD started conducting the National School on Neutron and X-ray Scattering (NXS) in conjunction with the Advanced Photon Source (APS) at Argonne National Laboratory in 2007. This survey was conducted to determine the most effective ways to reach students with information about what SNS and HFIR offer the scientific community, including content and communication vehicles. The emphasis is on gaining insights into compelling messages and the most effective channels, e.g., Web sites and social media, for communicating with students about neutron science The survey was conducted in two phases using a classic qualitative investigation to confirm language and content followed by a survey designed to quantify issues, assumptions, and working hypotheses. Phase I consisted of a focus group in late June 2010 with students attending NXS. The primary intent of the group was to inform development of an online survey. Phase two consisted of an online survey that was developed and pre-tested in July 2010 and launched on August 9, 2010 and remained in the field until September 9, 2010. The survey achieved an overall response rate of 48% for a total of 157 completions. The objective of this study is to determine the most effective ways to reach students with information about what SNS and HFIR offer the scientific community, including content and communication vehicles. The emphasis is on gaining insights into compelling messages and the most effective channels, e.g., Web sites, social media

  10. NuSTAR Hard X-ray Survey of the Galactic Center Region. I. Hard X-ray Morphology and Spectroscopy of the Diffuse Emission

    DEFF Research Database (Denmark)

    Mori, Kaya; Hailey, Charles J.; Krivonos, Roman

    2015-01-01

    We present the first sub-arcminute images of the Galactic Center above 10 keV, obtained with NuSTAR. NuSTAR resolves the hard X-ray source IGR J17456-2901 into non-thermal X-ray filaments, molecular clouds, point sources, and a previously unknown central component of hard X-ray emission (CHXE). Nu...

  11. NuSTAR Hard X-Ray Survey of the Galactic Center Region. II. X-Ray Point Sources

    DEFF Research Database (Denmark)

    Hong, JaeSub; Mori, Kaya; Hailey, Charles J.

    2016-01-01

    persistent luminous X-ray binaries (XBs) and the likely run-away pulsar called the Cannonball. New source-detection significance maps reveal a cluster of hard (>10 keV) X-ray sources near the Sgr. A diffuse complex with no clear soft X-ray counterparts. The severe extinction observed in the Chandra spectra...

  12. Radiation doses to patients in medical diagnostic x-ray examinations in New Zealand: a 1983-84 survey

    International Nuclear Information System (INIS)

    Williamson, B.D.P.; Poletti, J.L.; Cartwright, P.H.; Le Heron, J.C.

    1993-06-01

    A survey of doses to patients undergoing diagnostic x-ray examinations was performed in 1983-84. Developments since 1983-84 were reviewed and estimates made of the frequency of x-ray examinations, and doses to patients, as at 1992. The collective effective dose from general medical diagnostic radiology in 1983-84 was estimated to have been about 443 μSv per capita per annum. The figure excluded computed tomography which was estimated to have contributed about 5.6 μSv per capita per annum and mammography gave 0.3 μSv per annum. The total per capital effective dose from all medical diag over the whole period from 1983-84 to 1992. The highest dose examinations in 1983-84 were the fluoroscopic procedures barium enema and meal. Over the whole period 1983-84 to 1992 the genetically significant dose (GSD) to the population of New Zealand from medical diagnostic radiology was estimated to have been in the range 200-250 μSv per capita per annum. The two opposing tendencies noted for effective dose, viz, the fall in frequency of some examination types and the rise of Computed tomography, acted also upon this dose index. 43 refs., tabs., figs., ills

  13. Effects of High-Latitude Forcing Uncertainty on the Low-Latitude and Midlatitude Ionosphere

    Science.gov (United States)

    Pedatella, N. M.; Lu, G.; Richmond, A. D.

    2018-01-01

    Ensemble simulations are performed using the Thermosphere-Ionosphere-Electrodynamics General Circulation Model (TIE-GCM) in order to understand the role of high-latitude forcing uncertainty on the low-latitude and midlatitude ionosphere response to the April 2010 geomagnetic storm. The ensemble is generated by perturbing either the high-latitude electric potential or auroral energy flux in the assimilative mapping for ionosphere electrodynamics (AMIE). Simulations with perturbed high-latitude electric potential result in substantial intraensemble variability in the low-latitude and midlatitude ionosphere response to the geomagnetic storm, and the ensemble standard deviation for the change in NmF2 reaches 50-100% of the mean change. Such large intraensemble variability is not seen when perturbing the auroral energy flux. In this case, the effects of the forcing uncertainty are primarily confined to high latitudes. We therefore conclude that the specification of high-latitude electric fields is an important source of uncertainty when modeling the low-latitude and midlatitude ionosphere response to a geomagnetic storm. A multiple linear regression analysis of the results indicates that uncertainty in the storm time changes in the equatorial electric fields, neutral winds, and neutral composition can all contribute to the uncertainty in the ionosphere electron density. The results of the present study provide insight into the possible uncertainty in simulations of the low-latitude and midlatitude ionosphere response to geomagnetic storms due to imperfect knowledge of the high-latitude forcing.

  14. Observations of variable and transient X-ray sources with the Ariel V Sky Survey Experiment

    International Nuclear Information System (INIS)

    Pounds, K.A.; Cooke, B.A.; Ricketts, M.J.; Turner, M.J.; Peacock, A.; Eadie, G.

    1976-01-01

    Results obtained during the first six months in orbit of Aerial V with the Leicester Sky Survey are reviewed. Among 80 sources found by a scan of the Milky Way, 16 are new, and 11 UHURU sources in the scanned region are not detected. Some of these sources may be transient. The light curve of Cen X-3 in a binary cycle shows a dip between phase 0.5 and 0.75, and a secondary maximum at the centre of the dip. The dip and the maximum get progressively weaker in the succeeding cycles. These features are interpreted in terms of the stellar wind accretion model. Cyg X-1 observation for 14 days gives a broad minimum around superior conjunction. Four bright transient sources of nova-like light curves have been observed. The light curves and the spectra are given for TrA X-1 (A1524-62) and Tau X-T (A0535+26). (Auth.)

  15. Hospital and clinic survey estimates of medical X-ray exposure in Hiroshima and Nagasaki, 2

    International Nuclear Information System (INIS)

    Antoku, Shigetoshi; Hoshi, Masaharu; Sawada, Shozo; Russell, W.J.

    1987-07-01

    The technical factors used during radiological examinations performed in Hiroshima and Nagasaki medical institutions were analyzed. The most frequently performed examination was chest radiography, followed by upper GI series. More than half the radiographic exposures were from upper GI series due to the many spot films made during fluoroscopy. Comparison of the present survey results with those of a previous one showed that relatively high kVp, low mAs and mA, and smaller field sizes are now more widely used. Though there have been decreased in fluoroscopy times and tube currents over the past 10 years, the numbers of spot films used have increased. Based on these technical factors, tables of organ doses from fluoroscopic examinations were compiled. (author)

  16. Survey of the pharmacology of non-ionic X-ray contrast media

    International Nuclear Information System (INIS)

    Turnheim, K.

    1986-01-01

    The non-ionic X-ray contrast media metrizamide, iopamidol, iohexol, and iopromide do not bind calcium and are less hyperosmolar than the conventional ionic contrast media, for instance amidotrizoate (diatrizoate), iothalamte, or ioglicate. Hence the use of non-ionic contrast media is associated with less undesirable side-effects that are attributable to hypertonicity such as an increase in circulating plasma volume, decreased deformability of red blood cells, damage of vascular endothelium with consequent activation of blood coagulation, the complement system and fibrinolysis, increased release of bradykinin and histamine, cardiac arrhythimas, diuresis, vasodilation and decreased blood pressure, pain and heat sensation. Because of less dilution the quality of imaging is also better. According to the intravenous LD 50 in experimental animals the acute toxicity of non-ionic contrast media is lower than that of ionic media. With respect to contrast quality and the rate of side-effects tha various non-ionic contrast media appear to be equivalent. Despite their higher price and higher viscosity it is probable that the non-ionic contrast media will replace the classical ionic media, especially in angio- and myelography. (Author)

  17. Worldwide distribution of Total Reflection X-ray Fluorescence instrumentation and its different fields of application: A survey

    Energy Technology Data Exchange (ETDEWEB)

    Klockenkämper, Reinhold, E-mail: reinhold.klockenkaemper@isas.de; Bohlen, Alex von

    2014-09-01

    A survey was carried out with users and manufacturers of Total Reflection X-ray Fluorescence instrumentation in order to demonstrate the worldwide distribution of TXRF equipment and the different fields of applications. In general, TXRF users come from universities and scientific institutes, from working places at synchrotron beam-lines, or laboratories in semiconductor fabs. TXRF instrumentation is distributed in more than 50 countries on six continents and is applied at about 200 institutes and laboratories. The number of running desktop instruments amounts to nearly 300 units. About 60 beamlines run working places dedicated to TXRF. About 300 floor-mounted instruments are estimated to be used in about 150 fabs of the semiconductor industry. In total, 13 different fields of applications could be registered statistically from three different aspects. - Highlights: • According to the survey world maps show the distribution of TXRF equipment. • Nearly 700 individual units are running actually in 57 countries of 6 continents. • Users work at 200 universities, 60 synchrotron-beamlines, and 150 semiconductor fabs. • 13 fields of applications (e.g. environmental, chemical) are evaluated statistically. • Manufacturers, conference members and authors lead to 3 different pie-charts.

  18. Survey results of output measurements in diagnostic X ray equipments using glass dosimeter and the questionnaire. Aichi association of radiological technologists 50 year anniversary memorial work

    International Nuclear Information System (INIS)

    Kondo, Yuji; Hirofuji, Yoshiaki; Saiga, Osamu; Ishibashi, Kazuto

    2003-01-01

    The Aichi Association of Radiological Technologists executed the survey according to the task of radiation control in Aichi prefecture. The survey investigated the number of clinics/hospitals who own radiation dosimeters. The association also measured outputs using glass dosimeter (GD-450) manufactured by Chiyoda Technical in diagnostic X ray. The purpose and significance of the survey are: to illustrate that the radiation control task is not involved as routine maintenance work, to examine why the task is not routinely performed, to investigate the number of clinics/hospitals who own diagnostic X ray radiation dosimeters, to inform that the use of dosimeter is essential to achieve accurate measurement for exposed dose, and to motivate the significance of radiation control in routine work. The result of the survey clearly indicated the necessity of radiation control, and suggested the information needed for the Aichi Association of Radiological Technologists to determine the guideline for the medical radiation exposed dose. (author)

  19. Aerial gamma ray and magnetic survey, Van Horn and Pecos Quadrangles, Texas. Volume I. Final report

    International Nuclear Information System (INIS)

    1977-10-01

    A high sensitivity, airborne radiometric and magnetic survey of portions of the Big Bend, Texas area was conducted. The project area comprising the Van Horn and Pecos 1:250,000 NTMS sheets, consists of approximately 16,400 square miles. A total of 6,666 line miles of high sensitivity radiometric and magnetic data were collected. Traverse lines were flown at a spacing of 3.125 miles in an east/west direction with tie lines flown in a north/south direction at a 18.375 miles separation. All data were collected utilizing a fixed wing aircraft, Grumman G-89 and over 3,500 cubic inches of NaI crystal detector. Magnetometer data were collected utilizing a high sensitivity, 0.25 gamma, proton magnetometer. Data were digitally recorded at 0.5 second intervals. All field data were returned to the computer facilities for processing, statistical analysis, and interpretation. Other data are presented which include corrected profiles of all radiometric variables, magnetic data, radar altimeter data, barometric altimeter data, air temperature and airborne Bismuth contributions. Data presented have been summed to provide 1.0 second equivalent sample intervals, corrected for Compton Scatter, altitude dependence and atmospheric Bismuth. These data are presented in the form of strip charts, microfiche, and digital magnetic tapes containing raw spectral data, single record data, magnetic data, and statistical analysis results. In addition, computer generated anomaly maps along with interpretation maps are presented relating mapped geology to the collected radiometric data

  20. High Latitude Dust in the Earth System

    Science.gov (United States)

    Bullard, Joanna E.; Baddock, Matthew; Bradwell, Tom; Crusius, John; Darlington, Eleanor; Gaiero, Diego; Gasso, Santiago; Gisladottir, Gudrun; Hodgkins, Richard; McCulloch, Robert; hide

    2016-01-01

    Natural dust is often associated with hot, subtropical deserts, but significant dust events have been reported from cold, high latitudes. This review synthesizes current understanding of high-latitude (> or = 50degN and > or = 40degS) dust source geography and dynamics and provides a prospectus for future research on the topic. Although the fundamental processes controlling aeolian dust emissions in high latitudes are essentially the same as in temperate regions, there are additional processes specific to or enhanced in cold regions. These include low temperatures, humidity, strong winds, permafrost and niveo-aeolian processes all of which can affect the efficiency of dust emission and distribution of sediments. Dust deposition at high latitudes can provide nutrients to the marine system, specifically by contributing iron to high-nutrient, low-chlorophyll oceans; it also affects ice albedo and melt rates. There have been no attempts to quantify systematically the expanse, characteristics, or dynamics of high-latitude dust sources. To address this, we identify and compare the main sources and drivers of dust emissions in the Northern (Alaska, Canada, Greenland, and Iceland) and Southern (Antarctica, New Zealand, and Patagonia) Hemispheres. The scarcity of year-round observations and limitations of satellite remote sensing data at high latitudes are discussed. It is estimated that under contemporary conditions high-latitude sources cover >500,000 sq km and contribute at least 80-100 Tg/yr1 of dust to the Earth system (approx. 5% of the global dust budget); both are projected to increase under future climate change scenarios.

  1. Application of airborne gamma spectrometric survey data to estimating terrestrial gamma-ray dose rates: An example in California

    International Nuclear Information System (INIS)

    Wollenberg, H.A.; Revzan, K.L.; Smith, A.R.

    1992-01-01

    The authors examine the applicability of radioelement data from the National Aerial Radiometric Reconnaissance (NARR) to estimate terrestrial gamma-ray absorbed dose rates, by comparing dose rates calculated from aeroradiometric surveys of U, Th, and K concentrations in 1 x 2 degree quadrangles with dose rates calculated from a radiogeologic data base and the distribution of lithologies in California. Gamma-ray dose rates increase generally from north to south following lithological trends. Low values of 25--30 nG/h occur in the northernmost quadrangles where low-radioactivity basaltic and ultramafic rocks predominate. Dose rates then increase southward due to the preponderance of clastic sediments and basic volcanics of the Franciscan Formation and Sierran metamorphics in north central and central California, and to increasing exposure southward of the Sierra Nevada batholith, Tertiary marine sedimentary rocks, intermediate to acidic volcanics, and granitic rocks of the Coast Ranges. High values, to 100 nGy/h occur in southeastern California, due primarily to the presence of high-radioactivity Precambrian and pre Cenozoic metamorphic rocks. Lithologic-based estimates of mean dose rates in the quadrangles generally match those from aeroradiometric data, with statewide means of 63 and 60 nGy/h, respectively. These are intermediate between a population-weighted global average of 51 nGy/h and a weighted continental average of 70 nGy/h, based on the global distribution of rock types. The concurrence of lithologically- and aeroradiometrically- determined dose rates in California, with its varied geology and topography encompassing settings representative of the continents, indicates that the NARR data are applicable to estimates of terrestrial absorbed dose rates from natural gamma emitters

  2. XMM-Newton Survey of Local O VII Absorption Lines in the Spectra of Galactic X-Ray Sources

    Science.gov (United States)

    Luo, Yang; Fang, Taotao; Ma, Renyi

    2018-04-01

    The detection of highly ionized metal absorption lines in the X-ray spectra of the Galactic X-ray binaries (XRBs) implies the distribution of hot gas along the sightline toward the background sources. However, the origin of this hot gas is still unclear: it can arise in the hot interstellar medium (ISM), or is intrinsic to the XRBs. In this paper, we present an XMM-Newton survey of the O VII absorption lines in the spectra of Galactic XRBs. A total of 33 XRBs were selected, with 29 low-mass XRBs and 4 high-mass XRBs. At a more than 3σ threshold, O VII absorption line was detected in 16 targets, among which 4 were newly discovered in this work. The average line equivalent width is centered around ∼20 mÅ. Additionally, we do not find strong correlations between the O VII EWs and the Galactic neutral absorption N H, the Galactic coordinates, or the distance of background targets. Such non-correlation may suggest contamination of the circumstellar material, or a lack of constraints on the line Doppler-b parameter. We also find that regardless of the direction of the XRBs, the O VII absorption lines are always detected when the flux of the background XRBs reaches a certain level, suggesting a uniform distribution of this hot gas. We estimate a ratio of 0.004–0.4 between the hot and neutral phases of the ISM. This is the second paper in the series following Fang et al. (2015), in which we focused on the local O VII absorption lines detected in the background AGN spectra. Detailed modeling of the hot ISM distribution will be investigated in a future paper.

  3. A Survey of Structural Design of Diagnostic X-ray Imaging Facilities and Compliance to Shielding Design Goals in a Limited Resource Setting

    Directory of Open Access Journals (Sweden)

    Flavious B. Nkubli

    2017-11-01

    Full Text Available Purpose: To survey structural designs of x-ray rooms and compliance to shielding design goals of three x-ray imaging facilities. Methods and Materials: The survey was conducted in three radiodiagnostic centers in South East Nigeria, labeled X, Y and Z for anonymity. A stretchable non-elastic meter rule was used to measure x-ray room dimensions. A Vernier caliper was used to measure lead thickness while a calibrated digital survey meter Radalert 100x was used for radiation survey of controlled and uncontrolled areas. Simple statistical tools such as mean and standard deviation were used for analysis with the aid of Microsoft Excel version 2007. Results: Center X had a room dimension of 2.4 m × 2.1 m, Center Y had an x-ray room dimension of 3.6 m × 3.3 m, and Center Z had two x-ray rooms with identical dimensions of 6.3 m × 3.6 m. Measured exit radiation doses for controlled areas in all the centers were: 0.00152 mSv/wk; 0.00496 mSv/wk; 0.00168 mSv/wk; 0.00224 mSv/wk respectively. Lead was the common shielding material used. Conclusion: Based on the parameters studied, Center Z had the ideal room size and layout. Relative distances from the x-ray tubes to the nearest walls were not optimized in all the centers except in Center Z. Measured exit doses were within recommended limits except in Center Y. The location of the control consoles and measured doses were appropriate and within recommended design goals.

  4. LIFTING THE VEIL ON OBSCURED ACCRETION: ACTIVE GALACTIC NUCLEI NUMBER COUNTS AND SURVEY STRATEGIES FOR IMAGING HARD X-RAY MISSIONS

    International Nuclear Information System (INIS)

    Ballantyne, D. R.; Draper, A. R.; Madsen, K. K.; Rigby, J. R.; Treister, E.

    2011-01-01

    Finding and characterizing the population of active galactic nuclei (AGNs) that produces the X-ray background (XRB) is necessary to connect the history of accretion to observations of galaxy evolution at longer wavelengths. The year 2012 will see the deployment of the first hard X-ray imaging telescope which, through deep extragalactic surveys, will be able to measure the AGN population at the energies where the XRB peaks (∼20-30 keV). Here, we present predictions of AGN number counts in three hard X-ray bandpasses: 6-10 keV, 10-30 keV, and 30-60 keV. Separate predictions are presented for the number counts of Compton thick AGNs, the most heavily obscured active galaxies. The number counts are calculated for five different models of the XRB that differ in the assumed hard X-ray luminosity function, the evolution of the Compton thick AGNs, and the underlying AGN spectral model. The majority of the hard X-ray number counts will be Compton thin AGNs, but there is a greater than tenfold increase in the Compton thick number counts from the 6-10 keV to the 10-30 keV band. The Compton thick population shows enough variation that a hard X-ray number counts measurement will constrain the models. The computed number counts are used to consider various survey strategies for the NuSTAR mission, assuming a total exposure time of 6.2 Ms. We find that multiple surveys will allow a measurement of Compton thick evolution. The predictions presented here should be useful for all future imaging hard X-ray missions.

  5. OPTICAL STUDIES OF 13 HARD X-RAY SELECTED CATACLYSMIC BINARIES FROM THE SWIFT-BAT SURVEY

    International Nuclear Information System (INIS)

    Halpern, Jules P.; Thorstensen, John R.

    2015-01-01

    From a set of 13 cataclysmic binaries that were discovered in the Swift Burst Alert Telescope (BAT) survey, we conducted time-resolved optical spectroscopy and/or time-series photometry of 11, with the goal of measuring their orbital periods and searching for spin periods. Seven of the objects in this study are new optical identifications. Orbital periods are found for seven targets, ranging from 81 minutes to 20.4 hr. PBC J0706.7+0327 is an AM Herculis star (polar) based on its emission-line variations and large amplitude photometric modulation on the same period. Swift J2341.0+7645 may be a polar, although the evidence here is less secure. Coherent pulsations are detected from two objects, Swift J0503.7−2819 (975 s) and Swift J0614.0+1709 (1412 s and 1530 s, spin and beat periods, respectively), indicating that they are probable intermediate polars (DQ Herculis stars). For two other stars, longer spin periods are tentatively suggested. We also present the discovery of a 2.00 hr X-ray modulation from RX J2015.6+3711, possibly a contributor to Swift J2015.9+3715, and likely a polar

  6. NuSTAR HARD X-RAY SURVEY OF THE GALACTIC CENTER REGION. I. HARD X-RAY MORPHOLOGY AND SPECTROSCOPY OF THE DIFFUSE EMISSION

    Energy Technology Data Exchange (ETDEWEB)

    Mori, Kaya; Hailey, Charles J.; Perez, Kerstin; Nynka, Melania; Zhang, Shuo; Canipe, Alicia M. [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Krivonos, Roman; Tomsick, John A.; Barrière, Nicolas; Boggs, Steven E.; Craig, William W. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Hong, Jaesub [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Ponti, Gabriele [Max-Planck-Institut f. extraterrestrische Physik, HEG, Garching (Germany); Bauer, Franz [Instituto de Astrofísica, Facultad de Física, Pontificia Universidad Católica de Chile, 306, Santiago 22 (Chile); Alexander, David M. [Department of Physics, Durham University, Durham DH1 3LE (United Kingdom); Baganoff, Frederick K. [Kavli Institute for Astrophysics and Space Research, Massachusets Institute of Technology, Cambridge, MA 02139 (United States); Barret, Didier [Université de Toulouse, UPS-OMP, IRAP, Toulouse (France); Christensen, Finn E. [DTU Space—National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby (Denmark); Forster, Karl [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Giommi, Paolo, E-mail: kaya@astro.columbia.edu [ASI Science Data Center, Via del Politecnico snc I-00133, Roma (Italy); and others

    2015-12-01

    We present the first sub-arcminute images of the Galactic Center above 10 keV, obtained with NuSTAR. NuSTAR resolves the hard X-ray source IGR J17456–2901 into non-thermal X-ray filaments, molecular clouds, point sources, and a previously unknown central component of hard X-ray emission (CHXE). NuSTAR detects four non-thermal X-ray filaments, extending the detection of their power-law spectra with Γ ∼ 1.3–2.3 up to ∼50 keV. A morphological and spectral study of the filaments suggests that their origin may be heterogeneous, where previous studies suggested a common origin in young pulsar wind nebulae (PWNe). NuSTAR detects non-thermal X-ray continuum emission spatially correlated with the 6.4 keV Fe Kα fluorescence line emission associated with two Sgr A molecular clouds: MC1 and the Bridge. Broadband X-ray spectral analysis with a Monte-Carlo based X-ray reflection model self-consistently determined their intrinsic column density (∼10{sup 23} cm{sup −2}), primary X-ray spectra (power-laws with Γ ∼ 2) and set a lower limit of the X-ray luminosity of Sgr A* flare illuminating the Sgr A clouds to L{sub X} ≳ 10{sup 38} erg s{sup −1}. Above ∼20 keV, hard X-ray emission in the central 10 pc region around Sgr A* consists of the candidate PWN G359.95–0.04 and the CHXE, possibly resulting from an unresolved population of massive CVs with white dwarf masses M{sub WD} ∼ 0.9 M{sub ⊙}. Spectral energy distribution analysis suggests that G359.95–0.04 is likely the hard X-ray counterpart of the ultra-high gamma-ray source HESS J1745–290, strongly favoring a leptonic origin of the GC TeV emission.

  7. THE XMM-NEWTON X-RAY SPECTRA OF THE MOST X-RAY LUMINOUS RADIO-QUIET ROSAT BRIGHT SURVEY-QSOs: A REFERENCE SAMPLE FOR THE INTERPRETATION OF HIGH-REDSHIFT QSO SPECTRA

    International Nuclear Information System (INIS)

    Krumpe, M.; Markowitz, A.; Lamer, G.; Corral, A.

    2010-01-01

    We present the broadband X-ray properties of four of the most X-ray luminous (L X ≥ 10 45 erg s -1 in the 0.5-2 keV band) radio-quiet QSOs found in the ROSAT Bright Survey. This uniform sample class, which explores the extreme end of the QSO luminosity function, exhibits surprisingly homogenous X-ray spectral properties: a soft excess with an extremely smooth shape containing no obvious discrete features, a hard power law above 2 keV, and a weak narrow/barely resolved Fe Kα fluorescence line for the three high signal-to-noise ratio (S/N) spectra. The soft excess can be well fitted with only a soft power law. No signatures of warm or cold intrinsic absorbers are found. The Fe Kα centroids and the line widths indicate emission from neutral Fe (E = 6.4 keV) originating from cold material from distances of only a few light days or further out. The well-constrained equivalent widths (EW) of the neutral Fe lines are higher than expected from the X-ray Baldwin effect which has been only poorly constrained at very high luminosities. Taking into account our individual EW measurements, we show that the X-ray Baldwin effect flattens above L X ∼ 10 44 erg s -1 (2-10 keV band) where an almost constant (EW) of ∼100 eV is found. We confirm the assumption of having very similar X-ray active galactic nucleus properties when interpreting stacked X-ray spectra. Our stacked spectrum serves as a superb reference for the interpretation of low S/N spectra of radio-quiet QSOs with similar luminosities at higher redshifts routinely detected by XMM-Newton and Chandra surveys.

  8. Candidate isolated neutron stars and other optically blank x-ray fields identified from the rosat all-sky and sloan digital sky surveys

    Energy Technology Data Exchange (ETDEWEB)

    Agueros, Marcel A.; Anderson, Scott F.; /Washington U., Seattle, Astron. Dept.; Margon, Bruce; /Baltimore, Space Telescope Sci.; Haberl, Frank; Voges, Wolfgang; /Garching,; Annis, James; /Fermilab; Schneider, Donald P.; /Penn State U., Astron. Astrophys.; Brinkmann, Jonathan; /Apache Point Observ.

    2005-11-01

    Only seven radio-quiet isolated neutron stars (INSs) emitting thermal X rays are known, a sample that has yet to definitively address such fundamental issues as the equation of state of degenerate neutron matter. We describe a selection algorithm based on a cross-correlation of the ROSAT All-Sky Survey (RASS) and the Sloan Digital Sky Survey (SDSS) that identifies X-ray error circles devoid of plausible optical counterparts to the SDSS g {approx} 22 magnitudes limit. We quantitatively characterize these error circles as optically blank; they may host INSs or other similarly exotic X-ray sources such as radio-quiet BL Lacs, obscured AGN, etc. Our search is an order of magnitude more selective than previous searches for optically blank RASS error circles, and excludes the 99.9% of error circles that contain more common X-ray-emitting subclasses. We find 11 candidates, nine of which are new. While our search is designed to find the best INS candidates and not to produce a complete list of INSs in the RASS, it is reassuring that our number of candidates is consistent with predictions from INS population models. Further X-ray observations will obtain pinpoint positions and determine whether these sources are entirely optically blank at g {approx} 22, supporting the presence of likely isolated neutron stars and perhaps enabling detailed follow-up studies of neutron star physics.

  9. Finding counterparts for all-sky X-ray surveys with NWAY: a Bayesian algorithm for cross-matching multiple catalogues

    Science.gov (United States)

    Salvato, M.; Buchner, J.; Budavári, T.; Dwelly, T.; Merloni, A.; Brusa, M.; Rau, A.; Fotopoulou, S.; Nandra, K.

    2018-02-01

    We release the AllWISE counterparts and Gaia matches to 106 573 and 17 665 X-ray sources detected in the ROSAT 2RXS and XMMSL2 surveys with |b| > 15°. These are the brightest X-ray sources in the sky, but their position uncertainties and the sparse multi-wavelength coverage until now rendered the identification of their counterparts a demanding task with uncertain results. New all-sky multi-wavelength surveys of sufficient depth, like AllWISE and Gaia, and a new Bayesian statistics based algorithm, NWAY, allow us, for the first time, to provide reliable counterpart associations. NWAY extends previous distance and sky density based association methods and, using one or more priors (e.g. colours, magnitudes), weights the probability that sources from two or more catalogues are simultaneously associated on the basis of their observable characteristics. Here, counterparts have been determined using a Wide-field Infrared Survey Explorer (WISE) colour-magnitude prior. A reference sample of 4524 XMM/Chandra and Swift X-ray sources demonstrates a reliability of ∼94.7 per cent (2RXS) and 97.4 per cent (XMMSL2). Combining our results with Chandra-COSMOS data, we propose a new separation between stars and AGN in the X-ray/WISE flux-magnitude plane, valid over six orders of magnitude. We also release the NWAY code and its user manual. NWAY was extensively tested with XMM-COSMOS data. Using two different sets of priors, we find an agreement of 96 per cent and 99 per cent with published Likelihood Ratio methods. Our results were achieved faster and without any follow-up visual inspection. With the advent of deep and wide area surveys in X-rays (e.g. SRG/eROSITA, Athena/WFI) and radio (ASKAP/EMU, LOFAR, APERTIF, etc.) NWAY will provide a powerful and reliable counterpart identification tool.

  10. High-Latitude Space Plasma Physics

    International Nuclear Information System (INIS)

    Hultqvist, B.; Hagfors, T.

    1983-01-01

    This book constitutes the proceedings of the Nobel Symposium No. 54 on High Latitude Magnetospheric/Ionospheric Plasma Physics. The main purpose of the symposium was to prepare for the European research effort in space plasma physics in the mid-1980's, in which two major constituents are the European Incoherent Scatter Association (EISCAT) facilities and the Swedish satellite Viking. The physics of the high-latitude ionosphere and how this part of near space is affected by the properties of the solar wind and the interplanetary magnetic field are explored. A detailed discussion is provided on high-latitude magnetospheric physics at altitudes of 1-2 earth radii, the main focus of the Viking project. Specific topics considered include the role of the auroral ionosphere in magnetospheric substorms, the low altitude cleft, ionospheric modification and stimulated emissions, plasma physics on auroral field lines, solar wind-magnetosphere energy coupling, cold plasma distribution above a few thousand kilometers at high latitudes, hot electrons in and above the auroral ionosphere, the correlation of auroral kilometric radiation with visual auroras and with Birkeland currents, electrostatic waves in the topside ionosphere, solitary waves and double layers, and an Alfven wave model of auroral arcs

  11. Latitude SSTmax = 0 SSTmax = 10 SSTmax = 20

    Indian Academy of Sciences (India)

    . −10. −5. 0. 5. 10. V (m/s). −30. −20. −10. 0. 10. 20. 30. −10. −5. 0. 5. 10. Latitude. V (m/s). V Non−linear model. Non−linear advection term. Pressure gradient term. SSTmax = 0. SSTmax = 10. SSTmax = 20.

  12. The XMM deep survey in the CDF-S. X. X-ray variability of bright sources

    Science.gov (United States)

    Falocco, S.; Paolillo, M.; Comastri, A.; Carrera, F. J.; Ranalli, P.; Iwasawa, K.; Georgantopoulos, I.; Vignali, C.; Gilli, R.

    2017-12-01

    Aims: We aim to study the variability properties of bright hard X-ray selected active galactic nuclei (AGN) in the redshift range between 0.3 and 1.6 detected in the Chandra Deep Field South (XMM-CDFS) by a long ( 3 Ms) XMM observation. Methods: Taking advantage of the good count statistics in the XMM CDFS, we search for flux and spectral variability using the hardness ratio (HR) techniques. We also investigate the spectral variability of different spectral components (photon index of the power law, column density of the local absorber, and reflection intensity). The spectra were merged in six epochs (defined as adjacent observations) and in high and low flux states to understand whether the flux transitions are accompanied by spectral changes. Results: The flux variability is significant in all the sources investigated. The HRs in general are not as variable as the fluxes, in line with previous results on deep fields. Only one source displays a variable HR, anti-correlated with the flux (source 337). The spectral analysis in the available epochs confirms the steeper when brighter trend consistent with Comptonisation models only in this source at 99% confidence level. Finding this trend in one out of seven unabsorbed sources is consistent, within the statistical limits, with the 15% of unabsorbed AGN in previous deep surveys. No significant variability in the column densities, nor in the Compton reflection component, has been detected across the epochs considered. The high and low states display in general different normalisations but consistent spectral properties. Conclusions: X-ray flux fluctuations are ubiquitous in AGN, though in some cases the data quality does not allow for their detection. In general, the significant flux variations are not associated with spectral variability: photon index and column densities are not significantly variable in nine out of the ten AGN over long timescales (from three to six and a half years). Photon index variability is

  13. THE FORTUITOUS LATITUDE OF THE PIERRE AUGER OBSERVATORY AND TELESCOPE ARRAY FOR RECONSTRUCTING THE QUADRUPOLE MOMENT

    International Nuclear Information System (INIS)

    Denton, Peter B.; Weiler, Thomas J.

    2015-01-01

    Determining anisotropies in the arrival directions of cosmic rays at the highest energy is an important task in astrophysics. It is common and useful to partition the sky into spherical harmonics as a measure of anisotropy. The two lowest nontrivial spherical harmonics, the dipole and the quadrupole, are of particular interest, since these distributions encapsulate a dominant single source and a plane of sources, as well as offering relatively high statistics. The best experiments for the detection of ultra high energy cosmic rays currently are all ground-based, with highly nonuniform exposures on the sky resulting from the fixed experimental locations on the Earth. This nonuniform exposure increases the complexity and error in inferring anisotropies. It turns out that there is an optimal latitude for an experiment at which nonuniform exposure does not diminish the inference of the quadrupole moment. We derive the optimal latitude and find that (presumably by a fortuitous coincidence) this optimal latitude runs through the largest cosmic ray experiment, the Pierre Auger Observatory (PAO) in the Southern Hemisphere, and close to the largest cosmic ray experiment in the Northern Hemisphere, the Telescope Array (TA). Consequently, assuming a quadrupole distribution, PAO and TA can reconstruct the cosmic ray quadrupole distribution to a high precision without concern for their partial sky exposure

  14. A survey of costs incurred in U.K. X-ray diffraction research laboratories as a consequence of proposed regulations for radiological safety

    International Nuclear Information System (INIS)

    Blow, D.M.

    1981-01-01

    A small survey of British X-ray diffraction laboratories was undertaken, with the aim of discovering the effects of the Health and Safety at Work Act (1974) and the draft regulations on radiological protection and ionising radiations (1978) on the practice of X-ray crystallography. The responses lead to the conclusion that the average cost incurred in bringing X-ray diffraction equipment to a safety standard compatible with the draft regulations (as judged by the respondents) will exceed Pound2,000 per X-ray generator. The safety costs will represent an overhead charge of at least 15-18% on the purchase of an X-ray generator, requiring additional capital outlay of over Pound5m to maintain the current level of X-ray diffraction activity in the U.K. There seems to be no evidence of a high accident rate with diffraction equipment, and the cost of the safety precautions bears no relation to the risks involved. (author)

  15. The NuSTAR  Extragalactic Surveys: X-Ray Spectroscopic Analysis of the Bright Hard-band Selected Sample

    Science.gov (United States)

    Zappacosta, L.; Comastri, A.; Civano, F.; Puccetti, S.; Fiore, F.; Aird, J.; Del Moro, A.; Lansbury, G. B.; Lanzuisi, G.; Goulding, A.; Mullaney, J. R.; Stern, D.; Ajello, M.; Alexander, D. M.; Ballantyne, D. R.; Bauer, F. E.; Brandt, W. N.; Chen, C.-T. J.; Farrah, D.; Harrison, F. A.; Gandhi, P.; Lanz, L.; Masini, A.; Marchesi, S.; Ricci, C.; Treister, E.

    2018-02-01

    We discuss the spectral analysis of a sample of 63 active galactic nuclei (AGN) detected above a limiting flux of S(8{--}24 {keV})=7× {10}-14 {erg} {{{s}}}-1 {{cm}}-2 in the multi-tiered NuSTAR extragalactic survey program. The sources span a redshift range z=0{--}2.1 (median =0.58). The spectral analysis is performed over the broad 0.5–24 keV energy range, combining NuSTAR with Chandra and/or XMM-Newton data and employing empirical and physically motivated models. This constitutes the largest sample of AGN selected at > 10 {keV} to be homogeneously spectrally analyzed at these flux levels. We study the distribution of spectral parameters such as photon index, column density ({N}{{H}}), reflection parameter ({\\boldsymbol{R}}), and 10–40 keV luminosity ({L}{{X}}). Heavily obscured ({log}[{N}{{H}}/{{cm}}-2]≥slant 23) and Compton-thick (CT; {log}[{N}{{H}}/{{cm}}-2]≥slant 24) AGN constitute ∼25% (15–17 sources) and ∼2–3% (1–2 sources) of the sample, respectively. The observed {N}{{H}} distribution agrees fairly well with predictions of cosmic X-ray background population-synthesis models (CXBPSM). We estimate the intrinsic fraction of AGN as a function of {N}{{H}}, accounting for the bias against obscured AGN in a flux-selected sample. The fraction of CT AGN relative to {log}[{N}{{H}}/{{cm}}-2]=20{--}24 AGN is poorly constrained, formally in the range 2–56% (90% upper limit of 66%). We derived a fraction (f abs) of obscured AGN ({log}[{N}{{H}}/{{cm}}-2]=22{--}24) as a function of {L}{{X}} in agreement with CXBPSM and previous zvalues.

  16. X-ray Spectral Survey of WGACAT Quasars, II: Optical and Radio Properties of Quasars with Low Energy X-ray Cut-offs

    OpenAIRE

    Elvis, Martin; Fiore, Fabrizio; Giommi, Paolo; Padovani, Paolo

    1997-01-01

    We have selected quasars with X-ray colors suggestive of a low energy cut-off, from the ROSAT PSPC pointed archive. We examine the radio and optical properties of these 13 quasars. Five out of the seven quasars with good optical spectra show associated optical absorption lines, with two having high delta-v candidate systems. Two other cut-off quasars show reddening associated with the quasar. We conclude that absorption is highly likely to be the cause of the X-ray cut-offs, and that the abso...

  17. A deep x-ray survey of the Pleiades cluster and the B6-A3 main sequence stars in Orion

    Science.gov (United States)

    Caillault, Jean-Pierre

    1993-01-01

    We have obtained deep ROSAT images of three regions within the Pleiades open cluster. We have detected 317 X-ray sources in these ROSAT PSPC images, 171 of which we associate with certain probable members of the Pleiades cluster. We detect nearly all Pleiades members with spectral types later than G0 and within 25 arcminutes of our three field centers where our sensitivity is highest. This has allowed us to derive for the first time the luminosity function for the G, K, and M dwarfs of an open cluster without the need to use statistical techniques to account for the presence of upper limits in the data sample. Because of our high X-ray detection frequency down to the faint limit of the optical catalog, we suspect that some of our unidentified X-ray sources are previously unknown, very low-mass members of the Pleiades. A large fraction of the Pleiades members detected with ROSAT have published rotational velocities. Plots of L(sub x)/L(sub bol) versus spectroscopic rotational velocity show tightly correlated 'saturation' type relations for stars with (B - V)(sub O) greater than 0.60. For each of several color ranges, X-ray luminosities rise rapidly with increasing rotation rate until v sin i approximately equals 15 km/s, and then remain essentially flat for rotation rates up to at least v sin i approximately equal to 100 km/s. The dispersion in rotation among low-mass stars in the Pleiades is by far the dominant contributor to the dispersion in L(subx) at a given mass. Only about 35 percent of the B.A. and early F stars in the Pleiades are detected as X-ray sources in our survey. There is no correlation between X-ray flux and rotation for these stars. The X-ray luminosity function for the early-type Pleiades stars appears to be bimodal, with only a few exceptions. We either detect these stars at fluxes in the range found for low-mass stars or we derive X-ray limits below the level found for most Pleiades dwarfs. The X-ray spectra for the early-type Pleiades stars

  18. A polarized fast radio burst at low Galactic latitude

    Science.gov (United States)

    Petroff, E.; Burke-Spolaor, S.; Keane, E. F.; McLaughlin, M. A.; Miller, R.; Andreoni, I.; Bailes, M.; Barr, E. D.; Bernard, S. R.; Bhandari, S.; Bhat, N. D. R.; Burgay, M.; Caleb, M.; Champion, D.; Chandra, P.; Cooke, J.; Dhillon, V. S.; Farnes, J. S.; Hardy, L. K.; Jaroenjittichai, P.; Johnston, S.; Kasliwal, M.; Kramer, M.; Littlefair, S. P.; Macquart, J. P.; Mickaliger, M.; Possenti, A.; Pritchard, T.; Ravi, V.; Rest, A.; Rowlinson, A.; Sawangwit, U.; Stappers, B.; Sullivan, M.; Tiburzi, C.; van Straten, W.; ANTARES Collaboration; Albert, A.; André, M.; Anghinolfi, M.; Anton, G.; Ardid, M.; Aubert, J.-J.; Avgitas, T.; Baret, B.; Barrios-Martí, J.; Basa, S.; Bertin, V.; Biagi, S.; Bormuth, R.; Bourret, S.; Bouwhuis, M. C.; Bruijn, R.; Brunner, J.; Busto, J.; Capone, A.; Caramete, L.; Carr, J.; Celli, S.; Chiarusi, T.; Circella, M.; Coelho, J. A. B.; Coleiro, A.; Coniglione, R.; Costantini, H.; Coyle, P.; Creusot, A.; Deschamps, A.; de Bonis, G.; Distefano, C.; di Palma, I.; Donzaud, C.; Dornic, D.; Drouhin, D.; Eberl, T.; El Bojaddaini, I.; Elsässer, D.; Enzenhöfer, A.; Felis, I.; Fusco, L. A.; Galatà, S.; Gay, P.; Geißelsöder, S.; Geyer, K.; Giordano, V.; Gleixner, A.; Glotin, H.; Grégoire, T.; Gracia-Ruiz, R.; Graf, K.; Hallmann, S.; van Haren, H.; Heijboer, A. J.; Hello, Y.; Hernández-Rey, J. J.; Hößl, J.; Hofestädt, J.; Hugon, C.; Illuminati, G.; James, C. W.; de Jong, M.; Jongen, M.; Kadler, M.; Kalekin, O.; Katz, U.; Kießling, D.; Kouchner, A.; Kreter, M.; Kreykenbohm, I.; Kulikovskiy, V.; Lachaud, C.; Lahmann, R.; Lefèvre, D.; Leonora, E.; Lotze, M.; Loucatos, S.; Marcelin, M.; Margiotta, A.; Marinelli, A.; Martínez-Mora, J. A.; Mathieu, A.; Mele, R.; Melis, K.; Michael, T.; Migliozzi, P.; Moussa, A.; Mueller, C.; Nezri, E.; Pǎvǎlaş, G. E.; Pellegrino, C.; Perrina, C.; Piattelli, P.; Popa, V.; Pradier, T.; Quinn, L.; Racca, C.; Riccobene, G.; Roensch, K.; Sánchez-Losa, A.; Saldaña, M.; Salvadori, I.; Samtleben, D. F. E.; Sanguineti, M.; Sapienza, P.; Schnabel, J.; Seitz, T.; Sieger, C.; Spurio, M.; Stolarczyk, Th.; Taiuti, M.; Tayalati, Y.; Trovato, A.; Tselengidou, M.; Turpin, D.; Tönnis, C.; Vallage, B.; Vallée, C.; van Elewyck, V.; Vivolo, D.; Vizzoca, A.; Wagner, S.; Wilms, J.; Zornoza, J. D.; Zúñiga, J.; H.E.S.S. Collaboration; Abdalla, H.; Abramowski, A.; Aharonian, F.; Ait Benkhali, F.; Akhperjanian, A. G.; Andersson, T.; Angüner, E. O.; Arrieta, M.; Aubert, P.; Backes, M.; Balzer, A.; Barnard, M.; Becherini, Y.; Tjus, J. Becker; Berge, D.; Bernhard, S.; Bernlöhr, K.; Blackwell, R.; Böttcher, M.; Boisson, C.; Bolmont, J.; Bordas, P.; Bregeon, J.; Brun, F.; Brun, P.; Bryan, M.; Bulik, T.; Capasso, M.; Casanova, S.; Cerruti, M.; Chakraborty, N.; Chalme-Calvet, R.; Chaves, R. C. G.; Chen, A.; Chevalier, J.; Chrétien, M.; Colafrancesco, S.; Cologna, G.; Condon, B.; Conrad, J.; Cui, Y.; Davids, I. D.; Decock, J.; Degrange, B.; Deil, C.; Devin, J.; Dewilt, P.; Dirson, L.; Djannati-Ataï, A.; Domainko, W.; Donath, A.; Drury, L. O'c.; Dubus, G.; Dutson, K.; Dyks, J.; Edwards, T.; Egberts, K.; Eger, P.; Ernenwein, J.-P.; Eschbach, S.; Farnier, C.; Fegan, S.; Fernandes, M. V.; Fiasson, A.; Fontaine, G.; Förster, A.; Funk, S.; Füßling, M.; Gabici, S.; Gajdus, M.; Gallant, Y. A.; Garrigoux, T.; Giavitto, G.; Giebels, B.; Glicenstein, J. F.; Gottschall, D.; Goyal, A.; Grondin, M.-H.; Hadasch, D.; Hahn, J.; Haupt, M.; Hawkes, J.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hervet, O.; Hinton, J. A.; Hofmann, W.; Hoischen, C.; Holler, M.; Horns, D.; Ivascenko, A.; Jacholkowska, A.; Jamrozy, M.; Janiak, M.; Jankowsky, D.; Jankowsky, F.; Jingo, M.; Jogler, T.; Jouvin, L.; Jung-Richardt, I.; Kastendieck, M. A.; Katarzyński, K.; Kerszberg, D.; Khélifi, B.; Kieffer, M.; King, J.; Klepser, S.; Klochkov, D.; Kluźniak, W.; Kolitzus, D.; Komin, Nu.; Kosack, K.; Krakau, S.; Kraus, M.; Krayzel, F.; Krüger, P. P.; Laffon, H.; Lamanna, G.; Lau, J.; Lees, J.-P.; Lefaucheur, J.; Lefranc, V.; Lemière, A.; Lemoine-Goumard, M.; Lenain, J.-P.; Leser, E.; Lohse, T.; Lorentz, M.; Liu, R.; López-Coto, R.; Lypova, I.; Marandon, V.; Marcowith, A.; Mariaud, C.; Marx, R.; Maurin, G.; Maxted, N.; Mayer, M.; Meintjes, P. J.; Meyer, M.; Mitchell, A. M. W.; Moderski, R.; Mohamed, M.; Mohrmann, L.; Morâ, K.; Moulin, E.; Murach, T.; de Naurois, M.; Niederwanger, F.; Niemiec, J.; Oakes, L.; O'Brien, P.; Odaka, H.; Öttl, S.; Ohm, S.; Ostrowski, M.; Oya, I.; Padovani, M.; Panter, M.; Parsons, R. D.; Pekeur, N. W.; Pelletier, G.; Perennes, C.; Petrucci, P.-O.; Peyaud, B.; Piel, Q.; Pita, S.; Poon, H.; Prokhorov, D.; Prokoph, H.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Reimer, A.; Reimer, O.; Renaud, M.; Reyes, R. De Los; Rieger, F.; Romoli, C.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Salek, D.; Sanchez, D. A.; Santangelo, A.; Sasaki, M.; Schlickeiser, R.; Schulz, A.; Schüssler, F.; Schwanke, U.; Schwemmer, S.; Settimo, M.; Seyffert, A. S.; Shafi, N.; Shilon, I.; Simoni, R.; Sol, H.; Spanier, F.; Spengler, G.; Spies, F.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Stinzing, F.; Stycz, K.; Sushch, I.; Tavernet, J.-P.; Tavernier, T.; Taylor, A. M.; Terrier, R.; Tibaldo, L.; Tiziani, D.; Tluczykont, M.; Trichard, C.; Tuffs, R.; Uchiyama, Y.; Walt, D. J. Van Der; van Eldik, C.; van Rensburg, C.; van Soelen, B.; Vasileiadis, G.; Veh, J.; Venter, C.; Viana, A.; Vincent, P.; Vink, J.; Voisin, F.; Völk, H. J.; Vuillaume, T.; Wadiasingh, Z.; Wagner, S. J.; Wagner, P.; Wagner, R. M.; White, R.; Wierzcholska, A.; Willmann, P.; Wörnlein, A.; Wouters, D.; Yang, R.; Zabalza, V.; Zaborov, D.; Zacharias, M.; Zanin, R.; Zdziarski, A. A.; Zech, A.; Zefi, F.; Ziegler, A.; Żywucka, N.

    2017-08-01

    We report on the discovery of a new fast radio burst (FRB), FRB 150215, with the Parkes radio telescope on 2015 February 15. The burst was detected in real time with a dispersion measure (DM) of 1105.6 ± 0.8 pc cm-3, a pulse duration of 2.8^{+1.2}_{-0.5} ms, and a measured peak flux density assuming that the burst was at beam centre of 0.7^{+0.2}_{-0.1} Jy. The FRB originated at a Galactic longitude and latitude of 24.66°, 5.28° and 25° away from the Galactic Center. The burst was found to be 43 ± 5 per cent linearly polarized with a rotation measure (RM) in the range -9 < RM < 12 rad m-2 (95 per cent confidence level), consistent with zero. The burst was followed up with 11 telescopes to search for radio, optical, X-ray, γ-ray and neutrino emission. Neither transient nor variable emission was found to be associated with the burst and no repeat pulses have been observed in 17.25 h of observing. The sightline to the burst is close to the Galactic plane and the observed physical properties of FRB 150215 demonstrate the existence of sight lines of anomalously low RM for a given electron column density. The Galactic RM foreground may approach a null value due to magnetic field reversals along the line of sight, a decreased total electron column density from the Milky Way, or some combination of these effects. A lower Galactic DM contribution might explain why this burst was detectable whereas previous searches at low latitude have had lower detection rates than those out of the plane.

  19. Airborne gamma-ray survey around the Negoro fault. 1; Negoro danso shuhen chiiki ni okeru kuchu {gamma} sen tansa. 1

    Energy Technology Data Exchange (ETDEWEB)

    Nakayama, E.; Kasuya, Y.; Hasegawa, H. [Aero Asahi Corp., Tokyo (Japan); Tsukuda, E. [Geological Survey of Japan, Tsukuba (Japan)

    1997-05-27

    An airborne gamma-ray survey was carried out to investigate the active fault system in the central structure line in the peripheral area of the city of Wakayama. At the same time, with an objective to enhance applicability of the airborne gamma-ray survey to active fault investigation, fundamental data were acquired and discussed. The measurement data were processed according to the standard method specified by IAEA. An ID-FFT filter and a nonlinear filter were employed to extract anomalous gamma-ray intensity values. The gamma-ray intensity distribution chart shows a noticeable positive anomalous area extending from the central part of the western edge to the north-east direction. This area agrees nearly well with the Negoro fault, but its peak portion is positioned slightly more to south than the position of the Negoro fault shown in existing data. The Sakuraike fault and the vicinity of the central structure line also show positive anomaly as a whole, particularly remarkably in the vicinity of their converging portion. However, differing from the vicinity of the Negoro fault, the areas are not extracted as an anomalous area which has directionality and extends in a line form. One of the factors for this would be that it is a fault in unsolidified deposits with low opening trend, differing from the one in solidified rocks. 1 fig., 3 tabs.

  20. Imaging Polarimeter for a Sub-MeV Gamma-Ray All-sky Survey Using an Electron-tracking Compton Camera

    Energy Technology Data Exchange (ETDEWEB)

    Komura, S.; Takada, A.; Mizumura, Y.; Miyamoto, S.; Takemura, T.; Kishimoto, T.; Kubo, H.; Matsuoka, Y.; Mizumoto, T.; Nakamasu, Y.; Nakamura, K.; Oda, M.; Parker, J. D.; Sonoda, S.; Tanimori, T.; Tomono, D.; Yoshikawa, K. [Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502 (Japan); Kurosawa, S. [New Industry Creation Hatchery Center (NICHe), Tohoku University, Sendai, Miyagi, 980-8579 (Japan); Miuchi, K. [Department of Physics, Kobe University, Kobe, Hyogo, 658-8501 (Japan); Sawano, T., E-mail: komura@cr.scphys.kyoto-u.ac.jp [College of Science and Engineering, School of Mathematics and Physics, Kanazawa University, Kanazawa, Ishikawa, 920-1192 (Japan)

    2017-04-10

    X-ray and gamma-ray polarimetry is a promising tool to study the geometry and the magnetic configuration of various celestial objects, such as binary black holes or gamma-ray bursts (GRBs). However, statistically significant polarizations have been detected in few of the brightest objects. Even though future polarimeters using X-ray telescopes are expected to observe weak persistent sources, there are no effective approaches to survey transient and serendipitous sources with a wide field of view (FoV). Here we present an electron-tracking Compton camera (ETCC) as a highly sensitive gamma-ray imaging polarimeter. The ETCC provides powerful background rejection and a high modulation factor over an FoV of up to 2 π sr thanks to its excellent imaging based on a well-defined point-spread function. Importantly, we demonstrated for the first time the stability of the modulation factor under realistic conditions of off-axis incidence and huge backgrounds using the SPring-8 polarized X-ray beam. The measured modulation factor of the ETCC was 0.65 ± 0.01 at 150 keV for an off-axis incidence with an oblique angle of 30° and was not degraded compared to the 0.58 ± 0.02 at 130 keV for on-axis incidence. These measured results are consistent with the simulation results. Consequently, we found that the satellite-ETCC proposed in Tanimori et al. would provide all-sky surveys of weak persistent sources of 13 mCrab with 10% polarization for a 10{sup 7} s exposure and over 20 GRBs down to a 6 × 10{sup −6} erg cm{sup −2} fluence and 10% polarization during a one-year observation.

  1. Movie-maps of low-latitude magnetic storm disturbance

    Science.gov (United States)

    Love, Jeffrey J.; Gannon, Jennifer L.

    2010-06-01

    We present 29 movie-maps of low-latitude horizontal-intensity magnetic disturbance for the years 1999-2006: 28 recording magnetic storms and 1 magnetically quiescent period. The movie-maps are derived from magnetic vector time series data collected at up to 25 ground-based observatories. Using a technique similar to that used in the calculation of Dst, a quiet time baseline is subtracted from the time series from each observatory. The remaining disturbance time series are shown in a polar coordinate system that accommodates both Earth rotation and the universal time dependence of magnetospheric disturbance. Each magnetic storm recorded in the movie-maps is different. While some standard interpretations about the storm time equatorial ring current appear to apply to certain moments and certain phases of some storms, the movie-maps also show substantial variety in the local time distribution of low-latitude magnetic disturbance, especially during storm commencements and storm main phases. All movie-maps are available at the U.S. Geological Survey Geomagnetism Program Web site (http://geomag.usgs.gov).

  2. Splash albedo protons between 4 and 315 MeV at high and low geomagnetic latitudes

    International Nuclear Information System (INIS)

    Wenzel, K.; Stone, E.C.; Vogt, R.E.

    1975-01-01

    The differential energy spectrum of splash albedo protons has been measured at high geomagnetic latitude near Fort Churchill, Manitoba, at three periods of the solar cycle in 1966, and 1969 and at low latitude near Palestine, Texas, in 1967 by using a balloon-borne solid state detector telescope. We observed splash albedo proton fluxes between 4 and 315 MeV of 81plus-or-minus11, 70plus-or-minus11, and 48plus-or-minus8 protons/(m 2 s sr) at high latitude in 1966, 1967, and 1969 and of 37plus-or-minus9 protons/(m 2 s sr) at low latitude in 1967. The decreases from 1966 to 1969 are due to solar modulation of the cosmic ray parent nuclei. The albedo spectrum shows a similar shape for both latitudes. The difference in intensity can be explained by different local geomagnetic cutoffs; i.e., a significant contribution to the splash albedo flux arises from primary particles with rigidity below 4.5 GV. The splash albedo flux near Fort Churchill is consistent with corresponding fluxes previously reported near 53degree--55degreeN. The flux below 100 MeV near Palestine is significantly lower than that reported by Verma (1967)

  3. Survey on the frequency of typical X-Ray examinations and estimation of associated population doses in the Republic of Macedonia

    International Nuclear Information System (INIS)

    Gershan, V.; Stikova, E.

    2013-01-01

    Purpose: Medical X-ray exposures have been the largest man-made source of population exposure to ionizing radiation in developed countries for many years. It is therefore important for radiation protection and health care authorities in each country to regularly assess the magnitude and the distribution of this large and increasing source of population exposure. The purpose of this paper is to present results from the survey on the number of typical X-ray examination procedures in the Republic of Macedonia for 2010, the distribution of examination procedures by type per modality for adults and pediatric patients, the annual frequency per 1000 population and the collective effective dose per 1000 population from the X-ray examination procedures performed in the Republic of Macedonia in 2010. Materials and methods: In the beginning of 2011, a survey was initiated in the Republic of Macedonia for collecting data on the number of typical X-ray examination procedures conducted in 2010 as a basis for estimating frequency of these procedures and associated population doses. The survey was initiated within a Dose Data Med project launched by the European Commission to study population doses from medical exposures within the Union. The Republic of Macedonia was invited to participate in this project as a test country. Typical X-ray examination procedures encompass those that are recognized to be the most important for the total population dose, referred to as TOP20 X-ray procedures. The survey was based on a specific questionnaire being prepared and distributed to the 87 X-ray departments in the Republic of Macedonia intended to cover the data for the year of 2010. The data was collected and summarized. Based on data gathered, the total number of examination procedures, annual frequency and their distribution by modality were calculated. Thereafter, the annual collective effective dose per 1000 population for each examination procedure in the TOP20 group and collective

  4. Distribution of Latitudes and Speeds of Coronal Mass Ejections in ...

    Indian Academy of Sciences (India)

    CME activity occurs at all latitudes and is most common at low latitudes. ... implies that, statistically, there is no physical distinction between the CME .... made by first arranging the 18 points in decreasing order after taking their absolute.

  5. X-ray-bright optically faint active galactic nuclei in the Subaru Hyper Suprime-Cam wide survey

    Science.gov (United States)

    Terashima, Yuichi; Suganuma, Makoto; Akiyama, Masayuki; Greene, Jenny E.; Kawaguchi, Toshihiro; Iwasawa, Kazushi; Nagao, Tohru; Noda, Hirofumi; Toba, Yoshiki; Ueda, Yoshihiro; Yamashita, Takuji

    2018-01-01

    We construct a sample of X-ray-bright optically faint active galactic nuclei by combining Subaru Hyper Suprime-Cam, XMM-Newton, and infrared source catalogs. Fifty-three X-ray sources satisfying i-band magnitude fainter than 23.5 mag and X-ray counts with the EPIC-PN detector larger than 70 are selected from 9.1 deg2, and their spectral energy distributions (SEDs) and X-ray spectra are analyzed. Forty-four objects with an X-ray to i-band flux ratio FX/Fi > 10 are classified as extreme X-ray-to-optical flux sources. Spectral energy distributions of 48 among 53 are represented by templates of type 2 AGNs or star-forming galaxies and show the optical signature of stellar emission from host galaxies in the source rest frame. Infrared/optical SEDs indicate a significant contribution of emission from dust to the infrared fluxes, and that the central AGN is dust obscured. The photometric redshifts determined from the SEDs are in the range of 0.6-2.5. The X-ray spectra are fitted by an absorbed power-law model, and the intrinsic absorption column densities are modest (best-fit log NH = 20.5-23.5 cm-2 in most cases). The absorption-corrected X-ray luminosities are in the range of 6 × 1042-2 × 1045 erg s-1. Twenty objects are classified as type 2 quasars based on X-ray luminsosity and NH. The optical faintness is explained by a combination of redshifts (mostly z > 1.0), strong dust extinction, and in part a large ratio of dust/gas.

  6. Homogeneity of coral reef communities across 8 degrees of latitude in the Saudi Arabian Red Sea

    KAUST Repository

    Roberts, May B.; Jones, Geoffrey P.; McCormick, Mark I.; Munday, Philip L.; Neale, Stephen; Thorrold, Simon; Robitzch, Vanessa S.N.; Berumen, Michael L.

    2015-01-01

    Coral reef communities between 26.8°N and 18.6°N latitude in the Saudi Arabian Red Sea were surveyed to provide baseline data and an assessment of fine-scale biogeography of communities in this region. Forty reefs along 1100 km of coastline were surveyed using depth-stratified visual transects of fish and benthic communities. Fish abundance and benthic cover data were analyzed using multivariate approaches to investigate whether coral reef communities differed with latitude. A total of 215 fish species and 90 benthic categories were recorded on the surveys. There were no significant differences among locations in fish abundance, species richness, or among several diversity indices. Despite known environmental gradients within the Red Sea, the communities remained surprisingly similar. The communities do, however, exhibit subtle changes across this span of reefs that likely reflect the constrained distributions of several species of reef fish and benthic fauna.

  7. Homogeneity of coral reef communities across 8 degrees of latitude in the Saudi Arabian Red Sea.

    Science.gov (United States)

    Roberts, May B; Jones, Geoffrey P; McCormick, Mark I; Munday, Philip L; Neale, Stephen; Thorrold, Simon; Robitzch, Vanessa S N; Berumen, Michael L

    2016-04-30

    Coral reef communities between 26.8 °N and 18.6 °N latitude in the Saudi Arabian Red Sea were surveyed to provide baseline data and an assessment of fine-scale biogeography of communities in this region. Forty reefs along 1100 km of coastline were surveyed using depth-stratified visual transects of fish and benthic communities. Fish abundance and benthic cover data were analyzed using multivariate approaches to investigate whether coral reef communities differed with latitude. A total of 215 fish species and 90 benthic categories were recorded on the surveys. There were no significant differences among locations in fish abundance, species richness, or among several diversity indices. Despite known environmental gradients within the Red Sea, the communities remained surprisingly similar. The communities do, however, exhibit subtle changes across this span of reefs that likely reflect the constrained distributions of several species of reef fish and benthic fauna. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Homogeneity of coral reef communities across 8 degrees of latitude in the Saudi Arabian Red Sea

    KAUST Repository

    Roberts, May B.

    2015-11-20

    Coral reef communities between 26.8°N and 18.6°N latitude in the Saudi Arabian Red Sea were surveyed to provide baseline data and an assessment of fine-scale biogeography of communities in this region. Forty reefs along 1100 km of coastline were surveyed using depth-stratified visual transects of fish and benthic communities. Fish abundance and benthic cover data were analyzed using multivariate approaches to investigate whether coral reef communities differed with latitude. A total of 215 fish species and 90 benthic categories were recorded on the surveys. There were no significant differences among locations in fish abundance, species richness, or among several diversity indices. Despite known environmental gradients within the Red Sea, the communities remained surprisingly similar. The communities do, however, exhibit subtle changes across this span of reefs that likely reflect the constrained distributions of several species of reef fish and benthic fauna.

  9. Study tube housing leakage of 111 conventional diagnostic X-ray machines using ion chamber survey meter

    International Nuclear Information System (INIS)

    Lalrinmawia, Jonathan; Tiwari, Ramesh Chandra; Pau, Kham Suan

    2018-01-01

    This study aims at measuring the leakage radiation from X-ray tube and compare to national and international safety standard. The leakage radiation is formed at the anode inside the X-ray tube and transmitted through the tube housing. The tube housing is proposed to protect both patients and workers from leakage radiation. To the best of the authors' knowledge, no tube housing leakage measurements have been done so far in the present study area

  10. X-ray surveys - Weighting the dark matter haloes of X-ray AGN: towards a physical description of the accretion history of the Universe

    Science.gov (United States)

    Georgakakis, Antonis; Mountrichas, G.; Fanidakis, N.; Finoguenov, A.; Aegis Collaboration

    2012-09-01

    The masses of the dark matter haloes in which AGN live is powerful diagnostic of the conditions under which supermassive black holes form and evolve across cosmic time. A new clustering estimation method will be presented which requires spectroscopy only for the AGN and uses photometric redshift probability density functions for galaxies to determine the projected real-space AGN/galaxy cross-correlation function. Our method is superior to traditional AGN clustering estimators (e.g. auto-correlation function) because (i) random errors are significantly suppressed when counting AGN/galaxy pairs, (ii) the impact of sample variance is minimized, and (iii) the requirements for spectroscopy are minimal; only spectroscopic redshift measurements for the AGN are needed. This method is applied to the combined AEGIS, COSMOS and ECDFS fields to infer the bias and dark matter halo mass of moderate luminosity (Lx~10^43 erg/s/cm^2) X-ray AGN at z~1 (total of 400). Predictions from the GALFORM semi-analytic model will be compared to the observations to show that a combination of hot and cold-gas accretion (the latter triggered by disk instabilities in spirals rather than mergers) reproduce well the clustering properties of X-ray AGN over a range of redshifts and luminosities.

  11. Statistical evidences of absorption at high latitudes

    International Nuclear Information System (INIS)

    Fesenko, B.I.

    1980-01-01

    Evidences are considered which indicate to the significant effect of the irregular interstellar absorption at high latitudes b. The number density of faint galaxies grows with the increasing |b| even at the values of |b| exceeding 50 deg. The effects of interstellar medium are traced even in the directions of the stars and globular clusters with very low values of the colour excess. The coefficient of absorption, Asub(B)=0.29+-0.05, was estimated from the colours of the bright E-galaxies [ru

  12. NURE aerial gamma-ray and magnetic detail survey, Lost Creek, Washington area. Volume II. Final report

    International Nuclear Information System (INIS)

    1981-05-01

    Maps and the data from the aerial surveys are included in this report. The purposes of the surveys were to acquire and compile geologic and other information in order to assess the magnitude and distribution of uranium resources and to determine areas favorable for the occurrence of uranium in the USA

  13. A Determination of the Intergalactic Redshift Dependent UV-Optical-NIR Photon Density Using Deep Galaxy Survey Data and the Gamma-ray Opacity of the Universe

    Science.gov (United States)

    Stecker, Floyd W.; Malkan, Matthew A.; Scully, Sean T.

    2012-01-01

    We calculate the intensity and photon spectrum of the intergalactic background light (IBL) as a function of redshift using an approach based on observational data obtained in many different wavelength bands from local to deep galaxy surveys. This allows us to obtain an empirical determination of the IBL and to quantify its observationally based uncertainties. Using our results on the IBL, we then place 68% confidence upper and lower limits on the opacity of the universe to gamma-rays, free of the theoretical assumptions that were needed for past calculations. We compare our results with measurements of the extragalactic background light and upper limits obtained from observations made by the Fermi Gamma-ray Space Telescope.

  14. Detection of fatigue damage of high and medium pressure rotor by X-ray diffraction method. Survey and research of nondestructive examination of thermal power generation facilities

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Tatsuo; Suesada, Yasuhiko; Nishioka, Noriaki; Goto, Toru; Ito, Hitomi; Kadoya, Yoshikuni

    1987-03-25

    In recent years, the existing thermal power generation facilities have been required to be operated in securing dependability from the standpoints of the operating conditions which have been getting severer and the demands to use them for longer periods, accordingly it is hoped to establish the diagnostic technology of aged deterioration by the non-destructive examination method for the facilities. In the beginning of 1959 the Kansai Electric Power Co. surveyed the current situation of this technology at various thermal power generation turbine facilities and discovered that concerning the diagnostic technology of aged deterioration by the non-destructive examination method, there remained many matters untouched in the basic research field. The company consequently started a survey and research jointly with Mitsubishi Heavy Industries in the first half of 1959. This report summarizes the research on the detection of aged deterioration due to thermal fatigue of Cr-Mo-V rotor material by the X-ray diffraction method which was conducted during the full fiscal year of 1984 and the first half of FY 1985 as a part of the above joint research. With respect to the conditions for the detection method of thermal fatigue damages of dummy grooves of the high and medium pressure rotor by the application of the X-ray diffraction method, it is preferred to measure a diffraction strength curve of the diffraction surface by using a Co tube as X-ray tube and it is also desirable to use a position sensitive proportional counter tube for X-ray detector. (5 figs, 6 refs)

  15. Discovery of Temperate Latitude Clouds on Titan

    Science.gov (United States)

    Roe, H. G.; Bouchez, A. H.; Trujillo, C. A.; Schaller, E. L.; Brown, M. E.

    2005-01-01

    Until now, all the clouds imaged in Titan's troposphere have been found at far southern latitudes (60°-90° south). The occurrence and location of these clouds is thought to be the result of convection driven by the maximum annual solar heating of Titan's surface, which occurs at summer solstice (2002 October) in this south polar region. We report the first observations of a new recurring type of tropospheric cloud feature, confined narrowly to ~40° south latitude, which cannot be explained by this simple insolation hypothesis. We propose two classes of formation scenario, one linked to surface geography and the other to seasonally evolving circulation, which will be easily distinguished with continued observations over the next few years. 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 Observatory was made possible by the generous financial support of the W. M. Keck Foundation. Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (US), the Particle Physics and Astronomy Research Council (UK), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), CNPq (Brazil), and CONICET (Argentina).

  16. Ionospheric hot spot at high latitudes

    International Nuclear Information System (INIS)

    Schunk, R.W.; Sojka, J.J.

    1982-01-01

    A hot spot (or spots) can occur in the high-latitude ionosphere depending on the plasma convection pattern. The hot spot corresponds to a small magnetic local time-magnetic latitude region of elevated ion temperatures located near the dusk and/or dawn meridians. For asymmetric convection electric field patterns, with enhanced flow in either the dusk or dawn sector of the polar cap, a single hot spot should occur in association with the strong convection cell. However, on geomagnetically disturbed days, two strong convection cells can occur, and hence, two hot spots should exist. The hot spot should be detectable when the electric field in the strong convection cell exceeds about 40 mV m -1 . For electric fields of the order of 100 mV m -1 in the convection cell, the ion temperature in the hot spot is greatest at low altitudes, reaching 4000 0 K at 160 km, and decreases with altitude in the F-region. An ionospheric hot spot (or spots) can be expected at all seasons and for a wide range of solar cycle conditions

  17. Comparative survey of site and personnel monitoring characteristics for operation of various types of diagnostic-X ray equipment

    International Nuclear Information System (INIS)

    Lyarskij, P.P.; Zol'nikova, N.I.

    1977-01-01

    Diagnostic X-ray machines in present use at medical facilities differ in design and operating parameters, this diversity producing, in turn, a variety of local radiological situations and levels of personnel exposure. Based on radiological safety characterization of working conditions, the authors present a breakdown of contemporary diagnostic X-ray equipment types, based on detailed examination of each group in terms of their associated site monitoring and dosimetry patterns. The paper reports data on personnel exposure levels not only as a function of equipment design and operating characteristics but also according to types of occupational activities for particular medical personnel groups (radiologists, surgeons, anesthesiologists, etc.). Included are health physics data for domestic and foreign X-ray equipment, levels of local and absorbed doses for radiologists, cardiovascular surgeons, neurosurgeons, urologists, traumatologists, anesthesiologists, etc. Measures are recommended for optimizing their activities from the standpoint of radiation safety. (author)

  18. A high-latitude, low-latitude boundary layer model of the convection current system

    International Nuclear Information System (INIS)

    Siscoe, G.L.; Lotko, W.; Sonnerup, B.U.O.

    1991-01-01

    Observations suggest that both the high- and low-latitude boundary layers contribute to magnetospheric convection, and that their contributions are linked. In the interpretation pursued here, the high-latitude boundary layer (HBL) generates the voltage while the low-latitude boundary layer (LBL) generates the current for the part of the convection electric circuit that closes through the ionosphere. This paper gives a model that joins the high- and low-latitude boundary layers consistently with the ionospheric Ohm's law. It describes an electric circuit linking both boundary layers, the region 1 Birkeland currents, and the ionospheric Pedersen closure currents. The model works by using the convection electric field that the ionosphere receives from the HBL to determine two boundary conditions to the equations that govern viscous LBL-ionosphere coupling. The result provides the needed self-consistent coupling between the two boundary layers and fully specifies the solution for the viscous LBL-ionosphere coupling equations. The solution shows that in providing the current required by the ionospheric Ohm's law, the LBL needs only a tenth of the voltage that spans the HBL. The solution also gives the latitude profiles of the ionospheric electric field, parallel currents, and parallel potential. It predicts that the plasma in the inner part of the LBL moves sunward instead of antisunward and that, as the transpolar potential decreases below about 40 kV, reverse polarity (region 0) currents appear at the poleward border of the region 1 currents. A possible problem with the model is its prediction of a thin boundary layer (∼1000 km), whereas thicknesses inferred from satellite data tend to be greater

  19. Airborne gamma-ray spectrometer and magnetometer survey: Forsyth quadrangle, Round Up quadrangle, Hardin quadrangle (Montana), Sheridan quadrangle, (Wyoming). Final report

    International Nuclear Information System (INIS)

    1981-01-01

    An airborne combined radiometric and magnetic survey was performed for the Department of Energy (DOE) over the area covered by the Forsyth, Hardin, and Sheridan, and Roundup, 1:250,000 National Topographic Map Series (NTMS), quadrangle maps. The survey was part of DOE's National Uranium Resource Evaluation (NURE) program. Data were collected by a helicopter equipped with a gamma-ray spectrometer with a large crystal volume, and with a high sensitivity proton precession magnetometer. The radiometric system was calibrated at the Walker Field Calibration Pads and the Lake Mead Dynamic Test Range. Data quality was ensured during the survey by daily test flights and equipment checks. Radiometric data were corrected for live time, aircraft and equipment background, cosmic background, atmospheric radon, Compton scatter, and altitude dependence. The corrected data were statistically evaluated, plotted, and contoured to produce anomaly maps based on the radiometric response of individual geological units. The anomalies were interpreted and an interpretation map produced. Volume I contains a description of the systems used in the survey, a discussion of the calibration of the systems, the data collection procedures, the data processing procedures, the data presentation, the interpretation rationale, and the interpretation methodology. A separate Volume II for each quadrangle contains the data displays and the interpretation results

  20. Airborne gamma-ray spectrometer and magnetometer survey: Crescent Quadrangle, Burns Quadrangle, Canyon City Quadrangle, Bend Quadrangle, Salem Quadrangle (Oregon). Final report

    International Nuclear Information System (INIS)

    1981-01-01

    An airborne combining radiometric and magnetic survey was performed for the Department of Energy over the area covered by the Burns, Crescent, Canyon City, Bend, and Salem, Washington 1:250,000 National Topographic Map Series, 1 0 x 2 0 quadrangle maps. The survey was a part of DOE's National Aerial Radiometric Reconnaissance program, which is in turn a part of the National Uranium Resource Evaluation program. Data were collected by a helicopter equipped with a gamma-ray spectrometer having a large crystal volume, and a high sensitivity proton precession magnetometer. The radiometric system was calibrated at the Walker Field Calibration pads and the Lake Mead Dynamic Test range. Data quality was ensured throughout the survey by daily test flights and equipment checks. Radiometric data were corrected for live time, aircraft and equipment background, cosmic background, atmospheric radon, Compton scatter, and altitude dependence. The corrected data were statistically evaluated, plotted, and contoured to produce anomaly maps based on the radiometric response of individual geological units. These maps were interpreted and an anomaly interpretation map produced. Volume I contains a description of the systems used in the survey, a discussion of the calibration of the systems, the data processing procedures, the data display format, the interpretation rationale, and the interpretation methodology. A separate Volume II for each quadrangle contains the data displays and the interpretation results

  1. NURE aerial gamma-ray and magnetic-reconnaissance survey portions of New Mexico, Arizona, and Texas. Volume I. Instrumentation and data reduction. Final report

    International Nuclear Information System (INIS)

    1981-09-01

    As part of the Department of Energy (DOE) National Uranium Resource Evaluation Program, a rotary-wing high sensitivity radiometric and magnetic survey was flown covering portions of the State of New Mexico, Arizona and Texas. The survey encompassed six 1:250,000 scale quadrangles, Holbrook, El Paso, Las Cruces, Carlsbad, Fort Sumner and Roswell. The survey was flown with a Sikorsky S58T helicopter equipped with a high sensitivity gamma ray spectrometer which was calibrated at the DOE calibration facilities at Walker Field in Grand Junction, Colorado, and the Dynamic Test Range at Lake Mead, Arizona. The radiometric data were processed to compensate for Compton scattering effects and altitude variations. The data were normalized to 400 feet terrain clearance. The reduced data is presented in the form of stacked profiles, standard deviation anomaly plots, histogram plots and microfiche listings. The results of the geologic interpretation of the radiometric data together with the profiles, anomaly maps and histograms are presented in the individual quadrangle reports. The survey was awarded to LKB Resources, Inc. which completed the data acquisition. In April, 1980 Carson Helicopters, Inc. and Carson Geoscience Company agreed to manage the project and complete delivery of this final report

  2. NURE aerial gamma-ray and magnetic-reconnaissance survey portions of New Mexico, Arizona, and Texas. Volume I. Instrumentation and data reduction. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1981-09-01

    As part of the Department of Energy (DOE) National Uranium Resource Evaluation Program, a rotary-wing high sensitivity radiometric and magnetic survey was flown covering portions of the State of New Mexico, Arizona and Texas. The survey encompassed six 1:250,000 scale quadrangles, Holbrook, El Paso, Las Cruces, Carlsbad, Fort Sumner and Roswell. The survey was flown with a Sikorsky S58T helicopter equipped with a high sensitivity gamma ray spectrometer which was calibrated at the DOE calibration facilities at Walker Field in Grand Junction, Colorado, and the Dynamic Test Range at Lake Mead, Arizona. The radiometric data were processed to compensate for Compton scattering effects and altitude variations. The data were normalized to 400 feet terrain clearance. The reduced data is presented in the form of stacked profiles, standard deviation anomaly plots, histogram plots and microfiche listings. The results of the geologic interpretation of the radiometric data together with the profiles, anomaly maps and histograms are presented in the individual quadrangle reports. The survey was awarded to LKB Resources, Inc. which completed the data acquisition. In April, 1980 Carson Helicopters, Inc. and Carson Geoscience Company agreed to manage the project and complete delivery of this final report.

  3. NURE aerial gamma ray and magnetic detail survey of portions of northeast Washington. Volume I. Data acquisition, reduction and interpretation. Final report

    International Nuclear Information System (INIS)

    1981-11-01

    As part of the Department of Energy (DOE) National Uranium Evaluation Program a rotary wing detailed high sensitivity radiometric and magnetic survey was performed which encompassed 8 areas in the northeastern portion of Washington State. The total area surveyed consisted of approximately 9105 line miles. The survey was flown with a Sikorsky S58T helicopter equipped with a high sensitivity gamma ray spectrometer and magnetometer. The airborne spectrometer system was calibrated at the DOE calibration facilities at Walker Field in Grand Junction, Colorado and at the Dynamic Test Range at Lake Mead, Arizona. The radiometric data was corrected and normalized to 400 feet terrain clearance and identified as to rock type by correlating each sample with existing geologic map information. A multi-variate analysis was performed, which together with the radiometric and magnetic contour maps was utilized in the geochemical analysis of each area. The survey data is presented in the form of contour maps, stacked profiles, histograms and microfiche copies of the data listings. This graphic material is presented in the individual area reports. The results of the geologic and geochemical evaluation are presented as individual chapters of this narrative report

  4. Topside electron density at low latitudes

    International Nuclear Information System (INIS)

    Ezquer, R.G.; Cabrera, M.A.; Flores, R.F.; Mosert, M.

    2002-01-01

    The validity of IRI to predict the electron density at the topside electron density profile over the low latitude region is checked. The comparison with measurements obtained with the Taiyo satellite during low solar activity shows that, the disagreement between prediction and measurement is lower than 40% for 70% of considered cases. These IRI predictions are better than those obtained in a previous work at the southern peak of the equatorial anomaly for high solar activity. Additional studies for low solar activity, using ionosonde data as input parameters in the model, are needed in order to check if the observed deviations are due to the predicted peak characteristics or to the predicted shape of the topside profile. (author)

  5. Empirical high-latitude electric field models

    International Nuclear Information System (INIS)

    Heppner, J.P.; Maynard, N.C.

    1987-01-01

    Electric field measurements from the Dynamics Explorer 2 satellite have been analyzed to extend the empirical models previously developed from dawn-dusk OGO 6 measurements (J.P. Heppner, 1977). The analysis embraces large quantities of data from polar crossings entering and exiting the high latitudes in all magnetic local time zones. Paralleling the previous analysis, the modeling is based on the distinctly different polar cap and dayside convective patterns that occur as a function of the sign of the Y component of the interplanetary magnetic field. The objective, which is to represent the typical distributions of convective electric fields with a minimum number of characteristic patterns, is met by deriving one pattern (model BC) for the northern hemisphere with a +Y interplanetary magnetic field (IMF) and southern hemisphere with a -Y IMF and two patterns (models A and DE) for the northern hemisphere with a -Y IMF and southern hemisphere with a +Y IMF. The most significant large-scale revisions of the OGO 6 models are (1) on the dayside where the latitudinal overlap of morning and evening convection cells reverses with the sign of the IMF Y component, (2) on the nightside where a westward flow region poleward from the Harang discontinuity appears under model BC conditions, and (3) magnetic local time shifts in the positions of the convection cell foci. The modeling above was followed by a detailed examination of cases where the IMF Z component was clearly positive (northward). Neglecting the seasonally dependent cases where irregularities obscure pattern recognition, the observations range from reasonable agreement with the new BC and DE models, to cases where different characteristics appeared primarily at dayside high latitudes

  6. Gamma-ray dose rate surveys help investigating century-scale beach ridge progradation in the wave-dominated Catumbela delta (Angola)

    Science.gov (United States)

    Dinis, Pedro A.; Pereira, Alcides C.; Quinzeca, Domingos; Jombi, Domingos

    2017-10-01

    A strandplain at the downdrift side of the wave-dominated Catumbela delta (Angola) includes distinguishable deposits with very high natural radioactivity (up to 0.44 microSv/hour). In order to establish the geometry of these sedimentary units and understand their genetic processes, dose rate surveys were performed with the portable equipment Rados RDS-40WE. In addition, grain-size distribution, heavy-mineral composition and gamma-ray mass spectra of the high dose rate deposits were analysed. High dose rate values are found in ribbon units aligned parallel to the shoreline, which are a few tens of meters wide and up to approximately 3 km long. These units reflect the concentration of Th-bearing grains in coastal deposits enriched in heavy minerals. An integrated analysis of the high dose rate ribbons in GIS environment with aerial photography and topographic maps suggests that parts of the high dose rate units formed during the last two centuries may be related with the erosion of older shoreline deposits, due to updrift displacements of the Catumbela river outlet and recycling of shoreline accumulations with downdrift deposition. Simple gamma-ray surveys carried out with a portable detector can unravel depositional units characterised by significant enrichment in heavy-mineral grains that are likely to correspond to key events in the evolution of wave-dominated accumulations. The location of such deposits should be taken into account when planning future work using more expensive or time-consuming techniques.

  7. Level of compliance with the radiation protection regulation-A survey among Norwegian hospitals and X-ray institutes

    International Nuclear Information System (INIS)

    Friberg, E. G.; Widmark, A.; Solberg, M.; Woehni, T.

    2011-01-01

    To identify the level of compliance with the new radiation protection regulation among Norwegian health care enterprises (HCEs). Totally, 41 HCEs were authorised to use advanced X-ray equipment for medical purposes during 2005-07. Follow-up inspections with 14 HCEs were carried out during 2007-09. Main topics for the inspections were those requirements identified as most challenging to implement in the authorisation process. Totally, 192 non-conformities with the regulation were revealed during the authorisation process. The inspections revealed that 93 % of the inspected HCEs had non-conformities with the regulation. Most common non-conformities dealt with skills in radiation protection, establishment of local diagnostic reference levels, access to medical physicists and performance of quality control of X-ray equipment. Inspections are an effective tool for implementation of regulation the requirements at the HCEs, thus improving radiation protection awareness. (authors)

  8. Latitud sur y control económico del hogar por la mujer peruana

    OpenAIRE

    Federico R. León

    2011-01-01

    South latitude and household economic control by Peruvian women Southern women’s greater autonomy versus northern women’s more traditional submission to the husband were hypothesized in 1984 to explain variations in Peruvian women’s fertility desires. An analysis of data from Peru 2004-2008 Continuous Demographic and Family Health Survey supports this hypothesis by showing a significant north-to-south growth of women’s control upon husband’s income and, less consistently, household purchasing...

  9. The single event upset environment for avionics at high latitude

    International Nuclear Information System (INIS)

    Sims, A.J.; Dyer, C.S.; Peerless, C.L.; Farren, J.

    1994-01-01

    Modern avionic systems for civil and military applications are becoming increasingly reliant upon embedded microprocessors and associated memory devices. The phenomenon of single event upset (SEU) is well known in space systems and designers have generally been careful to use SEU tolerant devices or to implement error detection and correction (EDAC) techniques where appropriate. In the past, avionics designers have had no reason to consider SEU effects but is clear that the more prevalent use of memory devices combined with increasing levels of IC integration will make SEU mitigation an important design consideration for future avionic systems. To this end, it is necessary to work towards producing models of the avionics SEU environment which will permit system designers to choose components and EDAC techniques which are based on predictions of SEU rates correct to much better than an order of magnitude. Measurements of the high latitude SEU environment at avionics altitude have been made on board a commercial airliner. Results are compared with models of primary and secondary cosmic rays and atmospheric neutrons. Ground based SEU tests of static RAMs are used to predict rates in flight

  10. Bat and bird diversity along independent gradients of latitude and tree composition in European forests.

    Science.gov (United States)

    Charbonnier, Yohan M; Barbaro, Luc; Barnagaud, Jean-Yves; Ampoorter, Evy; Nezan, Julien; Verheyen, Kris; Jactel, Hervé

    2016-10-01

    Species assemblages are shaped by local and continental-scale processes that are seldom investigated together, due to the lack of surveys along independent gradients of latitude and habitat types. Our study investigated changes in the effects of forest composition and structure on bat and bird diversity across Europe. We compared the taxonomic and functional diversity of bat and bird assemblages in 209 mature forest plots spread along gradients of forest composition and vertical structure, replicated in 6 regions spanning from the Mediterranean to the boreal biomes. Species richness and functional evenness of both bat and bird communities were affected by the interactions between latitude and forest composition and structure. Bat and bird species richness increased with broadleaved tree cover in temperate and especially in boreal regions but not in the Mediterranean where they increased with conifer abundance. Bat species richness was lower in forests with smaller trees and denser understorey only in northern regions. Bird species richness was not affected by forest structure. Bird functional evenness increased in younger and denser forests. Bat functional evenness was also influenced by interactions between latitude and understorey structure, increasing in temperate forests but decreasing in the Mediterranean. Covariation between bat and bird abundances also shifted across Europe, from negative in southern forests to positive in northern forests. Our results suggest that community assembly processes in bats and birds of European forests are predominantly driven by abundance and accessibility of feeding resources, i.e., insect prey, and their changes across both forest types and latitudes.

  11. Impact of high-latitude energy input on the mid- and low-latitude ionosphere and thermosphere

    Science.gov (United States)

    Lu, G.; Sheng, C.

    2017-12-01

    High-latitude energy input has a profound impact on the ionosphere and thermosphere especially during geomagnetic storms. Intense auroral particle precipitation ionizes neutral gases and modifies ionospheric conductivity; collisions between neutrals and fast-moving ions accelerate the neutral winds and produce Joule frictional heating; and the excess Joule and particle heating causes atmospheric upwelling and changes neutral composition due to the rising of the heavier, molecular-rich air. In addition, impulsive Joule heating launches large-scale gravity waves that propagate equatorward toward middle and low latitudes and even into the opposite hemisphere, altering the mean global circulation of the thermosphere. Furthermore, high-latitude electric field can also directly penetrate to lower latitudes under rapidly changing external conditions, causing prompt ionospheric variations in the mid- and low-latitude regions. To study the effects of high-latitude energy input, we apply the different convection and auroral precipitation patterns based on both empirical models and the AMIE outputs. We investigate how the mid- and low-latitude regions respond to the different specifications of high-latitude energy input. The main purpose of the study is to delineate the various dynamical, electrodynamical, and chemical processes and to determine their relative importance in the resulting ionospheric and thermospheric properties at mid and low latitudes.

  12. X-ray survey of hot white dwarf stars - evidence for a m(He)/n(H) versus Teff correlation

    Energy Technology Data Exchange (ETDEWEB)

    Petre, R.; Shipman, H.L.; Canizares, C.R.

    1986-05-01

    Observations of 13 white dwarf and subdwarf stars using the Einstein Observatory High Resolution Image are reported. Included are stars of classes DA, DB, DAV, sDO, and sDB, with optically determined effective temperatures in the range 10,000-60,000 K. X-ray emission was detected from two of the 13: the very hot (55,000 K) DA1 star WD 2309 + 105 (= EG 233), with a count rate one-fifth that of HZ 43, and the relatively cool (26,000 K) DA3 star WD 1052 - 273 (=GD 125). The effective temperatures determined from ultraviolet and optical observations were used to place limits on the He content of the white dwarf photospheres, presuming that trace photospheric He is the missing opacity source which quenches the thermal X-rays in these stars. When presently obtained results were combined with those available from the literature evidence was found for a correlation between Teff and n(He)/n(H), in which HZ 43 is a conspicuous exception to the general trend. Both this correlation and the exceptional behavior of HZ 43 are qualitatively accounted for by a radiative acceleration model, in which the rate of upward movement of the He is a function of temperature and surface gravity 59 references.

  13. High-Latitude Neutral Mass Density Maxima

    Science.gov (United States)

    Huang, C. Y.; Huang, Y.; Su, Y.-J.; Huang, T.; Sutton, E. K.

    2017-10-01

    Recent studies have reported that thermospheric effects due to solar wind driving can be observed poleward of auroral latitudes. In these papers, the measured neutral mass density perturbations appear as narrow, localized maxima in the cusp and polar cap. They conclude that Joule heating below the spacecraft is the cause of the mass density increases, which are sometimes associated with local field-aligned current structures, but not always. In this paper we investigate neutral mass densities measured by accelerometers on the CHAllenging Minisatellite Payload (CHAMP) and Gravity Recovery and Climate Experiment (GRACE) spacecraft from launch until years 2010 (CHAMP) and 2012 (GRACE), approximately 10 years of observations from each satellite. We extract local maxima in neutral mass densities over the background using a smoothing window with size of one quarter of the orbit. The maxima have been analyzed for each year and also for the duration of each set of satellite observations. We show where they occur, under what solar wind conditions, and their relation to magnetic activity. The region with the highest frequency of occurrence coincides approximately with the cusp and mantle, with little direct evidence of an auroral zone source. Our conclusions agree with the "hot polar cap" observations that have been reported and studied in the past.

  14. The inland boundary layer at low latitudes

    Science.gov (United States)

    Garratt, J. R.

    1985-08-01

    Observations from the Koorin boundary-layer experiment in Australia (latitude 16 °S) were analysed in a study of the nocturnal jet development. For geostrophic winds in the range 10 20 m s-1, ageostrophic wind magnitudes of 5 10m s-1 were common above the surface layer near sunset, with cross-isobar flow angles of about 40 °. The jet that then developed by midnight was probably the result of these large ageostrophic winds, strong surface cooling and favourable baroclinity and sloping terrain. The analysis is supported by numerical model calculations with special emphasis on the role of long-wave radiative cooling on turbulent decay. Decay is rapid in the presence of radiation, although there is little influence on stress divergence levels. Evidence of sea-breeze influences on the jet evolution, and on features of deeply penetrating sea breezes in general, will be presented and discussed in part 2 of this study (submitted to Boundary-Layer Meteorol.).

  15. Prognoses of prospective areas for uranium metallogenesis with full-spectrum information of airborne gamma-ray survey

    International Nuclear Information System (INIS)

    Hu Mingkao; Shen Zhengxin; Li Binghai; Cai Genqing

    2010-01-01

    This paper briefly introduces the development of airborne radioactive survey and the background of carrying out full-spectrum study. It also introduces the method, standard and application example of using the full-spectrum information of airborne gamma spectrum to predict U-metallogenic prospective areas. The field checking has found that uranium in the water of the prospective area is three magnitude higher than that in the normal area. The developmment and the application of this method will play a multiplier role in reusing the library stored data evaluating uranium resource potential in our Country. (authors)

  16. A survey to establish ambient and personal dose equivalent standards in the X- and γ-ray field

    International Nuclear Information System (INIS)

    Morishita, Yuichiro

    2007-01-01

    National Institute of Advanced Industrial Science and Technology (AIST) develops and supplies standards of ionizing radiations as national primary references. Fundamental matters to establish ambient and personal dose equivalent standards of X- and γ-radiation are reviewed in this report. First, units of radiation dose in measurements of X- and γ-radiation are surveyed. Next, the present status of the preparation of X-radiation standard is explained, and finally the relationship between the physical dose and the radiation-protection dose is described. (J.P.N.)

  17. Effects of space weather on high-latitude ground systems

    Science.gov (United States)

    Pirjola, Risto

    Geomagnetically induced currents (GIC) in technological systems, such as power grids, pipelines, cables and railways, are a ground manifestation of space weather. The first GIC observations were already made in early telegraph equipment more than 150 years ago. In power networks, GIC may saturate transformers with possible harmful consequences extending even to a collapse of the whole system or to permanent damage of transformers. In pipelines, GIC and the associated pipe-to-soil voltages may enhance corrosion or disturb surveys associated with corrosion control. GIC are driven by the geoelectric field induced by a geomagnetic variation at the Earth’s surface. The electric and magnetic fields are primarily produced by ionospheric currents and secondarily affected by the ground conductivity. Of great importance is the auroral electrojet with other rapidly varying currents indicating that GIC are a particular high-latitude problem. In this paper, we summarize the GIC research done in Finland during about 25 years, and discuss the calculation of GIC in a given network. Special attention is paid to modelling a power system. It is shown that, when considering GIC at a site, it is usually sufficient to take account for a smaller grid in the vicinity of the particular site. Modelling GIC also provides a basis for developing forecasting and warning methods of GIC.

  18. Radioactive contamination of the 30-km zone according to the sampling data within bench-marks of gamma-ray survey in 1991

    International Nuclear Information System (INIS)

    Lesnoj, D.A.; Rybalko, S.I.; Solyanek, E.G.

    1992-01-01

    It is noted that formation of radioactive contamination of the Chernobyl' 30-km zone is conditioned by two main factors: state of operation of the reactor and movement of air masses within the period of 26.04.86 till 5.06.86. The analyses of formation of the radioactive traces in this period is presented. It is noted that ground radiometric and spectrometric investigations in 1991 according to the bench-marks with regard to gamma-ray survey of the 30-km zone make it possible to recognize 25% areas as having values close on background rates of the exposure doze in south-western and south-eastern sectors. However, these areas can be recommended for agricultural use after careful geochemical and hydrological mapping and inspecting settlements, plants and animals contamination. 1 tabs

  19. The NuSTAR Serendipitous Survey: The 40-month Catalog and the Properties of the Distant High-energy X-Ray Source Population

    Science.gov (United States)

    Lansbury, G. B.; Stern, D.; Aird, J.; Alexander, D. M.; Fuentes, C.; Harrison, F. A.; Treister, E.; Bauer, F. E.; Tomsick, J. A.; Baloković, M.; Del Moro, A.; Gandhi, P.; Ajello, M.; Annuar, A.; Ballantyne, D. R.; Boggs, S. E.; Brandt, W. N.; Brightman, M.; Chen, C.-T. J.; Christensen, F. E.; Civano, F.; Comastri, A.; Craig, W. W.; Forster, K.; Grefenstette, B. W.; Hailey, C. J.; Hickox, R. C.; Jiang, B.; Jun, H. D.; Koss, M.; Marchesi, S.; Melo, A. D.; Mullaney, J. R.; Noirot, G.; Schulze, S.; Walton, D. J.; Zappacosta, L.; Zhang, W. W.

    2017-02-01

    We present the first full catalog and science results for the Nuclear Spectroscopic Telescope Array (NuSTAR) serendipitous survey. The catalog incorporates data taken during the first 40 months of NuSTAR operation, which provide ≈20 Ms of effective exposure time over 331 fields, with an areal coverage of 13 deg2, and 497 sources detected in total over the 3-24 keV energy range. There are 276 sources with spectroscopic redshifts and classifications, largely resulting from our extensive campaign of ground-based spectroscopic follow-up. We characterize the overall sample in terms of the X-ray, optical, and infrared source properties. The sample is primarily composed of active galactic nuclei (AGNs), detected over a large range in redshift from z = 0.002 to 3.4 (median of =0.56), but also includes 16 spectroscopically confirmed Galactic sources. There is a large range in X-ray flux, from {log}({f}3-24{keV}/{erg} {{{s}}}-1 {{cm}}-2)≈ -14 to -11, and in rest-frame 10-40 keV luminosity, from {log}({L}10-40{keV}/{erg} {{{s}}}-1)≈ 39 to 46, with a median of 44.1. Approximately 79% of the NuSTAR sources have lower-energy ( {10}44 erg s-1) to ≈80% at the lowest luminosities ({L}{{X}}< {10}43 erg s-1). Our optical spectroscopic analysis finds that the observed fraction of optically obscured AGNs (I.e., the type 2 fraction) is {F}{Type2}={53}-15+14 % , for a well-defined subset of the 8-24 keV selected sample. This is higher, albeit at a low significance level, than the type 2 fraction measured for redshift- and luminosity-matched AGNs selected by <10 keV X-ray missions.

  20. Common origin of positive ionospheric storms at middle latitudes and the geomagnetic activity effect at low latitudes

    International Nuclear Information System (INIS)

    Proelss, G.W.

    1993-01-01

    The author looks for a correlation between two different atmospheric effects. They are a positive atmospheric storm (an anomalous increase in the F2 region ionization density), observed at middle latitudes, and the geomagnetic activity effect (the anomalous changes of temperature and gas density seen in the thermosphere), observed at low latitudes. A temporal correlation is sought to test the argument that both of these effects are the result of travelling atmospheric disturbances (TAD). A TAD is a pulselike atmospheric wave thought to be generated by substorm activity, and to propagate with high velocity (600 m/s) from polar latitudes toward equatorial latitudes. The author looks at data from five separate events correlating magnetic, ionospheric, and neutral atmospheric measurements. The conclusion is that there is a positive correlation between magnetic substorm activity at high latitudes, and positive ionospheric storms at middle latitudes and geomagnetic activity at low latitudes. The time correlations are consistent with high propagation speeds between these events. The author also presents arguments which indicate that the middle latitude positive ionospheric storms are not the result of electric field effects

  1. The High Time Resolution Universe surveys for pulsars and fast transients

    Science.gov (United States)

    Keith, Michael J.

    2013-03-01

    The High Time Resolution Universe survey for pulsars and transients is the first truly all-sky pulsar survey, taking place at the Parkes Radio Telescope in Australia and the Effelsberg Radio Telescope in Germany. Utilising multibeam receivers with custom built all-digital recorders the survey targets the fastest millisecond pulsars and radio transients on timescales of 64 μs to a few seconds. The new multibeam digital filter-bank system at has a factor of eight improvement in frequency resolution over previous Parkes multibeam surveys, allowing us to probe further into the Galactic plane for short duration signals. The survey is split into low, mid and high Galactic latitude regions. The mid-latitude portion of the southern hemisphere survey is now completed, discovering 107 previously unknown pulsars, including 26 millisecond pulsars. To date, the total number of discoveries in the combined survey is 135 and 29 MSPs These discoveries include the first magnetar to be discovered by it's radio emission, unusual low-mass binaries, gamma-ray pulsars and pulsars suitable for pulsar timing array experiments.

  2. An X-ray survey of the central molecular zone: Variability of the Fe Kα emission line

    Science.gov (United States)

    Terrier, R.; Clavel, M.; Soldi, S.; Goldwurm, A.; Ponti, G.; Morris, M. R.; Chuard, D.

    2018-05-01

    There is now abundant evidence that the luminosity of the Galactic super-massive black hole (SMBH) has not always been as low as it is nowadays. The observation of varying non-thermal diffuse X-ray emission in molecular complexes in the central 300 pc has been interpreted as delayed reflection of a past illumination by bright outbursts of the SMBH. The observation of different variability timescales of the reflected emission in the Sgr A molecular complex can be well explained if the X-ray emission of at least two distinct and relatively short events (i.e. about 10 yr or less) is currently propagating through the region. The number of such events or the presence of a long-duration illumination are open questions. Variability of the reflected emission all over of the central 300 pc, in particular in the 6.4 keV Fe Kα line, can bring strong constraints. To do so we performed a deep scan of the inner 300 pc with XMM-Newton in 2012. Together with all the archive data taken over the course of the mission, and in particular a similar albeit more shallow scan performed in 2000-2001, this allows for a detailed study of variability of the 6.4 keV line emission in the region, which we present here. We show that the overall 6.4 keV emission does not strongly vary on average, but variations are very pronounced on smaller scales. In particular, most regions showing bright reflection emission in 2000-2001 significantly decrease by 2012. We discuss those regions and present newly illuminated features. The absence of bright steady emission argues against the presence of an echo from an event of multi-centennial duration and most, if not all, of the emission can likely be explained by a limited number of relatively short (i.e. up to 10 yr) events. Images of the Fe Kα emission as FITS files are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/612/A102

  3. National Uranium Resource Evaluation. Aerial gamma ray and magnetic survey, Tawas City and Flint quadrangles, Michigan. Final report

    International Nuclear Information System (INIS)

    1981-07-01

    The Tawas City and Flint quadrangles of Michigan cover a land area of 6500 square miles, and an additional water surface area of 7200 square miles. Extremely thick Paleozoic deposits overlie a regional downwarp of the Precambrian basement called the Michigan Basin. These Paleozoic deposits shoal to only 1500 feet in the northeast corner. The entire survey area is covered by a mantle of Quaternary glacial material. A search of available literature revealed no economically feasible uranium deposits. Thirty-five uranium anomalies were detected and are discussed briefly. All appear to have cultural, and/or locally unsaturated associations, and none appear to contain significant measured quantities of uranium. Magnetic data appear to be in good agreement with existing structural interpretations of the area

  4. Rapid environmental surveying using mobile gamma ray spectrometry Processing of results from the RESUME99 exercise, Gaevle, Sweden

    CERN Document Server

    Smetkurst, M A

    2000-01-01

    Data from mobile measuring teams participating in the RESUME99 Fixed Route exercise in Sweden have been processed to facilitate a detailed comparison between the data sets. The exercise was organised by the Swedish Radiation Protection Institute (SSI) and is part of the BOK-1.2 project Mobile Measurements and Measurements Strategies within the Nordic Nuclear Safety Research (NKS) programme for 1998-2000. 11 car borne gamma ray spectrometer systems measured a fixed route in the vicinity of Gaevle in Sweden so that the capabilities of the different measuring systems in determining the levels and patterns of sup 1 37Cs contamination along the route could be studied. This report describes how the data sets from the different measuring systems were projected into the known trace of the fixed route so that the results can be compared. Estimates of equivalent surface activity of sup 1 37Cs from the different measuring systems were normalised to data obtained by the Danish Emergency management Agency (system DKA1) an...

  5. The impact of weathering on the uranium-bearing phosphates of Ain Laylon in the Syrian coast, using radon and gamma ray surveys

    International Nuclear Information System (INIS)

    Jubeli, Y.; Al-Hilal, M.; Al-Ali, A.

    1998-06-01

    A combination of several exploration techniques was carried out at the main phosphatic outcrop of Ain Laylon in the Syrian coastal region. The survey was extended along an E-W profile parallel to Wadi Al-Mzeraa over a distance of about 23 km from Ain Laylon site towards the shoreline of the Mediterranean Sea. The techniques used in this survey included soil radon emanometry, gamma ray spectrometry and soil geochemistry, with the purpose of evaluating the effects of weathering and erosion on the uranium-hearing phosphate formations in the study ares. Soil radon concentration and gamma ray total count rates found to be ranging between 115-472 pCi/l and 52-520 cps over the main phosphate deposit of Ain Layton and between 16-241 pCi/l and 15-300 cps along the profile of Wadi Al-Mzeraa - Rwemiyeh respectively. Some suitable elements such as U, Zn, Pb, Cr, Fe and Sr were also analyzed to trace the dispersion pattern of uranium and its controls throughout the area. The results showed that the distribution of both radon emission and gamma ray activity, in accordance with chemical uranium and some associated trace elements, were almost identical over the study area. The anomalously high values in all cases were basically found to be related to the main phosphatic outcrop and to the reprecipitation processes at their vicinity following the alteration of the phosphates. The prevailing topographic conditions of the drainage system has probably played a crucial role in carrying the uraniferous solutions from its phosphatic source down to the nearby sedimentary environment. This appears to be sufficient enough to produce an anomalous halo resulting in the detection of some relatively high radon and gamma values of about 7 and 15 times the background respectively, especially close to the main phosphate outcrop. A notable gradual decrease was then observed at the following sampling sites along the pathway west of Ain Laylon site approaching the background level at a distance of

  6. Feasibility study for an airborne high-sensitivity gamma-ray survey of Alaska. Phase II (final) report: 1976--1979 program

    International Nuclear Information System (INIS)

    1975-01-01

    This study constitutes a determination of the extent to which it is feasible to use airborne, high-sensitivity gamma spectrometer systems for uranium reconnaissance in the State of Alaska, and specification of a preliminary plan for surveying the entire state of the 1975--1979 time frame. Phase I included the design of a program to survey the highest priority areas in 1975 using available aircraft and spectrometer equipment. This has now resulted in a contract for 10,305 flight line miles to cover about 11 of the 1:250,000 scale quadrangles using a DC-3 aircraft with an average 6.25 x 25 mile grid of flight line. Phase II includes the design of alternative programs to cover the remaining 128 quadrangles using either a DC-3 and a Bell 205A helicopter or a Helio Stallion STOL aircraft and a Bell 205A helicopter during 1976-1979. The 1976-1979 time frame allows some time for possible new system developments in both airborne gamma-ray spectrometers and in ancillary equipment, and these are outlined. (auth)

  7. VizieR Online Data Catalog: Wisconsin soft X-ray diffuse background all-sky Survey (McCammon+ 1983)

    Science.gov (United States)

    McCammon, D.; Burrows, D. N.; Sanders, W. T.; Kraushaar, W. L.

    1997-10-01

    The catalog contains all-sky survey of the soft X-ray diffuse background and the count-rate data from which the maps were made for the ten flights included in the survey. It contains 40 files in the machine-readable version and includes documentation and utility subroutines. The data files contain different band maps (B, C, M, M1, M2, I, J, 2-6 keV) in a 0 degree-centered Aitoff projection, in a 180-degree-centered Aitoff projection, in a north polar projection, and in a south polar projection. Lookup tables in the form of FITS images are provided for conversion between pixel coordinates and Galactic coordinates for the various projections. The bands are: B = 130-188eV C = 160-284eV M1 = 440-930eV M2 = 600-1100eV I = 770-1500eV J = 1100-2200eV 2-6keV = 1800-6300eV (51 data files).

  8. Low latitude aurorae on October 21, 1989, 2

    International Nuclear Information System (INIS)

    Kuwashima, Masayuki; Tsunomura, Satoru; Uwai, Tetsuya; Saito, Buniti; Takahasi, Tosiyasu; Kiyama, Yositaka.

    1990-01-01

    Appearance of low-latitude aurorae was seen in Hokkaido, a northern district in Japan, on October 21 and November 17, 1989, during severe magnetic storms. Some characteristics of the associated magnetic variations are shown and discussed in the present short report. The appearance of low-latitude aurora events was found during a time interval of a sharp H-component increase succeeding to the maximum development of the storm time ring current. The cause of the increase in the H-component seems to be associated with the bay disturbance because Pi2 magnetic pulsations were always associated with the low-latitude aurora event. The period of an aurora associated Pi2 event is shorter (40-60 seconds) than that of a usual Pi2 event (100 seconds). During the main phase of geomagnetic storm on October 21, optical and spectroscopic observations of low latitude aurora were made with an airglow-photometer, spectrograph and an all sky camera at Niigata (latitude 37.7degN, longitude 138.8degE and geomagnetic latitude 27.7degN). Spectra of low latitude aurorae observed in Niigata are given and discussed. A model for the main part of the auroral emission is also presented. (N.K.)

  9. Survey of effective doses to patients undergoing contrast-based X-ray fluoroscopy procedures in Tanzania

    International Nuclear Information System (INIS)

    Ngaile, J.E.; Msaki, P.K.; Kazema, R.R.

    2017-01-01

    The aim of this study was to assess the radiation burden imparted to patients from contrast-based X-ray fluoroscopy procedures in Tanzania. The effective doses (EDs) to patients from five contrast-based fluoroscopy procedures were obtained from four hospitals. The ED was estimated using the knowledge of the patient characteristics, patient-related exposure parameters, measurements of air kerma area product and PCXCM software. The median EDs for the barium swallow (BS), barium meal (BM), barium enema (BE), hysterosalpingography (HSG) and retrograde urethrography (RUG) were 0.50, 1.43, 2.83, 0.65 and 0.59 mSv, respectively. The median ED per hospital for the BS and BM procedures varied by factors of up to 9.9 and 4.2, respectively, while for the BE, HSG and RUG varied by factors of up to 2.3, 2.4 and 4.3, respectively. The overall differences between individual EDs across the four hospitals varied by factors of up to 53, 58.9 and 11.4 for the BS, BM and BE, respectively, while for the HSG and RUG differed by factors of up to 22 and 46.7, respectively. The mean EDs in this study were mostly lower than reported values from Spain, the UK, Ghana and Greece, while slightly higher than those reported from India. The observed wide variations of procedural protocols and patient doses within and across the hospitals; and the observed high patient doses in this study relative to those from the literature call for the need to standardize procedural protocols and optimize contrast-based fluoroscopy procedures. (authors)

  10. Potential and limitations of X-Ray micro-computed tomography in arthropod neuroanatomy: A methodological and comparative survey

    Science.gov (United States)

    Sombke, Andy; Lipke, Elisabeth; Michalik, Peter; Uhl, Gabriele; Harzsch, Steffen

    2015-01-01

    Classical histology or immunohistochemistry combined with fluorescence or confocal laser scanning microscopy are common techniques in arthropod neuroanatomy, and these methods often require time-consuming and difficult dissections and sample preparations. Moreover, these methods are prone to artifacts due to compression and distortion of tissues, which often result in information loss and especially affect the spatial relationships of the examined parts of the nervous system in their natural anatomical context. Noninvasive approaches such as X-ray micro-computed tomography (micro-CT) can overcome such limitations and have been shown to be a valuable tool for understanding and visualizing internal anatomy and structural complexity. Nevertheless, knowledge about the potential of this method for analyzing the anatomy and organization of nervous systems, especially of taxa with smaller body size (e.g., many arthropods), is limited. This study set out to analyze the brains of selected arthropods with micro-CT, and to compare these results with available histological and immunohistochemical data. Specifically, we explored the influence of different sample preparation procedures. Our study shows that micro-CT is highly suitable for analyzing arthropod neuroarchitecture in situ and allows specific neuropils to be distinguished within the brain to extract quantitative data such as neuropil volumes. Moreover, data acquisition is considerably faster compared with many classical histological techniques. Thus, we conclude that micro-CT is highly suitable for targeting neuroanatomy, as it reduces the risk of artifacts and is faster than classical techniques. J. Comp. Neurol. 523:1281–1295, 2015. © 2015 Wiley Periodicals, Inc. PMID:25728683

  11. Storm time electric field penetration observed at mid-latitude

    International Nuclear Information System (INIS)

    Yeh, H.C.; Foster, J.C.; Rich, F.J.; Swider, W.

    1991-01-01

    During the height of the February 8-9, 1986, magnetic storm the Millstone Hill radar was in the evening local time sector (1600-2200 MLT). Radar observations indicate that high speed (>1,000 m s -1 ) westward ion flow penetrated deeply below 50 degree invariant latitude (Λ) and persisted for 6 hours between 2100 UT on February 8 and 0300 UT on February 9. The double-peaked ion convection feature was pronounced throughout the period, and the separation in the dual maxima ranged from 4 degree to 10 degree. The latitude positions of the high-latitude ion drift peak and the convection reversal varied in unison. The low-latitude ion drift peak (∼49 degree Λ or L =2.3) did not show significant universal time/magnetic local time (UT/MLT) variation in its latitude location but showed a decrease in magnitude during the initial recovery phase of the storm. Using simultaneous particle (30 eV-30 keV) precipitation data from the DMSP F6 and F7 satellites, the authors find the high-latitude ion drift peak to coincide with the boundary plasma sheet/central plasma sheet transition in the high ionospheric conductivity (>15 mho) region. The low-latitude ion drift peak lay between the equatorward edges of the electron and soft ( + dominated ring current energy density in magnetic latitude. The low-latitude ion drift peak is the low-altitude signature of the electric field shielding effect associated with ring current penetration into the outer layer of the storm time plasmasphere

  12. The low-latitude Rapitan glaciation (Invited)

    Science.gov (United States)

    MacDonald, F. A.; Schmitz, M. D.; Crowley, J. L.; Roots, C.; Maloof, A. C.; Jones, D. S.; Strauss, J.

    2009-12-01

    The snowball Earth hypothesis1 was developed in response to strong palaeomagnetic evidence for low-latitude glaciation from “Marinoan” glacial deposits in the Elatina Formation of Australia. An earlier Cryogenian glaciation, commonly referred to as the “Sturtian” glaciation, has been inferred from the ubiquity of pre-Marinoan glacial deposits; however, the synchroneity and global extent of this event have been questioned due to the lack of precise U/Pb ages and robust paleomagnetic data. Herein we provide new age constraints on the Franklin LIP with revised U/Pb ID-TIMS dates on the the Mt. Harper volcanic complex in the Yukon Territory and the Coronation sills of Victoria Island. Furthermore we present a new age from a tuff interbedded with diamictite in the Upper Mt. Harper Group. A glaciogenic origin of the diamictites is provided by striated clasts and laminae-penetrating dropstones. These glacial deposits can be traced from Alaska westward through the Yukon Territory and into the Northwest Territories, and are correlative to the Rapitan Group. Throughout the Cordillera, the Rapitan Group and its correlatives commonly host iron formation, are the lower of two Cryogenian glacial horizons, and globally are thought to be equivalent to the Sturtian glaciation. The age of the tuff interbedded with the glacial deposits in the Mt. Harper Group is within 1 million years of the revised age on the Franklin LIP. Several paleomagnetic studies on dikes, sills, and basalts spanning >2000 km of NW Canada have agreed that the Franklin LIP erupted when NW Laurentia was in an equatorial position2,3. Consequently, the Sturtian glaciation on Laurentia can now be confidently inferred to have occurred at a very low palaeolatitude. Thus, there were at least two Cryogenian glaciations of global extent. 1 Kirschvink, J.L., in The Proterozoic Biosphere, edited by J. W. Schopf and C. Klein (Cambridge University Press, Cambridge, 1992), pp. 51. 2 Park, J.K., Paleomagnetic

  13. Aerial gamma ray and magnetic survey: Raton Basin Project. The Raton and Santa Fe Quadrangles of New Mexico. Final report

    International Nuclear Information System (INIS)

    1979-11-01

    In 1978, EG and G geoMetrics collected 4955 line miles of high sensitivity airborne radiometric and magnetic data in New Mexico within the Raton and Santa Fe quadrangles. These quadrangles represent part of the Raton Basin Project. All radiometric and magnetic data for the two quadrangles were fully reduced and interpreted by geoMetrics, and are presented as three volumes; one Volume I covering both quadrangles and separate Volume II's for the individual quadrangles. Over 50% of the survey area is covered by flat lying Mesozoic and Cenozoic deposits of the southern Great Plains Province. The western and southern portions of the area contain a combination of Precambrian and Paleozoic igneous and metamorphic rocks. These rocks occur primarily within and in close proximity to the Sangre de Cristo Mountains and late Cenozoic volcanic deposits occur to the west of the mountains and in the Las Vegas Volcanic region. Uranium deposits are scattered throughout the region, but none are known to be economic at the time of this report

  14. Variation of the gravity acceleration with the latitude and altitude

    Directory of Open Access Journals (Sweden)

    Wilson Lopes

    2009-01-01

    Full Text Available The propose of this work is an equation for the module of the acceleration vector of the gravity, varying with the latitude and altitude. For this purpose, the following values of the gravity acceleration were used, at the sea level: in the equator, g0 = 9,7803 m/s2, and in the latitude of 450, gP = 9,8062 m/s2. The terrestrial profile were assumed as being a revolution ellipsoid, flattened in the poles, and the acceleration of the gravity varying with the altitude, at sea level, was considered dependent of the latitude too.

  15. Study of capillary absorption kinetics by X-ray CT imaging techniques: a survey on sedimentary rocks of Sicily

    Directory of Open Access Journals (Sweden)

    Tiziano Schillaci

    2008-04-01

    Full Text Available Sedimentary rocks are natural porous materials with a great percent of microscopic interconnected pores: they contain fluids, permitting their movement on macroscopic scale. Generally, these rocks present porosity higher then metamorphic rocks. Under certain points of view, this feature represents an advantage; on the other hand, this can constitute an obstacle for cultural heritage applications, because the porosity grade can lead to a deterioration of the lapideous monument for water capillary absorption. In this paper, CT (Computerized Tomography image techniques are applied to capillary absorption kinetics in sedimentary rocks utilized for the Greek temples as well as baroc monuments, respectively located in western and southeastern Sicily. Rocks were sampled near the archaeological areas of Agrigento, Segesta, Selinunte and Val di Noto. CT images were acquired at different times, before and after the water contact, using image elaboration techniques during the acquisition as well as the post-processing phases. Water distribution into porous spaces has been evaluated on the basis of the Hounsfield number, estimated for the 3-D voxel structure of samples. For most of the considered samples, assumptions based on Handy model permit to correlate the average height of the wetting front to the square root of time. Stochastic equations were introduced in order to describe the percolative water behavior in heterogeneous samples, as the Agrigento one. Before the CT acquisition, an estimate of the capillary absorption kinetics has been carried out by the gravimetric method. A petrographical characterization of samples has been performed by stereomicroscope observations, while porosity and morphology of porous have been surveyed by SEM (Scanning Electron Microscope images. Furthermore, the proposed methods have also permitted to define penetration depth as well as distribution uniformity of materials used for restoration and conservation of historical

  16. The CfA-Rosat Survey of Distant Clusters of Galaxies

    Science.gov (United States)

    McNamara, Brian

    1998-01-01

    We (Vikhlinin, McNamara, Forman, Jones, Hornstrup, Quintana) have completed a new survey of distant clusters of galaxies, which we use to to study cluster evolution over cosmological timescales. The clusters were identified as extended X-ray sources in 650 ROSAT PSPC images of high Galactic latitude fields. Our catalog of approximately 230 extended X-ray sources covers 160 square degrees on the sky. Ours is the largest of the several ROSAT serendipitous cluster surveys in progress (e.g. SHARC, Rosati, WARPS etc.). Using V,R,I imagery obtained at several observatories, we find that greater than 90% of the X-ray sources are associated with distant clusters of galaxies. We have obtained spectroscopic redshifts for nearly 80 clusters in our catalog, and we have measured photometric redshifts for the remaining clusters. Our sample contains more than 20 clusters at z > 0.5. I will discuss the logN-logS relationship for our clusters. Because our large survey area, we are able to confirm the evolution of the most luminous distant clusters first seen in the Einstein Extended Medium Sensitivity Survey. In addition, I will discuss the relationships between optical richness, core radius, and X-ray luminosity for distant, X-ray-selected clusters.

  17. Ulysses solar wind plasma observations at high southerly latitudes.

    Science.gov (United States)

    Phillips, J L; Bame, S J; Feldman, W C; Gosling, J T; Hammond, C M; McComas, D J; Goldstein, B E; Neugebauer, M; Scime, E E; Suess, S T

    1995-05-19

    Solar wind plasma observations made by the Ulysses spacecraft through -80.2 degrees solar latitude and continuing equatorward to -40.1 degrees are summarized. Recurrent high-speed streams and corotating interaction regions dominated at middle latitudes. The speed of the solar wind was typically 700 to 800 kilometers per second poleward of -35 degrees . Corotating reverse shocks persisted farther south than did forward shocks because of the tilt of the heliomagnetic streamer belt. Sporadic coronal mass ejections were seen as far south as -60.5 degrees . Proton temperature was higher and the electron strahl was broader at higher latitudes. The high-latitude wind contained compressional, pressure-balanced, and Alfvénic structures.

  18. Glacier-influenced sedimentation on high-latitude continental margins

    National Research Council Canada - National Science Library

    Dowdeswell, J. A; Cofaigh, C. Ó

    2002-01-01

    This book examines the process and patterns of glacier-influenced sedimentation on high-latitude continental margins and the geophysical and geological signatures of the resulting sediments and landform...

  19. Responses of arthropod populations to warming depend on latitude

    DEFF Research Database (Denmark)

    Youngsteadt, Elsa; Ernst, Andrew F.; Dunn, Robert Roberdeau

    2017-01-01

    Biological effects of climate change are expected to vary geographically, with a strong signature of latitude. For ectothermic animals, there is systematic latitudinal variation in the relationship between climate and thermal performance curves, which describe the relationship between temperature...

  20. Carbon stock of Moso bamboo (Phyllostachys pubescens) forests along a latitude gradient in the subtropical region of China.

    Science.gov (United States)

    Xu, Mengjie; Ji, Haibao; Zhuang, Shunyao

    2018-01-01

    Latitude is an important factor that influences the carbon stock of Moso bamboo (Phyllostachys pubescens) forests. Accurate estimation of the carbon stock of Moso bamboo forest can contribute to sufficient evaluation of forests in carbon sequestration worldwide. Nevertheless, the effect of latitude on the carbon stock of Moso bamboo remains unclear. In this study, a field survey with 36 plots of Moso bamboo forests along a latitude gradient was conducted to investigate carbon stock. Results showed that the diameter at breast height (DBH) of Moso bamboo culms increased from 8.37 cm to 10.12 cm that well fitted by Weibull model, whereas the bamboo culm density decreased from 4722 culm ha-1 to 3400 culm ha-1 with increasing latitude. The bamboo biomass carbon decreased from 60.58 Mg C ha-1 to 48.31 Mg C ha-1 from north to south. The total carbon stock of Moso bamboo forests, which comprises soil and biomass carbon, ranged from 87.83 Mg C ha-1 to 119.5 Mg C ha-1 and linearly increased with latitude. As a fast-growing plant, Moso bamboo could be harvested amounts of 6.0 Mg C ha-1 to 7.6 Mg C ha-1 annually, which indicates a high potential of this species for carbon sequestration. Parameters obtained in this study can be used to accurately estimate the carbon stock of Moso bamboo forest to establish models of the global carbon balance.

  1. X and gamma ray backgroud observations in Antarctic

    International Nuclear Information System (INIS)

    Jayanthi, U.B.

    1988-01-01

    Atmospheric X amd gamma rays are products of complex electromagnetic interation between charged particles and atmospheric constituents. The latitudinal dependence of the cosmic rays secondaries, auroral and South Atlantic Anomaly phenomena produce flux variations, especially the later temporal flux variations. We propose to discuss these variations in relevance to balloon flight observations of X and gamma ray atmospheric background at polar latitudes. (author) [pt

  2. On background radiation gradients – the use of airborne surveys when searching for orphan sources using mobile gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Kock, Peder; Rääf, Christopher; Samuelsson, Christer

    2014-01-01

    Systematic background radiation variations can lead to both false positives and failures to detect an orphan source when searching using car-borne mobile gamma-ray spectrometry. The stochastic variation at each point is well described by Poisson statistics, but when moving in a background radiation gradient the mean count rate will continually change, leading to inaccurate background estimations. Airborne gamma spectrometry (AGS) surveys conducted on the national level, usually in connection to mineral exploration, exist in many countries. These data hold information about the background radiation gradients which could be used at the ground level. This article describes a method that aims to incorporate the systematic as well as stochastic variations of the background radiation. We introduce a weighted moving average where the weights are calculated from existing AGS data, supplied by the Geological Survey of Sweden. To test the method we chose an area with strong background gradients, especially in the thorium component. Within the area we identified two roads which pass through the high-variability locations. The proposed method is compared with an unweighted moving average. The results show that the weighting reduces the excess false positives in the positive background gradients without introducing an excess of failures to detect a source during passage in negative gradients. -- Highlights: • We present a simple method to account for gradients in the natural background radiation. • Gradients in the natural radiation background can be modelled at the ground level using AGS data. • The number of false positives due to background gradients can be reduced by using airborne data

  3. Combining bathymetry, latitude, and phylogeny to understand the distribution of deep Atlantic hydroids (Cnidaria)

    Science.gov (United States)

    Fernandez, Marina O.; Marques, Antonio C.

    2018-03-01

    Water depth is associated with significant environmental changes and gradients that, together with biotic, geological, and evolutionary processes, define bathymetric ranges of individuals, populations, species, and even communities. However, inferences on bathymetric ranges of marine invertebrates are usually based on a few taxa or on restricted regional scales. In this study, we present a comprehensive literature survey of hydroids for the Atlantic Ocean and adjacent Arctic and Antarctic seas for records deeper than 50 m. We used these records in bathymetrical analyses along latitude and compared major patterns under an evolutionary framework. Our results show that hydroids are frequent inhabitants of the deep sea with mainly eurybathic species that extend their distributions from shallower to deeper waters, being rarely exclusively bathyal or abyssal. We also found increasing bathymetric ranges with mean depths of occurrence of the species for both families and regions. Moreover, vertical distribution proved to be taxonomically and regionally dependent, with reduced eurybathy in "Antarctic" species but increased eurybathy in "Tropical" and "Subtropical North" regions. Data also support early colonization of the deep sea in the evolution of the group. Finally, the unequal number of records across latitudes, scant at Equatorial and southern Tropical latitudes, provides evidence to the historically uneven sampling effort in the different regions of the Atlantic.

  4. AN XMM-NEWTON SURVEY OF THE SOFT X-RAY BACKGROUND. I. THE O VII AND O VIII LINES BETWEEN l = 120 DEG. AND l = 240 DEG

    International Nuclear Information System (INIS)

    Henley, David B.; Shelton, Robin L.

    2010-01-01

    We present measurements of the soft X-ray background (SXRB) O VII and O VIII intensity between l = 120 deg. and l = 240 deg., the first results of a survey of the SXRB using archival XMM-Newton observations. We do not restrict ourselves to blank-sky observations, but instead use as many observations as possible, removing bright or extended sources by hand if necessary. In an attempt to minimize contamination from near-Earth solar wind charge exchange (SWCX) emission, we remove times of high solar wind proton flux from the data. Without this filtering we are able to extract measurements from 586 XMM-Newton observations. With this filtering, ∼1/2 of the observations are rendered unusable, and we are able to extract measurements from 303 observations. The oxygen intensities are typically ∼0.5-10 photons cm -2 s -1 sr -1 (line units, L.U.) for O VII and ∼0-5 L.U. for O VIII. The proton flux filtering does not systematically reduce the oxygen intensities measured from a given observation. However, the filtering does preferentially remove the observations with higher oxygen intensities. Our data set includes 69 directions with multiple observations, whose oxygen intensity variations can be used to constrain SWCX models. One observation exhibits an O VII enhancement of ∼25 L.U. over two other observations of the same direction, although most SWCX enhancements are ∼ 6 K, in good agreement with previous studies.

  5. National Health and Nutrition Examination Survey whole-body dual-energy X-ray absorptiometry reference data for GE Lunar systems.

    Science.gov (United States)

    Fan, Bo; Shepherd, John A; Levine, Michael A; Steinberg, Dee; Wacker, Wynn; Barden, Howard S; Ergun, David; Wu, Xin P

    2014-01-01

    The National Health and Nutrition Examination Survey (NHANES 1999-2004) includes adult and pediatric comparisons for total body bone and body composition results. Because dual-energy x-ray absorptiometry (DXA) measurements from different manufacturers are not standardized, NHANES reference values currently are applicable only to a single make and model of Hologic DXA system. The purpose of this study was to derive body composition reference curves for GE Healthcare Lunar DXA systems. Published values from the NHANES 1999-2004 survey were acquired from the Centers for Disease Control and Prevention website. Using previously reported cross-calibration equations between Hologic and GE-Lunar, we converted the total body and regional bone and soft-tissue measurements from NHANES 1999-2004 to GE-Lunar values. The LMS (LmsChartMaker Pro Version 3.5) curve fitting method was used to generate GE-Lunar reference curves. Separate curves were generated for each sex and ethnicity. The reference curves were also divided into pediatric (≤20 years old) and adult (>20 years old) groups. Adult reference curves were derived as a function of age. Additional relationships of pediatric DXA values were derived as a function of height, lean mass, and bone area. Robustness was tested between Hologic and GE-Lunar Z-score values. The NHANES 1999-2004 survey included a sample of 20,672 participants' (9630 female) DXA scans. A total of 8056 participants were younger than 20 yr and were included in the pediatric reference data set. Participants enrolled in the study who weighed more than 136 kg (over scanner table limit) were excluded. The average Z-scores comparing the new GE-Lunar reference curves are close to zero, and the standard deviation of the Z-scores are close to one for all variables. As expected, all measurements on the GE-Lunar reference curves for participants younger than 20 yr increase monotonically with age. In the adult population, most of the curves are constant at younger

  6. High-latitude dust in the Earth system

    Science.gov (United States)

    Bullard, Joanna E; Baddock, Matthew; Bradwell, Tom; Crusius, John; Darlington, Eleanor; Gaiero, Diego; Gasso, Santiago; Gisladottir, Gudrun; Hodgkins, Richard; McCulloch, Robert; NcKenna Neuman, Cheryl; Mockford, Tom; Stewart, Helena; Thorsteinsson, Throstur

    2016-01-01

    Natural dust is often associated with hot, subtropical deserts, but significant dust events have been reported from cold, high latitudes. This review synthesizes current understanding of high-latitude (≥50°N and ≥40°S) dust source geography and dynamics and provides a prospectus for future research on the topic. Although the fundamental processes controlling aeolian dust emissions in high latitudes are essentially the same as in temperate regions, there are additional processes specific to or enhanced in cold regions. These include low temperatures, humidity, strong winds, permafrost and niveo-aeolian processes all of which can affect the efficiency of dust emission and distribution of sediments. Dust deposition at high latitudes can provide nutrients to the marine system, specifically by contributing iron to high-nutrient, low-chlorophyll oceans; it also affects ice albedo and melt rates. There have been no attempts to quantify systematically the expanse, characteristics, or dynamics of high-latitude dust sources. To address this, we identify and compare the main sources and drivers of dust emissions in the Northern (Alaska, Canada, Greenland, and Iceland) and Southern (Antarctica, New Zealand, and Patagonia) Hemispheres. The scarcity of year-round observations and limitations of satellite remote sensing data at high latitudes are discussed. It is estimated that under contemporary conditions high-latitude sources cover >500,000 km2 and contribute at least 80–100 Tg yr−1 of dust to the Earth system (~5% of the global dust budget); both are projected to increase under future climate change scenarios.

  7. Tracer Equivalent Latitude: A Diagnostic Tool for Isentropic Transport Studies.

    Science.gov (United States)

    Allen, Douglas R.; Nakamura, Noboru

    2003-01-01

    Area equivalent latitude based on potential vorticity (PV) is a widely used diagnostic for isentropic transport in the stratosphere and upper troposphere. Here, an alternate method for calculating equivalent latitude is explored, namely, a numerical synthesis of a PV-like tracer from a long-term integration of the advection-diffusion equation on isentropic surfaces. It is found that the tracer equivalent latitude (TrEL) behaves much like the traditional PV equivalent latitude (PVEL) despite the simplified governing physics; this is evidenced by examining the kinematics of the Arctic lower stratospheric vortex. Yet in some cases TrEL performs markedly better as a coordinate for long-lived trace species such as ozone. These instances include analysis of lower stratospheric ozone during the Stratospheric Aerosol and Gas Experiment (SAGE) III Ozone Loss and Validation Experiment (SOLVE) campaign and three-dimensional reconstruction of total column ozone during November-December 1999 from fitted ozone-equivalent latitude relationship. It is argued that the improvement is due to the tracer being free from the diagnostic errors and certain diabatic processes that affect PV. The sensitivity of TrEL to spatial and temporal resolution, advection scheme, and driving winds is also examined.

  8. Variable responses of benthic communities to anomalously warm sea temperatures on a high-latitude coral reef.

    Science.gov (United States)

    Bridge, Tom C L; Ferrari, Renata; Bryson, Mitch; Hovey, Renae; Figueira, Will F; Williams, Stefan B; Pizarro, Oscar; Harborne, Alastair R; Byrne, Maria

    2014-01-01

    High-latitude reefs support unique ecological communities occurring at the biogeographic boundaries between tropical and temperate marine ecosystems. Due to their lower ambient temperatures, they are regarded as potential refugia for tropical species shifting poleward due to rising sea temperatures. However, acute warming events can cause rapid shifts in the composition of high-latitude reef communities, including range contractions of temperate macroalgae and bleaching-induced mortality in corals. While bleaching has been reported on numerous high-latitude reefs, post-bleaching trajectories of benthic communities are poorly described. Consequently, the longer-term effects of thermal anomalies on high-latitude reefs are difficult to predict. Here, we use an autonomous underwater vehicle to conduct repeated surveys of three 625 m(2) plots on a coral-dominated high-latitude reef in the Houtman Abrolhos Islands, Western Australia, over a four-year period spanning a large-magnitude thermal anomaly. Quantification of benthic communities revealed high coral cover (>70%, comprising three main morphospecies) prior to the bleaching event. Plating Montipora was most susceptible to bleaching, but in the plot where it was most abundant, coral cover did not change significantly because of post-bleaching increases in branching Acropora. In the other two plots, coral cover decreased while macroalgal cover increased markedly. Overall, coral cover declined from 73% to 59% over the course of the study, while macroalgal cover increased from 11% to 24%. The significant differences in impacts and post-bleaching trajectories among plots underline the importance of understanding the underlying causes of such variation to improve predictions of how climate change will affect reefs, especially at high-latitudes.

  9. Variable responses of benthic communities to anomalously warm sea temperatures on a high-latitude coral reef.

    Directory of Open Access Journals (Sweden)

    Tom C L Bridge

    Full Text Available High-latitude reefs support unique ecological communities occurring at the biogeographic boundaries between tropical and temperate marine ecosystems. Due to their lower ambient temperatures, they are regarded as potential refugia for tropical species shifting poleward due to rising sea temperatures. However, acute warming events can cause rapid shifts in the composition of high-latitude reef communities, including range contractions of temperate macroalgae and bleaching-induced mortality in corals. While bleaching has been reported on numerous high-latitude reefs, post-bleaching trajectories of benthic communities are poorly described. Consequently, the longer-term effects of thermal anomalies on high-latitude reefs are difficult to predict. Here, we use an autonomous underwater vehicle to conduct repeated surveys of three 625 m(2 plots on a coral-dominated high-latitude reef in the Houtman Abrolhos Islands, Western Australia, over a four-year period spanning a large-magnitude thermal anomaly. Quantification of benthic communities revealed high coral cover (>70%, comprising three main morphospecies prior to the bleaching event. Plating Montipora was most susceptible to bleaching, but in the plot where it was most abundant, coral cover did not change significantly because of post-bleaching increases in branching Acropora. In the other two plots, coral cover decreased while macroalgal cover increased markedly. Overall, coral cover declined from 73% to 59% over the course of the study, while macroalgal cover increased from 11% to 24%. The significant differences in impacts and post-bleaching trajectories among plots underline the importance of understanding the underlying causes of such variation to improve predictions of how climate change will affect reefs, especially at high-latitudes.

  10. Multiflash whistlers in ELF-band observed at low latitude

    Directory of Open Access Journals (Sweden)

    A. K. Singh

    2011-01-01

    Full Text Available Multiflash whistler-like event in the ELF-band, observed during March 1998 at low latitude station Jammu, is reported. The most prominent feature of these events is the multiflash nature along with the decrease in frequency within a very short span of time resembling similar to terrestrial whistlers. The events have a significantly smaller time duration (0.5–3.5 s than those reported earlier from high, mid and low latitudes and also display a diurnal maximum occurring around 09:30 h (IST. There have been similar reportings from other latitudes, but whistlers in the ELF-band with a multiflash nature along with a precursor emission have never been reported. Lightning seems to be the dominant source for the ELF whistlers reported here.

  11. Letter to the Editor: Geomagnetic storm effects at low latitudes

    Directory of Open Access Journals (Sweden)

    R. G. Rastogi

    Full Text Available The geomagnetic horizontal (H field from the chain of nine observatories in India are used to study the storm-time and disturbance daily variations. The peak decrease in storm-time variation in H showed significant enhancements at the equatorial electrojet stations over and above the normally expected decrease due to the ring current effects corrected for geomagnetic latitudes. The disturbance daily variation of H at equatorial stations showed a large decrease around midday hours over and above the usual dawn-maximum and dusk-minimum seen at any mid-latitude stations around the world. These slow and persistent additional decreases of H of disturbance daily variation at equatorial latitudes could be the effect of a westward electric field due to the Disturbance Ionospheric dynamo coupled with abnormally large electrical conductivities in the E region over the equator.Key words. Ionosphere (electric fields and currents · Magnetospheric physics (electric fields; storms and substorms

  12. Letter to the Editor: Geomagnetic storm effects at low latitudes

    Directory of Open Access Journals (Sweden)

    R. G. Rastogi

    1999-03-01

    Full Text Available The geomagnetic horizontal (H field from the chain of nine observatories in India are used to study the storm-time and disturbance daily variations. The peak decrease in storm-time variation in H showed significant enhancements at the equatorial electrojet stations over and above the normally expected decrease due to the ring current effects corrected for geomagnetic latitudes. The disturbance daily variation of H at equatorial stations showed a large decrease around midday hours over and above the usual dawn-maximum and dusk-minimum seen at any mid-latitude stations around the world. These slow and persistent additional decreases of H of disturbance daily variation at equatorial latitudes could be the effect of a westward electric field due to the Disturbance Ionospheric dynamo coupled with abnormally large electrical conductivities in the E region over the equator.Key words. Ionosphere (electric fields and currents · Magnetospheric physics (electric fields; storms and substorms

  13. CORAL REEFS. Genomic determinants of coral heat tolerance across latitudes.

    Science.gov (United States)

    Dixon, Groves B; Davies, Sarah W; Aglyamova, Galina A; Meyer, Eli; Bay, Line K; Matz, Mikhail V

    2015-06-26

    As global warming continues, reef-building corals could avoid local population declines through "genetic rescue" involving exchange of heat-tolerant genotypes across latitudes, but only if latitudinal variation in thermal tolerance is heritable. Here, we show an up-to-10-fold increase in odds of survival of coral larvae under heat stress when their parents come from a warmer lower-latitude location. Elevated thermal tolerance was associated with heritable differences in expression of oxidative, extracellular, transport, and mitochondrial functions that indicated a lack of prior stress. Moreover, two genomic regions strongly responded to selection for thermal tolerance in interlatitudinal crosses. These results demonstrate that variation in coral thermal tolerance across latitudes has a strong genetic basis and could serve as raw material for natural selection. Copyright © 2015, American Association for the Advancement of Science.

  14. THEORY OF SOLAR MERIDIONAL CIRCULATION AT HIGH LATITUDES

    International Nuclear Information System (INIS)

    Dikpati, Mausumi; Gilman, Peter A.

    2012-01-01

    We build a hydrodynamic model for computing and understanding the Sun's large-scale high-latitude flows, including Coriolis forces, turbulent diffusion of momentum, and gyroscopic pumping. Side boundaries of the spherical 'polar cap', our computational domain, are located at latitudes ≥ 60°. Implementing observed low-latitude flows as side boundary conditions, we solve the flow equations for a Cartesian analog of the polar cap. The key parameter that determines whether there are nodes in the high-latitude meridional flow is ε = 2ΩnπH 2 /ν, where Ω is the interior rotation rate, n is the radial wavenumber of the meridional flow, H is the depth of the convection zone, and ν is the turbulent viscosity. The smaller the ε (larger turbulent viscosity), the fewer the number of nodes in high latitudes. For all latitudes within the polar cap, we find three nodes for ν = 10 12 cm 2 s –1 , two for 10 13 , and one or none for 10 15 or higher. For ν near 10 14 our model exhibits 'node merging': as the meridional flow speed is increased, two nodes cancel each other, leaving no nodes. On the other hand, for fixed flow speed at the boundary, as ν is increased the poleward-most node migrates to the pole and disappears, ultimately for high enough ν leaving no nodes. These results suggest that primary poleward surface meridional flow can extend from 60° to the pole either by node merging or by node migration and disappearance.

  15. Projected beam irradiation at low latitudes using Meteonorm database

    DEFF Research Database (Denmark)

    Hatwaambo, Sylvester; Perers, Bengt; Karlsson, Björn

    2009-01-01

    by a collector provided the projection angle lies within the acceptance angle. The Meteonorm method of calculating solar radiation on any arbitrary oriented surface uses the globally simulated meteorological databases. Meteonorm has become a valuable too for estimating solar radiation where measured solar...... radiation data is missing or irregular. In this paper we present the projected beam solar radiation at low latitudes based on the standard Meteonorm calculations. The conclusion is that there is potential in using solar concentrators at these latitudes since the projected beam radiation is more during...

  16. Elevated temperatures and bleaching on a high latitude coral reef: the 1988 Bermuda event

    Science.gov (United States)

    Cook, Clayton B.; Logan, Alan; Ward, Jack; Luckhurst, Brian; Berg, Carl J.

    1990-03-01

    Sea temperatures were normal in Bermuda during 1987, when Bermuda escaped the episodes of coral bleaching which were prevalent throughout the Caribbean region. Survey transecs in 1988 on 4 6 m reefs located on the rim margin and on a lagoonal patch reef revealed bleaching only of zoanthids between May and July. Transect and tow surveys in August and September revealed bleaching of several coral species; Millepora alcicornis on rim reefs was the most extensively affected. The frequency of bleaching in this species, Montastrea annularis and perhaps Diploria labyrinthiformis was significantly higher on outer reefs than on inshore reefs. This bleaching period coincided with the longest period of elevated sea temperatures in Bermuda in 38 years (28.9 30.9°C inshore, >28° offshore). By December, when temperatures had returned to normal, bleaching of seleractinians continued, but bleaching of M. alcicornis on the outer reefs was greatly reduced. Our observations suggest that corals which normally experience wide temperature ranges are less sensitive to thermal stress, and that high-latitude reef corals are sensitive to elevated temperatures which are within the normal thermal range of corals at lower latitudes.

  17. Global model of the upper atmosphere with a variable step of integration in latitude

    International Nuclear Information System (INIS)

    Namgaladze, A.A.; Martynenko, O.V.; Namgaladze, A.N.

    1996-01-01

    New version of model for the Earth thermosphere, ionosphere and protonosphere with increased spatial distribution, realized at personal computer, is developed. Numerical solution algorithm for modeling equations solution, which makes it possible to apply variable (depending on latitude) integrating pitch by latitude and to increase hereby the model latitude resolutions in the latitude zones of interest. Comparison of the model calculational results of ionosphere and thermosphere parameters, accomplished with application of different integrating pitches by geomagnetic latitude, is conducted. 10 refs.; 3 figs

  18. X-ray sources

    International Nuclear Information System (INIS)

    Masswig, I.

    1986-01-01

    The tkb market survey comparatively evaluates the X-ray sources and replacement tubes for stationary equipment currently available on the German market. It lists the equipment parameters of 235 commercially available X-ray sources and their replacement tubes and gives the criteria for purchase decisions. The survey has been completed with December 1985, and offers good information concerning medical and technical aspects as well as those of safety and maintenance. (orig.) [de

  19. An ASCA Survey of GeV Sources

    Science.gov (United States)

    Roberts, M. S. E.; Romani, R. W.; Kawai, N.

    1999-04-01

    We present an ASCA survey of GeV selected EGRET sources with E>1 GeV gamma -ray photon flux >5.0 x 10(-8) cm(-2) s(-1) . A combination of archival and new data covers ~ 75% of the sky contained within the 95% confidence position contours of these sources, and additional data obtained during the current observing cycle will increase this coverage to ~ 90%. We start with flat-fielded 2-10 keV images from the GIS data, and fit power-law spectra to potential counterparts. SIS, ROSAT, and Einstein data are used to confirm source detections and extend survey coverage. We then use the X-ray sources to identify radio counterparts in continuum survey data. Of the 26 GeV sources above our flux threshhold (Lamb and Macomb, 1997), 3 of the 4 at high galactic latitudes (bga 10(deg) ) are known blazars, while 5 of the low latitude sources are young pulsars. Of the remaining sources, 5 are plausibly associated with known young pulsars and/or plerionic SNR, one is at the Galactic center, and one may be associated with LSI+61 303. We focus here on the remaining 11 sources. By comparison with the known radio and X-ray properties of blazars and pulsars, we can identify potential members of these source classes, and potential new classes of gamma -ray emitters. We also estimate source luminosities using distances inferred from nearby tracers of star formation (Yadigaroglu and Romani, 1997). Data from several fields are consistent with these sources being synchrotron nebulae surrounding radio-quiet `Geminga-like' pulsars. These data provide incentives for further searches for pulsations at high energies and in the radio. In other fields identification is more problematic. We compare our results to models of the relative beaming fractions inferred from the radio and gamma -ray ray pulse shapes. The fraction of `pulsar candidate' detections is shown to provide useful constraints on pulsar luminosity evolution and beaming statistics.

  20. Beryllium-10 concentrations in water samples of high northern latitudes

    Energy Technology Data Exchange (ETDEWEB)

    Strobl, C.; Eisenhauer, A.; Schulz, V.; Baumann, S.; Mangini, A. [Heidelberger Akademie der Wissenschaften, Heildelberg (Germany); Kubik, P.W. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-09-01

    {sup 10}Be concentrations in the water column of high northern latitudes were not available so far. We present different {sup 10}Be profiles from the Norwegian-Greenland Sea, the Arctic Ocean, and the Laptev Sea. (author) 3 fig., 3 refs.

  1. Heating and dehumidification in production greenhouses at northern latitudes

    NARCIS (Netherlands)

    Kempkes, F.; Zwart, De H.F.; Munoz, P.; Montero, J.I.; Baptista, F.J.; Giuffrida, F.; Gilli, Celine; Stepowska, Agnieszka; Stanghellini, C.

    2017-01-01

    The majority of greenhouses in northern latitudes are heated, in the winter mainly for temperature control and year round to control humidity. Heating is accepted by most organic regulations in different countries; if heating efficiently and the energy source is predominantly renewable energy,

  2. Molecular substitution rate increases with latitude in butterflies

    DEFF Research Database (Denmark)

    Schär, Sämi; Vila, Roger; Petrović, Andjeljko

    2017-01-01

    of five lycaenid butterfly species with varied ecological adaptations, sampled across a latitudinal gradient in the Holarctic region. We found a positive correlation between latitude and substitution rate of mitochondrial DNA sequences in all species investigated. We propose that this result is the signal...

  3. Imaging of structures in the high-latitude ionosphere: model comparisons

    Directory of Open Access Journals (Sweden)

    D. W. Idenden

    Full Text Available The tomographic reconstruction technique generates a two-dimensional latitude versus height electron density distribution from sets of slant total electron content measurements (TEC along ray paths between beacon satellites and ground-based radio receivers. In this note, the technique is applied to TEC values obtained from data simulated by the Sheffield/UCL/SEL Coupled Thermosphere/Ionosphere/Model (CTIM. A comparison of the resulting reconstructed image with the 'input' modelled data allows for verification of the reconstruction technique. All the features of the high-latitude ionosphere in the model data are reproduced well in the tomographic image. Reconstructed vertical TEC values follow closely the modelled values, with the F-layer maximum density (NmF2 agreeing generally within about 10%. The method has also been able successfully to reproduce underlying auroral-E ionisation over a restricted latitudinal range in part of the image. The height of the F2 peak is generally in agreement to within about the vertical image resolution (25 km.

    Key words. Ionosphere (modelling and forecasting; polar ionosphere · Radio Science (instruments and techniques

  4. In-situ gamma-ray survey of rare-earth tailings dams – A case study in Baotou and Bayan Obo Districts, China

    International Nuclear Information System (INIS)

    Li, Baochuan; Wang, Nanping; Wan, Jianhua; Xiong, Shengqing; Liu, Hongtao; Li, Shijun; Zhao, Rong

    2016-01-01

    An in-situ gamma-ray spectrometer survey with a scintillation detector of NaI(Tl) (Φ75 mm × 75 mm) was carried out in the Baotou and Bayan Obo Districts in order to estimate the levels of natural radionuclides near rare-earth (RE) tailings dams. In the RE tailings dam of Baotou, the mean concentrations of "2"3"8U and "2"3"2Th were 3.0 ± 1.0 mg/kg (range: 1.9–4.6 mg/kg) and 321 ± 31 mg/kg (range: 294–355 mg/kg), respectively. In the Bayan Obo tailings dam, the mean concentrations of "2"3"8U and "2"3"2Th were 5.7 ± 0.5 mg/kg (range: 5.3–6.1 mg/kg) and 276 ± 0.5 mg/kg (range: 275.5–276.3 mg/kg), respectively. The average "2"3"2Th concentrations in the mining areas of the Bayan Obo Mine and the living areas of the Bayan Obo Town were 18.7 ± 7.5 and 26.2 ± 9.1 mg/kg, respectively. The "2"3"2Th concentration recorded in the tailings dams was much higher than the global average (7.44 mg/kg). Our investigation shows that the "2"3"2Th concentration in the tailings in the Baotou dam was 34.6 times greater than that in the local soil (in Guyang County); the average concentrations of "2"3"2Th in the soil in the Baotou District and Bayan Obo Districts were about 1.35 and 2.82 times greater, respectively, than that in the soil in Guyang County. Based on our results, the highest estimated effective dose due to gamma irradiation was 1.15 mSv per year, estimated from the data observed in the Baotou tailings dams. The results of this preliminary study indicate the potential importance of radioactivity in RE tailings dams and that remedial measures may be required. - Highlights: • In-situ gamma-ray spectrometry to measure natural radionuclides in rare-earth tailings dam. • Comparisons were among the tailings dam, mining area and living areas in Baotou and Bayan Obo. • "2"3"2Th concentrations in tailings dams in Baotou and Bayan Obo were much higher than global average. • Results provide a baseline useful to assess the radiation

  5. THE CHANDRA SURVEY OF EXTRAGALACTIC SOURCES IN THE 3CR CATALOG: X-RAY EMISSION FROM NUCLEI, JETS, AND HOTSPOTS IN THE CHANDRA ARCHIVAL OBSERVATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Massaro, F. [Dipartimento di Fisica, Università degli Studi di Torino, via Pietro Giuria 1, I-10125 Torino (Italy); Harris, D. E.; Paggi, A.; Wilkes, B. J.; Kuraszkiewicz, J. [Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States); Liuzzo, E.; Orienti, M.; Paladino, R. [Istituto di Radioastronomia, INAF, via Gobetti 101, I-40129, Bologna (Italy); Tremblay, G. R. [Yale Center for Astronomy and Astrophysics, Physics Department, Yale University, P.O. Box 208120, New Haven, CT 06520-8120 (United States); Baum, S. A.; O’Dea, C. P. [University of Manitoba, Dept of Physics and Astronomy, Winnipeg, MB R3T 2N2 (Canada)

    2015-09-15

    As part of our program to build a complete radio and X-ray database of all Third Cambridge catalog extragalactic radio sources, we present an analysis of 93 sources for which Chandra archival data are available. Most of these sources have already been published. Here we provide a uniform re-analysis and present nuclear X-ray fluxes and X-ray emission associated with radio jet knots and hotspots using both publicly available radio images and new radio images that have been constructed from data available in the Very Large Array archive. For about 1/3 of the sources in the selected sample, a comparison between the Chandra and radio observations was not reported in the literature: we find X-ray detections of 2 new radio jet knots and 17 hotspots. We also report the X-ray detection of extended emission from the intergalactic medium for 15 galaxy clusters.

  6. In-situ gamma-ray survey of rare-earth tailings dams--A case study in Baotou and Bayan Obo Districts, China.

    Science.gov (United States)

    Li, Baochuan; Wang, Nanping; Wan, Jianhua; Xiong, Shengqing; Liu, Hongtao; Li, Shijun; Zhao, Rong

    2016-01-01

    An in-situ gamma-ray spectrometer survey with a scintillation detector of NaI(Tl) (Φ75 mm × 75 mm) was carried out in the Baotou and Bayan Obo Districts in order to estimate the levels of natural radionuclides near rare-earth (RE) tailings dams. In the RE tailings dam of Baotou, the mean concentrations of (238)U and (232)Th were 3.0 ± 1.0 mg/kg (range: 1.9-4.6 mg/kg) and 321 ± 31 mg/kg (range: 294-355 mg/kg), respectively. In the Bayan Obo tailings dam, the mean concentrations of (238)U and (232)Th were 5.7 ± 0.5 mg/kg (range: 5.3-6.1 mg/kg) and 276 ± 0.5 mg/kg (range: 275.5-276.3 mg/kg), respectively. The average (232)Th concentrations in the mining areas of the Bayan Obo Mine and the living areas of the Bayan Obo Town were 18.7 ± 7.5 and 26.2 ± 9.1 mg/kg, respectively. The (232)Th concentration recorded in the tailings dams was much higher than the global average (7.44 mg/kg). Our investigation shows that the (232)Th concentration in the tailings in the Baotou dam was 34.6 times greater than that in the local soil (in Guyang County); the average concentrations of (232)Th in the soil in the Baotou District and Bayan Obo Districts were about 1.35 and 2.82 times greater, respectively, than that in the soil in Guyang County. Based on our results, the highest estimated effective dose due to gamma irradiation was 1.15 mSv per year, estimated from the data observed in the Baotou tailings dams. The results of this preliminary study indicate the potential importance of radioactivity in RE tailings dams and that remedial measures may be required. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  7. Upsurge of X-ray astronomy 230-

    International Nuclear Information System (INIS)

    Hudec, D.R.

    1978-01-01

    Instruments are described used for X-ray astronomy, namely X-ray detectors and X-ray telescopes. Unlike telescopes, the detectors do not comprise X-ray optics. A survey is given of the results obtained in solar and stellar X-ray astronomy and hypotheses are submitted on the origin of X radiation in the interstellar space. (J.B.)

  8. NURE aerial gamma-ray and magnetic reconnaissance survey of portions of New Mexico, Arizona and Texas. Volume II. New Mexico-Carlsbad NI 31-11 Quadrangle. Final report

    International Nuclear Information System (INIS)

    1981-09-01

    As part of the Department of Energy (DOE) Nation Uranium Resource Evaluation Program, a rotary-wing high sensitivity radiometric and magnetic survey was flown covering the Carlsbad Quadrangle of the State of New Mexico. The area surveyed consisted of approximately 1732 line miles. The survey was flown with a Sikorsky S58T helicopter equipped with a high sensitivity gamma ray spectrometer which was calibrated at the DOE calibration facilities at Walker Field in Grand Junction, Colorado, and the Dynamic Test Range at Lake Mead, Arizona. Instrumentation and data reduction methods are presented in Volume I of this report. The reduced data is presented in the form of stacked profiles, standard deviation anomaly plots, histogram plots and microfiche listings. The results of the geologic interpretation of the radiometric data together with the profiles, anomaly maps and histograms are presented in this Volume II final report

  9. Coordinated observations of postmidnight irregularities and thermospheric neutral winds and temperatures at low latitudes

    Science.gov (United States)

    Dao, Tam; Otsuka, Yuichi; Shiokawa, Kazuo; Nishioka, Michi; Yamamoto, Mamoru; Buhari, Suhaila M.; Abdullah, Mardina; Husin, Asnawi

    2017-07-01

    We investigated a postmidnight field-aligned irregularity (FAI) event observed with the Equatorial Atmosphere Radar at Kototabang (0.2°S, 100.3°E, dip latitude 10.4°S) in Indonesia on the night of 9 July 2010 using a comprehensive data set of both neutral and plasma parameters. We examined the rate of total electron content change index (ROTI) obtained from GPS receivers in Southeast Asia, airglow images detected by an all-sky imager, and thermospheric neutral winds and temperatures obtained by a Fabry-Perot interferometer at Kototabang. Altitudes of the F layer (h'F) observed by ionosondes at Kototabang, Chiang Mai, and Chumphon were also surveyed. We found that the postmidnight FAIs occurred within plasma bubbles and coincided with kilometer-scale plasma density irregularities. We also observed an enhancement of the magnetically equatorward thermospheric neutral wind at the same time as the increase of h'F at low-latitude stations, but h'F at a station near the magnetic equator remained invariant. Simultaneously, a magnetically equatorward gradient of thermospheric temperature was identified at Kototabang. The convergence of equatorward neutral winds from the Northern and Southern Hemispheres could be associated with a midnight temperature maximum occurring around the magnetic equator. Equatorward neutral winds can uplift the F layer at low latitudes and increase the growth rate of Rayleigh-Taylor instabilities, causing more rapid extension of plasma bubbles. The equatorward winds in both hemispheres also intensify the eastward Pedersen current, so a large polarization electric field generated in the plasma bubble might play an important role in the generation of postmidnight FAIs.

  10. Cosmic rays and ancient planetary magnetic fields

    International Nuclear Information System (INIS)

    Wesson, P.S.

    1977-01-01

    The possibility is discussed of using the latitude-dependent cutoff in the intensity and flux of cosmic ray particles reaching the surface of a planet to investigate ancient magnetic fields in the Moon, Mars and the Earth. In the last case, the method could provide a validity test for conventional palaeomagnetism. (Auth.)

  11. Restless legs syndrome: relationship between prevalence and latitude.

    Science.gov (United States)

    Koo, Brian B

    2012-12-01

    Restless legs syndrome (RLS) has a broad worldwide prevalence between 0.01% and 18.3%. While differences in RLS definitions and data ascertainment methods account for some variability, other factors likely contribute. The circadian nature of RLS and the fact that RLS symptoms track with endogenous melatonin levels suggest that light or ultraviolet radiation (UVR) may be related to RLS expression. As the amount of UVR decreases with latitude, we considered the potential effect of geography on RLS prevalence with the thought being that RLS prevalence rises with increasing latitude. RLS epidemiologic studies were sought via Pubmed search in the period between January 1, 1992 and November 15, 2010. Prevalence was mapped for each country or specific region studied and examined by continent. Pearson's correlational testing was carried out for RLS prevalence and latitude of the region studied. Global RLS prevalence ranges from 0.01% in Africa, 0.7% to 12.5% in Asia, 2.0% to 18.9% in the Americas, and 3.2% to 18.3% in Europe. Mapping RLS prevalence by country or region in both the Americas and in Europe suggests increasing RLS frequency with greater northern latitude. RLS prevalence is positively correlated with northern latitude in both North America and Europe with correlation coefficients of r = 0.77 (0.15, 0.96; p = 0.02) and r = 0.74 (0.44, 0.89; p = 0.0002), respectively. In Europe, lower latitudinal countries like Greece and Turkey had RLS prevalence (per 1,000 persons) of 38 and 34, respectively, middle latitudinal countries like France and England of 108 and 86, respectively, and high latitudinal countries like Norway and Iceland of 143 and 183, respectively. RLS epidemiology indicates an increase in RLS frequency in northern latitudinal countries as a function of distance from the equator, an effect most evident in Europe. This suggests that factors that track with latitude like UVR may be involved in the expression of RLS.

  12. On The gamma-ray emission from Reticulum II and other dwarf galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Hooper, Dan; Linden, Tim

    2015-09-01

    The recent discovery of ten new dwarf galaxy candidates by the Dark Energy Survey (DES) and the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) could increase the Fermi Gamma-Ray Space Telescope's sensitivity to annihilating dark matter particles, potentially enabling a definitive test of the dark matter interpretation of the long-standing Galactic Center gamma-ray excess. In this paper, we compare the previous analyses of Fermi data from the directions of the new dwarf candidates (including the relatively nearby Reticulum II) and perform our own analysis, with the goal of establishing the statistical significance of any gamma-ray signal from these sources. We confirm the presence of an excess from Reticulum II, with a spectral shape that is compatible with the Galactic Center signal. The significance of this emission is greater than that observed from 99.84% of randomly chosen high-latitude blank-sky locations, corresponding to a local detection significance of 3.2σ. We caution that any dark matter interpretation of this excess must be validated through observations of additional dwarf spheroidal galaxies, and improved calculations of the relative J-factor of dwarf spheroidal galaxies. We improve upon the standard blank-sky calibration approach through the use of multi-wavelength catalogs, which allow us to avoid regions that are likely to contain unresolved gamma-ray sources.

  13. Latitude, temperature, and habitat complexity predict predation pressure in eelgrass beds across the Northern Hemisphere.

    Science.gov (United States)

    Reynolds, Pamela L; Stachowicz, John J; Hovel, Kevin; Boström, Christoffer; Boyer, Katharyn; Cusson, Mathieu; Eklöf, Johan S; Engel, Friederike G; Engelen, Aschwin H; Eriksson, Britas Klemens; Fodrie, F Joel; Griffin, John N; Hereu, Clara M; Hori, Masakazu; Hanley, Torrance C; Ivanov, Mikhail; Jorgensen, Pablo; Kruschel, Claudia; Lee, Kun-Seop; McGlathery, Karen; Moksnes, Per-Olav; Nakaoka, Masahiro; O'Connor, Mary I; O'Connor, Nessa E; Orth, Robert J; Rossi, Francesca; Ruesink, Jennifer; Sotka, Erik E; Thormar, Jonas; Tomas, Fiona; Unsworth, Richard K F; Whalen, Matthew A; Duffy, J Emmett

    2018-01-01

    Latitudinal gradients in species interactions are widely cited as potential causes or consequences of global patterns of biodiversity. However, mechanistic studies documenting changes in interactions across broad geographic ranges are limited. We surveyed predation intensity on common prey (live amphipods and gastropods) in communities of eelgrass (Zostera marina) at 48 sites across its Northern Hemisphere range, encompassing over 37° of latitude and four continental coastlines. Predation on amphipods declined with latitude on all coasts but declined more strongly along western ocean margins where temperature gradients are steeper. Whereas in situ water temperature at the time of the experiments was uncorrelated with predation, mean annual temperature strongly positively predicted predation, suggesting a more complex mechanism than simply increased metabolic activity at the time of predation. This large-scale biogeographic pattern was modified by local habitat characteristics; predation declined with higher shoot density both among and within sites. Predation rates on gastropods, by contrast, were uniformly low and varied little among sites. The high replication and geographic extent of our study not only provides additional evidence to support biogeographic variation in predation intensity, but also insight into the mechanisms that relate temperature and biogeographic gradients in species interactions. © 2017 by the Ecological Society of America.

  14. Vitamin B12 deficiency is associated with geographical latitude and solar radiation in the older population.

    Science.gov (United States)

    Cabrera, Sebastián; Benavente, David; Alvo, Miriam; de Pablo, Paola; Ferro, Charles J

    2014-11-01

    Vitamin B12 and folic acid deficiency are common in the older and are associated with several conditions including anaemia, cardiovascular disease, cognitive impairment and cancer. Evidence from in vitro studies suggests that solar radiation can degrade both vitamins in the skin. Chile is the longest country in the world running perfectly North-South making it an ideal place to study potential associations of latitude and solar radiation on vitamin B12 and folic acid deficiency. The objective was to examine the association between vitamin B12 and folic acid deficiencies and latitude. Plasma samples were collected from Chileans aged 65+ years (n=1013) living across the whole country and assayed for vitamin B12 and folic acid concentrations as part of the Chilean Health Survey 2009-2010, which is a national representative sample study. Overall, the prevalence of vitamin B12 deficiency was 11.3%, with the prevalence in the North of the country being significantly greater than in the Central and South zones (19.1%,10.5%, and 5.7%, respectively; Psolar radiation (OR 1.203 [95% confidence intervals 1.119-1.294], Psolar radiation. Although degradation by solar radiation might explain this observation, further work is required to establish the potential mechanisms. In countries that routinely fortify food with folic acid, efforts to identify vitamin B12 deficiency might be more cost-efficiently targeted in areas closest to the Equator. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. A low-latitude southern atlas of galactic hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Poeppel, W G.L. [Instituto Argentino de Radioastronomia, Villa Elisa, Buenos Aires, Argentina; Olano, C A [Rio Grande do Sul, Universidade Federal, Porto Alegre, Brazil

    1979-01-01

    An atlas of 21 cm line profiles is described, which was made using a 30 m radio telescope with angular resolution of 0.5 deg, to study the properties of the low latitude H I gas excluding the complexity of the galactic plane. The results of the atlas itself are presented in two sets of diagrams: average profiles for each point, and contour maps. Analyses of the data have centered on an anomalous velocity cloud near galactic longitude (1) equals 349 deg, and latitude (b) equals plus 3 deg, strong kinematic asymmetries of the interstellar gas in the region of 1 between 348 and 12 deg and b between plus 3 and plus 17 deg, with positive radial velocities predominant, caused by a very intense source seemingly identical to Lindblad's (1967) feature A, and a comparative study of optical and radioastronomical data of the section of Gould's belt from 1 equals 300 to 12 deg.

  16. Trapped waves on the mid-latitude β-plane

    Science.gov (United States)

    Paldor, Nathan; Sigalov, Andrey

    2008-08-01

    A new type of approximate solutions of the Linearized Shallow Water Equations (LSWE) on the mid-latitude β-plane, zonally propagating trapped waves with Airy-like latitude-dependent amplitude, is constructed in this work, for sufficiently small radius of deformation. In contrast to harmonic Poincare and Rossby waves, these newly found trapped waves vanish fast in the positive half-axis, and their zonal phase speed is larger than that of the corresponding harmonic waves for sufficiently large meridional domains. Our analysis implies that due to the smaller radius of deformation in the ocean compared with that in the atmosphere, the trapped waves are relevant to observations in the ocean whereas harmonic waves typify atmospheric observations. The increase in the zonal phase speed of trapped Rossby waves compared with that of harmonic ones is consistent with recent observations that showed that Sea Surface Height features propagated westwards faster than the phase speed of harmonic Rossby waves.

  17. Specialization of mutualistic interaction networks decreases toward tropical latitudes

    DEFF Research Database (Denmark)

    Schleuning, M.; Fründ, J.; Klein, A.-M.

    2012-01-01

    that current conditions have a stronger effect on biotic specialization than historical community stability. Biotic specialization decreased with increasing local and regional plant diversity. This suggests that high specialization of mutualistic interactions is a response of pollinators and seed dispersers......] or differences in plant diversity [10, 11]. Thus, the direction of the latitudinal specialization gradient remains contentious. With an unprecedented global data set, we investigated how biotic specialization between plants and animal pollinators or seed dispersers is associated with latitude, past...... and contemporary climate, and plant diversity. We show that in contrast to expectation, biotic specialization of mutualistic networks is significantly lower at tropical than at temperate latitudes. Specialization was more closely related to contemporary climate than to past climate stability, suggesting...

  18. High-Latitude Ionospheric Dynamics During Conditions of Northward IMF

    Science.gov (United States)

    Sharber, J. R.

    1996-01-01

    In order to better understand the physical processes operating during conditions of northward interplanetary magnetic field (IMF), in situ measurements from the Dynamics Explorer-2 (low altitude) polar satellite and simultaneous observations from the auroral imager on the Dynamics Explorer-1 (high altitude) satellite were used to investigate the relationships between optical emissions, particle precipitation, and convective flows in the high-latitude ionosphere. Field aligned current and convective flow patterns during IMF north include polar cap arcs, the theta aurora or transpolar arc, and the 'horse-collar' aurora. The initial part of the study concentrated on the electrodynamics of auroral features in the horse-collar aurora, a contracted but thickened emission region in which the dawn and dusk portions can spread to very high latitudes, while the latter part focused on the evolution of one type of IMF north auroral pattern to another, specifically the quiet-time horse-collar pattern to a theta aurora.

  19. High accurate time system of the Low Latitude Meridian Circle.

    Science.gov (United States)

    Yang, Jing; Wang, Feng; Li, Zhiming

    In order to obtain the high accurate time signal for the Low Latitude Meridian Circle (LLMC), a new GPS accurate time system is developed which include GPS, 1 MC frequency source and self-made clock system. The second signal of GPS is synchronously used in the clock system and information can be collected by a computer automatically. The difficulty of the cancellation of the time keeper can be overcomed by using this system.

  20. Low-latitude particle precipitation and associated local magnetic disturbances

    International Nuclear Information System (INIS)

    Rassoul, H.K.; Rohrbaugh, R.P.; Tinsley, B.A.

    1992-01-01

    The time variations of optical emissions during low-latitude auroral events have been shown to correlate well with those of magnetograms in the region where the aurorae are observed. Two events not previously reported are analyzed and are shown to confirm the nature of the correlations found for two earlier events. The maximum optical emissions at mid-latitudes occur in concert with the maximum positive (northward) excursions in the H trace and with rapid fluctuations in the D trace of nearby magnetograms. The fluctuation in ΔD is usually from the east (positive) to the west (negative) in the vicinity of the ΔH perturbation. The positive excursions in H at low-latitude observatories at the time of the maximum optical emissions are associated with negative H excursions at high latitude observatories in the same longitude sector. The source of the particles has been inferred to be the ring current, with precipitation occurring when the |Dst| index is large at the time of the large short term excursions in the local magnetic field. This result is consistent with the funding of Voss and Smith (1979), derived from a series of rocket measurements of precipitating heavy particles, that the flux correlates better with the product of |Dst| and the exponential of K p than with either alone. In the present case it is shown that the product of |Dst| and the amplitude of the short term excursions in the horizontal component in local magnetograms has better time resolution and better correlation with the observed emission rates than the index using K p

  1. Seasonal variations of the high-latitude F region for

    International Nuclear Information System (INIS)

    Sojka, J.J.; Schunk, R.W.; Raitt, W.J.

    1982-01-01

    We combined a plasma convection model with an inosphere-atmospheric composition model in order to study the seasonal variations of the high-latitude F region for strong convection. Our numerical study produced time-dependent, three-dimensional, ion density distributions for the ions NO + , O 2 + , N 2 + , O + , N + , and He + . We covered the high-latitude ionosphere above 42 0 N magnetic latitude and at altitudes between 160 and 800 km for a time period of one complete day. From our study we found the following: (1) For strong convection, the high-altitude ionosphere exhibits a significant UT variation both during winter and summer. (2) In general, the electron density is lower in winter than in summer. However, at certain universal times the electron density in the dayside polar cap is larger in winter than in summer owing to the effect of the mid-latitude 'winter anomaly' in combination with strong antisunward convection. (3) In both summer and winter, the major region of low electron density is associated with the main or mid-latitudde trough. The trough is deeper and its local time extend is much greater in winter than in summer. (4) Typically, the electron density exhibits a much larger variation with altitude in winter than in summer. (5) The ion composition and molecular/atomic ion transition altitude are highly UT dependent in both summer and winter. (6) The ion composition also displays a significant seasonal variation. However, at a given location the seasonal variation can be opposite at different universal times. (7) High-speed convection cells should display a marked seasonal variation, with a much larger concentration of molecular ions near the F region peak in summer than in winter

  2. An accelerating high-latitude jet in Earth's core

    OpenAIRE

    Livermore, PW; Hollerbach, R; Finlay, CC

    2017-01-01

    Observations of the change in Earth's magnetic field—the secular variation—provide information about the motion of liquid metal within the core that is responsible for the magnetic field's generation. High-resolution observations from the European Space Agency's Swarm satellite mission show intense field change at high latitude, localized in a distinctive circular daisy-chain configuration centred on the north geographic pole. Here we show that this feature can be explained by a localized, no...

  3. Energy-Efficient Office Buildings at High Latitudes

    Energy Technology Data Exchange (ETDEWEB)

    Lerum, V.

    1996-12-31

    This doctoral thesis describes a method for energy efficient office building design at high latitudes and cold climates. The method combines daylighting, passive solar heating, solar protection, and ventilative cooling. The thesis focuses on optimal design of an equatorial-facing fenestration system. A spreadsheet framework linking existing simplified methods is used. The daylight analysis uses location specific data on frequency distribution of diffuse daylight on vertical surfaces to estimate energy savings from optimal window and room configurations in combination with a daylight-responsive electric lighting system. The passive solar heating analysis is a generalization of a solar load ratio method adapted to cold climates by combining it with the Norwegian standard NS3031 for winter months when the solar savings fraction is negative. The emphasis is on very high computational efficiency to permit rapid and comprehensive examination of a large number of options early in design. The procedure is illustrated for a location in Trondheim, Norway, testing the relative significance of various design improvement options relative to a base case. The method is also tested for two other locations in Norway, at latitudes 58 and 70 degrees North. The band of latitudes between these limits covers cities in Alaska, Canada, Greenland, Iceland, Scandinavia, Finland, Russia, and Northern Japan. A comprehensive study of the ``whole building approach`` shows the impact of integrated daylighting and low-energy design strategies. In general, consumption of lighting electricity may be reduced by 50-80%, even at extremely high latitudes. The reduced internal heat from electric lights is replaced by passive solar heating. 113 refs., 85 figs., 25 tabs.

  4. Characterization of SEP events at high heliographic latitudes

    International Nuclear Information System (INIS)

    Dalla, S.; Balogh, A.; Krucker, S.; Posner, A.; Mueller-Mellin, R.; Anglin, J.D.; Hofer, M.Y.; Marsden, R.G.; Sanderson, T.R.; Heber, B.; Zhang, M.; McKibben, R.B.

    2003-01-01

    Between February 2000 and May 2002, the Ulysses spacecraft made the first ever measurements of solar energetic particles (SEPs) at high heliographic latitudes. Nine large gradual SEP events were detected at latitudes greater than 45 deg., their signatures being clearest at high particle energies, i.e. protons >30 MeV and electrons >0.1 MeV. In this paper we measure the onset times of Ulysses high latitude events in several energy channels, and plot them versus inverse particle speed. We repeat the procedure for near Earth observations by Wind and SOHO. Velocity dispersion is observed in all the events near Earth and in most of them at Ulysses. The plots of onset times versus inverse speed allow to derive an experimental path length and time of release from the solar atmosphere. We find that the derived path lengths at Ulysses are longer than the length of a Parker spiral magnetic field line connecting it to the Sun, by a factor between 1.2-2.7. The time of particle release from the Sun is typically between 100 and 200 mins later than the release time derived from in-ecliptic measurements. Unlike near Earth observations, Ulysses measurements are therefore not compatible with scatter-free propagation from the Sun to the spacecraft

  5. Lidar measurements of mesospheric temperature inversion at a low latitude

    Energy Technology Data Exchange (ETDEWEB)

    Siva Kumar, V.; Bhavani Kumar, Y.; Raghunath, K.; Rao, P.B. [National MST Radar Facility, Tirupati (India); Krishnaiah, M. [Sri Venkateswara Univ., Tirupati (India). Dept. of Physics; Mizutani, K.; Aoki, T.; Yasui, M.; Itabe, T. [Communication Research Lab., Tokyo (Japan)

    2001-08-01

    The Rayleigh lidar data collected on 119 nights from March 1998 to February 2000 were used to study the statistical characteristics of the low latitude mesospheric temperature inversion observed over Gadanki (13.5 N, 79.2 E), India. The occurrence frequency of the inversion showed semiannual variation with maxima in the equinoxes and minima in the summer and winter, which was quite different from that reported for the mid-latitudes. The peak of the inversion layer was found to be confined to the height range of 73 to 79 km with the maximum occurrence centered around 76 km, with a weak seasonal dependence that fits well to an annual cycle with a maximum in June and a minimum in December. The magnitude of the temperature deviation associated with the inversion was found to be as high as 32 K, with the most probable value occurring at about 20 K. Its seasonal dependence seems to follow an annual cycle with a maximum in April and a minimum in October. The observed characteristics of the inversion layer are compared with that of the mid-latitudes and discussed in light of the current understanding of the source mechanisms. (orig.)

  6. Lidar measurements of mesospheric temperature inversion at a low latitude

    Directory of Open Access Journals (Sweden)

    V. Siva Kumar

    2001-08-01

    Full Text Available The Rayleigh lidar data collected on 119 nights from March 1998 to February 2000 were used to study the statistical characteristics of the low latitude mesospheric temperature inversion observed over Gadanki (13.5° N, 79.2° E, India. The occurrence frequency of the inversion showed semiannual variation with maxima in the equinoxes and minima in the summer and winter, which was quite different from that reported for the mid-latitudes. The peak of the inversion layer was found to be confined to the height range of 73 to 79 km with the maximum occurrence centered around 76 km, with a weak seasonal dependence that fits well to an annual cycle with a maximum in June and a minimum in December. The magnitude of the temperature deviation associated with the inversion was found to be as high as 32 K, with the most probable value occurring at about 20 K. Its seasonal dependence seems to follow an annual cycle with a maximum in April and a minimum in October. The observed characteristics of the inversion layer are compared with that of the mid-latitudes and discussed in light of the current understanding of the source mechanisms.Key words. Atmospheric composition and structure (pressure, density and temperature. Meterology and atmospheric dynamics (climatology

  7. Mid-latitude afforestation shifts general circulation and tropical precipitation.

    Science.gov (United States)

    Swann, Abigail L S; Fung, Inez Y; Chiang, John C H

    2012-01-17

    We show in climate model experiments that large-scale afforestation in northern mid-latitudes warms the Northern Hemisphere and alters global circulation patterns. An expansion of dark forests increases the absorption of solar energy and increases surface temperature, particularly in regions where the land surface is unable to compensate with latent heat flux due to water limitation. Atmospheric circulation redistributes the anomalous energy absorbed in the northern hemisphere, in particular toward the south, through altering the Hadley circulation, resulting in the northward displacement of the tropical rain bands. Precipitation decreases over parts of the Amazon basin affecting productivity and increases over the Sahel and Sahara regions in Africa. We find that the response of climate to afforestation in mid-latitudes is determined by the amount of soil moisture available to plants with the greatest warming found in water-limited regions. Mid-latitude afforestation is found to have a small impact on modeled global temperatures and on global CO(2), but regional heating from the increase in forest cover is capable of driving unintended changes in circulation and precipitation. The ability of vegetation to affect remote circulation has implications for strategies for climate mitigation.

  8. Ionosphere Scintillation at Low and High Latitudes (Modelling vs Measurement)

    Science.gov (United States)

    Béniguel, Yannick

    2016-04-01

    This paper will address the problem of scintillations characteristics, focusing on the parameters of interest for a navigation system. Those parameters are the probabilities of occurrence of simultaneous fading, the bubbles surface at IPP level, the cycle slips and the fades duration statistics. The scintillation characteristics obtained at low and high latitudes will be compared. These results correspond to the data analysis performed after the ESA Monitor ionosphere measurement campaign [1], [2]. A second aspect of the presentation will be the modelling aspect. It has been observed that the phase scintillation dominates at high latitudes while the intensity scintillation dominates at low latitudes. The way it can be reproduced and implemented in a propagation model (e.g. GISM model [3]) will be presented. Comparisons of measurements with results obtained by modelling will be presented on some typical scenarios. References [1] R. Prieto Cerdeira, Y. Beniguel, "The MONITOR project: architecture, data and products", Ionospheric Effects Symposium, Alexandria (Va), May 2011 [2] Y. Béniguel, R Orus-Perez , R. Prieto-Cerdeira , S. Schlueter , S. Scortan, A. Grosu "MONITOR 2: ionospheric monitoring network in support to SBAS and other GNSS and scientific purposes", IES Conference, Alexandria (Va), May 2015-05-22 [3] Y. Béniguel, P. Hamel, "A Global Ionosphere Scintillation Propagation Model for Equatorial Regions", Journal of Space Weather Space Climate, 1, (2011), doi: 10.1051/swsc/2011004

  9. Early onset of significant local warming in low latitude countries

    International Nuclear Information System (INIS)

    Mahlstein, I; Knutti, R; Solomon, S; Portmann, R W

    2011-01-01

    The Earth is warming on average, and most of the global warming of the past half-century can very likely be attributed to human influence. But the climate in particular locations is much more variable, raising the question of where and when local changes could become perceptible enough to be obvious to people in the form of local warming that exceeds interannual variability; indeed only a few studies have addressed the significance of local signals relative to variability. It is well known that the largest total warming is expected to occur in high latitudes, but high latitudes are also subject to the largest variability, delaying the emergence of significant changes there. Here we show that due to the small temperature variability from one year to another, the earliest emergence of significant warming occurs in the summer season in low latitude countries (∼25 deg. S-25 deg. N). We also show that a local warming signal that exceeds past variability is emerging at present, or will likely emerge in the next two decades, in many tropical countries. Further, for most countries worldwide, a mean global warming of 1 deg. C is sufficient for a significant temperature change, which is less than the total warming projected for any economically plausible emission scenario. The most strongly affected countries emit small amounts of CO 2 per capita and have therefore contributed little to the changes in climate that they are beginning to experience.

  10. Lidar measurements of mesospheric temperature inversion at a low latitude

    Directory of Open Access Journals (Sweden)

    V. Siva Kumar

    Full Text Available The Rayleigh lidar data collected on 119 nights from March 1998 to February 2000 were used to study the statistical characteristics of the low latitude mesospheric temperature inversion observed over Gadanki (13.5° N, 79.2° E, India. The occurrence frequency of the inversion showed semiannual variation with maxima in the equinoxes and minima in the summer and winter, which was quite different from that reported for the mid-latitudes. The peak of the inversion layer was found to be confined to the height range of 73 to 79 km with the maximum occurrence centered around 76 km, with a weak seasonal dependence that fits well to an annual cycle with a maximum in June and a minimum in December. The magnitude of the temperature deviation associated with the inversion was found to be as high as 32 K, with the most probable value occurring at about 20 K. Its seasonal dependence seems to follow an annual cycle with a maximum in April and a minimum in October. The observed characteristics of the inversion layer are compared with that of the mid-latitudes and discussed in light of the current understanding of the source mechanisms.

    Key words. Atmospheric composition and structure (pressure, density and temperature. Meterology and atmospheric dynamics (climatology

  11. Delay in solar energetic particle onsets at high heliographic latitudes

    Directory of Open Access Journals (Sweden)

    S. Dalla

    2003-06-01

    Full Text Available Ulysses observations have shown that solar energetic particles (SEPs can easily reach high heliographic latitudes. To obtain information on the release and propagation of SEPs prior to their arrival at Ulysses, we analyse the onsets of nine large high-latitude particle events. We measure the onset times in several energy channels, and plot them versus inverse particle speed. This allows us to derive an experimental path length and time of release from the solar atmosphere. We repeat the procedure for near-Earth observations by Wind and SOHO. We find that the derived path lengths at Ulysses are 1.06 to 2.45 times the length of a Parker spiral magnetic field line connecting the spacecraft to the Sun. The time of particle release from the Sun is between 100 and 350 min later than the release time derived from in-ecliptic measurements. We find no evidence of correlation between the delay in release and the inverse of the speed of the CME associated with the event, or the inverse of the speed of the corresponding interplanetary shock. The main parameter determining the magnitude of the delay appears to be the difference in latitude between the flare and the footpoint of the spacecraft.Key words. Interplanetary physics (energetic particles – Solar physics, astrophysics and astronomy (energetic particles, flares and mass ejections

  12. Titan's Stratospheric Condensibles at High Northern Latitudes During Northern Winter

    Science.gov (United States)

    Anderson, Carrie; Samuelson, R.; Achterberg, R.

    2012-01-01

    The Infrared Interferometer Spectrometer (IRIS) instrument on board Voyager 1 caught the first glimpse of an unidentified particulate feature in Titan's stratosphere that spectrally peaks at 221 per centimeter. Until recently, this feature that we have termed 'the haystack,' has been seen persistently at high northern latitudes with the Composite Infrared Spectrometer (CIRS) instrument onboard Cassini, The strength of the haystack emission feature diminishes rapidly with season, becoming drastically reduced at high northern latitudes, as Titan transitions from northern winter into spring, In contrast to IRIS whose shortest wavenumber was 200 per centimeter, CIRS extends down to 10 per centimeter, thus revealing an entirely unexplored spectral region in which nitrile ices have numerous broad lattice vibration features, Unlike the haystack, which is only found at high northern latitudes during northern winter/early northern spring, this geometrically thin nitrile cloud pervades Titan's lower stratosphere, spectrally peaking at 160 per centimeter, and is almost global in extent spanning latitudes 85 N to 600 S, The inference of nitrile ices are consistent with the highly restricted altitude ranges over which these features are observed, and appear to be dominated by a mixture of HCN and HC3N, The narrow range in altitude over which the nitrile ices extend is unlike the haystack, whose vertical distribution is significantly broader, spanning roughly 70 kilometers in altitude in Titan's lower stratosphere, The nitrile clouds that CIRS observes are located in a dynamically stable region of Titan's atmosphere, whereas CH4 clouds, which ordinarily form in the troposphere, form in a more dynamically unstable region, where convective cloud systems tend to occur. In the unusual situation where Titan's tropopause cools significantly from the HASI 70.5K temperature minimum, CH4 should condense in Titan's lower stratosphere, just like the aforementioned nitrile clouds, although

  13. Latitud sur y control económico del hogar por la mujer peruana

    Directory of Open Access Journals (Sweden)

    Federico R. León

    2011-12-01

    Full Text Available South latitude and household economic control by Peruvian women Southern women’s greater autonomy versus northern women’s more traditional submission to the husband were hypothesized in 1984 to explain variations in Peruvian women’s fertility desires. An analysis of data from Peru 2004-2008 Continuous Demographic and Family Health Survey supports this hypothesis by showing a significant north-to-south growth of women’s control upon husband’s income and, less consistently, household purchasing decisions. These relationships are not explained by variables also correlated with meridionality, such as aboriginal ethnicity, women’s material/informational power, age difference with the husband’s, or working for cash. Findings suggest new hypotheses, concerning the distribution of assertiveness and warmth in the Peruvian territory.

  14. The Abnormal Quiet Days in SQ(H) in Mid and Low Latitudes Regions

    African Journals Online (AJOL)

    From the analysis and study of abnormal quiet days (AQDs) at mid and low latitudes locations, it was found that there is difference between the characteristics of phase variability Sq (H) of the low latitude locations. This suggests that the origin and cause of AQDs are of different sources in the two latitude regions. The AQDs ...

  15. Polar Motion Studies and NOAA's Legacy of International Scientific Cooperation: Ukiah and Gaithersburg Latitude Observatories

    Science.gov (United States)

    Caccamise, D. J., II; Stone, W. A.

    2017-12-01

    In 1895, the International Geodetic Association invited the United States Coast and Geodetic Survey (USC&GS) to join in an unprecedented international effort to observe and measure the earth's polar motion. This effort was in response to the American astronomer Seth C. Chandler Jr. announcing his 1891 discovery that the earth's axis of rotation—and hence the direction of true north—wobbles within the earth with a period of about 14 months, varying latitude everywhere on the globe. In 1899, two astro-geodetic observatories were built in Gaithersburg, Maryland and Ukiah, California with three others in Caloforte, Italy; Kitab, Russia (now Uzbekistan); and Mizusawa, Japan. (A sixth station was located and operated at an astronomical observatory in Cincinnati, Ohio until 1916 using instruments loaned by USC&GS). All five observatories were located along the same parallel - approximately 35 degrees - 8 minutes. The observatories were decommissioned in 1982, and subsequently, NOAA deeded the two remaining U.S. observatories to the cities of Gaithersburg and Ukiah. The observatories and adjacent property were to be used as parkland. Both cities have restored the observatories and opened public parks. Recently, Gaithersburg (Ukiah in progress) has had its latitude observatory dedicated as a National Historic Landmark. In 2014-15, the National Geodetic Survey (NGS, the present-day NOAA successor to the USC&GS) loaned the original zenith telescopes to the communities, returning the observatories to their original configuration. The contribution of NOAA observers and the data collected is still important to astronomers and geophysicists and has practical applications in spacecraft navigation and geospatial positioning. This poster will bring to fruition this multiyear effort among partners by providing examples of NOAA's mission and contribution to science, service, and stewardship at both geodetic observatories, through programs and historic exhibits for students and the

  16. Spatially-Dependent Measurements of Surface and Near-Surface Radioactive Material Using In situ Gamma Ray Spectrometry (ISGRS) For Final Status Surveys

    Energy Technology Data Exchange (ETDEWEB)

    J. A. Chapman, A. J. Boerner, E. W. Abelquist

    2006-11-15

    In-situ, high-resolution gamma-ray spectrometry (ISGRS) measurements were conducted at the Oak Ridge Institute for Science and Education (ORISE) field laboratory in Oak Ridge, Tennessee. The purpose of these tests was to provide analytical data for assessing how “fit for use” this technology is for detecting discrete particles in soil.

  17. Spatially-Dependent Measurements of Surface and Near-Surface Radioactive Material Using In situ Gamma Ray Spectrometry (ISGRS) For Final Status Surveys

    International Nuclear Information System (INIS)

    J. A. Chapman, A. J. Boerner, E. W. Abelquist

    2006-01-01

    In-situ, high-resolution gamma-ray spectrometry (ISGRS) measurements were conducted at the Oak Ridge Institute for Science and Education ORISE field laboratory in Oak Ridge, Tennessee. The purpose of these tests was to provide analytical data for assessing how 'fit for use' this technology is for detecting discrete particles in soil

  18. Precision Survey of X-Rays from $\\overline{p}p (\\overline{p}d)$ Atoms Using the Initial LEAR Beam

    CERN Multimedia

    2002-01-01

    The experiment searches for the K and L X-ray series from @*p~(@*d) atoms, then measures their shift and width relative to QED predictions, and investigates their yields as a function of gas density. \\\\ \\\\ The @* are stopped in 1 atmosphere of H2 (D2) gas in a large aluminium flask whose 1 mm wall thickness eliminates externally produced low energy X-rays. The gas is cooled from a remote helium refrigerator and its temperature varied between 30|0K and 300|0K, giving a density range of 10 and large changes in relative line intensities. With 300~mm|2 area and 250~eV resolution FWHM at 5.9~keV, the Si(Li) X-ray detector penetrates the vacuum to come very close to a large beryllium window. Withstanding the large, charged particle flux from @*p annihilations has required special development of the Si(Li) detector. High purity metals are used for flask, window and detector end-housing to reduce background X-ray lines. A NaI ring suppresses the continuum background that comes principally from Compton scattering in t...

  19. Latitude variation of the diffuse component of the mean energy gamma radiation

    International Nuclear Information System (INIS)

    Espirito Santo, C.M. do.

    1981-03-01

    For determining the diffuse component of gamma ray in the 15 to 75 MeV range arriving from near the galactic center, a digitized spark chamber was launched aboard two balloons from Resende, Brazil on 19 November and 3 December 1975. In each flight the detector reached an altitude of 2,2 g.cm - 2 . Based on these data, we obtained a diffuse gamma ray flux 6,0 x 10 - 5 , 2,0 x 10 - 5 , 4,6 x 10 - 6 and 1,3 x 10 - 6 photons/cm 2 .s.sterad.MeV at energies of 21, 36, 52 and 67 MeV respectively. These values give a power law spectrum with spectral index equal to - 3,3. The dependence of this radiation with the galactic latitude and longitude in the interval - 5 0 0 and 325 0 0 was also obtained. Finally, results obtained were compared with other experimenters' results. (Author) [pt

  20. The geomagnetic cutoff rigidities at high latitudes for different solar wind and geomagnetic conditions

    International Nuclear Information System (INIS)

    Chu, W.; Univ. of Chinese Academy of Sciences, Beijing; Qin, G.

    2016-01-01

    Studying the access of the cosmic rays (CRs) into the magnetosphere is important to understand the coupling between the magnetosphere and the solar wind. In this paper we numerically studied CRs' magnetospheric access with vertical geomagnetic cutoff rigidities using the method proposed by Smart and Shea (1999). By the study of CRs' vertical geomagnetic cutoff rigidities at high latitudes we obtain the CRs' window (CRW) whose boundary is determined when the vertical geomagnetic cutoff rigidities drop to a value lower than a threshold value. Furthermore, we studied the area of CRWs and found out they are sensitive to different parameters, such as the z component of interplanetary magnetic field (IMF), the solar wind dynamic pressure, AE index, and Dst index. It was found that both the AE index and Dst index have a strong correlation with the area of CRWs during strong geomagnetic storms. However, during the medium storms, only AE index has a strong correlation with the area of CRWs, while Dst index has a much weaker correlation with the area of CRWs. This result on the CRW can be used for forecasting the variation of the cosmic rays during the geomagnetic storms.

  1. Seasonal dependence of high-latitude electric fields

    International Nuclear Information System (INIS)

    de la Beaujardiere, O.; Leger, C.; Alcayde, D.; Fontanari, J.

    1991-01-01

    The seasonal dependence of the high-latitude electric field was investigated using Sondrestrom incoherent scatter radar data. Average ExB drifts were derived from 5 years of measurements centered around solar minimum. The electrostatic potentials that best fit the observed average electric field were calculated. It was found that the large-scale convection pattern significantly changes with season. This change involves the overall shape of the convection pattern, as well as the electric field intensity, and thus the total dawn-dusk potential across the polar cap. The cross polar cap potential drop is largest in fall, followed by winter, spring and summer. The small difference found between the summer and winter cross polar cap potential can be attributed to differing field-aligned potential drops. In view of the well-known relationship between field-aligned currents and parallel potential drop, this is consistent with the observations that Birkeland currents are larger in the summer than in winter. Changes in the overall shape of the convection pattern are consistent with the simple notion that the whole pattern is shifted toward the nightside as well as, to a lesser extent, toward the dawnside in summer as compared to winter. This assumption is based on the following observed effects: (1) The rotation of the overall convection pattern toward earlier local times with respect to the noon-midnight direction is maximum for summer on the dayside. (2) On the nightside, the Harang discontinuity is typically located within the radar field of view (Λ=67 to 82) in the winter averaged patterns, but it is equatorward of the field of view in summer. (3) The line that joins the dawn and dusk potential maxima is shifted toward the midnight sector in summer as compared to winter by about 5 degree. (4) In the dawn cell, the latitude of the convection reversal is the lowest during summer; in the dusk cell the latitude of the reversal is the lowest during winter

  2. Containment test in area of high latitude and low temperature

    International Nuclear Information System (INIS)

    Cai Jiantao; Ni Yongsheng; Jia Wutong

    2014-01-01

    The effects of high latitude and low temperature on containment test are detailed analyzed from the view of design, equipment, construct and start-up, and the solution is put forward. The major problems resolved is as below: the effects of low temperature and high wind on defect inspection of the containment surface, the effects of test load on the affiliated equipment of containment in the condition of low temperature, and the effects of low temperature on the containment leak rate measurement. Application in Hongyanhe Unit 1 showed that the proposed scheme can effectively overcome the influence of adverse weather on the containment test. (authors)

  3. Photographic and photometric observations of mid-latitude red arcs

    International Nuclear Information System (INIS)

    Alekseev, V.N.; Ievenko, I.B.; Oshchepkov, S.M.; Ignat'ev, V.M.; Zhondorov, V.A.

    1989-01-01

    Stable auroral red arcs (SAR-arcs) were observed in Majmaga (Φ S ∼56.5deg) at the Yakutsk meridian in November-December, 1987 and February, 1988. The SAR-arcs were observed to the equator of diffuse glow, located at lower latitudes with respect to discrete auroral forms, obviously, in the external plasmospheric projection area. It is noted that they appear both in disturbed periods and in those with medium magnetic activity (K p =3). The SAR-arc height is ∼450km

  4. Earth's magnetosphere formed by the low-latitude boundary layer

    CERN Document Server

    Heikkila, W J

    2011-01-01

    The author argues that, after five decades of debate about the interactive of solar wind with the magnetosphere, it is time to get back to basics. Starting with Newton's law, this book also examines Maxwell's equations and subsidiary equations such as continuity, constitutive relations and the Lorentz transformation; Helmholtz' theorem, and Poynting's theorem, among other methods for understanding this interaction. Includes chapters on prompt particle acceleration to high energies, plasma transfer event, and the low latitude boundary layer More than 200 figures illustrate the text Includes a color insert.

  5. Signature of rapid subauroral ion drifts in the high-latitude ionosphere structure

    International Nuclear Information System (INIS)

    Galperin, Y.I.; Khalipov, V.L.; Filippov, V.M.

    1986-01-01

    Characteristics of fast subauroral ion drifts were studied for several cases where synchronous satellite measurements and ground-based ionospheric data from vertical and oblique-incidence sounding were available. Also some relevant data were analyzed concerning apparent irregularities drift velocity measurements by the multipoint spaced receiver at HF range (DI method). Changes of high-latitude ionosphere structure were investigated to identify the signature on the ionograms, and to provide a semiquantitative description of this phenomenon. It is shown that, above a particular station, the time development of the rapid subauroral ion drift band, or the ''polarization jet'' according to Galperin et al., 1973, 1974 in about 5-30 minutes leads to the formation of a trough which is narrow in latitude (approximately 100-200 km) but extended in longitude (several hours of MLT) and rather deep (N sub(emin)approximately 2.10 4 cm -3 in the electron density distribution in the F-region. Such narrow troughs can be observed in the evening sector superimposed on the undisturbed ionization density level, while in the near-midnight sector they contribute to the deepening of the preexisting, and much wider, main ionospheric through A qualitative scenario for the formation of the ''trough in the trough'' on the nightside, as a result of the increase of the loss processes related to rapid drift speed, is supported by ''synthetic'' ionograms deduced from numerical ray-tracing calculations for a model electron density distribution that is in reasonable accord with the observed vertical and oblique sounding ionograms and from satellite data

  6. Latitude-dependent delay in the responses of the equatorial electrojet and Sq currents to X-class solar flares

    Science.gov (United States)

    Nogueira, Paulo A. B.; Abdu, Mangalathayil A.; Souza, Jonas R.; Denardini, Clezio M.; Barbosa Neto, Paulo F.; Serra de Souza da Costa, João P.; Silva, Ana P. M.

    2018-01-01

    We have analyzed low-latitude ionospheric current responses to two intense (X-class) solar flares that occurred on 13 May 2013 and 11 March 2015. Sudden intensifications, in response to solar flare radiation impulses, in the Sq and equatorial electrojet (EEJ) currents, as detected by magnetometers over equatorial and low-latitude sites in South America, are studied. In particular we show for the first time that a 5 to 8 min time delay is present in the peak effect in the EEJ, with respect that of Sq current outside the magnetic equator, in response to the flare radiation enhancement. The Sq current intensification peaks close to the flare X-ray peak, while the EEJ peak occurs 5 to 8 min later. We have used the Sheffield University Plasmasphere-Ionosphere Model at National Institute for Space Research (SUPIM-INPE) to simulate the E-region conductivity enhancement as caused by the flare enhanced solar extreme ultraviolet (EUV) and soft X-rays flux. We propose that the flare-induced enhancement in neutral wind occurring with a time delay (with respect to the flare radiation) could be responsible for a delayed zonal electric field disturbance driving the EEJ, in which the Cowling conductivity offers enhanced sensitivity to the driving zonal electric field.

  7. The Nustar Extragalactic Surveys: The Number Counts of Active Galactic Nuclei and the Resolved Fraction of the Cosmic X-Ray Background

    DEFF Research Database (Denmark)

    Harrison, F. A.; Aird, J.; Civano, F.

    2016-01-01

    . The measured NuSTAR counts lie significantly abovesimple extrapolation with a Euclidian slope to low flux of the Swift/BAT 15–55 keV number counts measured at higher fluxes (S(15–55 keV) ≤ 10−11 erg s-1 cm-2), reflecting the evolution of the AGN population between the Swift/BAT local (z ...STAR’s z ~ 1 sample. CXB synthesis models, which account for AGNevolution, lie above the Swift/BAT measurements, suggesting that they do not fully capture the evolution of obscured AGNs at low redshifts....... cm-2 ≤ 10-12, a factor ∼100 fainter than previous measurements. The 8–24 keV number counts match predictions from AGN populationsynthesis models, directly confirming the existence of a population of obscured and/or hard X-ray sources inferredfrom the shape of the integrated cosmic X-ray background...

  8. Phonon-mediated distributed transition-edge-sensor X-ray detectors for surveys of galaxy clusters and the warm-hot interstellar medium

    International Nuclear Information System (INIS)

    Leman, Steven W.; Brink, Paul L.; Cabrera, Blas; Castle, Joseph P.; Chakraborty, Sudeepto; Deiker, Steve; Kahn, Steve; Martinez-Galarce, Dennis S.; Stern, Robert A.; Tomada, Astrid

    2006-01-01

    We are developing a novel phonon-mediated distributed-TES X-ray detector in which X-rays are absorbed in a large germanium or silicon crystal, and the energy is read out by four distributed TESs. This design takes advantage of existing TES technology while overcoming the difficulties of designing spatially large arrays. The sum of the four TES signals will yield energy resolution of E/δE∼1000 and the partitioning of energy between the four will yield position resolution of X/δX and Y/δY∼100. These macropixels, with advances in multiplexing, could be close-packed into 30x30 arrays equivalent to imaging instruments of 10 megapixels or more. We report on our progress to date and discuss its application to galaxy cluster searches and studies of the Warm-Hot Interstellar Medium

  9. Biomarkers of a Low-Latitude Neoproterozoic Glaciation

    Science.gov (United States)

    Olcott, A. N.; Sessions, A. L.; Corsetti, F. A.; Kaufman, A. J.

    2005-12-01

    Neoproterozoic low-latitude glaciations are often considered times of great biologic limitation because of the hypothesized presence of thick, global sea ice. Alternatively, climate models have suggested that tropical oceans could have remained ice-free, or covered by only thin sea ice, allowing life to continue unimpeded throughout the glaciations. The analysis of organic remains from synglacial sediments provides an approach to address the debate. Here we describe molecular, isotopic, and petrographic analyses of organic rich strata (up to 3.0 percent TOC) deposited in southeastern Brazil during Neoproterozoic low-latitude glaciation ca. 700 Ma. These strata contain extractable biomarkers, including 2-α-methyl hopanes, 2,3,6-trimethylarylisoprenoids, C29-C31 hopanes, and C27-C29 steranes. The preserved biomarkers reflect the presence of a complex and productive ecosystem comprised of both aerobic and anaerobic phototrophs, heterotrophs, and eukaryotes. The biomarker data indicate euxinia extending into the photic zone, providing evidence that the oceans were strongly stratified. Significantly, the occurrence of photosynthetic cyanobacteria and green sulfur bacteria at this time indicates that sea-ice cover at this location was thin to nonexistent, and is incompatible with models for snowball Earth that envision kilometers of ice thickness.

  10. Space weather at Low Latitudes: Considerations to improve its forecasting

    Science.gov (United States)

    Chau, J. L.; Goncharenko, L.; Valladares, C. E.; Milla, M. A.

    2013-05-01

    In this work we present a summary of space weather events that are unique to low-latitude regions. Special emphasis will be devoted to events that occur during so-called quiet (magnetically) conditions. One of these events is the occurrence of nighttime F-region irregularities, also known Equatorial Spread F (ESF). When such irregularities occur navigation and communications systems get disrupted or perturbed. After more than 70 years of studies, many features of ESF irregularities (climatology, physical mechanisms, longitudinal dependence, time dependence, etc.) are well known, but so far they cannot be forecast on time scales of minutes to hours. We present a summary of some of these features and some of the efforts being conducted to contribute to their forecasting. In addition to ESF, we have recently identified a clear connection between lower atmospheric forcing and the low latitude variability, particularly during the so-called sudden stratospheric warming (SSW) events. During SSW events and magnetically quiet conditions, we have observed changes in total electron content (TEC) that are comparable to changes that occur during strong magnetically disturbed conditions. We present results from recent events as well as outline potential efforts to forecast the ionospheric effects during these events.

  11. Ionosonde observations of daytime spread F at low latitudes

    Science.gov (United States)

    Jiang, Chunhua; Yang, Guobin; Liu, Jing; Yokoyama, Tatsuhiro; Komolmis, Tharadol; Song, Huan; Lan, Ting; Zhou, Chen; Zhang, Yuannong; Zhao, Zhengyu

    2016-12-01

    Spread F on ionograms has been considered to be a phenomenon mainly occurred at nighttime. This study presented a case study of daytime spread F observed by the ionosonde installed at Puer (PUR; 22.7°N, 101.05°E; dip latitude 12.9°N), where daytime spread F that lasted for more than 2 h (about 08:30 LT 10:45 LT) was observed on 14 November 2015. To investigate the possible mechanism, ionograms recorded at PUR and Chiang Mai (18.76°N, 98.93°E; dip latitude 9.04°N) were used in this study. We found that traveling ionospheric disturbances were observed before the occurrence of daytime spread F. Meanwhile, the movement of the peak height of the ionosphere was downward. We suggested that downward vertical neutral winds excited by traveling atmospheric disturbances/atmospheric gravity waves might play a significant role in forming daytime spread F over PUR during geomagnetic storms.

  12. High-latitude molecular clouds and infrared cirrus

    International Nuclear Information System (INIS)

    Vries, H.W. de.

    1988-01-01

    The high-latitude infrared cirrus detected by IRAS is identified with atomic and molecular clouds. These clouds are small (usually less than 1 sq. deg.) and show weak CO emission. On the basis of a distance of 100 pc they are characterized by a mass of a few solar masses and a radius of about 1 pc. Thermal radiation by dust as a results of heating by the diffuse interstellar radiation field is the most-plausible origin of the cirrus emission at far-infrared wavelengths. On the basis of plausible assumptions regarding the uniformity of both the gas-to-dust ratio and the heating and cooling of the dust, the flux density at 100 μm from regions with low visual extinction should be a good tracer of the gas column density. Indeed, the data show an approximately linear proportionality between N(HI), obtained from 21-cm observations, and I 100 (HI), the flux density from dust associated with HI. If the ratio of column density to flux density in high-latitude molecular clouds is equal to the corresponding relation in atomic ones, a value for the ratio of H 2 column density to CO velocity-integrated radiation temperature may be obtained. Although low-mass clouds may be large in number, the fraction of the Galactic molecular mass in the form of these clouds is probably no more than 1%

  13. The NuSTAR serendipitous survey: the 40-month catalog and the properties of the distant high-energy X-ray source population

    DEFF Research Database (Denmark)

    Lansbury, G. B.; Stern, D.; Aird, J.

    2017-01-01

    We present the first full catalog and science results for the Nuclear Spectroscopic Telescope Array (NuSTAR) serendipitous survey. The catalog incorporates data taken during the first 40 months of NuSTAR operation, which provide ≈20 Ms of effective exposure time over 331 fields, with an areal cov...

  14. A medium-deep Chandra and Subaru survey of the 13-h XMM/ROSAT deep survey area

    Science.gov (United States)

    McHardy, I. M.; Gunn, K. F.; Newsam, A. M.; Mason, K. O.; Page, M. J.; Takata, T.; Sekiguchi, K.; Sasseen, T.; Cordova, F.; Jones, L. R.; Loaring, N.

    2003-07-01

    We present the results of a Chandra ACIS-I survey of a high-latitude region at 13 h +38° which was earlier observed with ROSAT and which has recently been observed by XMM-Newton for 200 ks. XMM-Newton will provide good-quality X-ray spectra for over 200 sources with fluxes around the knee of the log N/ log S, which are responsible for the bulk of the X-ray background. The main aim of the Chandra observations is to provide arcsecond, or better, positions, and hence reliable identifications, for the XMM-Newton sources. The ACIS-I observations were arranged in a mosaic of four 30-ks pointings, covering almost all of the 15-arcmin radius XMM-Newton/ROSAT field. We detect 214 Chandra sources above a Cash likelihood statistic of 25, which approximates to 5σ significance, to a limiting flux of ~1.3 × 10-15 erg cm-2 s-1 (0.5-7 keV). Optical counterparts are derived from a Subaru SuprimeCam image reaching to R~ 27. The very large majority of the Chandra sources have an optical counterpart, with the distribution peaking at 23 high LX/Lopt ratios, implying absorption at moderate redshift. Comparison with the earlier ROSAT survey shows that the accuracy of the ROSAT positions agrees very well with the predictions from simulations by McHardy et al. and that the large majority of the identifications were correct.

  15. The 2HWC HAWC Observatory Gamma-Ray Catalog

    Energy Technology Data Exchange (ETDEWEB)

    Abeysekara, A. U.; Barber, A. S. [Department of Physics and Astronomy, University of Utah, Salt Lake City, UT (United States); Albert, A. [Physics Division, Los Alamos National Laboratory, Los Alamos, NM (United States); Alfaro, R.; Becerril, A.; Belmont-Moreno, E. [Instituto de Física, Universidad Nacional Autónoma de México, Mexico City (Mexico); Alvarez, C.; Arceo, R.; Caballero-Mora, K. S. [Universidad Autónoma de Chiapas, Tuxtla Gutiérrez, Chiapas (Mexico); Álvarez, J. D.; Arteaga-Velázquez, J. C. [Universidad Michoacana de San Nicolás de Hidalgo, Morelia (Mexico); Solares, H. A. Ayala; Brisbois, C. [Department of Physics, Michigan Technological University, Houghton, MI (United States); Baughman, B.; Berley, D. [Department of Physics, University of Maryland, College Park, MD (United States); Bautista-Elivar, N. [Universidad Politecnica de Pachuca, Pachuca, Hidalgo (Mexico); Gonzalez, J. Becerra [NASA Goddard Space Flight Center, Greenbelt, MD (United States); BenZvi, S. Y. [Department of Physics and Astronomy, University of Rochester, Rochester, NY (United States); Bernal, A. [Instituto de Astronomía, Universidad Nacional Autónoma de México, Mexico City (Mexico); Braun, J., E-mail: riviere@umdgrb.umd.edu [Department of Physics, University of Wisconsin-Madison, Madison, WI (United States); and others

    2017-07-01

    We present the first catalog of TeV gamma-ray sources realized with data from the newly completed High Altitude Water Cherenkov Observatory (HAWC). It is the most sensitive wide field-of-view TeV telescope currently in operation, with a one-year survey sensitivity of ∼5%–10% of the flux of the Crab Nebula. With an instantaneous field of view >1.5 sr and >90% duty cycle, it continuously surveys and monitors the sky for gamma-ray energies between hundreds of GeV and tens of TeV. HAWC is located in Mexico, at a latitude of 19° N, and was completed in 2015 March. Here, we present the 2HWC catalog, which is the result of the first source search performed with the complete HAWC detector. Realized with 507 days of data, it represents the most sensitive TeV survey to date for such a large fraction of the sky. A total of 39 sources were detected, with an expected number of false detections of 0.5 due to background fluctuation. Out of these sources, 19 are new sources that are not associated with previously known TeV sources (association criteria: <0.°5 away). The source list, including the position measurement, spectrum measurement, and uncertainties, is reported, then each source is briefly discussed. Of the 2HWC associated sources, 10 are reported in TeVCat as PWN or SNR: 2 as blazars and the remaining eight as unidentified.

  16. A statistical survey of x-ray CT cases at the Clinic of Oral and Maxillofacial Radiology, Chiba Hospital, Tokyo Dental College

    International Nuclear Information System (INIS)

    Kitagawa, Hiromi; Wakoh, Mamoru; Shibuya, Hitoshi; Yamada, Masayuki; Harada, Takuya; Yamamoto, Kazuhiro; Makihara, Masahiro; Kuroyanagi, Kinya

    1997-01-01

    Statistical study was performed of x-ray CT cases at the Clinic of Oral and Maxillofacial Radiology, Chiba Hospital, Tokyo Dental College since a Toshiba CT Scanner TCT-700S was settled in 1988, until December 1994. Total number of cases photographed was 2645 cases, Male; 1447 (54.7%), Female; 1198 cases (45.3%). Total number of cases yearly photographed have increased every year. 95.43% of the cases were the diseases of oral surgery regions. X-ray CT has been used to malignant tumors (730 cases; 29.7%), cyst (435 cases; 17.7%), inflammation (362 cases; 14.7%), benign tumors (261 cases; 10.6%), injury (171 cases; 7.0%), salivary gland diseases (126 cases; 5.1%) and others. The number of tumors and cyst have been increasing every year. Average number of slices in every diseases were counted. Malignant tumor, injury, temporomandibular joint diseases, and congenital anomalies and malformations were counted many slices. Percentages of number of enhanced CT cases have been increased every year. Recently, number of enhanced CT cases have more number than non-enhanced CT cases. This attitude is correlated with the number of malignant tumors which have been increasing every year. Total number of cases of three dimensional imaging CT (3D-CT) was 316 cases. 3D-CT has been used to injury (146 cases; 46.2%), temporomandibular joint diseases (52 cases; 16.4%), congenital anomalies and malformations (49 cases; 15.5%), tumors (21 cases; 6.7%), cyst (13 cases; 4.1%) and others. The need of x-ray CT in our field and the tendency of dental treatment at Chiba Hospital might be changed in the future. In order to this situation, this type of statistical study will be performed again. (author)

  17. Tropical influence on boreal summer mid-latitude stationary waves

    Energy Technology Data Exchange (ETDEWEB)

    Douville, Herve [Meteo-France/CNRM-GAME, Toulouse (France); CNRM/GMGEC/VDR, Toulouse (France); Bielli, S.; Deque, M.; Tyteca, S.; Voldoire, A. [Meteo-France/CNRM-GAME, Toulouse (France); Cassou, C. [CNRS-Cerfacs, Toulouse (France); Hall, N.M.J. [CNES/LEGOS, Toulouse (France)

    2011-11-15

    While organized tropical convection is a well-known source of extratropical planetary waves, state-of-the-art climate models still show serious deficiencies in simulating accurately the atmospheric response to tropical sea surface temperature (SST) anomalies and the associated teleconnections. In the present study, the remote influence of the tropical atmospheric circulation is evaluated in ensembles of global boreal summer simulations in which the Arpege-Climat atmospheric General Circulation Model (GCM) is nudged towards 6-h reanalyses. The nudging is applied either in the whole tropical band or in a regional summer monsoon domain. Sensitivity tests to the experimental design are first conducted using prescribed climatological SST. They show that the tropical relaxation does not improve the zonal mean extratropical climatology but does lead to a significantly improved representation of the mid-latitude stationary waves in both hemispheres. Low-pass filtering of the relaxation fields has no major effect on the model response, suggesting that high-frequency tropical variability is not responsible for extratropical biases. Dividing the nudging strength by a factor 10 only decreases the magnitude of the response. Model errors in each monsoon domain contribute to deficiencies in the model's mid-latitude climatology, although an exaggerated large-scale subsidence in the central equatorial Pacific appears as the main source of errors for the representation of stationary waves in the Arpege-Climat model. Case studies are then conducted using either climatological or observed SST. The focus is first on summer 2003 characterized by a strong and persistent anticyclonic anomaly over western Europe. This pattern is more realistic in nudging experiments than in simulations only driven by observed SST, especially when the nudging domain is centred over Central America. Other case studies also show a significant tropical forcing of the summer mid-latitude stationary waves

  18. NURE aerial gamma-ray and magnetic reconnaissance survey: NE Washington area, Okanogan NM 11-10, Sandpoint NM 11-11 Quadrangles. Volume I. Narrative report

    Energy Technology Data Exchange (ETDEWEB)

    1979-08-01

    As part of the Department of Energy (DOE) National Uranium Resource Evaluation (NURE) Program, LKB Resources, Inc. has performed a rotary-wing, reconnaissance high sensitivity radiometric and magnetic survey in north-east Washington. Three 1:250,000 scale NTMS quadrangles (Spokane, Sandpoint, and Okanogan) were surveyed. A total of 14,421 line miles (23,203 kilometers) of data were collected utilizing a Sikorsky S58T helicopter. Traverse lines were flown in an east-west direction at 1.0 and 3.0 mile (1.6 and 4.8 kilometers) spacing, with tie lines flown in a north-south direction at 12 mile (20 kilometer) spacing. The data were digitally recorded at 1.0 second intervals. The NaI terrestrial detectors used in this survey had a total volume of 2,154 cubic inches. The magnetometer employed was a modified ASQ-10 fluxgate system. This report covers only the Okanogan and Sandpoint 1:250,000 scale NTMS quadrangles. Spokane 1:250,000 scale NTMS quadrangle is covered in a separate report. The radiometric data were normalized to 400 feet terrain clearance. The data are presented in the form of computer listings on microfiche and as stacked profile plots. Profile plots are contained in Volume II of this report. A geologic interpretation of the radiometric and magnetic data is included as part of this report.

  19. NURE aerial gamma-ray and magnetic reconnaissance survey: NE Washington area, Okanogan NM 11-10, Sandpoint NM 11-11 Quadrangles. Volume I. Narrative report

    International Nuclear Information System (INIS)

    1979-08-01

    As part of the Department of Energy (DOE) National Uranium Resource Evaluation (NURE) Program, LKB Resources, Inc. has performed a rotary-wing, reconnaissance high sensitivity radiometric and magnetic survey in north-east Washington. Three 1:250,000 scale NTMS quadrangles (Spokane, Sandpoint, and Okanogan) were surveyed. A total of 14,421 line miles (23,203 kilometers) of data were collected utilizing a Sikorsky S58T helicopter. Traverse lines were flown in an east-west direction at 1.0 and 3.0 mile (1.6 and 4.8 kilometers) spacing, with tie lines flown in a north-south direction at 12 mile (20 kilometer) spacing. The data were digitally recorded at 1.0 second intervals. The NaI terrestrial detectors used in this survey had a total volume of 2,154 cubic inches. The magnetometer employed was a modified ASQ-10 fluxgate system. This report covers only the Okanogan and Sandpoint 1:250,000 scale NTMS quadrangles. Spokane 1:250,000 scale NTMS quadrangle is covered in a separate report. The radiometric data were normalized to 400 feet terrain clearance. The data are presented in the form of computer listings on microfiche and as stacked profile plots. Profile plots are contained in Volume II of this report. A geologic interpretation of the radiometric and magnetic data is included as part of this report

  20. An X-ray survey of hot white dwarf stars - Evidence for a m(He)/n(H) versus Teff correlation

    Science.gov (United States)

    Petre, R.; Shipman, H. L.; Canizares, C. R.

    1986-01-01

    Observations of 13 white dwarf and subdwarf stars using the Einstein Observatory High Resolution Image are reported. Included are stars of classes DA, DB, DAV, sDO, and sDB, with optically determined effective temperatures in the range 10,000-60,000 K. X-ray emission was detected from two of the 13: the very hot (55,000 K) DA1 star WD 2309 + 105 (= EG 233), with a count rate one-fifth that of HZ 43, and the relatively cool (26,000 K) DA3 star WD 1052 - 273 (=GD 125). The effective temperatures determined from ultraviolet and optical observations were used to place limits on the He content of the white dwarf photospheres, presuming that trace photospheric He is the missing opacity source which quenches the thermal X-rays in these stars. When presently obtained results were combined with those available from the literature evidence was found for a correlation between Teff and n(He)/n(H), in which HZ 43 is a conspicuous exception to the general trend. Both this correlation and the exceptional behavior of HZ 43 are qualitatively accounted for by a radiative acceleration model, in which the rate of upward movement of the He is a function of temperature and surface gravity

  1. Suzaku  Observations of Heavily Obscured (Compton-thick) Active Galactic Nuclei Selected by the Swift/BAT Hard X-Ray Survey

    Science.gov (United States)

    Tanimoto, Atsushi; Ueda, Yoshihiro; Kawamuro, Taiki; Ricci, Claudio; Awaki, Hisamitsu; Terashima, Yuichi

    2018-02-01

    We present a uniform broadband X-ray (0.5–100.0 keV) spectral analysis of 12 Swift/Burst Alert Telescope selected Compton-thick ({log}{N}{{H}}/{{cm}}-2≥slant 24) active galactic nuclei (CTAGNs) observed with Suzaku. The Suzaku data of three objects are published here for the first time. We fit the Suzaku and Swift spectra with models utilizing an analytic reflection code and those utilizing the Monte-Carlo-based model from an AGN torus by Ikeda et al. The main results are as follows: (1) The estimated intrinsic luminosity of a CTAGN strongly depends on the model; applying Compton scattering to the transmitted component in an analytic model may largely overestimate the intrinsic luminosity at large column densities. (2) Unabsorbed reflection components are commonly observed, suggesting that the tori are clumpy. (3) Most of CTAGNs show small scattering fractions (<0.5%), implying a buried AGN nature. (4) Comparison with the results obtained for Compton-thin AGNs suggests that the properties of these CTAGNs can be understood as a smooth extension from Compton-thin AGNs with heavier obscuration; we find no evidence that the bulk of the population of hard-X-ray-selected CTAGNs are different from less obscured objects.

  2. Statistical survey of ten criteria established by Portaria 453 of Brazilian Ministry of Health for dentists who use X-rays

    International Nuclear Information System (INIS)

    Almeida, Claudio Domingues de

    2005-01-01

    In July 1998, the Ministry of Health (MS) published the Guidelines for Radiological Protection in Medical and Dental Radiodiagnosis that became known as Portaria 453 - Ordinance 453. This study is designed to evaluate the dentists of Rio de Janeiro on the knowledge and application of the criteria laid down by Ordinance. For this, it was sent to dentists, a form with 13 questions. The issues are related to the use of personal protective clothing (VPI), working procedures for the exam and processing of the image, radioprotection training and quality control. Of 1528 dentists, only 40% have a copy of the Ordinance. Regarding the use of VPI, 94% has lead apron and 76% thyroid shield. Only 63% of dentists observe patients during exposure to X-rays. In 96% of doctor's rooms the revelation of the film is made in a portable box, 71% of these use the visual method to stop processing. The results show the need for greater dissemination of the Ordinance by the odontologist's associations; for an educational work on the topics discussed and training that allow the dentists be prepared to apply the correct work procedures in the production of diagnostic imaging with X-rays

  3. Vorticity and divergence in the high-latitude upper thermosphere

    International Nuclear Information System (INIS)

    Thayer, J.P.; Killeen, T.L.

    1991-01-01

    Measurements made from the Dynamics Explorer-2 satellite in November 1981 through January 1982 and November 1982 through January 1983 have been analyzed to determine the divergence and vertical component of vorticity of the high-latitude neutral wind field in the upper thermosphere for quiet (kp≤6) geomagnetic conditions and for both northern (winter) and southern (summer) hemispheres in the polar thermosphere and provides insight into the relative strengths of the different sources of momentum and energy responsible for driving the winds. The principal findings from this work include the following: The mean neutral wind pattern is dominated by rotational flow rather than by divergent flow, with a typical vorticity: divergence ratio of ∼ 2:1 for active conditions and ∼ 4:1 for quiet conditions. Comparison of the divergence and vorticity patterns for quiet and active conditions indicates that the divergent component of the neutral flow intensifies more significantly with increasing geomagnetic activity than does the rotational component

  4. CONDITIONED ANALYSIS OF HIGH-LATITUDE SOLAR WIND INTERMITTENCY

    International Nuclear Information System (INIS)

    D'Amicis, R.; Consolini, G.; Bavassano, B.; Bruno, R.

    2012-01-01

    The solar wind is a turbulent medium displaying intermittency. Its intermittent features have been widely documented and studied, showing how the intermittent character is different in fast and slow wind. In this paper, a statistical conditioned analysis of the solar wind intermittency for a period of high-latitude fast solar wind is presented. In particular, the intermittent features are investigated as a function of the Alfvénic degree of fluctuations at a given scale. The results show that the main contribution to solar wind intermittency is due to non-Alfvénic structures, while Alfvénic increments are found to be characterized by a smaller level of intermittency than the previous ones. Furthermore, the lifetime statistics of Alfvénic periods are discussed in terms of a multiscale texture of randomly oriented flux tubes.

  5. Microinstabilities in the high latitude F region: a brief review

    International Nuclear Information System (INIS)

    Gary, S.P.

    1983-01-01

    This is a review of the theory of plasma microinstabilities that may arise in the high latitude F region ionosphere below 1000 km. Three free energy sources are considered: a density gradient perpendicular to the ambient magnetic field B, a current parallel to B and a steady electric field perpendicular to B. The BGK model for charged-neutral collisions is used, and the short wavelength properties of the universal density drift, current convective and E x B gradient drift instabilities are compared. At sufficiently high altitudes and sufficiently steep gradients, the universal instability is the short wavelength mode most likely to grow and, through wave-particle diffusion, to cause relatively steep wavenumber dependences in power spectra

  6. Low-latitude ionospheric disturbances associated with earthquakes

    Energy Technology Data Exchange (ETDEWEB)

    Depueva, A.; Rotanova, N. [Russian Academy of Sciences, Inst. of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation, Moscow (Russian Federation)

    2001-04-01

    Topside electron density measured on satellite board was analysed. It was shown that before the two considered earthquakes with their epicenters located at low and equatorial latitudes the stable modification of the ionosphere both at and above the height of the F-layer peak was observed. Electron density gradually decreased and its spatial distribution looked like a funnel located either immediately over the epicenter or from its one side. Electron density irregularities of 300-500 km size in a meridional direction also occurred side by side with aforesaid background large-scale depletions. For detection of local structures of more than 1000 km extent, the method of natural orthogonal component expansion was applied; spectra of smaller scale inhomogeneities were investigated by means of the Blackman-Tukey method. A proposal is made for observed experimental data interpretation.

  7. A polarized fast radio burst at low Galactic latitude

    OpenAIRE

    Petroff, E.; Kasliwal, M.; Ravi, V.

    2017-01-01

    We report on the discovery of a new fast radio burst (FRB), FRB 150215, with the Parkes radio telescope on 2015 February 15. The burst was detected in real time with a dispersion measure (DM) of 1105.6 ± 0.8 pc cm^(−3), a pulse duration of 2.8 ^(+1.2)_(−0.5)ms, and a measured peak flux density assuming that the burst was at beam centre of 0.7 ^(+0.2)_(−0.1) Jy. The FRB originated at a Galactic longitude and latitude of 24.66°, 5.28° and 25° away from the Galactic Center. The burst was found t...

  8. A High Galactic Latitude HI 21 cm-line Absorption Survey using the ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    using the NRAO 3-element interferometer. They obtained the corresponding HI emission using the Effelsberg 100 m telescope, the 91 m Green ..... of sight obtained from the Galactic rotation model by Brand & Blitz (1993). We have used R0 = 8.5 Kpc as the Galacto-centric distance and 0 = 220 km s−1 as the solar orbital ...

  9. Latitude gradient influences the age of onset of rheumatoid arthritis: a worldwide survey

    NARCIS (Netherlands)

    Ramos-Remus, Cesar; Ramirez-Gomez, Andrea; Brambila-Barba, Victor; Barajas-Ochoa, Aldo; Castillo-Ortiz, Jose D.; Adebajo, Adewale O.; Espinoza, Luis R.; Aceves-Avila, Francisco J.; Sánchez-González, Jorge M.; Boudersa, Nadia; Slimani, Samy; Ladjouze-Rezig, Aicha; Diaz, Mónica P.; Kirmayr, Karin I.; Asnal, Cecilia A.; Catoggio, Luis J.; Citera, Gustavo; Casado, Gustavo C.; Alvarez, Analia P.; Pisoni, Cecilia N.; Benavente, Emilio; Lopez-Cabanillas, Adriana; Baez, Roberto M.; Pons-Estel, Bernardo A.; Sacnún, Mónica P.; Cavallasca, Javier A.; Paniego, Raúl H.; Proudman, Susanna M.; Thomas, Ranjeny; Major, Gabor; Mathers, David M.; Schrieber, Leslie; Haq, Syed A.; Islam, Nazrul; Dessein, Patrick H.; von Muhlen, Carlos A.; Bianchi, Washington A.; da R Castelar-Pinheiro, Geraldo; Feldman-Pollak, Daniel; Cossermelli, Waldenise; Bonfiglioli, Karina R.; Giorgi, Rina D.; Zabsonre-Tiendrebeogo, Wendlassida J.; Russell, Anthony S.; Olaru, Lilia; Karsh, Jacob; Fuentealba, Carlos; Aguilera, Sergio; de Vries, Niek; van Vollenhoven, Ronald F.

    2017-01-01

    The age of onset of rheumatoid arthritis (RA) is an important outcome predictor. Northern countries report an age of RA onset of around 50 years, but apparently, variability exists across different geographical regions. The objective of the present study is to assess whether the age of onset of RA

  10. New Particle Formation in the Mid-Latitude Upper Troposphere

    Science.gov (United States)

    Axisa, Duncan

    Primary aerosol production due to new particle formation (NPF) in the upper troposphere and the impact that this might have on cloud condensation nuclei (CCN) concentration can be of sufficient magnitude to contribute to the uncertainty in radiative forcing. This uncertainty affects our ability to estimate how sensitive the climate is to greenhouse gas emissions. Therefore, new particle formation must be accurately defined, parametrized and accounted for in models. This research involved the deployment of instruments, data analysis and interpretation of particle formation events during the Mid-latitude Airborne Cirrus Properties Experiment (MACPEX) campaign. The approach combined field measurements and observations with extensive data analysis and modeling to study the process of new particle formation and growth to CCN active sizes. Simultaneous measurements of O3, CO, ultrafine aerosol particles and surface area from a high-altitude research aircraft were used to study tropospheric-stratospheric mixing as well as the frequency and location of NPF. It was found that the upper troposphere was an active region in the production of new particles by gas-to-particle conversion, that nucleation was triggered by convective clouds and mixing processes, and that NPF occurred in regions with high relative humidity and low surface area. In certain cases, mesoscale and synoptic features enhanced mixing and facilitated the formation of new particles in the northern mid-latitudes. A modeling study of particle growth and CCN formation was done based on measured aerosol size distributions and modeled growth. The results indicate that when SO2 is of sufficient concentration NPF is a significant source of potential CCN in the upper troposphere. In conditions where convective cloud outflow eject high concentrations of SO2, a large number of new particles can form especially in the instance when the preexisting surface area is low. The fast growth of nucleated clusters produces a

  11. Low-latitude ionospheric turbulence observed by Aureol-3 satellite

    Directory of Open Access Journals (Sweden)

    Y. Hobara

    2005-06-01

    Full Text Available Using PSD (Power Spectral Density data on electron density and electric field variations observed on board Aureol-3 satellite at low-to-mid-latitude ionosphere we analyze a scale distribution of the ionospheric turbulence in a form k, where k is the wave number and α is the spectral index. At first, high-resolution data in the near-equator region for several orbits have been processed. In this case the frequency range is from 6Hz to 100Hz (corresponding spatial scales from 80m to 1.3km, each power spectrum obeys a single power law fairly well, and the mean spectral indices are rather stable with αN=2.2±0.3 and αE=1.8±0.2, for the density and electric field, respectively. Then we produce a statistical study of 96 electric field bursts in the frequency range 10-100Hz from low-time resolution data (filter bank envelope. These bursts concentrate on the side of the Equatorial Anomaly crest (geomagnetic latitude 30-40°. Spectral indices of the bursts vary in the interval αE=2.0-2.5 but are fairly stable in seasons and local times. The electric field power of the burst has rather a large variability but has a relative increase in mean values for the summer and winter, as well as the daytime. The effect of major seismic activities toward the ionospheric turbulence is not conclusive either for the refractive index or for the electric field power. However, the mean value for the electric field power of bursts during seismic periods is larger than that for non seismic periods, and the statistical difference of the mean values is rather significant.

  12. Low-latitude ionospheric turbulence observed by Aureol-3 satellite

    Directory of Open Access Journals (Sweden)

    Y. Hobara

    2005-06-01

    Full Text Available Using PSD (Power Spectral Density data on electron density and electric field variations observed on board Aureol-3 satellite at low-to-mid-latitude ionosphere we analyze a scale distribution of the ionospheric turbulence in a form k-α, where k is the wave number and α is the spectral index. At first, high-resolution data in the near-equator region for several orbits have been processed. In this case the frequency range is from 6Hz to 100Hz (corresponding spatial scales from 80m to 1.3km, each power spectrum obeys a single power law fairly well, and the mean spectral indices are rather stable with αN=2.2±0.3 and αE=1.8±0.2, for the density and electric field, respectively. Then we produce a statistical study of 96 electric field bursts in the frequency range 10-100Hz from low-time resolution data (filter bank envelope. These bursts concentrate on the side of the Equatorial Anomaly crest (geomagnetic latitude 30-40°. Spectral indices of the bursts vary in the interval αE=2.0-2.5 but are fairly stable in seasons and local times. The electric field power of the burst has rather a large variability but has a relative increase in mean values for the summer and winter, as well as the daytime. The effect of major seismic activities toward the ionospheric turbulence is not conclusive either for the refractive index or for the electric field power. However, the mean value for the electric field power of bursts during seismic periods is larger than that for non seismic periods, and the statistical difference of the mean values is rather significant.

  13. Daylighting in linear atrium buildings at high latitudes

    Energy Technology Data Exchange (ETDEWEB)

    Matusiak, Barbara

    1998-12-31

    This thesis proposes new criteria for visual comfort based on knowledge of visual perception and a method for estimating the modelling ability of light by using inter-reflection calculations. Simplified calculations are presented for the daylight factor in linear building structures, using the projected solid angle principle, for uniform sky and for CIE overcast sky conditions. The calculations are compared with experimental results. Simple diagrams are created based on calculations of the mean daylight factor in rooms adjacent to a narrow street. These diagrams and presented formulas and tables can be used as a simple design tool. Daylighting strategies for linear atrium buildings at high latitudes are developed and examined. These strategies are divided into three groups: (1) the atrium space and facades as light conductor/reflector, (2) the glass roof as a light conductor, and (3) light reflectors on the neighbouring roof. The atrium space and facade strategies are subdivided into passive and active. The strategies connected to the glazed roof includes different configurations of glazing: horizontal, single pitched, double pitched, and the use of laser cut panels and prismatic panels in the glazed roof. The shapes of reflectors on the neighbouring roof are a flat reflector, a parabolic reflector and a parabolic concentrator. Strategies from all three groups are examined on a physical model of scale 1:20 in the artificial sky of mirror box type. Simulations with artificial sun have also been done. The results from model studies are compared with computer simulations. All the active daylighting systems designed for use in the atrium space or on the atrium facades have a huge potential for use in atrium buildings. From the strategies connected with the glazed roof the negatively sloped glass is found to be the best alternative for glazed roofs at high latitudes. Among the roof reflectors, the flat one performs best. 82 refs., 122 figs., 27 tabs.

  14. Ground level cosmic ray observations

    Energy Technology Data Exchange (ETDEWEB)

    Stephens, S.A. [Tata Institute of Fundamental Research, Bombay (International Commission on Radiation Units and Measurements); Grimani, C.; Brunetti, M.T.; Codino, A. [Perugia Univ. (Italy)]|[INFN, Perugia (Italy); Papini, P.; Massimo Brancaccio, F.; Piccardi, S. [Florence Univ. (Italy)]|[INFN, Florence (Italy); Basini, G.; Bongiorno, F. [INFN, Laboratori Nazionali di Frascati, Rome (Italy); Golden, R.L. [New Mexico State Univ., Las Cruces, NM (United States). Particle Astrophysics Lab.; Hof, M. [Siegen Univ. (Germany). Fachbereich Physik

    1995-09-01

    Cosmic rays at ground level have been collected using the NMSU/Wizard - MASS2 instrument. The 17-hr observation run was made on September 9. 1991 in Fort Sumner, New Mexico, Usa. Fort Sumner is located at 1270 meters a.s.l., corresponding to an atmospheric depth of about 887 g/cm{sup 2}. The geomagnetic cutoff is 4.5 GV/c. The charge ratio of positive and negative muons and the proton to muon ratio have been determined. These observations will also be compared with data collected at a higher latitude using the same basic apparatus.

  15. Measurement of secondary cosmic ray intensity at Regener-Pfotzer height using low-cost weather balloons and its correlation with solar activity

    OpenAIRE

    Sarkar, Ritabrata; Chakrabarti, Sandip K.; Pal, Partha Sarathi; Bhowmick, Debashis; Bhattacharya, Arnab

    2017-01-01

    Cosmic ray flux in our planetary system is primarily modulated by solar activity. Radiation effects of cosmic rays on the Earth strongly depend on latitude due to the variation of the geomagnetic field strength. To study these effects we carried out a series of measurements of the radiation characteristics in the atmosphere due to cosmic rays from various places (geomagnetic latitude: ~ 14.50 deg N) in West Bengal, India, located near the Tropic of Cancer, for several years (2012-2016) partic...

  16. Airborne Detection of Cosmic-Ray Albedo Neutrons for Regional-Scale Surveys of Root-Zone Soil Water on Earth

    Science.gov (United States)

    Schrön, M.; Bannehr, L.; Köhli, M.; Zreda, M. G.; Weimar, J.; Zacharias, S.; Oswald, S. E.; Bumberger, J.; Samaniego, L. E.; Schmidt, U.; Zieger, P.; Dietrich, P.

    2017-12-01

    While the detection of albedo neutrons from cosmic rays became a standard method in planetary space science, airborne neutron sensing has never been conceived for hydrological research on Earth. We assessed the applicability of atmospheric neutrons to sense root-zone soil moisture averaged over tens of hectares using neutron detectors on an airborne vehicle. Large-scale quantification of near-surface water content is an urgent challenge in hydrology. Information about soil and plant water is crucial to accurately assess the risks for floods and droughts, to adjust regional weather forecasts, and to calibrate and validate the corresponding models. However, there is a lack of data at scales relevant for these applications. Most conventional ground-based geophysical instruments provide root-zone soil moisture only within a few tens of m2, while electromagnetic signals from conventional remote-sensing instruments can only penetrate the first few centimeters below surface, though at larger spatial areas.In the last couple of years, stationary and roving neutron detectors have been used to sense the albedo component of cosmic-ray neutrons, which represents the average water content within 10—15 hectares and 10—50 cm depth. However, the application of these instruments is limited by inaccessible terrain and interfering local effects from roads. To overcome these limitations, we have pioneered first simulations and experiments of such sensors in the field of airborne geophysics. Theoretical investigations have shown that the footprint increases substantially with height above ground, while local effects smooth out throughout the whole area. Campaigns with neutron detectors mounted on a lightweight gyrocopter have been conducted over areas of various landuse types including agricultural fields, urban areas, forests, flood plains, and lakes. The neutron signal showed influence of soil moisture patterns in heights of up to 180 m above ground. We found correlation with

  17. Dawn-dusk asymmetries and sub-Alfvénic flow in the high and low latitude magnetosheath

    Directory of Open Access Journals (Sweden)

    M. Longmore

    2005-11-01

    Full Text Available We present the results of a statistical survey of the magnetosheath using four years of Cluster orbital coverage. Moments of the plasma distribution obtained from the electron and ion instruments together with magnetic field data are used to characterise the flow and density in the magnetosheath. We note two important differences between our survey and the gasdynamic model predictions: a deceleration of the flow at higher latitudes close to the magnetopause, resulting in sub-Alfvénic flow near the cusp, and a dawn-dusk asymmetry with higher velocity magnitudes and lower densities measured on the dusk side of the magnetosheath in the Northern Hemisphere. The latter observation is in agreement with studies carried out by Paularena et al. (2001, Němeček et al. (2000, and Šafránková et al. (2004. In equations of hydrodynamics for a single-component additon to this we observe a reverse of this asymmetry for the Southern Hemisphere. High-latitude sub-Alfvénic flow is thought to be a necessary condition for steady state reconnection pole-ward of the cusp.

  18. Survey of doses and frequency of X-ray examinations on children at the intensive care unit of a large reference pediatric hospital

    International Nuclear Information System (INIS)

    Pedrosa de Azevedo, Ana Cecilia; Osibote, Adelaja Otolorin; Bastos Boechat, Marcia Cristina

    2006-01-01

    Objective: This work aims to evaluate the entrance surface dose (ESD), the body organ dose (BOD) and the effective dose (E) resulting from pediatric radiological procedures with the use of portable X-ray equipments. Materials and methods: The software DoseCal was used to evaluate the doses imparted to patients. The children were classified according to their weight and age groups, and the study included three sectors of the intensive care unit of a large reference pediatric hospital in Rio de Janeiro. Results: A total of 518 radiographs have been performed (424 for chest and 94 for abdomen). The statistical data were compared with previously published results. The BOD is presented for the most exposed organs. Conclusion: The mean value of ESD and E varied widely among neonates. The highest number of radiographs per infant peaked 33 for chest examination in the age group 0-1 year

  19. Latitude dependence of long-term geomagnetic activity and its solar wind drivers

    Energy Technology Data Exchange (ETDEWEB)

    Myllys, M. [Helsinki Univ. (Finland). Dept. of Physics; Partamies, N. [Finnish Meteorological Institute, Helsinki (Finland); University Centre in Svalbard, Longyearbyen (Norway). Dept. of Arctic Geophysics; Juusola, L. [Finnish Meteorological Institute, Helsinki (Finland)

    2015-09-01

    To validate the usage of global indices in studies of geomagnetic activity, we have examined the latitude dependence of geomagnetic variations in Fennoscandia and Svalbard from 1994 to 2010. Daily standard deviation (SD) values of the horizontal magnetic field have been used as a measure of the ground magnetic disturbance level.We found that the timing of the geomagnetic minimum depends on the latitude region: corresponding to the minimum of sunspot cycle 22 (in 1996), the geomagnetic minimum occurred between the geomagnetic latitudes 57-61 in 1996 and at the latitudes 64-67 in 1997, which are the average auroral oval latitudes. During sunspot cycle 23, all latitude regions experienced the minimum in 2009, a year after the sunspot minimum. These timing differences are due to the latitude dependence of the 10 s daily SD on the different solar wind drivers. In the latitude region of 64-67 , the impact of the high-speed solar wind streams (HSSs) on the geomagnetic activity is the most pronounced compared to the other latitude groups, while in the latitude region of 57-61 , the importance of the coronal mass ejections (CMEs) dominates. The geomagnetic activity maxima during ascending solar cycle phases are typically caused by CME activity and occur especially in the oval and sub-auroral regions. The strongest geomagnetic activity occurs during the descending solar cycle phases due to a mixture of CME and HSS activity. Closer to the solar minimum, less severe geomagnetic activity is driven by HSSs and mainly visible in the poleward part of the auroral region. According to our study, however, the timing of the geomagnetic activity minima (and maxima) in different latitude bands is different, due to the relative importance of different solar wind drivers at different latitudes.

  20. Characteristics and sources of the electron density irregularities in the mid latitude E and Fregions

    Science.gov (United States)

    2017-05-10

    and has since been monitoring the occurrence of field-aligned irregularities ( FAIs ) in the northern middle latitudes. We investigated the...characteristics and occurrence climatology of the FAIs in the middle latitude E- and F-region ionosphere using the Daejeon VHF radar data. Depending on the...sunset and post-sunrise periods. The F-region FAIs in the mid-latitude are bounded to occur during the nighttime between local sunset and sunrise [J

  1. Latitude dependence of long-term geomagnetic activity and its solar wind drivers

    International Nuclear Information System (INIS)

    Myllys, M.

    2015-01-01

    To validate the usage of global indices in studies of geomagnetic activity, we have examined the latitude dependence of geomagnetic variations in Fennoscandia and Svalbard from 1994 to 2010. Daily standard deviation (SD) values of the horizontal magnetic field have been used as a measure of the ground magnetic disturbance level.We found that the timing of the geomagnetic minimum depends on the latitude region: corresponding to the minimum of sunspot cycle 22 (in 1996), the geomagnetic minimum occurred between the geomagnetic latitudes 57-61 in 1996 and at the latitudes 64-67 in 1997, which are the average auroral oval latitudes. During sunspot cycle 23, all latitude regions experienced the minimum in 2009, a year after the sunspot minimum. These timing differences are due to the latitude dependence of the 10 s daily SD on the different solar wind drivers. In the latitude region of 64-67 , the impact of the high-speed solar wind streams (HSSs) on the geomagnetic activity is the most pronounced compared to the other latitude groups, while in the latitude region of 57-61 , the importance of the coronal mass ejections (CMEs) dominates. The geomagnetic activity maxima during ascending solar cycle phases are typically caused by CME activity and occur especially in the oval and sub-auroral regions. The strongest geomagnetic activity occurs during the descending solar cycle phases due to a mixture of CME and HSS activity. Closer to the solar minimum, less severe geomagnetic activity is driven by HSSs and mainly visible in the poleward part of the auroral region. According to our study, however, the timing of the geomagnetic activity minima (and maxima) in different latitude bands is different, due to the relative importance of different solar wind drivers at different latitudes.

  2. NURE aerial gamma-ray and magnetic reconnaissance survey of portions of New Mexico, Arizona and Texas. Volume II. Arizona-Holbrook NI 12-5 Quadrangle. Final report

    International Nuclear Information System (INIS)

    1981-09-01

    The results of a high-sensitivity, aerial gamma-ray spectrometer and magnetometer survey of the Holbrook two degree quadrangle, Arizona are presented. Instrumentation and methods are described in Volume 1 of this final report. The work was done by Carson Helicopters, Inc., and Carson Helicopters was assisted in the interpretation by International Exploration, Inc. The work was performed for the US Department of Energy - National Uranium Resource Evaluation (NURE) program. Analysis of this radiometric data yielded 260 statistically significant eU anomalies. Of this number, forty-four were considered to be of sufficient strength to warrant further investigation. These preferred anomalies are separated into groups having some geologic aspect in common

  3. An Empirical Determination of the Intergalactic Background Light Using Near-Infrared Deep Galaxy Survey Data Out to 5 Micrometers and the Gamma-Ray Opacity of the Universe

    Science.gov (United States)

    Scully, Sean T.; Malkan, Matthew A.; Stecker, Floyd W.

    2014-01-01

    We extend our previous model-independent determination of the intergalactic background light, based purely on galaxy survey data, out to a wavelength of 5 micrometers. Our approach enables us to constrain the range of photon densities, based on the uncertainties from observationally determined luminosity densities and colors. We further determine a 68% confidence upper and lower limit on the opacity of the universe to gamma-rays up to energies of 1.6/(1 + z) terraelectron volts. A comparison of our lower limit redshift-dependent opacity curves to the opacity limits derived from the results of both ground-based air Cerenkov telescope and Fermi-LAT observations of PKS 1424+240 allows us to place a new upper limit on the redshift of this source, independent of IBL modeling.

  4. Heliographic latitude dependence of the IMF dominant polarity in 1972--1973 using Pioneer 10 data

    International Nuclear Information System (INIS)

    Rosenberg, R.L.

    1975-01-01

    The heliographic latitude dependence of the interplanetary magnetic field (IMF) was studied by using Pioneer 10 data taken from March 1972 through June 1973 over Bartels solar rotation (SR) periods 1896--1913. The daily IMF sector polarities were plotted for each of these SR periods. Then the number of days of positive polarity (''away'' directed fields) per SR was plotted versus the average heliographic latitude. The dominant polarity behaved in accordance with the latitude effects found by Rosenberg and Coleman in 1969. The phase of the cycle has reversed from what it was prior to the sunspot maximum in 1968. The polarity is now predominantly positive at northern heliographic latitudes. (auth)

  5. ROTATION RATE DIFFERENCES OF POSITIVE AND NEGATIVE SOLAR MAGNETIC FIELDS BETWEEN ±60° LATITUDES

    Energy Technology Data Exchange (ETDEWEB)

    Shi, X. J.; Xie, J. L., E-mail: shixiangjun@ynao.ac.cn [Yunnan Observatories, Chinese Academy of Sciences, Kunming 650011 (China)

    2015-04-15

    Based on a cross-correlation analysis of the Carrington synoptic maps of solar photospheric magnetic fields from Carrington Rotations Nos. 1625 to 2135 (from 1975 February to 2013 March), the sidereal rotation rates of the positive and negative magnetic fields in the latitude range of ±60° are obtained, and the rotation rate differences between them are investigated. The time–latitude distribution of the rate differences is shown, which looks like a butterfly diagram at the low and middle latitudes. For comparison, the time–latitude distribution of the longitudinally averaged photospheric magnetic fields is shown. We conclude that the magnetic fields having the same polarity as the leading sunspots at a given hemisphere rotate faster than those exhibiting the opposite polarity at low and middle latitudes. However, at higher latitudes, the magnetic fields having the same polarity as the leading sunspots at a given hemisphere do not always rotate faster than those with the opposite polarity. Furthermore, the relationship between the rotation rate differences and solar magnetic fields is studied through a correlation analysis. Our result shows that the correlation coefficients between them reach maximum values at 13° (14°) latitude in the northern (southern) hemisphere, and change sign at 28° latitude in both hemispheres, then reach their minimum values at 58° (53°) latitude in the northern (southern) hemisphere.

  6. On the cause of IMF By related mid- and low latitude magnetic disturbances

    DEFF Research Database (Denmark)

    Vennerstrøm, Susanne; Christiansen, Freddy; Olsen, Nils

    2007-01-01

    An analysis of the effect of the IMF By on near-Earth low and mid-latitude magnetic disturbances is presented. In particular the contribution from field-aligned currents ( FACs) connected to the polar regions is investigated. Based on statistically determined high-latitude FAC patterns for various...... that the long-distance effect of the high-latitude FACs constitute the major source to IMF By and B-z related magnetic east-west disturbances at mid-and low latitudes....

  7. Aerial gamma ray and magnetic survey: Idaho Project, Hailey, Idaho Falls, Elk City quadrangles of Idaho/Montana and Boise quadrangle, Oregon/Idaho. Final report

    International Nuclear Information System (INIS)

    1979-09-01

    During the months of July and August, 1979, geoMetrics, Inc. collected 11561 line mile of high sensitivity airborne radiometric and magnetic data in Idaho and adjoining portions of Oregon and Montana over four 1 0 x 2 0 NTMS quadrangles (Boise, Hailey, Idaho Falls, and Elk City) as part of the Department of Energy's National Uranium Resource Evaluation Program. All radiometric and magnetic data were fully corrected and interpreted by geoMetrics and are presented as five volumes (one Volume I and four Volume II's). Approximately 95 percent of the surveyed areas are occupied by exposures of intrusive and extrusive rocks. The Cretaceous-Tertiary Idaho Batholith dominates the Elk City and Hailey quadrangles. The Snake River volcanics of Cenozoic Age dominate the Idaho Falls quadrangle and southeast part of the Hailey sheet. Tertiary Columbia River basalts and Idaho volcanics cover the Boise quadrangle. There are only two uranium deposits within the four quadrangles. The main uranium producing areas of Idaho lie adjacent to the surveyed area in the Challis and Dubois quadrangles

  8. Cosmic rays

    International Nuclear Information System (INIS)

    Tkachev, I.I.

    2014-01-01

    In this talk I will review results of cosmic ray observations at the highest energies. This year the new results on energy spectra, composition and the study of arrival directions of cosmic ray primaries came from the Telescope Array collaboration. I present these results in comparison with measurements done by other recent experiments and discuss their implications for the search of cosmic ray sources. Some related results in gamma-ray astronomy and selected recent advances in theory are also covered. (author)

  9. National Uranium Resource Evaluation. Aerial gamma ray and magnetic survey, Racine and Grand Rapids quadrangles, Michigan, Wisconsin and Illinois. Final report

    International Nuclear Information System (INIS)

    1981-07-01

    The Racine and Grand Rapids quadrangles of southeastern Wisconsin, northeastern Illinois, and Michigan cover a land area of 8785 square miles, and an additional water surface area of 5215 square miles. In the northeast, thick Paleozoic deposits overlie a regional downwarp of the Precambrian basement called the Michigan Basin. These Paleozoic deposits shoal to only 500 feet in the southwest corner of the survey area. The entire region is covered by a mantle of Quaternary glacial material. A search of available literature revealed no economically feasible uranium deposits. A total of 83 uranium anomalies were detected and are discussed briefly. All appear to have cultural, and/or locally unsaturated associations, and none appear to contain significant measured quantities of uranium. Magnetic data appear to be in general agreement with existing structural interpretations of the area. There are local exceptions which suggest some lithologic and/or structural complexities in the basement material

  10. New results on the mid-latitude midnight temperature maximum

    Science.gov (United States)

    Mesquita, Rafael L. A.; Meriwether, John W.; Makela, Jonathan J.; Fisher, Daniel J.; Harding, Brian J.; Sanders, Samuel C.; Tesema, Fasil; Ridley, Aaron J.

    2018-04-01

    (18 %). Also seen is a northwestward propagation of the MTM signature with a latitude-dependent amplitude. This behavior suggests either a latitudinal dependence of thermosphere tidal dissipation or a night-to-night variation of the composition of the higher-order tidal modes that contribute to the production of the MTM peak at mid-latitudes. Also presented in this paper is the perturbation on the divergence of the wind fields, which is associated with the passage of each MTM peak analyzed with the 2-D interpolation.

  11. Paleoclimate records at high latitude in Arctic during the Paleogene

    Science.gov (United States)

    Salpin, Marie; Schnyder, Johann; Baudin, François; Suan, Guillaume; Labrousse, Loïc; Popescu, Speranta; Suc, Jean-Pierre

    2015-04-01

    Paleoclimate records at high latitude in Arctic during the Paleogene SALPIN Marie1,2, SCHNYDER Johann1,2, BAUDIN François1,2, SUAN Guillaume3, LABROUSSE Loïc1,2, POPESCU Speranta4, SUC Jean-Pierre1,4 1: Sorbonne Universités, UPMC Univ Paris 06, UMR 7193, Institut des Sciences de la Terre Paris (iSTeP), F 75005, Paris, France 2: CNRS, UMR 7193, Institut des Sciences de la Terre Paris (iSTeP), F 75005 Paris, France 3: UCB Lyon 1, UMR 5276, LGLTPE, 69622 Villeurbanne Cedex, France 4: GEOBIOSTRATDATA.CONSULTING, 385 Route du Mas Rillier 69140 Rillieux la Pape, France The Paleogene is a period of important variations of the Earth climate system either in warming or cooling. The climatic optima of the Paleogene have been recognized both in continental and marine environment. This study focus on high latitudes of the northern hemisphere, in the Arctic Basin. The basin has had an influence on the Cenozoic global climate change according to its polar position. Is there a specific behaviour of the Arctic Basin with respect to global climatic stimuli? Are there possible mechanisms of coupling/decoupling of its dynamics with respect to the global ocean? To answer these questions a unique collection of sedimentary series of Paleogene age interval has been assembled from the Laurentian margin in Northern Yukon (Canada) and from the Siberian margin (New Siberian Islands). Selected continental successions of Paleocene-Eocene age were used to study the response of the Arctic system to known global events, e.g. the climatic optima of the Paleogene (the so-called PETM, ETM2 or the Azolla events). Two sections of Paleocene-Eocene age were sampled near the Mackenzie delta, the so-called Coal Mine (CoMi) and Caribou Hills (CaH) sections. The aim of the study is to precise the climatic fluctuations and to characterise the source rock potential of the basin, eventually linked to the warming events. This study is based on data of multi-proxy analyses: mineralogy on bulk and clay

  12. Characteristic analysis of a photovoltaic system flying at fixed latitude

    International Nuclear Information System (INIS)

    Lee, Shun Ching

    2011-01-01

    Highlights: → Relative sunrise and noon are different for different flight speeds. → ECSC cells are disposed for ECSC batteries matching each PV module. → Working ranges of ECSC battery are determined. → Secondary ECSC battery is considered. → Heat energy to thermostat keeps PV modules at ice point. - Abstract: The characteristic analysis of a PV system equipped with ECSC battery and moving in the air at fixed latitude is presented. The flight plans for 1 year trips at three latitudes from four seasons and with four speeds are considered under the condition that the flying system must come back every 24 h whatever the speed may be. The relative sunrise, solar noon, and sunset are different on each day not only for different seasons but also for different flight speeds, so the times for the moving PV system to take two U turns on each day are different and the durations of insolation on PV modules on each day are also different. The ECSC cells are disposed in series and in parallel for ECSC batteries matching each PV module. The working ranges of ECSC battery are determined by the characteristics of two components, ECSC battery and DC motor, for ensuring that the discharge current from an ECSC battery is always larger than the current driving the DC motor. While the PV modules on the flying machine are not under insolation or does not produce enough after relative sunrise, the primary ECSC battery discharges. The PV generator drives the DC motor and charges the primary ECSC battery during the time about solar noon, and it will charge the secondary ECSC battery when the primary battery is recharged to the full state. Once the PV generator does not produce enough again before relative sunset, the secondary battery discharges until its fractional state of charge backs to the minimum. The thermostat keeps the PV modules at ice point, if the temperature of PV module in the air is less than the 0 deg. C. The heat energy controlled by the thermostat is supplied

  13. Supersonic plasma flow between high latitude conjugate ionospheres

    International Nuclear Information System (INIS)

    Roesler, G.

    1975-01-01

    The polar wind problem has been investigated for closed field lines in situations where one of the two conjugate ionospheric regions is fully illuminated by the sun and the other darkness (solstices at high latitudes). A supersonic flow between hemispheres is possible; the magnetospheric part of this flow must be symmetric with respect to the equator. The daytime fluxes are proportional to the neutral hydrogen density. Fluxes of the order of 10 8 cm -2 sec -1 are only possible with density considerably higher than given by CIRA models. For stationary solutions higher flow speeds are needed on the dark side than provided from the illuminated side. It is concluded that shock waves with upward velocities of about 5 km/sec would form above the dark ionosphere. This implies a reduction by a factor of 3 to 5 of the plasma influx into the dark hemisphere, whereby F-layer densities of only up to 2 x 10 4 cm -3 can be maintained. (orig.) [de

  14. Habitable periglacial landscapes in martian mid-latitudes

    Science.gov (United States)

    Ulrich, M.; Wagner, D.; Hauber, E.; de Vera, J.-P.; Schirrmeister, L.

    2012-05-01

    Subsurface permafrost environments on Mars are considered to be zones where extant life could have survived. For the identification of possible habitats it is important to understand periglacial landscape evolution and related subsurface and environmental conditions. Many landforms that are interpreted to be related to ground ice are located in the martian mid-latitudinal belts. This paper summarizes the insights gained from studies of terrestrial analogs to permafrost landforms on Mars. The potential habitability of martian mid-latitude periglacial landscapes is exemplarily deduced for one such landscape, that of Utopia Planitia, by a review and discussion of environmental conditions influencing periglacial landscape evolution. Based on recent calculations of the astronomical forcing of climate changes, specific climate periods are identified within the last 10 Ma when thaw processes and liquid water were probably important for the development of permafrost geomorphology. No periods could be identified within the last 4 Ma which met the suggested threshold criteria for liquid water and habitable conditions. Implications of past and present environmental conditions such as temperature variations, ground-ice conditions, and liquid water activity are discussed with respect to the potential survival of highly-specialized microorganisms known from terrestrial permafrost. We conclude that possible habitable subsurface niches might have been developed in close relation to specific permafrost landform morphology on Mars. These would have probably been dominated by lithoautotrophic microorganisms (i.e. methanogenic archaea).

  15. Tracking strategy for photovoltaic solar systems in high latitudes

    International Nuclear Information System (INIS)

    Quesada, Guillermo; Guillon, Laura; Rousse, Daniel R.; Mehrtash, Mostafa; Dutil, Yvan; Paradis, Pierre-Luc

    2015-01-01

    Highlights: • In cloudy conditions tracking the sun is ineffective. • A methodology to estimate a theoretical threshold for solar tracking was developed. • A tracking strategy to maximize electricity production was proposed. - Abstract: Several studies show that from about 20% to 50% more solar energy can be recovered by using photovoltaic systems that track the sun rather than systems set at a fixed angle. For overcast or cloudy days, recent studies propose the use of a set position in which each photovoltaic panel faces toward the zenith (horizontal position). Compared to a panel that follows the sun’s path, this approach claims that a horizontal panel increases the amount of solar radiation captured and subsequently the quantity of electricity produced. The present work assesses a solar tracking photovoltaic panel hourly and seasonally in high latitudes. A theoretical method based on an isotropic sky model was formulated, implemented, and used in a case study analysis of a grid-connected photovoltaic system in Montreal, Canada. The results obtained, based on the definition of a critical hourly global solar radiation, were validated numerically and experimentally. The study confirmed that a zenith-set sun tracking strategy for overcast or mostly cloudy days in summer is not advantageous

  16. Analysis of the atmospheric upward radiation in low latitude area

    Science.gov (United States)

    Li, Haiying; Wu, Zhensen; Lin, Leke; Lu, Changsheng

    2016-10-01

    Remote sensing using THz wave has irreplaceable advantage comparing to the microwave and the infrared waves, and study on the THz remote sensing become more and more popular in recent years. The major applications of the remote sensing in THz wavelengths are the retrieval of the atmospheric parameters and the microphysical information of the ice cloud. The remote sensing of the atmosphere is based on the radiation of THz wave along the earth-space path of which the most significant part is the upward radiation of the atmosphere. The upward radiation of the atmosphere in sunny day in the low latitude area is computed and analyzed in this paper. The absorption of THz wave by the atmosphere is calculated using the formulations illustrated in the Recommendation ITU-R P.676 to save machine hour, the frequency range is then restricted below 1THz. The frequencies used for the retrieval of atmospheric parameters such as temperature and water content are usually a few hundred GHz, at the lower end of THz wavelengths, so this frequency range is sufficient. The radiation contribution of every atmospheric layer for typical frequencies such as absorption window frequencies and peak frequencies are analyzed. Results show that at frequencies which absorption is severe, information about lower atmosphere cannot reach the receiver onboard a satellite or other high platforms due to the strong absorption along the path.

  17. High latitude plasma convection: Predictions for EISCAT and Sondre Stromfjord

    International Nuclear Information System (INIS)

    Sojka, J.J.; Raitt, W.J.; Schunk, R.W.

    1979-01-01

    We have used a plasma convection model to predict diurnal patterns of horizontal drift velocities in the vicinity of the EISCAT incoherent scatter facility at Tromso, Norway and for Sondre Stromfjord, Greenland, a proposed new incoherent scatter facility site. The convection model includes the offset of 11.4 0 between the geographic and geomagnetic poles (northern hemisphere), the tendency of plasma to corotate about the geographic pole, and a magnetospheric electric field mapped to a circle about a center offset by 5 0 in the antisunward direction from the magnetic pole. Four different magnetospheric electric field configurations were considered, including a constant cross-tail electric field, asymmetric electric fields with enhancements on the dawn and dusk sides of the polar cap, and an electric field pattern that is not aligned parallel to the noon-midnight magnetic meridian. The different electric field configurations produce different signatures in the plasma convection pattern which are clearly identified. Both of the high-latitude sites are better suited to study magnetospheric convection effects than either Chatanika, Alaska or Millstone Hill, Massachusetts. Also, each site appears to have unique capabilities with regard to studying certain aspects of the magnetospheric electric field

  18. Geosynchronous inclined orbits for high-latitude communications

    Science.gov (United States)

    Fantino, E.; Flores, R. M.; Di Carlo, M.; Di Salvo, A.; Cabot, E.

    2017-11-01

    We present and discuss a solution to the growing demand for satellite telecommunication coverage in the high-latitude geographical regions (beyond 55°N), where the signal from geostationary satellites is limited or unavailable. We focus on the dynamical issues associated to the design, the coverage, the maintenance and the disposal of a set of orbits selected for the purpose. Specifically, we identify a group of highly inclined, moderately eccentric geosynchronous orbits derived from the Tundra orbit (geosynchronous, eccentric and critically inclined). Continuous coverage can be guaranteed by a constellation of three satellites in equally spaced planes and suitably phased. By means of a high-precision model of the terrestrial gravity field and the relevant environmental perturbations, we study the evolution of these orbits. The effects of the different perturbations on the ground track (which is more important for coverage than the orbital elements themselves) are isolated and analyzed. The physical model and the numerical setup are optimized with respect to computing time and accuracy. We show that, in order to maintain the ground track unchanged, the key parameters are the orbital period and the argument of perigee. Furthermore, corrections to the right ascension of the ascending node are needed in order to preserve the relative orientation of the orbital planes. A station-keeping strategy that minimizes propellant consumption is then devised, and comparisons are made between the cost of a solution based on impulsive maneuvers and one with continuous thrust. Finally, the issue of end-of-life disposal is discussed.

  19. Urbanization disrupts latitude-size rule in 17-year cicadas.

    Science.gov (United States)

    Beasley, DeAnna E; Penick, Clint A; Boateng, Nana S; Menninger, Holly L; Dunn, Robert R

    2018-03-01

    Many ectotherms show a decrease in body size with increasing latitude due to changes in climate, a pattern termed converse Bergmann's rule. Urban conditions-particularly warmer temperatures and fragmented landscapes-may impose stresses on development that could disrupt these body size patterns. To test the impact of urbanization on development and latitudinal trends in body size, we launched a citizen science project to collect periodical cicadas ( Magicicada septendecim ) from across their latitudinal range during the 2013 emergence of Brood II. Periodical cicadas are long-lived insects whose distribution spans a broad latitudinal range covering both urban and rural habitats. We used a geometric morphometric approach to assess body size and developmental stress based on fluctuating asymmetry in wing shape. Body size of rural cicadas followed converse Bergmann's rule, but this pattern was disrupted in urban habitats. In the north, urban cicadas were larger than their rural counterparts, while southern populations showed little variation in body size between habitats. We detected no evidence of differences in developmental stress due to urbanization. To our knowledge, this is the first evidence that urbanization disrupts biogeographical trends in body size, and this pattern highlights how the effects of urbanization may differ over a species' range.

  20. An accelerating high-latitude jet in Earth's core

    Science.gov (United States)

    Livermore, P. W.; Finlay, C. C.; Hollerbach, R.

    2017-12-01

    Observations of the change in Earth's magnetic field, the secular variation, provide information on the motion of liquid metal within the core that is responsible for its generation. The very latest high-resolution observations from ESA's Swarm satellite mission show intense field change at high-latitude localised in a distinctive circular daisy-chain configuration centred on the north geographic pole. Here we explain this feature with a localised, nonaxisymmetric, westwards jet of 420 km width on the tangent cylinder, the cylinder of fluid within the core that is aligned with the rotation axis and tangent to the solid inner core. We find that the jet has increased in magnitude by a factor of three over the period 2000-2016 to about 40 km/yr, and is now much stronger than typical large-scale flows inferred for the core. The current accelerating phase may be a part of a longer term fluctuation of the jet causing both eastwards and westwards movement of magnetic features over historical periods, and may contribute to recent changes in torsional wave activity and the rotation direction of the inner core.

  1. Preface: The International Reference Ionosphere (IRI) at equatorial latitudes

    Science.gov (United States)

    Reinisch, Bodo; Bilitza, Dieter

    2017-07-01

    This issue of Advances in Space Research includes papers that report and discuss improvements of the International Reference Ionosphere (IRI). IRI is the international standard for the representation of the plasma in Earth's ionosphere and recognized as such by the Committee on Space Research (COSPAR), the International Union of Radio Science (URSI), the International Telecommunication Union (ITU), and the International Standardization Organization (ISO). As requested, particularly by COSPAR and URSI, IRI is an empirical model relying on most of the available and reliable ground and space observations of the ionosphere. As new data become available and as older data sources are fully exploited the IRI model undergoes improvement cycles to stay as close to the existing data record as possible. The latest episode of this process is documented in the papers included in this issue using data from the worldwide network of ionosondes, from a few of the incoherent scatter radars, from the Alouette and ISIS topside sounders, and from the Global Navigation Satellite Systems (GNSS). The focus of this issue is on the equatorial and low latitude region that is of special importance for ionospheric physics because it includes the largest densities and steep density gradients in the double hump latitudinal structure, the Equatorial Ionization Anomaly (EIA), which is characteristic for this region.

  2. Movements of the mid-latitude ionospheric trough

    International Nuclear Information System (INIS)

    Rodger, A.S.; Pinnock, M.

    1982-01-01

    A new method for monitoring the position and movement of large ionospheric structures is described. The technique uses data from an ionosonde nominally operating at vertical incidence, but relies on there being present a significant gradient in electron concentration. The position and dynamics of the poleward edge of the mid-latitude trough over Halley Bay, Antarctica (L = 4.2) is investigated using this method. Analyses show that the trough moves rapidly equatorward over Halley Bay in the early evening hours, during geomagnetically active periods. For magnetically quiet periods, the trough is not observed till after midnight, when its equatorward motion is comparatively slow. These results showed marked differences from those predicted from published empirical relationships describing variations in trough position with time, particularly before midnight. Changes in the position of the plasma pause with time, determined from two theoretical models and from observations are compared with these results for the trough. Also, one case study is presented in which there is determination of the positions of both the trough and the plasmapause over a 7 h period. Similarities and differences in their relative positions and movements of the two features are identified and their possible causes are briefly discussed. (author)

  3. Cluster observations of mid-latitude hiss near the plasmapause

    Directory of Open Access Journals (Sweden)

    A. Masson

    2004-07-01

    Full Text Available In the vicinity of the plasmapause, around the geomagnetic equator, the four Cluster satellites often observe banded hiss-like electromagnetic emissions (BHE; below the electron gyrofrequency but above the lower hybrid resonance, from 2kHz to 10kHz. We show that below 4kHz, these waves propagate in the whistler mode. Using the first year of scientific operations of WHISPER, STAFF and WBD wave experiments on Cluster, we have identified the following properties of the BHE waves: (i their location is strongly correlated with the position of the plasmapause, (ii no MLT dependence has been found, (iii their spectral width is generally 1 to 2kHz, and (iv the central frequency of their emission band varies from 2kHz to 10kHz. All these features suggest that BHE are in fact mid-latitude hiss emissions (MLH. Moreover, the central frequency was found to be correlated with the Kp index. This suggests either that these banded emissions are generated in a given f/fce range, or that there is a Kp dependent Doppler shift between the satellites and a possible moving source of the MLH.

  4. Sun position calculator (SPC) for Landsat imagery with geodetic latitudes

    Science.gov (United States)

    Seong, Jeong C.

    2015-12-01

    Landsat imagery comes with sun position information such as azimuth and sun elevation, but they are available only at the center of a scene. To aid in the use of Landsat imagery for various solar radiation applications such as topographic correction, solar power, urban heat island, agriculture, climate and vegetation, it is necessary to calculate the sun position information at every pixel. This research developed a PC application that creates sun position data layers in ArcGIS at every pixel in a Landsat scene. The SPC program is composed of two major routines - converting universal transverse Mercator (UTM) projection coordinates to geographic longitudes and latitudes, and calculating sun position information based on the Meeus' routine. For the latter, an innovative method was also implemented to account for the Earth's flattening on an ellipsoid. The Meeus routine implemented in this research showed about 0.2‧ of mean absolute difference from the National Renewable Energy Laboratory (NREL) Solar Position Algorithm (SPA) routine when solar zenith and azimuth angles were tested with every 30 min data at four city locations (Fairbanks, Atlanta, Sydney and Rio Grande) on June 30, 2014. The Meeus routine was about ten times faster than the SPA routine. Professionals who need the Sun's position information for Landsat imagery will benefit from the SPC application.

  5. The NuSTAR Extragalactic Survey: A First Sensitive Look at the High-Energy Cosmic X-Ray Background Population

    Science.gov (United States)

    Alexander, D. M.; Stern, D.; DelMoro, A.; Lansbury, G. B.; Assef, R. J.; Aird, J.; Ajello, M.; Ballantyne, D. R.; Bauer, F. E.; Boggs, S. E.; hide

    2013-01-01

    We report on the first 10 identifications of sources serendipitously detected by the Nuclear Spectroscopic Telescope Array (NuSTAR) to provide the first sensitive census of the cosmic X-ray background source population at approximately greater than 10 keV. We find that these NuSTAR-detected sources are approximately 100 times fainter than those previously detected at approximately greater than 10 keV and have a broad range in redshift and luminosity (z = 0.020-2.923 and L(sub 10-40 keV) approximately equals 4 × 10(exp 41) - 5 × 10(exp 45) erg per second; the median redshift and luminosity are z approximately equal to 0.7 and L(sub 10-40 keV) approximately equal to 3 × 10(exp 44) erg per second, respectively. We characterize these sources on the basis of broad-band approximately equal to 0.5 - 32 keV spectroscopy, optical spectroscopy, and broad-band ultraviolet-to-mid-infrared spectral energy distribution analyses. We find that the dominant source population is quasars with L(sub 10-40 keV) greater than 10(exp 44) erg per second, of which approximately 50% are obscured with N(sub H) approximately greater than 10(exp 22) per square centimeters. However, none of the 10 NuSTAR sources are Compton thick (N(sub H) approximately greater than 10(exp 24) per square centimeters) and we place a 90% confidence upper limit on the fraction of Compton-thick quasars (L(sub 10-40 keV) greater than 10(exp 44) erg per second) selected at approximately greater than 10 keV of approximately less than 33% over the redshift range z = 0.5 - 1.1. We jointly fitted the rest-frame approximately equal to 10-40 keV data for all of the non-beamed sources with L(sub 10-40 keV) greater than 10(exp 43) erg per second to constrain the average strength of reflection; we find R less than 1.4 for gamma = 1.8, broadly consistent with that found for local active galactic nuclei (AGNs) observed at approximately greater than 10 keV. We also constrain the host-galaxy masses and find a median stellar

  6. CONNECTING GRBs AND ULIRGs: A SENSITIVE, UNBIASED SURVEY FOR RADIO EMISSION FROM GAMMA-RAY BURST HOST GALAXIES AT 0 < z < 2.5

    Energy Technology Data Exchange (ETDEWEB)

    Perley, D. A. [Department of Astronomy, California Institute of Technology, MC 249-17, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Perley, R. A. [National Radio Astronomy Observatory, P.O. Box O, Socorro, NM 87801 (United States); Hjorth, J.; Malesani, D. [Dark Cosmology Centre, Niels Bohr Institute, DK-2100 Copenhagen (Denmark); Michałowski, M. J. [Scottish Universities Physics Alliance, Institute for Astronomy, University of Edinburgh, Royal Observatory, Edinburgh, EH9 3HJ (United Kingdom); Cenko, S. B. [NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Jakobsson, P. [Centre for Astrophysics and Cosmology, Science Institute, University of Iceland, Dunhagi 5, 107 Reykjavík (Iceland); Krühler, T. [European Southern Observatory, Alonso de Córdova 3107, Vitacura, Casilla 19001, Santiago 19 (Chile); Levan, A. J. [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Tanvir, N. R., E-mail: dperley@astro.caltech.edu [Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH (United Kingdom)

    2015-03-10

    Luminous infrared galaxies and submillimeter galaxies contribute significantly to stellar mass assembly and provide an important test of the connection between the gamma-ray burst (GRB) rate and that of overall cosmic star formation. We present sensitive 3 GHz radio observations using the Karl G. Jansky Very Large Array of 32 uniformly selected GRB host galaxies spanning a redshift range from 0 < z < 2.5, providing the first fully dust- and sample-unbiased measurement of the fraction of GRBs originating from the universe's most bolometrically luminous galaxies. Four galaxies are detected, with inferred radio star formation rates (SFRs) ranging between 50 and 300 M {sub ☉} yr{sup –1}. Three of the four detections correspond to events consistent with being optically obscured 'dark' bursts. Our overall detection fraction implies that between 9% and 23% of GRBs between 0.5 < z < 2.5 occur in galaxies with S {sub 3GHz} > 10 μJy, corresponding to SFR > 50 M {sub ☉} yr{sup –1} at z ∼ 1 or >250 M {sub ☉} yr{sup –1} at z ∼ 2. Similar galaxies contribute approximately 10%-30% of all cosmic star formation, so our results are consistent with a GRB rate that is not strongly biased with respect to the total SFR of a galaxy. However, all four radio-detected hosts have stellar masses significantly lower than IR/submillimeter-selected field galaxies of similar luminosities. We suggest that the GRB rate may be suppressed in metal-rich environments but independently enhanced in intense starbursts, producing a strong efficiency dependence on mass but little net dependence on bulk galaxy SFR.

  7. Status of the UMC cosmic ray experiment

    International Nuclear Information System (INIS)

    Nitz, D.

    1989-01-01

    The UMC Ultra High Energy cosmic ray experiment is a collaboration among the University of Utah, the University of Michigan, and the University of Chicago. It is located at the site of the Fly's Eye II experiment at Dugway, Utah, at latitude 40.2 0 and an atmospheric depth of 850 gm/cm 2 . Extensive air shower (EAS) surface arrays, a large area muon counter array, tracking Cerenkov telescopes, and the Fly's Eye detector constitute the elements of a versatile cosmic ray observatory for > or approx. 10 14 eV extensive air showers. (orig.)

  8. "Michael Jackson World Tour:" Maps and Globes--Latitude and Longitude.

    Science.gov (United States)

    Benscoter, Gloria Dee

    1988-01-01

    Presents a mapping activity which helps students understand the purpose of latitude and longitude lines. Gives students an opportunity to use longitude and latitude in a meaningful way by asking them to plan a world concert tour for a rock star. Includes a reproducible activity page. (LS)

  9. Environmental variation, vegetation distribution, carbon dynamics and water/energy exchange at high latitudes

    Science.gov (United States)

    McGuire, A.D.; Wirth, C.; Apps, M.; Beringer, J.; Clein, J.; Epstein, H.; Kicklighter, D.W.; Bhatti, J.; Chapin, F. S.; De Groot, B.; Efremov, D.; Eugster, W.; Fukuda, M.; Gower, T.; Hinzman, L.; Huntley, B.; Jia, G.J.; Kasischke, E.; Melillo, J.; Romanovsky, V.; Shvidenko, A.; Vaganov, E.; Walker, D.

    2002-01-01

    The responses of high latitude ecosystems to global change involve complex interactions among environmental variables, vegetation distribution, carbon dynamics, and water and energy exchange. These responses may have important consequences for the earth system. In this study, we evaluated how vegetation distribution, carbon stocks and turnover, and water and energy exchange are related to environmental variation spanned by the network of the IGBP high latitude transects. While the most notable feature of the high latitude transects is that they generally span temperature gradients from southern to northern latitudes, there are substantial differences in temperature among the transects. Also, along each transect temperature co-varies with precipitation and photosynthetically active radiation, which are also variable among the transects. Both climate and disturbance interact to influence latitudinal patterns of vegetation and soil carbon storage among the transects, and vegetation distribution appears to interact with climate to determine exchanges of heat and moisture in high latitudes. Despite limitations imposed by the data we assembled, the analyses in this study have taken an important step toward clarifying the complexity of interactions among environmental variables, vegetation distribution, carbon stocks and turnover, and water and energy exchange in high latitude regions. This study reveals the need to conduct coordinated global change studies in high latitudes to further elucidate how interactions among climate, disturbance, and vegetation distribution influence carbon dynamics and water and energy exchange in high latitudes.

  10. Novel Solar Sail Mission Concepts for High-Latitude Earth and Lunar Observation

    NARCIS (Netherlands)

    Heiligers, M.J.; Parker, Jeffrey S.; Macdonald, Malcolm

    2016-01-01

    This paper proposes the use of solar sail periodic orbits in the Earth-Moon system for ob-servation of the high-latitudes of the Earth and Moon. At the Earth, the high-latitudes will be crucial in answering questions concerning global climate change, monitoring space weather events and ensuring

  11. Schizophrenia and vitamin D related genes could have been subject to latitude-driven adaptation

    Directory of Open Access Journals (Sweden)

    Monticelli Antonella

    2010-11-01

    Full Text Available Abstract Background Many natural phenomena are directly or indirectly related to latitude. Living at different latitudes, indeed, has its consequences with being exposed to different climates, diets, light/dark cycles, etc. In humans, one of the best known examples of genetic traits following a latitudinal gradient is skin pigmentation. Nevertheless, also several diseases show latitudinal clinals such as hypertension, cancer, dismetabolic conditions, schizophrenia, Parkinson's disease and many more. Results We investigated, for the first time on a wide genomic scale, the latitude-driven adaptation phenomena. In particular, we selected a set of genes showing signs of latitude-dependent population differentiation. The biological characterization of these genes showed enrichment for neural-related processes. In light of this, we investigated whether genes associated to neuropsychiatric diseases were enriched by Latitude-Related Genes (LRGs. We found a strong enrichment of LRGs in the set of genes associated to schizophrenia. In an attempt to try to explain this possible link between latitude and schizophrenia, we investigated their associations with vitamin D. We found in a set of vitamin D related genes a significant enrichment of both LRGs and of genes involved in schizophrenia. Conclusions Our results suggest a latitude-driven adaptation for both schizophrenia and vitamin D related genes. In addition we confirm, at a molecular level, the link between schizophrenia and vitamin D. Finally, we discuss a model in which schizophrenia is, at least partly, a maladaptive by-product of latitude dependent adaptive changes in vitamin D metabolism.

  12. Schizophrenia and vitamin D related genes could have been subject to latitude-driven adaptation.

    Science.gov (United States)

    Amato, Roberto; Pinelli, Michele; Monticelli, Antonella; Miele, Gennaro; Cocozza, Sergio

    2010-11-11

    Many natural phenomena are directly or indirectly related to latitude. Living at different latitudes, indeed, has its consequences with being exposed to different climates, diets, light/dark cycles, etc. In humans, one of the best known examples of genetic traits following a latitudinal gradient is skin pigmentation. Nevertheless, also several diseases show latitudinal clinals such as hypertension, cancer, dismetabolic conditions, schizophrenia, Parkinson's disease and many more. We investigated, for the first time on a wide genomic scale, the latitude-driven adaptation phenomena. In particular, we selected a set of genes showing signs of latitude-dependent population differentiation. The biological characterization of these genes showed enrichment for neural-related processes. In light of this, we investigated whether genes associated to neuropsychiatric diseases were enriched by Latitude-Related Genes (LRGs). We found a strong enrichment of LRGs in the set of genes associated to schizophrenia. In an attempt to try to explain this possible link between latitude and schizophrenia, we investigated their associations with vitamin D. We found in a set of vitamin D related genes a significant enrichment of both LRGs and of genes involved in schizophrenia. Our results suggest a latitude-driven adaptation for both schizophrenia and vitamin D related genes. In addition we confirm, at a molecular level, the link between schizophrenia and vitamin D. Finally, we discuss a model in which schizophrenia is, at least partly, a maladaptive by-product of latitude dependent adaptive changes in vitamin D metabolism.

  13. Comparison of a low and a middle latitude GPS-TEC in Africa during ...

    African Journals Online (AJOL)

    In this work, we compared TEC values at Libreville (a low latitude station) with Sutherland (a middle latitude station) over Africa using Global Positioning System (GPS) receivers during high solar activity (HSA), moderate solar activity (MSA) and low solar activity (LSA). Apart from our confirmation that high, moderate and low ...

  14. Aerial gamma ray and magnetic survey: Fremont Quadrangle, Nebraska, Iowa; Lincoln Quadrangle, Nebraska; Manhattan Quadrangle, Kansas; Hutchinson Quadrangle, Kansas. Final report. Volume I

    International Nuclear Information System (INIS)

    1977-11-01

    A high sensitivity airborne radiometric and magnetic survey of the East Salina Basin Area (Kansas and Nebraska) was conducted. The project area, the Hutchinson and Manhattan, Kansas sheets, consists of approximately 30,800 square miles. A total of 11,287 line miles of high sensitivity radiometric and magnetic data were collected. All data were collected utilizing a fixed wing aircraft, and over 3,500 cubic inches of NaI crystal detector. Magnetometer data were collected utilizing a high sensitivity 0.25 gamma, proton magnetometer. All field data were returned to GeoMetrics, Sunnyvale, California computer facilities for processing, statistical analysis and interpretation. As an integral part of this final report, other data are presented which include corrected profiles of all radiometric variables (total count, K, U, Th, U/Th, U/K, and Th/K, ratios), magnetic data, radar altimeter data, barometric altimeter data, air temperature and airborne Bi contributions. Radiometric data presented are corrected for Compton Scatter, altitude dependence and atmospheric Bismuth. These data are presented in the form of strip charts as averaged one second samples using a 5 second moving average window, microfiche and digital magnetic tapes containing raw spectral data, single record data, averaged record data, and statistical analysis results. In addition, computer generated anomaly maps and interpretation maps are presented relating known geology or soil distribution to the corrected radiometric data

  15. Increasing the X-ray Diffraction Power of Protein Crystals by Dehydration: The Case of Bovine Serum Albumin and a Survey of Literature Data

    Directory of Open Access Journals (Sweden)

    Irene Russo Krauss

    2012-03-01

    Full Text Available Serum albumin is one of the most widely studied proteins. It is the most abundant protein in plasma with a typical concentration of 5 g/100 mL and the principal transporter of fatty acids in plasma. While the crystal structures of human serum albumin (HSA free and in complex with fatty acids, hemin, and local anesthetics have been characterized, no crystallographic models are available on bovine serum albumin (BSA, presumably because of the poor diffraction power of existing hexagonal BSA crystals. Here, the crystallization and diffraction data of a new BSA crystal form, obtained by the hanging drop method using MPEG 5K as precipitating agent, are presented. The crystals belong to space group C2, with unit-cell parameters a = 216.45 Å, b = 44.72 Å, c = 140.18 Å, β = 114.5°. Dehydration was found to increase the diffraction limit of BSA crystals from ~8 Å to 3.2 Å, probably by improving the packing of protein molecules in the crystal lattice. These results, together with a survey of more than 60 successful cases of protein crystal dehydration, confirm that it can be a useful procedure to be used in initial screening as a method of improving the diffraction limits of existing crystals.

  16. Cosmic and solar gamma-ray x-ray and particle measurements from high altitude balloons in Antarctica

    International Nuclear Information System (INIS)

    Lin, R.P.

    1990-01-01

    For measurements of cosmic and solar gamma-rays, hard X-rays, and particles, Antarctica offers the potential for very long, 10--20 day, continuous, twenty-four-hour-a-day observations, with balloon flights circling the South Pole during austral summer. For X-ray/gamma-ray sources at high south latitude the overlying atmosphere is minimized, and for cosmic ray measurements the low geomagnetic cutoff permits entry of low rigidity particles. The first Antarctic flight of a heavy (∼2400 lb.) payload on a large (11.6x10 6 cu. ft.) balloon took place in January, 1988, to search for the gamma-ray lines of 56 Co produced in the new supernova SN 1987A in the Large Magellanic Cloud. The long duration balloon flights presently planned from Antarctica include those for further gamma-ray/hard X-ray studies of SN 1987A and for the NASA Max '91 program for solar flare studies

  17. The prevalence of headache in Greece: correlations to latitude and climatological factors.

    Science.gov (United States)

    Mitsikostas, D D; Tsaklakidou, D; Athanasiadis, N; Thomas, A

    1996-03-01

    A questionnaire study on headaches, using a door-to-door survey, was carried out in a representative sample of the general Greek population, including 1737 men and 1764 women, from 15 to 75 years of age. The parameters evaluated included age, sex, education, socioeconomic status, region of domicile, frequency of headache, use of medication, medical consultation, and family history. Latitude and climatologic factors such as humidity, temperature, and atmospheric pressure were also investigated. Headaches were not classified because the interviewers were not specialists. Nineteen percent of men and 40% of women (mean 29%) suffered from headaches in the prior year. Headaches were more frequent in lower social classes, in people with less education, and in those between 45 and 64 years of age. Nineteen percent of sufferers did not take any medication and 33% used medication every time that they had a headache, while 36% sought medical consultation. Twenty-nine percent of headache sufferers had a family history of headaches. Daily headache was present in 15% of headache sufferers. Humidity and atmospheric pressure were not correlated to headache frequency. However, in the northern areas of Greece, as well as in the regions with low mean temperature, more people suffered from daily headaches. These data may explain the lower 1-year prevalence of headaches in other Greece as compared to the prevalence of headaches in other northern European countries.

  18. Identifications of Einstein Slew Survey sources

    Science.gov (United States)

    Schachter, Jonathan F.; Elvis, Martin S.; Plummer, David; Fabbiano, G.

    1992-01-01

    The status of identifications of the Einstien Slew Survey, a bright soft x-ray catalog with 550 new x-ray sources, is discussed. Possible counterparts were found for greater than 95 percent of the Slew Survey based on positional coincidences and color-color diagnostics. The survey will be fully identified via upcoming radio and optical observations.

  19. Abrupt climate change and high to low latitude teleconnections as simulated in climate models

    DEFF Research Database (Denmark)

    Cvijanovic, Ivana

    of the present day atmospheric mid-latitude energy transport compared to that of the Last Glacial Maximum, suggesting its ability to reorganize more easily and thereby dampen high latitude temperature anomalies that could arise from changes in the oceanic transport. The role of tropical SSTs in the tropical......High to low latitude atmospheric teleconnections have been a topic of increasing scientific interest since it was shown that high latitude extratropical forcing can induce tropical precipitation shifts through atmosphere-surface ocean interactions. In this thesis, several aspects of high to low...... precipitation shifts was further re-examined in idealized simulations with the fixed tropical sea surface temperatures, showing that the SST changes are fundamental to the tropical precipitation shifts. Regarding the high latitude energy loss, it was shown that the main energy compensation comes from...

  20. Educational Cosmic Ray Arrays

    International Nuclear Information System (INIS)

    Soluk, R. A.

    2006-01-01

    In the last decade a great deal of interest has arisen in using sparse arrays of cosmic ray detectors located at schools as a means of doing both outreach and physics research. This approach has the unique advantage of involving grade school students in an actual ongoing experiment, rather then a simple teaching exercise, while at the same time providing researchers with the basic infrastructure for installation of cosmic ray detectors. A survey is made of projects in North America and Europe and in particular the ALTA experiment at the University of Alberta which was the first experiment operating under this paradigm

  1. Gamma Ray Bursts

    Science.gov (United States)

    Gehrels, Neil; Meszaros, Peter

    2012-01-01

    Gamma-ray bursts (GRBs) are bright flashes of gamma-rays coming from the cosmos. They occur roughly once per day ,last typically lOs of seconds and are the most luminous events in the universe. More than three decades after their discovery, and after pioneering advances from space and ground experiments, they still remain mysterious. The launch of the Swift and Fermi satellites in 2004 and 2008 brought in a trove of qualitatively new data. In this review we survey the interplay between these recent observations and the theoretical models of the prompt GRB emission and the subsequent afterglows.

  2. Airborne gamma-ray spectrometer and magnetometer survey, Durango A, B, C, and D, Colorado. Volume I. Detail area. Final report

    International Nuclear Information System (INIS)

    1983-01-01

    An airborne combined radiometric and magnetic survey was performed for the Department of Energy (DOE) over the Durango A, Durango B, Durango C, and Durango D Detail Areas of southwestern Colorado. The Durango A Detail Area is within the coverage of the Needle Mountains and Silverton 15' map sheets, and the Pole Creek Mountain, Rio Grande Pyramid, Emerald Lake, Granite Peak, Vallecito Reservoir, and Lemon Reservoir 7.5' map sheets of the National Topographic Map Series (NTMS). The Durango B Detail Area is within the coverage of the Silverton 15' map sheet and the Wetterhorn Peak, Uncompahgre Peak, Lake City, Redcloud Peak, Lake San Cristobal, Pole Creek Mountain, and Finger Mesa 7.5' map sheets of the NTMS. The Durango C Detail Area is within the coverage of the Platoro and Wolf Creek Pass 15' map sheets of the NTMS. The Durango D Detail Area is within the coverage of the Granite Lake, Cimarrona Peak, Bear Mountain, and Oakbrush Ridge 7.5' map sheets of the NTMS. Radiometric data were corrected for live time, aircraft and equipment background, cosmic background, atmospheric radon, Compton scatter, and altitude dependence. The corrected data were statistically evaluated, gridded, and contoured to produce maps of the radiometric variables, uranium, potassium, and thorium; their ratios; and the residual magnetic field. These maps have been analyzed in order to produce a multi-variant analysis contour map based on the radiometric response of the individual geological units. A geochemical analysis has been performed, using the radiometric and magnetic contour maps, the multi-variant analysis map, and factor analysis techniques, to produce a geochemical analysis map for the area

  3. A Survey of X-Ray Variability in Seyfert 1 Galaxies with XMM-Newton to study the soft excess and the broad Fe lines

    Science.gov (United States)

    Ponti, Gabriele

    The nature of the soft excess and the presence of the broad Fe lines is still nowadays highly debated because the different absorption/emission models are degenerate. Spectral variability studies have the potential to break this degeneracy. I will present the results of a spectral variability RMS survey of the 36 brightest type 1 Seyfert galaxies observed by XMM-Newton for more than 30 ks. More than 80 as already measured, on longer timescales, with RXTE (Markowitz et al. 2004). About half of the sample show lower variability in the soft energy band, indicating that the emission from the soft excess is more stable than the one of the continuum. While the other sources show a soft excess that is as variable as the continuum. About half of the sample do not show an excess of variability where the warm absorber component imprints its stronger features, suggesting that for these sources the soft excess is not produced by a relativistic absorbing wind. In a few bright and well exposed sources it has been possible to measure an excess of variability at the energy of the broad component of the Fe K line, in agreement with the broad emission line interpretation. For the sources where more than one observation was available the stability of the shape of the RMS spectrum has been investigated. Moreover, it will be presented the results of the computation of the excess variance of all the radio quiet type 1 AGN of the XMM-Newton database. The relations between variability, black hole mass, accretion rate and luminosity are investigated and their scatter measured.

  4. An introduction to mid-latitude ecotone: sustainability and environmental challenges

    Directory of Open Access Journals (Sweden)

    J. Moon

    2017-12-01

    Full Text Available The mid-latitude zone can be broadly defined as part of the hemisphere between 30°–60° latitude. This zone is home to over 50 % of the world population and encompasses about 36 countries throughout the principal region, which host most of the world’s development and poverty related problems. In reviewing some of the past and current major environmental challenges that parts of mid-latitudes are facing, this study sets the context by limiting the scope of mid-latitude region to that of Northern hemisphere, specifically between 30°–45° latitudes which is related to the warm temperate zone comprising the Mid-Latitude ecotone – a transition belt between the forest zone and southern dry land territories. The ongoing climate change reveals a substantial increase of temperature and simultaneous decrease in the amount of precipitation across vast continental regions in the mid-latitudes. According to climatic predictions, these tendencies will continue during the 21st century, which will likely increase the frequency and severity of droughts and water stress of vegetation. Along with climate change, ongoing land degradation and deforestation are observed in many regions of the mid-latitude region. For example, the Korean peninsula, which is divided into South and North Korea, is characterized by drastically different forest conditions. Deforestation in North Korea has been exacerbating at a noticeable pace due to excessive logging and human intervention. Such problems are not confined to Korean peninsula but are witnessed across vast regions of the mid-latitude region. Within this context – acquiring better understanding in the role of terrestrial ecosystems located at different latitudes is critical – for building resilience against the negative impact of climate change and for maintaining the stability of the environment and landscapes.

  5. Mid-latitude mesospheric clouds and their environment from SOFIE observations

    Science.gov (United States)

    Hervig, Mark E.; Gerding, Michael; Stevens, Michael H.; Stockwell, Robert; Bailey, Scott M.; Russell, James M.; Stober, Gunter

    2016-11-01

    Observations from the Solar Occultation For Ice Experiment (SOFIE) on the Aeronomy of Ice in the Mesosphere (AIM) satellite are used to examine noctilucent clouds (NLC) and their environment at middle latitudes ( 56°N and 52°S). Because SOFIE is uniquely capable of measuring NLC, water vapor, and temperature simultaneously, the local cloud environment can be specified to examine what controls their formation at mid-latitudes. Compared to higher latitudes, mid-latitude NLCs are less frequent and have lower ice mass density, by roughly a factor of five. Compared to higher latitudes at NLC heights, mid-latitude water vapor is only 12% lower while temperatures are more than 10 K higher. As a result the reduced NLC mass and frequency at mid-latitudes can be attributed primarily to temperature. Middle and high latitude NLCs contain a similar amount of meteoric smoke, which was not anticipated because smoke abundance increases towards the equator in summer. SOFIE indicates that mid-latitude NLCs may or may not be associated with supersaturation with respect to ice. It is speculated that this situation is due in part to SOFIE uncertainties related to the limb measurement geometry combined with the non-uniform nature of NLCs. SOFIE is compared with concurrent NLC, temperature, and wind observations from Kühlungsborn, Germany (54°N) during the 2015 summer. The results indicate good agreement in temperature and NLC occurrence frequency, backscatter, and height. SOFIE indicates that NLCs were less frequent over Europe during 2015 compared to other longitudes, in contrast to previous years at higher latitudes that showed no clear longitude dependence. Comparisons of SOFIE and the Solar Backscatter Ultraviolet (SBUV) indicate good agreement in average ice water column (IWC), although differences in occurrence frequency were often large.

  6. Surveying Future Surveys

    Science.gov (United States)

    Carlstrom, John E.

    2016-06-01

    The now standard model of cosmology has been tested and refined by the analysis of increasingly sensitive, large astronomical surveys, especially with statistically significant millimeter-wave surveys of the cosmic microwave background and optical surveys of the distribution of galaxies. This talk will offer a glimpse of the future, which promises an acceleration of this trend with cosmological information coming from new surveys across the electromagnetic spectrum as well as particles and even gravitational waves.

  7. Relation of schizophrenia prevalence to latitude, climate, fish consumption, infant mortality, and skin color: a role for prenatal vitamin d deficiency and infections?

    Science.gov (United States)

    Kinney, Dennis K; Teixeira, Pamela; Hsu, Diane; Napoleon, Siena C; Crowley, David J; Miller, Andrea; Hyman, William; Huang, Emerald

    2009-05-01

    Previous surveys found a large (>10-fold) variation in schizophrenia prevalence at different geographic sites and a tendency for prevalence to increase with latitude. We conducted meta-analyses of prevalence studies to investigate whether these findings pointed to underlying etiologic factors in schizophrenia or were the result of methodological artifacts or the confounding of sites' latitude with level of healthcare at those sites. We found that these patterns were still present after controlling for an index of healthcare--infant mortality--and focusing on 49 studies that used similar diagnostic and ascertainment methods. The tendencies for schizophrenia prevalence to increase with both latitude and colder climate were still large and significant and present on several continents. The increase in prevalence with latitude was greater for groups with low fish consumption, darker skin, and higher infant mortality--consistent with a role of prenatal vitamin D deficiency in schizophrenia. Previous research indicates that poor prenatal healthcare and nutrition increase risk for schizophrenia within the same region. These adverse conditions are more prevalent in developing countries concentrated near the equator, but schizophrenia prevalence is lowest at sites near the equator. This suggests that schizophrenia-producing environmental factors associated with higher latitude may be so powerful they overwhelm protective effects of better healthcare in industrialized countries. The observed patterns of correlations of risk factors with prevalence are consistent with an etiologic role for prenatal vitamin D deficiency and exposure to certain infectious diseases. Research to elucidate environmental factors that underlie variations in schizophrenia prevalence deserves high priority.

  8. Arctic East Siberia had a lower latitude in the Pleistocene

    Directory of Open Access Journals (Sweden)

    Willy Woelfli

    2007-06-01

    Full Text Available Remains of mammoths in Arctic East Siberia, where there is not sufficient sunlight over the year for the growth of the plants on which these animals feed, indicate that the latitude of this region was lower before the end of the Pleistocene than now. Reconstructing this geographic pole shift, we introduce a massive object, which moved in an extremely eccentric orbit and was hot from tidal work and solar radiation. Evaporation produced a disk-shaped cloud of ions around the Sun. This cloud partially shielded the solar radiation, producing the cold and warm periods characterizing the Pleistocene. The shielding depends on the inclination of Earth's orbit, which has a period of 100. 000 years. The cloud builds up to a point where inelastic particle collisions induce its collapse The resulting near-periodic time dependence resembles that of Dansgaard-Oeschger events. The Pleistocene ended when the massive object had a close encounter with the Earth, which suffered a one per mil extensional deformation. While the deformation relaxed to an equilibrium shape in one to several years, the globe turned relative to the rotation axis: The North Pole moved from Greenland to the Arctic Sea. The massive object split into fragments, which evaporated.Na Sibéria Oriental Ártica, onde há sobras de mamutes, a luzsolar durante o ano é insuficiente para sustentar as plantas que alimentam esses animais. Isto prova que a latitude dessas regiões era menor durante o Pleistoceno. Reconstruindo esse deslocamento geográfico dos pólos introduzimos um planeta adicional numa órbita tão excêntrica que a energia da maré e da radiação solar o esquentou. A sua evaporação criava em torno do sol uma nuvem de íons que espalhava a radiação solar e assim causava os períodos quentes e frios do Pleistoceno. O efeito depende da inclinação da órbita da terra, que varia com um período de 100. 000 anos. Quase periodicamente anuvem se formava até o ponto em que as colis

  9. High Latitude Reefs: A Potential Refuge for Reef Builders

    Science.gov (United States)

    Amat, A.; Bates, N.

    2003-04-01

    Coral reefs globally show variable signs of deterioration or community structure changes due to a host of anthropogenic and natural factors. In these global scenarios, rates of calcification by reef builders such as Scleractinian corals are predicted to significantly decline in the future due to the increase in atmospheric CO_2. When considering the response of reefs to the present climate change, temperature effects should also be taken into account. Here, we investigate the simultaneous impact of temperature and CO_2 on the high-latitude Bermuda coral reef system (32^oN, 64^oE)through a series of in vitro experiments at different CO_2 levels and seasonally different summer (27^oC) and winter (20^oC) temperature conditions. Four species of Scleractinian corals (Porites astreoides, Diploria labyrinthiformis, Madracis mirabilis and decactis) were acclimated for three months at: 20^oC and 27^oC (both with CO_2 levels at 400 ppm (control) and 700 ppm). Growth was assessed by buoyant weight techniques during the acclimation period. Photosynthesis, respiration and calcification were measured at the end of this period using respirometric chambers. A reproduction experiment was also undertaken under 27^oC. Photosynthesis mainly remains constant or increases under high CO_2 conditions. The results of the integrated calcification measurements confirm the hypothesis that an increase in CO_2 induces a decrease in calcification. However an increase in photosynthesis can be observed when CO_2 is unfavorable for calcification suggesting that a biological control of calcification through photosynthesis could prevent a drop in the calcification potential. Buoyant weight results indicate that the CO_2 impact could be less detrimental under lower temperature. This result will be compared with the instantaneous calcification measurements in the chambers and some in situ coral growth assessments in winter and summer conditions. The consequences for the response of marginal reefs

  10. Crossing latitudes--long-distance tracking of an apex predator.

    Directory of Open Access Journals (Sweden)

    Luciana C Ferreira

    Full Text Available Tiger sharks (Galeocerdo cuvier are apex predators occurring in most tropical and warm temperate marine ecosystems, but we know relatively little of their patterns of residency and movement over large spatial and temporal scales. We deployed satellite tags on eleven tiger sharks off the north-western coast of Western Australia and used the Brownian Bridge kernel method to calculate home ranges and analyse movement behaviour. One individual recorded one of the largest geographical ranges of movement ever reported for the species, travelling over 4000 km during 517 days of monitoring. Tags on the remainder of the sharks reported for shorter periods (7-191 days. Most of these sharks had restricted movements and long-term (30-188 days residency in coastal waters in the vicinity of the area where they were tagged. Core home range areas of sharks varied greatly from 1166.9 to 634,944 km2. Tiger sharks spent most of their time in water temperatures between 23°-26°C but experienced temperatures ranging from 6°C to 33°C. One shark displayed seasonal movements among three distinct home range cores spread along most of the coast of Western Australia and generalized linear models showed that this individual had different patterns of temperature and depth occupancy in each region of the coast, with the highest probability of residency occurring in the shallowest areas of the coast with water temperatures above 23°C. These results suggest that tiger sharks can migrate over very large distances and across latitudes ranging from tropical to the cool temperate waters. Such extensive long-term movements may be a key element influencing the connectivity of populations within and among ocean basins.

  11. Ion escape fluxes from the terrestrial high-latitude ionosphere

    International Nuclear Information System (INIS)

    Barakat, A.R.; Schunk, R.W.; Moore, T.E.; Waite, J.H. Jr.

    1987-01-01

    The coupled continuity and momentum equations for H + , O + , and electrons were solved for the terrestrial ionosphere in order to determine the limiting ion escape fluxes at high latitudes. The effects of solar cycle, season, geomagnetic activity, and the altitude of the acceleration region on the ion escape fluxes were studied for average conditions. In addition, a systematic parameter study was conducted to determine the extent to which variations in ionospheric conditions (for example, electron temperature, ion temperature, induced vertical ion drifts, etc.) can affect the results. The main conclusions of the study are as follows: (1) as solar activity increases, the general trend is for an increase in the limiting O + escape flux and a decrease in the limiting H + escape flux; (2) in winter the limiting escape fluxes of both O + and H + are larger than those in summer, particularly for low geomagnetic activity; (3) the O + content of the ion outflow increases with increasing ''demand'' imposed on the ionosphere by a high-altitude acceleration process, with increasing solar activity, with increasing geomagnetic activity, with increasing solar elevation from winter to summer, and with a lowering of the altitude of the acceleration region; (4) when H + is in a near-diffusive equilibrium state and a selective mechanism accelerates O + , the limiting O + escape flux is significantly reduced compared to that obtained when an H + outflow also occurs; and (5) at a given time or location the general trends described above can be significantly modified or even reversed owing to natural variations of the ionospheric ion and electron temperatures, induced vertical ion drifts, etc. The general trends obtained for average conditions appear to mimic the qualitative behavior determined from statistically averaged data for comparable absolute escape flux magnitudes

  12. A numerical study of ionospheric profiles for mid-latitudes

    Directory of Open Access Journals (Sweden)

    S.-R. Zhang

    1995-05-01

    Full Text Available This paper presents a numerical model and results for the mid-latitude ionospheric profile below the peak of the F2-layer. The basis of the model is the solving of equations for four ionic species O+, NO+, O+2 and N+2, as well as the meta-stable O+(2D and O+(2P. Diffusion and wind-induced drifts and 21 photo-chemical reactions are also taken into account. Neutral atmospheric density and temperature are derived from the MSIS86 model and solar extreme ultraviolate irradiance from the EUV91 model. In an effort to obtain a more realistic ionospheric profile, the key point at foF2 and hmF2 is fitted from the simulation to observations. The model also utilizes the vertical drifts derived from ionosonde data with the help of the Servo model. It is shown that the ionospheric height of peak can be reproduced more accurately under the derived vertical drifts from the Servo theory than with the HWM90 model. Results from the simulation are given for Wuchang (30.5°N, 114.4°E and Wakkanai (45.6°N, 141.7°E, showing the profile changes with season and solar activity, and the E-F valley structure (the depth and the width. This simulation also reveals the importance of meta-stable ions and dynamical transport processes on the formation of the F1-ledge and F1-F2 valley.

  13. Ionospheric irregularities at low latitudes in the American sector

    International Nuclear Information System (INIS)

    Nakamura, Y.

    1981-10-01

    A detailed analysis of the atomic oxigem airglow emission at the wavelength of 6300 A observed at Cachoeira Paulista (22 0 41'S, 45 0 00'W) shows that intensity perturbations frequently occur and propagate from north to south and from west to east. Such irregularities originated in the ionospheric F region and occur essencially during the premidnight period. These perturbations have a high frequency of occurrence during spring and summer and are rare during winter and fall. The disturbances are correlated with range type spread F detected over Cachoeira Paulista, and have characteristics similar to equatorial ionospheric plasma bubbles (i.e., similar seazonal variation, time of occurrence, ionogram signatures, direction and speed of propagation, etc.). A numerical simulation is carried out for the generation and evolution of ionospheric bubbles based on the theory of the collisional Rayleigh-Taylor instability for the equatorial and Cachoeira Paulista regions. Also a study was made of the, evolution of the bubble as a function of the electron density profile and as a function of the amplitude of the initial density perturbation. Assuming the electron density profile perturbed by the bubble, the [OI] 6300 A intensity was calculated for various latitudes arbitrarily taken within the photometer scanning range. The bubble was assumed to be aligned with the Earth's magnetic field and extending from higher altitudes at the equatorial region down to be arbitrary height of 150 Km at which a negligible conductivity is assumed. It was also assumed that the bubble was moving upwards with the velocity of 120 m/s, which in turn was estimated from initial numerical simulation results. The airglow calculation results show that as the bubble goes up, the disturbances in the airglow intensity propagate from north to south, in accord with observed experimental results. (Author) [pt

  14. Structure of the low-latitude boundary layer

    International Nuclear Information System (INIS)

    Sckopke, N.; Paschmann, G.; Haerendel, G.; Sonnerup, B.U.O.; Bame, S.J.; Forbes, T.G.; Hones, E.W. Jr.; Russell, C.T.

    1981-01-01

    Observations at high temporal resolution of the frontside magnetopause and plasma boundary layer, made with the Los Alamos Scientific Laboratory/Max-Planck-Institut, Institut fuer Extraterrestrische Physik, fast plasma analyzer on board the Isee 1 and 2 spacecraft, have revealed a complex quasi-periodic structure of some of the observed boundary layers: cool tailward streaming boundary layer plasma is seen intermittently, with intervening periods of hot tenuous plasma which has properties similar to the magnetospheric population. While individual encounters with the boundary layer plasma last only a few minutes, the total observation time may extend over 1 hour or more. One such crossing, at 0800 hours local time and 40 0 northern GSM latitude, is examined in detail, including a quantitative comparison of the boundary layer entry and exit times of the two spacecraft. The data are found to be compatible with a boundary layer that is always attached to the magnetopause but where the layer thickness has a large-scale spatial modulation pattern which travels tailward past the spacecraft. Included are periods when the thickness is essentially zero and others when it is of the order of 1 R/sub E/. The duration of these periods is highly variable but is typically in the range of 2--5 min, corresponding to a distance along the magnetopause of the order of 3--8 R/sub E/. The observed boundary layer features include a steep density gradient at the magnetopause, with an approximately constant boundary layer plasma density amounting to about 25% of the magnetosheath density, and a second abrupt density decrease at the inner edge of the layer. It also appears that the purely magnetospheric plasma is ocassionally separated from the boundary layer by a halo region in which the plasma density is somewhat higher, and the temperature somewhat lower, than in the magnetosphere. A tentative model is proposed

  15. Mapping high-latitude plasma convection with coherent HF radars

    International Nuclear Information System (INIS)

    Ruohoniemi, J.M.; Greenwald, R.A.; Baker, K.B.; Villain, J.-P.; Hanuise, C.; Kelly, J.

    1989-01-01

    In this decade, a new technique for the study of ionosphere electrodynamics has been implemented in an evolving generation of high-latitude HF radars. Coherent backscatter from electron density irregularities at F region altitudes is utilized to observe convective plasma motion. The electronic beam forming and scanning capabilities of the radars afford an excellent combination of spatial (∼50 km) and temporal (∼1 min) resolution of the large-scale (∼10 6 km 2 ) convection pattern. In this paper, we outline the methods developed to synthesize the HF radar data into two-dimensional maps of convection velocity. Although any single radar can directly measure only the line-of-sight, or radial, component of the plasma motion, the convection pattern is sometimes so uniform and stable that scanning in azimuth serves to determine the transverse component as well. Under more variable conditions, data from a second radar are necessary to unambiguously resolve velocity vectors. In either case, a limited region of vector solution can be expanded into contiguous areas of single-radar radial velocity data by noting that the convection must everywhere be divergence-free, i.e., ∇·v=0. It is thus often possible to map velocity vectors without extensive second-radar coverage. We present several examples of two-dimensional velocity maps. These show instances of L shell-aligned flow in the dusk sector, the reversal of convection near magnetic midnight, and counterstreaming in the dayside cleft. We include a study of merged coherent and incoherent radar data that illustrates the applicability of these methods to other ionospheric radar systems. copyright American Geophysical Union 1989

  16. EDITORIAL: Northern Hemisphere high latitude climate and environmental change

    Science.gov (United States)

    Groisman, Pavel; Soja, Amber

    2007-10-01

    High Northern Hemisphere latitudes are undergoing rapid and significant change associated with climate warming. Climatic change in this region interacts with and affects the rate of the global change through atmospheric circulation, biogeophysical, and biogeochemical feedbacks. Changes in the surface energy balance, hydrologic cycle, and carbon budget feedback to regional and global weather and climate systems. Two-thirds of the Northern Hemisphere high latitude land mass resides in Northern Eurasia (~20% of the global land mass), and this region has undergone sweeping socio-economic change throughout the 20th century. How this carbon-rich, cold region component of the Earth system functions as a regional entity and interacts with and feeds back to the greater global system is to a large extent unknown. To mitigate the deficiencies in understanding these feedbacks, which may in turn hamper our understanding of the global change rates and patterns, an initiative was formed. Three years ago the Northern Eurasia Earth Science Partnership Initiative (NEESPI) was established to address large-scale and long-term manifestations of climate and environmental change in this region. The NEESPI Science Plan and its Executive Summary have been published at the NEESPI web site (neespi.org). Since 2004, NEESPI participants have been able to seed several waves of research proposals to international and national funding agencies and institutions and also contribute to the International Polar Year. Currently, NEESPI is widely recognized and endorsed by several Earth System Science Partnership (ESSP) programmes and projects: the International Geosphere and Biosphere Programme, the World Climate Research Programme through the Global Energy and Water Cycle Experiment and Climate and Cryosphere Projects, the Global Water System Project, Global Carbon Project, Global Land Project, and the Integrated Land Ecosystem—Atmosphere Processes Study. Through NEESPI, more than 100 individually

  17. Gamma-rays from decaying dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Bertone, G. [Paris-6 Univ., 75 (France). Inst. d' Astrophysique; Buchmueller, W.; Covi, L.; Ibarra, A. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2007-10-15

    We study the prospects for detecting gamma-rays from decaying Dark Matter (DM), focusing in particular on gravitino DM in R-parity breaking vacua. Given the substantially different angular distribution of the predicted gamma-ray signal with respect to the case of annihilating DM, and the relatively poor (of order 0.1 ) angular resolution of gamma-ray detectors, the best strategy for detection is in this case to look for an exotic contribution to the gamma-ray flux at high galactic latitudes, where the decaying DM contribution would resemble an astrophysical extragalactic component, similar to the one inferred by EGRET observations. Upcoming experiments such as GLAST and AMS-02 may identify this exotic contribution and discriminate it from astrophysical sources, or place significant constraints on the mass and lifetime of DM particles. (orig.)

  18. A prospective study comparing whole-body skeletal X-ray survey with 18F-FDG-PET/CT, 18F-NaF-PET/CT and whole-body MRI in the detection of bone lesions in multiple myeloma patients

    DEFF Research Database (Denmark)

    Dyrberg, Eva; Hendel, Helle W; Al-Farra, Gina

    2017-01-01

    Background: For decades, the most widely used imaging technique for myeloma bone lesions has been a whole-body skeletal X-ray survey (WBXR), but newer promising imaging techniques are evolving. Purpose: To compare WBXR with the advanced imaging techniques 18F-fluorodeoxyglucose (FDG) positron emi...

  19. X-ray astronomy

    International Nuclear Information System (INIS)

    Giacconi, R.; Setti, G.

    1980-01-01

    This book contains the lectures, and the most important seminars held at the NATO meeting on X-Ray astronomy in Erice, July 1979. The meeting was an opportune forum to discuss the results of the first 8-months of operation of the X-ray satellite, HEAO-2 (Einstein Observatory) which was launched at the end of 1978. Besides surveying these results, the meeting covered extragalactic astronomy, including the relevant observations obtained in other portions of the electromagnetic spectrum (ultra-violet, optical, infrared and radio). The discussion on galactic X-ray sources essentially covered classical binaries, globular clusters and bursters and its significance to extragalactic sources and to high energy astrophysics was borne in mind. (orig.)

  20. A Mid-Latitude Skywave Propagation Experiment: Overview and Results

    Science.gov (United States)

    Munton, D. C.; Calfas, R. S.; Gaussiran, T., II; Rainwater, D.; Flesichmann, A. M.; Schofield, J. R.

    2016-12-01

    We will describe a mid-latitude HF skywave propagation experiment conducted during 19-27 January, 2014. There were two primary goals to the experiment. First, we wanted to build an understanding of the impact that medium scale traveling ionospheric disturbances have on the angles of arrival of the HF signals. The second goal was to provide a diverse data set that could serve as a baseline for propagation model development and evaluation. We structured individual tests during the experiment to increase the knowledge of temporal and spatial length scales of various ionospheric features. The experiment was conducted during both day and night periods and spanned a wide range of ionospheric states. We conducted the experiment at White Sands Missile Range, New Mexico and in the surrounding area. As part of the experiment, we deployed a number of active HF transmitters, and an array of dipole antennas to provide angle of arrival measurements. We also deployed a smaller array of more novel compact electro-magnetic vector sensors (EMVSs). Other instrumentation specific to the remote sensing of the ionosphere included digisondes, GNSS receivers, beacon satellite receivers, and optical instruments. We will provide a complete description of the experiment configuration and the data products.Finally, we will provide a discussion of experimental results, focusing on ionospheric conditions during the angle-of-arrival determinations, and the impact ionospheric disturbances can have on these measurements. We use the angle-of-arrival determinations to estimate TID properties, including velocity and direction.This research is based upon work supported in part by the Office of the Director of National Intelligence (ODNI), Intelligence Advanced Research Projects Activity (IARPA), via US Navy Contract N00024-07-D-6200. The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements

  1. Exchange across the shelf break at high southern latitudes

    Directory of Open Access Journals (Sweden)

    J. M. Klinck

    2010-05-01

    Full Text Available Exchange of water across the Antarctic shelf break has considerable scientific and societal importance due to its effects on circulation and biology of the region, conversion of water masses as part of the global overturning circulation and basal melt of glacial ice and the consequent effect on sea level rise. The focus in this paper is the onshore transport of warm, oceanic Circumpolar Deep Water (CDW; export of dense water from these shelves is equally important, but has been the focus of other recent papers and will not be considered here. A variety of physical mechanisms are described which could play a role in this onshore flux. The relative importance of some processes are evaluated by simple calculations. A numerical model for the Ross Sea continental shelf is used as an example of a more comprehensive evaluation of the details of cross-shelf break exchange. In order for an ocean circulation model to simulate these processes at high southern latitudes, it needs to have high spatial resolution, realistic geometry and bathymetry. Grid spacing smaller than the first baroclinic radius of deformation (a few km is required to adequately represent the circulation. Because of flow-topography interactions, bathymetry needs to be represented at these same small scales. Atmospheric conditions used to force these circulation models also need to be known at a similar small spatial resolution (a few km in order to represent orographically controlled winds (coastal jets and katabatic winds. Significantly, time variability of surface winds strongly influences the structure of the mixed layer. Daily, if not more frequent, surface fluxes must be imposed for a realistic surface mixed layer. Sea ice and ice shelves are important components of the coastal circulation. Ice isolates the ocean from exchange with the atmosphere, especially in the winter. Melting and freezing of both sea ice and glacial ice influence salinity and thereby the character of shelf

  2. Automated Detection of Thermo-Erosion in High Latitude Ecosystems

    Science.gov (United States)

    Lara, M. J.; Chipman, M. L.; Hu, F.

    2017-12-01

    conditions or wildfire. This work demonstrates the utility of meso-scale high frequency remote sensing products for advancing high latitude permafrost research.

  3. Electrodynamic coupling of high and low latitudes: Observations on May 27, 1993

    DEFF Research Database (Denmark)

    Kobea, A.T.; Richmond, A.D.; Emery, B.A.

    2000-01-01

    The penetration of disturbance electric fields from the polar region to the magnetic equator on the dayside of the Earth is examined with geomagnetic data on May 27, 1993. First, we examine a dayside equatorial disturbance that followed the rapid recovery of magnetic activity from a storm...... than 1 min for fluctuations having periods like those examined here. A synoptic inversion analysis of the high-latitude magnetic data to estimate the time-varying high-latitude electric potential patterns shows that fluctuations of the high-latitude east-west potential gradient tended...

  4. Galaxies in x-ray selected clusters and groups in Dark Energy Survey Data I: Stellar mass growth of bright central galaxies since Z similar to 1.2

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Y.; Miller, C.; McKay, T.; Rooney, P.; Evrard, A. E.; Romer, A. K.; Perfecto, R.; Song, J; Desai, S.; Mohr, J. J.; Vikram, V.

    2016-01-10

    Using the science verification data of the Dark Energy Survey for a new sample of 106 X-ray selected clusters and groups, we study the stellar mass growth of bright central galaxies (BCGs) since redshift z similar to 1.2. Compared with the expectation in a semi-analytical model applied to the Millennium Simulation, the observed BCGs become under-massive/under-luminous with decreasing redshift. We incorporate the uncertainties associated with cluster mass, redshift, and BCG stellar mass measurements into an analysis of a redshift-dependent BCG-cluster mass relation, m(*) proportional to (M-200/1.5 x 10(14)M(circle dot))(0.24 +/- 0.08)(1+z)(-0.19 +/- 0.34), and compare the observed relation to the model prediction. We estimate the average growth rate since z = 1.0 for BCGs hosted by clusters of M-200,M-z = 10(13.8)M(circle dot); at z = 1.0: m(*, BCG) appears to have grown by 0.13 +/- 0.11 dex, in tension at the similar to 2.5 sigma significance level with the 0.40 dex growth rate expected from the semi-analytic model. We show that the build-up of extended intracluster light after z = 1.0 may alleviate this tension in BCG growth rates.

  5. South latitude and household economic control by Peruvian women

    OpenAIRE

    León, Federico

    2012-01-01

    Southern women’s greater autonomy versus northern women’s more traditional submission to the husband were hypothesized in 1984 to explain variations in Peruvian women’s fertility desires. An analysis of data from Peru 2004-2008 Continuous Demographic and Family Health Survey supports this hypothesis by showing a significant north-to-south growth of women’s control upon husband’s income and, less consistently, household purchasing decisions. These relationships are not explained by variables a...

  6. Heliospheric Modulation of Galactic Cosmic Rays; Diurnal Variability Abstract Details

    Science.gov (United States)

    Kalu, D. F.; Okpala, K. C.

    2017-12-01

    We have studied the variability of Cosmic rays flux during solar quiet days at mid and high latitudes in the Northern Hemisphere. By using the five (5) quietest days for each month and the five disturbed days for each month, the monthly mean diurnal variation of cosmic ray anisotropy have been derived for the period 1999-2015, which covers part of cycles 23, and cycle 24. This study seeks to understand the heliospheric contribution to the variation of these Cosmic rays on quietest days, three stations (Inuvik, Moscow, Rome) Neutron Monitors were employed. This study seeks to understand the important features of the high latitude and mid latitude diurnal wave, and how solar and geomagnetic activity may be influencing the wave characteristics. Cosmic ray wave characteristics were obtained by discrete Fourier transform (DFT). The mean, diurnal amplitude, phase and dispersion for each month's diurnal wave were calculated and profiled. There was clear indication that the terrestrial effect on the variability of the monthly mean was more associated with geomagnetic activity rather than rigidity of the cosmic rays. Correlation of the time series of these wave characteristic with solar and geomagnetic activity index showed better association with solar activity.

  7. Observation of low energy (0,05-3,0 MeV) γ radiation with Ge(Li) telescope in Λ=120S geomagnetic latitude

    International Nuclear Information System (INIS)

    Costa, J.M. da.

    1980-02-01

    The observation of low energy gamma ray at the geomagnetic latitude Λ = 12 0 S with detectors on board of balloons could provide important informations on the astrophysical processes occuring in the region of the Galatic Center. Four experiments of low energy gamma ray were flown in 1976-1977 from Guaratingueta with a balloon-borne Ge(Li) 140 cm 3 of volume for the detection of gamma ray lines from the direction of the Galactic Center. The gamma ray spectra measured in these experiments, were submitted to a fine spectroscopic analysis in order to study the contribution of atmospheric and induced lines in the detector as well as in the payload. Several atmospheric and induced lines could be identified in the gamma ray spectra. The analysis of the gamma ray spectra of the flights of 14 and 17 February 1977 showed an intensity of (4, 19 + - 1,56) x 10 -3 photons cm -2 s -1 for the flux of the annihilation line from the direction of the Galactic Center. The astrophysical implications of this result are discussed in the present work. (Author) [pt

  8. Associations between emotional exhaustion, social capital, workload, and latitude in decision-making among professionals working with people with disabilities.

    Science.gov (United States)

    Kowalski, Christoph; Driller, Elke; Ernstmann, Nicole; Alich, Saskia; Karbach, Ute; Ommen, Oliver; Schulz-Nieswandt, Frank; Pfaff, Holger

    2010-01-01

    Many people working in human services in Western countries suffer from burnout, characterized by emotional exhaustion, depersonalization, and decreased personal performance. Prevention of emotional exhaustion (the first phase of burnout) constitutes a great challenge because emotional exhaustion may cause increasing turnover rates in staff and lead to a lesser quality of care. Prevention of emotional exhaustion requires knowledge of its predictors. The aim of this study was to investigate the associations between emotional exhaustion, social capital, workload, and latitude in decision-making among German professionals working in the care of persons with intellectual and physical disabilities. The study was based on a survey in a sheltered workshop and 5 homes for disabled persons with 175 professionals. Burnout was measured with the German version of the Maslach Burnout Inventory-General Survey (MBI-GS). A multivariate logistic regression analysis was computed. Logistic regression identified the following three significant predictors of emotional exhaustion in the sample: workload (OR, 4.192; CI, 2.136-8.227), latitude in decision-making (OR, 0.306; CI, 0.115-0.811), and male gender (OR, 4.123; CI, 1.796-9.462). Nagelkerke's Pseudo-R(2) was 0.344. The results of this study demonstrate that specific factors in work organization are associated with emotional exhaustion. Taking into account sociodemographic changes and the upcoming challenges for human services professionals, the results underline the importance of considering aspects of organization at the workplace to prevent burnout. Specific circumstances of male employees must be considered. Copyright 2009 Elsevier Ltd. All rights reserved.

  9. Dosimetry of environmental radiations (cosmic ray)

    International Nuclear Information System (INIS)

    Yamasaki, Keizo

    1978-01-01

    Cosmic ray is dominant as environmental radiation, though the experimental determination made on cosmic ray doses is few in Japan. The free air ionization intensity at sea level due to cosmic ray has been estimated in the Bay of Wakasa, Japan, at middle geomagnetic latitude (25 deg. N), in October 1977. The ionization chambers used were two air and one argon types. Where the responses to cosmic and terrestrial gamma rays were equal, the ionization intensity due to cosmic ray was obtained by subtracting the ionizati