WorldWideScience

Sample records for supernova search pipeline

  1. Automated search for supernovae

    Energy Technology Data Exchange (ETDEWEB)

    Kare, J.T.

    1984-11-15

    This thesis describes the design, development, and testing of a search system for supernovae, based on the use of current computer and detector technology. This search uses a computer-controlled telescope and charge coupled device (CCD) detector to collect images of hundreds of galaxies per night of observation, and a dedicated minicomputer to process these images in real time. The system is now collecting test images of up to several hundred fields per night, with a sensitivity corresponding to a limiting magnitude (visual) of 17. At full speed and sensitivity, the search will examine some 6000 galaxies every three nights, with a limiting magnitude of 18 or fainter, yielding roughly two supernovae per week (assuming one supernova per galaxy per 50 years) at 5 to 50 percent of maximum light. An additional 500 nearby galaxies will be searched every night, to locate about 10 supernovae per year at one or two percent of maximum light, within hours of the initial explosion.

  2. The Search for Lensed Supernovae

    Science.gov (United States)

    Kohler, Susanna

    2017-01-01

    Type Ia supernovae that have multiple images due to gravitational lensing can provide us with a wealth of information both about the supernovae themselves and about our surrounding universe. But how can we find these rare explosions?Clues from Multiple ImagesWhen light from a distant object passes by a massive foreground galaxy, the galaxys strong gravitational pull can bend the light, distorting our view of the backgroundobject. In severe cases, this process can cause multiple images of the distant object to appear in the foreground lensing galaxy.An illustration of gravitational lensing. Light from the distant supernova is bent as it passes through a giant elliptical galaxy in the foreground, causing multiple images of the supernova to appear to be hosted by the elliptical galaxy. [Adapted from image by NASA/ESA/A. Feild (STScI)]Observations of multiply-imaged Type Ia supernovae (explosions that occur when white dwarfs in binary systems exceed their maximum allowed mass) could answer a number of astronomical questions. Because Type Ia supernovae are standard candles, distant, lensed Type Ia supernovae can be used to extend the Hubble diagram to high redshifts. Furthermore, the lensing time delays from the multiply-imaged explosion can provide high-precision constraints on cosmological parameters.The catch? So far, weve only found one multiply-imaged Type Ia supernova: iPTF16geu, discovered late last year. Were going to need a lot more of them to develop a useful sample! So how do we identify themutiply-imaged Type Ias among the many billions of fleeting events discovered in current and future surveys of transients?Searching for AnomaliesAbsolute magnitudes for Type Ia supernovae in elliptical galaxies. None are expected to be above -20 in the B band, so if we calculate a magnitude for a Type Ia supernova thats larger than this, its probably not hosted by the galaxy we think it is! [Goldstein Nugent 2017]Two scientists from University of California, Berkeley and

  3. The CHilean Automatic Supernova sEarch

    DEFF Research Database (Denmark)

    Hamuy, M.; Pignata, G.; Maza, J.

    2012-01-01

    The CHilean Automatic Supernova sEarch (CHASE) project began in 2007 with the goal to discover young, nearby southern supernovae in order to (1) better understand the physics of exploding stars and their progenitors, and (2) refine the methods to derive extragalactic distances. During the first...

  4. The CHilean Automatic Supernova sEarch

    DEFF Research Database (Denmark)

    Hamuy, M.; Pignata, G.; Maza, J.

    2012-01-01

    The CHilean Automatic Supernova sEarch (CHASE) project began in 2007 with the goal to discover young, nearby southern supernovae in order to (1) better understand the physics of exploding stars and their progenitors, and (2) refine the methods to derive extragalactic distances. During the first...... four years of operation, CHASE has produced more than 130 supernovae, being the most successful project of its type in the southern hemisphere. Here we describe the project and present illustrative examples of CHASE discoveries of particular relevance....

  5. Gravitational wave triggered searches for failed supernovae

    Science.gov (United States)

    Annis, James; Dark Energy Survey Collaboration

    2016-03-01

    Stellar core collapses occur to all stars of sufficiently high mass and often result in supernovae. A small fraction of supergiant stars, however, are thought to collapse directly into black holes without producing supernovae. A survey of such ``failed'' supernovae would require monitoring millions of supergiants for several years. That is very challenging even for current surveys. With the start of the Advanced LIGO science run, we investigate the possibility of detecting failed supernovae by looking for missing supergiants associated with gravitational wave triggers. We use the Dark Energy Camera (DECam). Our project is a joint effort between the community and the Dark Energy Survey (DES) collaboration. In this talk we report on our ongoing efforts and discuss prospects for future searches.

  6. Texas Supernova Search: A Wide Field Search for Nearby SNe

    Science.gov (United States)

    Quimby, R. M.; Castro, F.; Gerardy, C. L.; Hoeflich, P.; Kannappan, S. J.; Mondol, P.; Sellers, M.; Wheeler, J. C.

    2005-12-01

    ROTSE-IIIb is one four robotic telescopes built by the University of Michigan to observe the prompt optical afterglows associated with gamma-ray bursts. At just 0.45m in diameter, it is the smallest research telescope at McDonald, but its 1.85 x 1.85 deg field of view and autonomous operation make it an excellent survey instrument for rare transient phenomena. We have been using ROTSE-IIIb for the past year to search for supernovae in nearby galaxy clusters such as the Virgo, Coma, and Ursa Major clusters. ROTSE-IIIb's wide field of view allows us to search the thousands of galaxies in these clusters, which cover hundreds of square degrees on the sky, in just a few tens of exposures. We can therefore observe all of these fields in a single night, and repeat the search every night. When we identify a new supernova candidate, we invoke our target of opportunity time on the neighboring 9.2m Hobby-Eberly Telescope (HET) the following night to obtain a spectrum. Because of the rolling search and the quick spectral turn-around possible with the HET, we are able to capture spectra of the earliest phases of the explosion. By combining this information with spectra taken at later epochs, we can construct a complete description of the explosion. Through this work we aim to better understand the physical conditions of supernova explosions, identify any systematic effects that may affect how Type Ia supernovae are calibrated as standard candles and used to probe cosmology, and also to better calibrate Type II supernovae as standard candles.

  7. Supernovae

    Science.gov (United States)

    March, Marisa

    2014-03-01

    We live in a Universe that is getting bigger faster. This astonishing discovery of Universal acceleration was made in the late 1990s by two teams who made observations of a special type of exploded star known as a `Supernova Type Ia'. (SNeIa) Since the discovery of the accelerating Universe, one of the biggest questions in modern cosmology has been to determine the cause of that acceleration - the answer to this question will have far reaching implications for our theories of cosmology and fundamental physics more broadly. The two main competing explanations for this apparent late time acceleration of the Universe are modified gravity and dark energy. The Dark Energy Survey (DES) has been designed and commissioned to find to find answers to these questions about the nature of dark energy and modified gravity. The new 570 megapixel Dark Energy Camera is currently operating with the Cerro-Tololo Inter American Observatory's 4m Blanco teleccope, carrying out a systematic search for SNeIa, and mapping out the large scale structure of the Universe by making observations of galaxies. The DES science program program which saw first light in September 2013 will run for five years in total. DES SNeIa data in combination with the other DES observations of large scale structure will enable us to put increasingly accurate constraints on the expansion history of the Universe and will help us distinguish between competing theories of dark energy and modified gravity. As we draw to the close of the first observing season of DES in March 2014, we will report on the current status of the DES supernova survey, presenting first year supernovae data, preliminary results, survey strategy, discovery pipeline, spectroscopic target selection and data quality. This talk will give the first glimpse of the DES SN first year data and initial results as we begin our five year survey in search of dark energy. On behalf of the Dark Energy Survey collaboration.

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

    CERN Multimedia

    2003-01-01

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

  9. A Framework for Assessing the Performance of Pulsar Search Pipelines

    CERN Document Server

    van Heerden, E; Roberts, S J

    2016-01-01

    In this paper, we present a framework for assessing the effect of non-stationary Gaussian noise and radio frequency interference (RFI) on the signal to noise ratio, the number of false positives detected per true positive and the sensitivity of standard pulsar search pipelines. The results highlight the necessity to develop algorithms that are able to identify and remove non-stationary variations from the data before RFI excision and searching is performed in order to limit false positive detections. The results also show that the spectrum whitening algorithms currently employed, severely affect the efficiency of pulsar search pipelines by reducing their sensitivity to long period pulsars.

  10. HAWK-I infrared supernova search in starburst galaxies

    CERN Document Server

    Miluzio, M; Botticella, M T; Cresci, G; Greggio, L; Mannucci, F; Benetti, S; Bufano, F; Elias-Rosa, N; Pastorello, A; Turatto, M; Zampieri, L

    2013-01-01

    The use of SN rates to probe explosion scenarios and to trace the cosmic star formation history received a boost from a number of synoptic surveys. There has been a recent claim of a mismatch by a factor of two between star formation and core collapse SN rates, and different explanations have been proposed for this discrepancy.} We attempted an independent test of the relation between star formation and supernova rates in the extreme environment of starburst galaxies, where both star formation and extinction are extremely high. To this aim we conducted an infrared supernova search in a sample of local starburts galaxies. The rational to search in the infrared is to reduce the bias due to extinction, which is one of the putative reasons for the observed discrepancy between star formation and supernova rates. To evaluate the outcome of the search we developed a MonteCarlo simulation tool that is used to predict the number and properties of the expected supernovae based on the search characteristics and the curr...

  11. Search for Type Ia supernova NUV-optical subclasses

    Science.gov (United States)

    Cinabro, David; Scolnic, Daniel; Kessler, Richard; Li, Ashley; Miller, Jake

    2017-04-01

    In response to a recently reported observation of evidence for two classes of Type Ia supernovae (SNe Ia) distinguished by their brightness in the rest-frame near-ultraviolet (NUV), we search for the phenomenon in publicly available light-curve data. We use the SNANA supernova analysis package to simulate SN Ia light curves in the Sloan Digital Sky Survey (SDSS) Supernova Search and the Supernova Legacy Survey (SNLS) with a model of two distinct ultraviolet classes of SNe Ia and a conventional model with a single broad distribution of SN-Ia ultraviolet brightnesses. We compare simulated distributions of rest-frame colours with these two models to those observed in 158 SNe Ia in the SDSS and SNLS data. The SNLS sample of 99 SNe Ia is in clearly better agreement with a model with one class of SN Ia light curves and shows no evidence for distinct NUV sub-classes. The SDSS sample of 59 SNe Ia with poorer colour resolution does not distinguish between the two models.

  12. Search For Type Ia Supernova NUV-Optical Subclasses

    CERN Document Server

    Cinabro, David; Kessler, Richard; Li, Ashley; Miller, Jake

    2016-01-01

    In response to a recently reported observation of evidence for two classes of Type Ia Supernovae (SNe Ia) distinguished by their brightness in the rest-frame near ultraviolet (NUV), we search for the phenomenon in publicly available light-curve data. We use the SNANA supernova analysis package to simulate SN Ia-light curves in the Sloan Digital Sky Survey Supernova Search (SDSS) and the Supernova Legacy Survey (SNLS) with a model of two distinct ultraviolet classes of SNe Ia and a conventional model with a single broad distribution of SN-Ia ultraviolet brightnesses. We compare simulated distributions of rest-frame colors with these two models to those observed in 158 SNe Ia in the SDSS and SNLS data. The SNLS sample of 99 SNe Ia is in clearly better agreement with a model with one class of SN Ia light curves and shows no evidence for distinct NUV sub-classes. The SDSS sample of 59 SNe Ia with poorer color resolution does not distinguish between the two models.

  13. Background Study on Supernova Relic Neutrinos Search in SuperK-Gd

    CERN Document Server

    Zhang, Yang

    2016-01-01

    The detection of supernova relic neutrinos could provide precious information on the evolution of the universe, the formation of stars, the mechanism of supernova bursts and the related neutrino physics. Many experiments, such as Kamland, Borexino, Sudbury Neutrino Observatory and Super-Kamiokande have conducted searches for the supernova relic neutrinos. However, no supernova relic neutrino signal has been observed until now. This paper reports the background study on the supernova relic neutrinos search for the future neutrino experiment in SuperK-Gd project. The expected event rate for various background sources and supernova relic neutrino models are calculated, respectively.

  14. Searching for Hydrogen in Type Ib Supernovae

    CERN Document Server

    James, Spencer

    2010-01-01

    We present synthetic spectral fits of the typical Type Ib SN 1999dn and the Hydrogen Rich Ib SN 2000H using the generalized non-local thermodynamic equilibrium stellar atmospheres code \\phx. We fit model spectra to five epochs of SN 1999dn ranging from ten days pre-maximum light to 17 days post-maximum light and the two earliest epochs of SN 2000H available, maximum light and six days post-maximum. Our goal is to investigate the possibility of hydrogen in Type Ib Supernovae (SNe Ib), specifically a feature around 6200\\AA\\ which has previously been attributed to high velocity H-alpha. In earlier work on SN 1999dn we found the most plausible alternative to H-alpha to be a blend of Si II and Fe II lines which can be adjusted to fit by increasing the metallicity. Our models are simple; they assume a powerlaw density profile with radius, homologous expansion, and solar compositions. The helium core is produced by burning 4H --> He in order to conserve nucleon number. For models with hydrogen the outer skin of the ...

  15. Simulation tool of a Supernova search with VST

    OpenAIRE

    Calvi, R.; Cappellaro, E; Botticella, M. T.; Riello, M.

    2007-01-01

    To improve the estimate of SN rates for all types as a function of redshift has been proposed and accepted a three years SN search with the VST telescope. To help planning an optimal strategy for the search, we have developed a simulation tool used to predict the numbers of Supernovae of different types which are expected to be discovered in a magnitude-limited survey. In our simulation a most important ingredient has been the determination of the K-correction as function of redshift for ever...

  16. Search for Kilonovae in Dark Energy Survey Supernova Fields

    Science.gov (United States)

    Doctor, Zoheyr; DES-GW Team; DES-SN Team

    2016-03-01

    The Dark Energy Camera on the Blanco 4-m Telescope is an ideal instrument for identifying rapid optical transients with its large field of view and four optical filters. We utilize two seasons of data from the Dark Energy Survey to search for kilonovae, an optical counterpart to gravitational waves from binary neutron star mergers. Kilonova lightcurves from Barnes and Kasen inform our analysis for removing background signals such as supernovae. We simulate DES observations of kilonovae with the SNANA software package to estimate our search efficiency and optimize cuts. Finally, we report rate limits for binary neutron star mergers and compare to existing rate estimates.

  17. The Difference Imaging Pipeline for the Transient Search in the Dark Energy Survey

    CERN Document Server

    Kessler, R; Childress, M; Covarrubias, R; D'Andrea, C B; Finley, D A; Fischer, J; Foley, R J; Goldstein, D; Gupta, R R; Kuehn, K; Marcha, M; Nichol, R C; Papadopoulos, A; Sako, M; Scolnic, D; Smith, M; Sullivan, M; Wester, W; Yuan, F; Abbott, T; Abdalla, F B; Allam, S; Benoit-Levy, A; Bernstein, G M; Bertin, E; Brooks, D; Rosell, A Carnero; Kind, M Carrasco; Castander, F J; Crocce, M; da Costa, L N; Desai, S; Diehl, H T; Eifler, T F; Neto, A Fausti; Flaugher, B; Frieman, J; Gruen, D; Gruendl, R A; Honscheid, K; James, D J; Kuropatkin, N; Li, T S; Maia, M A G; Marshall, J L; Martini, P; Miller, C J; Miquel, R; Ogando, R; Plazas, A A; Romer, A K; Roodman, A; Sanchez, E; Sevilla-Noarbe, I; Smith, R C; Soares-Santos, M; Sobreira, F; Tarle, G; Thaler, J; Thomas, R C; Tucker, D; Walker, A R

    2015-01-01

    We describe the difference imaging pipeline (DiffImg) used to detect transients in deep images from the Dark Energy Survey Supernova program (DES-SN) in its first observing season from Aug 2013 through Feb 2014. DES-SN is a search for transients in which ten 3-deg^2 fields are repeatedly observed in the g,r,i,z passbands with a cadence of about 1 week. The observing strategy has been optimized to measure high-quality light curves and redshifts for thousands of Type Ia supernova (SN Ia) with the goal of measuring dark energy parameters. The essential DiffImg functions are to align each search image to a deep reference image, do a pixel-by-pixel subtraction, and then examine the subtracted image for significant positive detections of point-source objects. The vast majority of detections are subtraction artifacts, but after selection requirements and image filtering with an automated scanning program, there are 130 detections per deg^2 per observation in each band, of which only 25% are artifacts. Of the 7500 tr...

  18. Directed Searches for Broadband Extended Gravitational Wave Emission in Nearby Energetic Core-collapse Supernovae

    Science.gov (United States)

    van Putten, Maurice H. P. M.

    2016-03-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-03-10

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

  20. Supernova Relic Neutrino Search at Super-Kamiokande

    CERN Document Server

    Bays, K; Abe, K; Hayato, Y; Iyogi, K; Kameda, J; Koshio, Y; Marti, L; Miura, M; Moriyama, S; Nakahata, M; Nakayama, S; Obayashi, Y; Sekiya, H; Shiozawa, M; Suzuki, Y; Takeda, A; Takenaga, Y; Ueno, K; Kajita, K Ueshima S Yamada T Yokozawa H Kaji T; Kaneyuki, K; McLachlan, T; Okumura, K; Pik, L K; Martens, K; Vagins, M; Labarga, L; Kearns, E; Litos, M; Raaf, J L; Stone, J L; Sulak, L R; Kropp, W R; Mine, S; Regis, C; Renshaw, A; Smy, M B; Sobel, H W; Ganezer, K S; Hill, J; Keig, W E; Cho, S; Jang, J S; Kim, J Y; Lim, I T; Albert, J; Scholberg, K; Walter, C W; Wendell, R; Wongjirad, T; Ishizuka, T; Tasaka, S; Learned, J G; Matsuno, S; Smith, S; Hasegawa, T; Ishida, T; Ishii, T; Kobayashi, T; Nakadaira, T; Nakamura, K; Nishikawa, K; Oyama, Y; Sakashita, K; Sekiguchi, T; Tsukamoto, T; Suzuki, A T; Takeuchi, Y; Ikeda, M; Matsuoka, K; Minamino, A; Murakami, A; Nakaya, T; Fukuda, Y; Itow, Y; Mitsuka, G; Miyake, M; Tanaka, T; Hignight, J; Imber, J; Jung, C K; Taylor, I; Yanagisawa, C; Kibayashi, A; Ishino, H; Mino, S; Sakuda, M; Mori, T; Toyota, H; Kuno, Y; Kim, S B; Yang, B S; Okazawa, H; Choi, Y; Nishijima, K; Koshiba, M; Totsuka, Y; Yokoyama, M; Heng, Y; Chen, S; Zhang, H; Yang, Z; Mijakowski, P; Connolly, K; Dziomba, M; Wilkes, R J

    2011-01-01

    A new Super-Kamiokande (SK) search for Supernova Relic Neutrinos (SRNs) was conducted using 2853 live days of data. Sensitivity is now greatly improved compared to the 2003 SK result, which placed a flux limit near many theoretical predictions. This more detailed analysis includes a variety of improvements such as increased efficiency, a lower energy threshold, and an expanded data set. New combined upper limits on SRN flux are between 2.8 and 3.0 nu_e cm^-2 s^-1 > 16 MeV total positron energy (17.3 MeV E_nu).

  1. Constraints on Type IIn Supernova Progenitor Outbursts from the Lick Observatory Supernova Search

    CERN Document Server

    Bilinski, Christopher; Li, Weidong; Williams, G Grant; Zheng, WeiKang; Filippenko, Alexei V

    2015-01-01

    We searched through roughly 12 years of archival survey data acquired by the Katzman Automatic Imaging Telescope (KAIT) as part of the Lick Observatory Supernova Search (LOSS) in order to detect or place limits on possible progenitor outbursts of Type IIn supernovae (SNe~IIn). The KAIT database contains multiple pre-SN images for 5 SNe~IIn (plus one ambiguous case of a SN IIn/imposter) within 50 Mpc. No progenitor outbursts are found using the false discovery rate (FDR) statistical method in any of our targets. Instead, we derive limiting magnitudes (LMs) at the locations of the SNe. These limiting magnitudes (typically reaching $m_R \\approx 19.5\\,\\mathrm{mag}$) are compared to outbursts of SN 2009ip and $\\eta$ Car, plus additional simulated outbursts. We find that the data for SN 1999el and SN 2003dv are of sufficient quality to rule out events $\\sim40$ days before the main peak caused by initially faint SNe from blue supergiant (BSG) precursor stars, as in the cases of SN 2009ip and SN 2010mc. These SNe~IIn...

  2. Nearby Supernova Rates from the Lick Observatory Supernova Search. I. The Methods and Database

    CERN Document Server

    Leaman, Jesse; Chornock, Ryan; Filippenko, Alexei V

    2010-01-01

    This is the first paper of a series in which we present new measurements of the observed rates of supernovae (SNe) in the local Universe, determined from the Lick Observatory Supernova Search (LOSS). We have obtained 2.3 million observations of 14,882 sample galaxies over an interval of 11 years (March 1998 through Dec. 2008). We considered 1036 SNe detected in our sample and used an optimal subsample of 726 SNe (274 SNe~Ia, 116 SNe~Ibc, 324 SNe~II) to determine our SN rates. This is the largest and most homogeneous set of nearby SNe ever assembled for this purpose, and ours is the first local SN rate analysis based on CCD imaging and modern image-subtraction techniques. In this paper, we lay the foundation of the study. We derive the recipe for the control-time calculation for SNe with a known luminosity function, and provide details on the construction of the galaxy and SN samples used in the calculations. Compared with a complete volume-limited galaxy sample, our sample has a deficit of low-luminosity gala...

  3. Searches for continuous gravitational waves from nine young supernova remnants

    CERN Document Server

    Aasi, J; Abbott, R; Abbott, T; Abernathy, M R; Acernese, F; Ackley, K; Adams, C; Adams, T; Addesso, P; Adhikari, R X; Adya, V; Affeldt, C; Agathos, M; Agatsuma, K; Aggarwal, N; Aguiar, O D; Ain, A; Ajith, P; Alemic, A; Allen, B; Allocca, A; Amariutei, D; Anderson, S B; Anderson, W G; Arai, K; Araya, M C; Arceneaux, C; Areeda, J S; Ast, S; Aston, S M; Astone, P; Aufmuth, P; Aulbert, C; Aylott, B E; Babak, S; Baker, P T; Baldaccini, F; Ballardin, G; Ballmer, S W; Barayoga, J C; Barbet, M; Barclay, S; Barish, B C; Barker, D; Barone, F; Barr, B; Barsotti, L; Barsuglia, M; Bartlett, J; Barton, M A; Bartos, I; Bassiri, R; Basti, A; Batch, J C; Bauer, Th S; Baune, C; Bavigadda, V; Behnke, B; Bejger, M; Belczynski, C; Bell, A S; Bell, C; Benacquista, M; Bergman, J; Bergmann, G; Berry, C P L; Bersanetti, D; Bertolini, A; Betzwieser, J; Bhagwat, S; Bhandare, R; Bilenko, I A; Billingsley, G; Birch, J; Biscans, S; Bitossi, M; Biwer, C; Bizouard, M A; Blackburn, J K; Blackburn, L; Blair, C D; Blair, D; Bloemen, S; Bock, O; Bodiya, T P; Boer, M; Bogaert, G; Bojtos, P; Bond, C; Bondu, F; Bonelli, L; Bonnand, R; Bork, R; Born, M; Boschi, V; Bose, Sukanta; Bradaschia, C; Brady, P R; Braginsky, V B; Branchesi, M; Brau, J E; Briant, T; Bridges, D O; Brillet, A; Brinkmann, M; Brisson, V; Brooks, A F; Brown, D A; Brown, D D; Brown, N M; Buchman, S; Buikema, A; Bulik, T; Bulten, H J; Buonanno, A; Buskulic, D; Buy, C; Cadonati, L; Cagnoli, G; Bustillo, J Calderón; Calloni, E; Camp, J B; Cannon, K C; Cao, J; Capano, C D; Carbognani, F; Caride, S; Caudill, S; Cavaglià, M; Cavalier, F; Cavalieri, R; Cella, G; Cepeda, C; Cesarini, E; Chakraborty, R; Chalermsongsak, T; Chamberlin, S J; Chao, S; Charlton, P; Chassande-Mottin, E; Chen, Y; Chincarini, A; Chiummo, A; Cho, H S; Cho, M; Chow, J H; Christensen, N; Chu, Q; Chua, S; Chung, S; Ciani, G; Clara, F; Clark, J A; Cleva, F; Coccia, E; Cohadon, P -F; Colla, A; Collette, C; Colombini, M; Cominsky, L; Constancio,, M; Conte, A; Cook, D; Corbitt, T R; Cornish, N; Corsi, A; Costa, C A; Coughlin, M W; Coulon, J -P; Countryman, S; Couvares, P; Coward, D M; Cowart, M J; Coyne, D C; Coyne, R; Craig, K; Creighton, J D E; Creighton, T D; Cripe, J; Crowder, S G; Cumming, A; Cunningham, L; Cuoco, E; Cutler, C; Dahl, K; Canton, T Dal; Damjanic, M; Danilishin, S L; D'Antonio, S; Danzmann, K; Dartez, L; Dattilo, V; Dave, I; Daveloza, H; Davier, M; Davies, G S; Daw, E J; Day, R; DeBra, D; Debreczeni, G; Degallaix, J; De Laurentis, M; Deléglise, S; Del Pozzo, W; Denker, T; Dent, T; Dereli, H; Dergachev, V; De Rosa, R; DeRosa, R T; DeSalvo, R; Dhurandhar, S; Díaz, M; Di Fiore, L; Di Lieto, A; Di Palma, I; Di Virgilio, A; Dojcinoski, G; Dolique, V; Dominguez, E; Donovan, F; Dooley, K L; Doravari, S; Douglas, R; Downes, T P; Drago, M; Driggers, J C; Du, Z; Ducrot, M; Dwyer, S; Eberle, T; Edo, T; Edwards, M; Effler, A; Eggenstein, H -B; Ehrens, P; Eichholz, J; Eikenberry, S S; Essick, R; Etzel, T; Evans, M; Evans, T; Factourovich, M; Fafone, V; Fairhurst, S; Fan, X; Fang, Q; Farinon, S; Farr, B; Farr, W M; Favata, M; Fays, M; Fehrmann, H; Fejer, M M; Feldbaum, D; Ferrante, I; Ferreira, E C; Ferrini, F; Fidecaro, F; Fiori, I; Fisher, R P; Flaminio, R; Fournier, J -D; Franco, S; Frasca, S; Frasconi, F; Frei, Z; Freise, A; Frey, R; Fricke, T T; Fritschel, P; Frolov, V V; Fuentes-Tapia, S; Fulda, P; Fyffe, M; Gair, J R; Gammaitoni, L; Gaonkar, S; Garufi, F; Gatto, A; Gehrels, N; Gemme, G; Gendre, B; Genin, E; Gennai, A; Gergely, L Á; Ghosh, S; Giaime, J A; Giardina, K D; Giazotto, A; Gleason, J; Goetz, E; Goetz, R; Gondan, L; González, G; Gordon, N; Gorodetsky, M L; Gossan, S; Goßler, S; Gouaty, R; Gräf, C; Graff, P B; Granata, M; Grant, A; Gras, S; Gray, C; Greenhalgh, R J S; Gretarsson, A M; Groot, P; Grote, H; Grunewald, S; Guidi, G M; Guido, C J; Guo, X; Gushwa, K; Gustafson, E K; Gustafson, R; Hacker, J; Hall, E D; Hammond, G; Hanke, M; Hanks, J; Hanna, C; Hannam, M D; Hanson, J; Hardwick, T; Harms, J; Harry, G M; Harry, I W; Hart, M; Hartman, M T; Haster, C -J; Haughian, K; Hee, S; Heidmann, A; Heintze, M; Heinzel, G; Heitmann, H; Hello, P; Hemming, G; Hendry, M; Heng, I S; Heptonstall, A W; Heurs, M; Hewitson, M; Hild, S; Hoak, D; Hodge, K A; Hofman, D; Hollitt, S E; Holt, K; Hopkins, P; Hosken, D J; Hough, J; Houston, E; Howell, E J; Hu, Y M; Huerta, E; Hughey, B; Husa, S; Huttner, S H; Huynh, M; Huynh-Dinh, T; Idrisy, A; Indik, N; Ingram, D R; Inta, R; Islas, G; Isler, J C; Isogai, T; Iyer, B R; Izumi, K; Jacobson, M; Jang, H; Jaranowski, P; Jawahar, S; Ji, Y; Jiménez-Forteza, F; Johnson, W W; Jones, D I; Jones, R; Jonker, R J G; Ju, L; K, Haris; Kalogera, V; Kandhasamy, S; Kang, G; Kanner, J B; Kasprzack, M; Katsavounidis, E; Katzman, W; Kaufer, H; Kaufer, S; Kaur, T; Kawabe, K; Kawazoe, F; Kéfélian, F; Keiser, G M; Keitel, D; Kelley, D B; Kells, W; Keppel, D G; Key, J S; Khalaidovski, A; Khalili, F Y; Khazanov, E A; Kim, C; Kim, K; Kim, N G; Kim, N; Kim, Y -M; King, E J; King, P J; Kinzel, D L; Kissel, J S; Klimenko, S; Kline, J; Koehlenbeck, S; Kokeyama, K; Kondrashov, V; Korobko, M; Korth, W Z; Kowalska, I; Kozak, D B; Kringel, V; Krishnan, B; Królak, A; Krueger, C; Kuehn, G; Kumar, A; Kumar, P; Kuo, L; Kutynia, A; Landry, M; Lantz, B; Larson, S; Lasky, P D; Lazzarini, A; Lazzaro, C; Le, J; Leaci, P; Leavey, S; Lebigot, E; Lebigot, E O; Lee, C H; Lee, H K; Lee, H M; Leonardi, M; Leong, J R; Leroy, N; Letendre, N; Levin, Y; Levine, B; Lewis, J; Li, T G F; Libbrecht, K; Libson, A; Lin, A C; Littenberg, T B; Lockerbie, N A; Lockett, V; Logue, J; Lombardi, A L; Lorenzini, M; Loriette, V; Lormand, M; Losurdo, G; Lough, J; Lubinski, M J; Lück, H; Lundgren, A P; Lynch, R; Ma, Y; Macarthur, J; MacDonald, T; Machenschalk, B; MacInnis, M; Macleod, D M; Magaña-Sandoval, F; Magee, R; Mageswaran, M; Maglione, C; Mailand, K; Majorana, E; Maksimovic, I; Malvezzi, V; Man, N; Mandel, I; Mandic, V; Mangano, V; Mansell, G L; Mantovani, M; Marchesoni, F; Marion, F; Márka, S; Márka, Z; Markosyan, A; Maros, E; Martelli, F; Martellini, L; Martin, I W; Martin, R M; Martynov, D; Marx, J N; Mason, K; Masserot, A; Massinger, T J; Matichard, F; Matone, L; Mavalvala, N; Mazumder, N; Mazzolo, G; McCarthy, R; McClelland, D E; McCormick, S; McGuire, S C; McIntyre, G; McIver, J; McLin, K; McWilliams, S; Meacher, D; Meadors, G D; Meidam, J; Meinders, M; Melatos, A; Mendell, G; Mercer, R A; Meshkov, S; Messenger, C; Meyers, P M; Mezzani, F; Miao, H; Michel, C; Middleton, H; Mikhailov, E E; Milano, L; Miller, A; Miller, J; Millhouse, M; Minenkov, Y; Ming, J; Mirshekari, S; Mishra, C; Mitra, S; Mitrofanov, V P; Mitselmakher, G; Mittleman, R; Moe, B; Moggi, A; Mohan, M; Mohanty, S D; Mohapatra, S R P; Moore, B; Moraru, D; Moreno, G; Morriss, S R; Mossavi, K; Mours, B; Mow-Lowry, C M; Mueller, C L; Mueller, G; Mukherjee, S; Mullavey, A; Munch, J; Murphy, D; Murray, P G; Mytidis, A; Nagy, M F; Nardecchia, I; Nash, T; Naticchioni, L; Nayak, R K; Necula, V; Nedkova, K; Nelemans, G; Neri, I; Neri, M; Newton, G; Nguyen, T; Nielsen, A B; Nissanke, S; Nitz, A H; Nocera, F; Nolting, D; Normandin, M E N; Nuttall, L K; Ochsner, E; O'Dell, J; Oelker, E; Ogin, G H; Oh, J J; Oh, S H; Ohme, F; Oppermann, P; Oram, R; O'Reilly, B; Ortega, W; O'Shaughnessy, R; Osthelder, C; Ott, C D; Ottaway, D J; Ottens, R S; Overmier, H; Owen, B J; Padilla, C; Pai, A; Pai, S; Palashov, O; Palomba, C; Pal-Singh, A; Pan, H; Pankow, C; Pannarale, F; Pant, B C; Paoletti, F; Papa, M A; Paris, H; Pasqualetti, A; Passaquieti, R; Passuello, D; Patrick, Z; Pedraza, M; Pekowsky, L; Pele, A; Penn, S; Perreca, A; Phelps, M; Pichot, M; Piergiovanni, F; Pierro, V; Pillant, G; Pinard, L; Pinto, I M; Pitkin, M; Poeld, J; Poggiani, R; Post, A; Poteomkin, A; Powell, J; Prasad, J; Predoi, V; Premachandra, S; Prestegard, T; Price, L R; Prijatelj, M; Principe, M; Privitera, S; Prix, R; Prodi, G A; Prokhorov, L; Puncken, O; Punturo, M; Puppo, P; Pürrer, M; Qin, J; Quetschke, V; Quintero, E; Quiroga, G; Quitzow-James, R; Raab, F J; Rabeling, D S; Rácz, I; Radkins, H; Raffai, P; Raja, S; Rajalakshmi, G; Rakhmanov, M; Ramirez, K; Rapagnani, P; Raymond, V; Razzano, M; Re, V; Reed, C M; Regimbau, T; Rei, L; Reid, S; Reitze, D H; Reula, O; Ricci, F; Riles, K; Robertson, N A; Robie, R; Robinet, F; Rocchi, A; Rolland, L; Rollins, J G; Roma, V; Romano, R; Romanov, G; Romie, J H; Rosińska, D; Rowan, S; Rüdiger, A; Ruggi, P; Ryan, K; Sachdev, S; Sadecki, T; Sadeghian, L; Saleem, M; Salemi, F; Sammut, L; Sandberg, V; Sanders, J R; Sannibale, V; Santiago-Prieto, I; Sassolas, B; Sathyaprakash, B S; Saulson, P R; Savage, R; Sawadsky, A; Scheuer, J; Schilling, R; Schmidt, P; Schnabel, R; Schofield, R M S; Schreiber, E; Schuette, D; Schutz, B F; Scott, J; Scott, S M; Sellers, D; Sengupta, A S; Sentenac, D; Sequino, V; Sergeev, A; Serna, G; Sevigny, A; Shaddock, D A; Shah, S; Shahriar, M S; Shaltev, M; Shao, Z; Shapiro, B; Shawhan, P; Shoemaker, D H; Sidery, T L; Siellez, K; Siemens, X; Sigg, D; Silva, A D; Simakov, D; Singer, A; Singer, L; Singh, R; Sintes, A M; Slagmolen, B J J; Smith, J R; Smith, M R; Smith, R J E; Smith-Lefebvre, N D; Son, E J; Sorazu, B; Souradeep, T; Staley, A; Stebbins, J; Steinke, M; Steinlechner, J; Steinlechner, S; Steinmeyer, D; Stephens, B C; Steplewski, S; Stevenson, S; Stone, R; Strain, K A; Straniero, N; Strigin, S; Sturani, R; Stuver, A L; Summerscales, T Z; Sutton, P J; Swinkels, B; Szczepanczyk, M; Szeifert, G; Tacca, M; Talukder, D; Tanner, D B; Tápai, M; Tarabrin, S P; Taracchini, A; Taylor, R; Tellez, G; Theeg, T; Thirugnanasambandam, M P; Thomas, M; Thomas, P; Thorne, K A; Thorne, K S; Thrane, E; Tiwari, V; Tomlinson, C; Tonelli, M; Torres, C V; Torrie, C I; Travasso, F; Traylor, G; Tse, M; Tshilumba, D; Ugolini, D; Unnikrishnan, C S; Urban, A L; Usman, S A; Vahlbruch, H; Vajente, G; Valdes, G; Vallisneri, M; van Bakel, N; van Beuzekom, M; Brand, J F J van den; Broeck, C van den; van der Sluys, M V; van Heijningen, J; van Veggel, A A; Vass, S; Vasúth, M; Vaulin, R; Vecchio, A; Vedovato, G; Veitch, J; Veitch, P J; Venkateswara, K; Verkindt, D; Vetrano, F; Viceré, A; Vincent-Finley, R; Vinet, J -Y; Vitale, S; Vo, T; Vocca, H; Vorvick, C; Vousden, W D; Vyatchanin, S P; Wade, A R; Wade, L; Wade, M; Walker, M; Wallace, L; Walsh, S; Wang, H; Wang, M; Wang, X; Ward, R L; Warner, J; Was, M; Weaver, B; Wei, L -W; Weinert, M; Weinstein, A J; Weiss, R; Welborn, T; Wen, L; Wessels, P; Westphal, T; Wette, K; Whelan, J T; White, D J; Whiting, B F; Wilkinson, C; Williams, L; Williams, R; Williamson, A R; Willis, J L; Willke, B; Wimmer, M; Winkler, W; Wipf, C C; Wittel, H; Woan, G; Worden, J; Xie, S; Yablon, J; Yakushin, I; Yam, W; Yamamoto, H; Yancey, C C; Yang, Q; Yvert, M; Zadrożny, A; Zanolin, M; Zendri, J -P; Zhang, Fan; Zhang, L; Zhang, M; Zhang, Y; Zhao, C; Zhou, M; Zhu, X J; Zucker, M E; Zuraw, S; Zweizig, J

    2014-01-01

    We describe directed searches for continuous gravitational waves in data from the sixth LIGO science data run. The targets were nine young supernova remnants not associated with pulsars; eight of the remnants are associated with non-pulsing suspected neutron stars. One target's parameters are uncertain enough to warrant two searches, for a total of ten. Each search covered a broad band of frequencies and first and second frequency derivatives for a fixed sky direction. The searches coherently integrated data from the two LIGO interferometers over time spans from 5.3-25.3 days using the matched-filtering F-statistic. We found no credible gravitational-wave signals. We set 95% confidence upper limits as strong (low) as $4\\times10^{-25}$ on intrinsic strain, $2\\times10^{-7}$ on fiducial ellipticity, and $4\\times10^{-5}$ on r-mode amplitude. These beat the indirect limits from energy conservation and are within the range of theoretical predictions for neutron-star ellipticities and r-mode amplitudes.

  4. Searches for Continuous Gravitational Waves from Nine Young Supernova Remnants

    Science.gov (United States)

    Aasi, J.; Abbott, B. P.; Abbott, R.; Abbott, T.; Abernathy, M. R.; Acernese, F.; Ackley, K.; Adams, C.; Adams, T.; Addesso, P.; Adhikari, R. X.; Adya, V.; Affeldt, C.; Agathos, M.; Agatsuma, K.; Aggarwal, N.; Aguiar, O. D.; Ain, A.; Ajith, P.; Alemic, A.; Allen, B.; Allocca, A.; Amariutei, D.; Anderson, S. B.; Anderson, W. G.; Arai, K.; Araya, M. C.; Arceneaux, C.; Areeda, J. S.; Ast, S.; Aston, S. M.; Astone, P.; Aufmuth, P.; Aulbert, C.; Aylott, B. E.; Babak, S.; Baker, P. T.; Baldaccini, F.; Ballardin, G.; Ballmer, S. W.; Barayoga, J. C.; Barbet, M.; Barclay, S.; Barish, B. C.; Barker, D.; Barone, F.; Barr, B.; Barsotti, L.; Barsuglia, M.; Bartlett, J.; Barton, M. A.; Bartos, I.; Bassiri, R.; Basti, A.; Batch, J. C.; Bauer, Th. S.; Baune, C.; Bavigadda, V.; Behnke, B.; Bejger, M.; Belczynski, C.; Bell, A. S.; Bell, C.; Benacquista, M.; Bergman, J.; Bergmann, G.; Berry, C. P. L.; Bersanetti, D.; Bertolini, A.; Betzwieser, J.; Bhagwat, S.; Bhandare, R.; Bilenko, I. A.; Billingsley, G.; Birch, J.; Biscans, S.; Bitossi, M.; Biwer, C.; Bizouard, M. A.; Blackburn, J. K.; Blackburn, L.; Blair, C. D.; Blair, D.; Bloemen, S.; Bock, O.; Bodiya, T. P.; Boer, M.; Bogaert, G.; Bojtos, P.; Bond, C.; Bondu, F.; Bonelli, L.; Bonnand, R.; Bork, R.; Born, M.; Boschi, V.; Bose, Sukanta; Bradaschia, C.; Brady, P. R.; Braginsky, V. B.; Branchesi, M.; Brau, J. E.; Briant, T.; Bridges, D. O.; Brillet, A.; Brinkmann, M.; Brisson, V.; Brooks, A. F.; Brown, D. A.; Brown, D. D.; Brown, N. M.; Buchman, S.; Buikema, A.; Bulik, T.; Bulten, H. J.; Buonanno, A.; Buskulic, D.; Buy, C.; Cadonati, L.; Cagnoli, G.; Calderón Bustillo, J.; Calloni, E.; Camp, J. B.; Cannon, K. C.; Cao, J.; Capano, C. D.; Carbognani, F.; Caride, S.; Caudill, S.; Cavaglià, M.; Cavalier, F.; Cavalieri, R.; Cella, G.; Cepeda, C.; Cesarini, E.; Chakraborty, R.; Chalermsongsak, T.; Chamberlin, S. J.; Chao, S.; Charlton, P.; Chassande-Mottin, E.; Chen, Y.; Chincarini, A.; Chiummo, A.; Cho, H. S.; Cho, M.; Chow, J. H.; Christensen, N.; Chu, Q.; Chua, S.; Chung, S.; Ciani, G.; Clara, F.; Clark, J. A.; Cleva, F.; Coccia, E.; Cohadon, P.-F.; Colla, A.; Collette, C.; Colombini, M.; Cominsky, L.; Constancio, M., Jr.; Conte, A.; Cook, D.; Corbitt, T. R.; Cornish, N.; Corsi, A.; Costa, C. A.; Coughlin, M. W.; Coulon, J.-P.; Countryman, S.; Couvares, P.; Coward, D. M.; Cowart, M. J.; Coyne, D. C.; Coyne, R.; Craig, K.; Creighton, J. D. E.; Creighton, T. D.; Cripe, J.; Crowder, S. G.; Cumming, A.; Cunningham, L.; Cuoco, E.; Cutler, C.; Dahl, K.; Dal Canton, T.; Damjanic, M.; Danilishin, S. L.; D'Antonio, S.; Danzmann, K.; Dartez, L.; Dattilo, V.; Dave, I.; Daveloza, H.; Davier, M.; Davies, G. S.; Daw, E. J.; Day, R.; DeBra, D.; Debreczeni, G.; Degallaix, J.; De Laurentis, M.; Deléglise, S.; Del Pozzo, W.; Denker, T.; Dent, T.; Dereli, H.; Dergachev, V.; De Rosa, R.; DeRosa, R. T.; DeSalvo, R.; Dhurandhar, S.; Díaz, M.; Di Fiore, L.; Di Lieto, A.; Di Palma, I.; Di Virgilio, A.; Dojcinoski, G.; Dolique, V.; Dominguez, E.; Donovan, F.; Dooley, K. L.; Doravari, S.; Douglas, R.; Downes, T. P.; Drago, M.; Driggers, J. C.; Du, Z.; Ducrot, M.; Dwyer, S.; Eberle, T.; Edo, T.; Edwards, M.; Edwards, M.; Effler, A.; Eggenstein, H.-B.; Ehrens, P.; Eichholz, J.; Eikenberry, S. S.; Essick, R.; Etzel, T.; Evans, M.; Evans, T.; Factourovich, M.; Fafone, V.; Fairhurst, S.; Fan, X.; Fang, Q.; Farinon, S.; Farr, B.; Farr, W. M.; Favata, M.; Fays, M.; Fehrmann, H.; Fejer, M. M.; Feldbaum, D.; Ferrante, I.; Ferreira, E. C.; Ferrini, F.; Fidecaro, F.; Fiori, I.; Fisher, R. P.; Flaminio, R.; Fournier, J.-D.; Franco, S.; Frasca, S.; Frasconi, F.; Frei, Z.; Freise, A.; Frey, R.; Fricke, T. T.; Fritschel, P.; Frolov, V. V.; Fuentes-Tapia, S.; Fulda, P.; Fyffe, M.; Gair, J. R.; Gammaitoni, L.; Gaonkar, S.; Garufi, F.; Gatto, A.; Gehrels, N.; Gemme, G.; Gendre, B.; Genin, E.; Gennai, A.; Gergely, L. Á.; Ghosh, S.; Giaime, J. A.; Giardina, K. D.; Giazotto, A.; Gleason, J.; Goetz, E.; Goetz, R.; Gondan, L.; González, G.; Gordon, N.; Gorodetsky, M. L.; Gossan, S.; Gossler, S.; Gouaty, R.; Gräf, C.; Graff, P. B.; Granata, M.; Grant, A.; Gras, S.; Gray, C.; Greenhalgh, R. J. S.; Gretarsson, A. M.; Groot, P.; Grote, H.; Grunewald, S.; Guidi, G. M.; Guido, C. J.; Guo, X.; Gushwa, K.; Gustafson, E. K.; Gustafson, R.; Hacker, J.; Hall, E. D.; Hammond, G.; Hanke, M.; Hanks, J.; Hanna, C.; Hannam, M. D.; Hanson, J.; Hardwick, T.; Harms, J.; Harry, G. M.; Harry, I. W.; Hart, M.; Hartman, M. T.; Haster, C.-J.; Haughian, K.; Heidmann, A.; Heintze, M.; Heinzel, G.; Heitmann, H.; Hello, P.; Hemming, G.; Hendry, M.; Heng, I. S.; Heptonstall, A. W.; Heurs, M.; Hewitson, M.; Hild, S.; Hoak, D.; Hodge, K. A.; Hofman, D.; Hollitt, S. E.; Holt, K.; Hopkins, P.; Hosken, D. J.; Hough, J.; Houston, E.; Howell, E. J.; Hu, Y. M.

    2015-11-01

    We describe directed searches for continuous gravitational waves (GWs) in data from the sixth Laser Interferometer Gravitational-wave Observatory (LIGO) science data run. The targets were nine young supernova remnants not associated with pulsars; eight of the remnants are associated with non-pulsing suspected neutron stars. One target's parameters are uncertain enough to warrant two searches, for a total of 10. Each search covered a broad band of frequencies and first and second frequency derivatives for a fixed sky direction. The searches coherently integrated data from the two LIGO interferometers over time spans from 5.3-25.3 days using the matched-filtering {F}-statistic. We found no evidence of GW signals. We set 95% confidence upper limits as strong (low) as 4 × 10-25 on intrinsic strain, 2 × 10-7 on fiducial ellipticity, and 4 × 10-5 on r-mode amplitude. These beat the indirect limits from energy conservation and are within the range of theoretical predictions for neutron-star ellipticities and r-mode amplitudes.

  5. Supernova rates from the SUDARE VST-Omegacam search. I

    CERN Document Server

    Cappellaro, E; Pignata, G; Grado, L; Greggio, L; Limatola, L; Vaccari, M; Baruffolo, A; Benetti, S; Bufano, F; Capaccioli, M; Cascone, E; Covone, G; De Cicco, D; Falocco, S; Della Valle, M; Jarvis, M; Marchetti, L; Napolitano, N R; Paolillo, M; Pastorello, A; Radovich, M; Schipani, P; Spiro, S; Tomasella, L; Turatto, M

    2015-01-01

    We describe the observing strategy, data reduction tools and early results of a supernova (SN) search project, named SUDARE, conducted with the ESO VST telescope aimed at measuring the rate of the different types of SNe in the redshift range 0.2search was performed in two of the best-studied extragalactic fields, CDFS and COSMOS, for which a wealth of ancillary data are available in the literature or public archives. (abridged) We obtained a final sample of 117 SNe, most of which are SNIa (57%) and the remaining core collapse events of which 44% type II, 22% type IIn and 34% type Ib/c. In order to link the transients, we built a catalog of ~1.3x10^5 galaxies in the redshift range 0

  6. A Search for supernova relic neutrinos at Super-Kamiokande

    Energy Technology Data Exchange (ETDEWEB)

    Iida, Takashi; Bays, Kirk, E-mail: iida@suketto.icrr.u-tokyo.ac.j [ICRR, University of Tokyo, Mozumi, Hida, Gifu (Japan)

    2010-01-01

    Supernova relic neutrinos (SRN) are the diffuse supernova neutrino background from all past supernovae. No experiment has succeeded in detecting SRN yet. Currently, the Super-Kamiokande experiment has the world's best flux upper limit of 1.2 {nu}-bar {sub e}/cm{sup 2}/sec for E{sub v} < 19.3 MeV. We have worked to improve this value by improving the data analysis. We have achieved better reduction efficiency and lowered the analysis energy threshold by developing a new spallation cut as well as optimizing other cuts.

  7. In search of Mahutonga: a possible supernova recorded in Maori astronomical traditions?

    Science.gov (United States)

    Green, David A.; Orchiston, Wayne

    Maori astronomical traditions refer to Mahutonga, which can be interpreted as a possible record of a southern supernova (SN) in or near Crux. A search for any known "young" supernova remnants in this region does not reveal any obvious candidate to associate with this possible supernova. Relaxing the positional constraint somewhat, the SN of A.D. 185 near a Centauri is nearby. If this is associated with Mahutonga, then the Maori term must be a relic of an earlier Proto-Polynesian record.

  8. Methodological studies on the search for Gravitational Waves and Neutrinos from Type II Supernovae

    Science.gov (United States)

    Casentini, Claudio

    2016-02-01

    Type II SNe, also called Core-collapse SuperNovae have a neutrino (v) emission, as confirmed by SN 1987A, and are also potential sources of gravitational waves. Neutrinos and gravitational waves from these sources reach Earth almost contemporaneously and without relevant interaction with stellar matter and interstellar medium. The upcoming advanced gravitational interferometers would be sensitive enough to detect gravitational waves signals from close galactic Core-collapse SuperNovae events. Nevertheless, significant uncertainties on theoretical models of emission remain. A joint search of coincident low energy neutrinos and gravitational waves events from these sources would bring valuable information from the inner core of the collapsing star and would enhance the detection of the so-called Silent SuperNovae. Recently a project for a joint search involving gravitational wave interferometers and neutrino detectors has started. We discuss the benefits of a joint search and the status of the search project.

  9. THE DIFFERENCE IMAGING PIPELINE FOR THE TRANSIENT SEARCH IN THE DARK ENERGY SURVEY

    Energy Technology Data Exchange (ETDEWEB)

    Kessler, R.; Scolnic, D. [Kavli Institute for Cosmological Physics, University of Chicago, Chicago, IL 60637 (United States); Marriner, J.; Finley, D. A.; Wester, W. [Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510 (United States); Childress, M.; Yuan, F. [ARC Centre of Excellence for All-sky Astrophysics (CAASTRO), Australian National University, Canberra ACT 2611 (Canada); Covarrubias, R. [National Center for Supercomputing Applications, 1205 West Clark St., Urbana, IL 61801 (United States); D’Andrea, C. B.; Nichol, R. C.; Papadopoulos, A. [Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth, PO1 3FX (United Kingdom); Fischer, J.; Sako, M. [Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104 (United States); Foley, R. J. [Department of Astronomy, University of Illinois, 1002 W. Green Street, Urbana, IL 61801 (United States); Goldstein, D. [Department of Astronomy, University of California, Berkeley, 501 Campbell Hall, Berkeley, CA 94720 (United States); Gupta, R. R. [Argonne National Laboratory, 9700 South Cass Avenue, Lemont, IL 60439 (United States); Kuehn, K. [Australian Astronomical Observatory, North Ryde, NSW 2113 (Australia); Marcha, M. [Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT (United Kingdom); Smith, M.; Sullivan, M., E-mail: kessler@kicp.uchicago.edu [School of Physics and Astronomy, University of Southampton, Southampton, SO17 1BJ (United Kingdom); Collaboration: DES Collaboration; and others

    2015-12-15

    We describe the operation and performance of the difference imaging pipeline (DiffImg) used to detect transients in deep images from the Dark Energy Survey Supernova program (DES-SN) in its first observing season from 2013 August through 2014 February. DES-SN is a search for transients in which ten 3 deg{sup 2} fields are repeatedly observed in the g, r, i, z passbands with a cadence of about 1 week. The observing strategy has been optimized to measure high-quality light curves and redshifts for thousands of Type Ia supernovae (SNe Ia) with the goal of measuring dark energy parameters. The essential DiffImg functions are to align each search image to a deep reference image, do a pixel-by-pixel subtraction, and then examine the subtracted image for significant positive detections of point-source objects. The vast majority of detections are subtraction artifacts, but after selection requirements and image filtering with an automated scanning program, there are ∼130 detections per deg{sup 2} per observation in each band, of which only ∼25% are artifacts. Of the ∼7500 transients discovered by DES-SN in its first observing season, each requiring a detection on at least two separate nights, Monte Carlo (MC) simulations predict that 27% are expected to be SNe Ia or core-collapse SNe. Another ∼30% of the transients are artifacts in which a small number of observations satisfy the selection criteria for a single-epoch detection. Spectroscopic analysis shows that most of the remaining transients are AGNs and variable stars. Fake SNe Ia are overlaid onto the images to rigorously evaluate detection efficiencies and to understand the DiffImg performance. The DiffImg efficiency measured with fake SNe agrees well with expectations from a MC simulation that uses analytical calculations of the fluxes and their uncertainties. In our 8 “shallow” fields with single-epoch 50% completeness depth ∼23.5, the SN Ia efficiency falls to 1/2 at redshift z ≈ 0.7; in our 2

  10. A method of searching for supernova candidates from massive galaxy spectra

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    This paper presents a novel spectroscopic method for searching for supernova candidates from massive galaxy spectra,which is expected to be applied to the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST).This method includes mainly five steps.The first step is spectral preprocessing,including removing spectral noise using wavelet transform,spectral de-redshift,etc.The second step is decomposition of galactic spectra;we can get the galaxy component and supernova component and calculate the Supernova Statistical Characterization Vector (SNSCV) of each galaxy spectrum.The third step is to decrease samples in all the galaxy spectral datasets according to SNSCV of each spectrum,and to use the LOF (Local Outlier Factor)-based outlier detection algorithm to obtain the preliminary selected spectral data.The fourth step is template matching by cross-correlation,according to the matched results we get the secondary selected spectral data.Finally,we choose the final supernova candidates manually through checking the spectral features characteristic of a supernova.By the spectroscopic method proposed in this paper,thirty-six supernova candidates have been detected in a dataset including 294843 galaxy spectra from the Sloan Digital Sky Survey Data Release 7.Nine of these objects are detected first and the other twenty-seven have been reported in other publications (fifteen of which are detected and reported first by us).The twenty-four new super-nova candidates include twenty Ia type supernova candidates,three Ic type supernova candidates and one II type supernova candidate.

  11. COORDINATE-BASED META-ANALYTIC SEARCH FOR THE SPM NEUROIMAGING PIPELINE

    DEFF Research Database (Denmark)

    Wilkowski, Bartlomiej; Szewczyk, Marcin; Rasmussen, Peter Mondrup

    2009-01-01

    of the databases offer so- called coordinate-based searching to the users (e.g. Brede, BrainMap). For such search, the publications, which relate to the brain locations represented by the user coordinates, are retrieved. In this paper we present BredeQuery – a plugin for the widely used SPM5 data analytic pipeline...

  12. A Radio Survey of Type Ib and Ic Supernovae: Searching for Engine Driven Supernovae

    CERN Document Server

    Berger, E; Frail, D A; Soderberg, A M

    2003-01-01

    The association of gamma-ray bursts (GRBs) and core-collapse supernovae (SNe) of Type Ib and Ic was motivated by the detection of SN 1998bw in the error box of GRB 980425 and the now-secure identification of a SN 1998bw-like event in the cosmological GRB 030329. The bright radio emission from SN 1998bw indicated that it possessed some of the unique attributes expected of GRBs, namely a large reservoir of energy in (mildly) relativistic ejecta and variable energy input. The two popular scenarios for the origin of SN 1998bw are a typical cosmological burst observed off-axis or a member of a new distinct class of supernova explosions (gSNe). In the former, about 0.5% of local Type Ib/c SNe are expected to be similar to SN1998bw; for the latter no such constraint exists. Motivated thus, we began a systematic program of radio observations of most reported Type Ib/c SNe accessible to the Very Large Array. Of the 33 SNe observed from late 1999 to the end of 2002 at most one is as bright as SN 1998bw. From this we co...

  13. Search for supernova produced {sup 60}Fe in Earth's microfossil record

    Energy Technology Data Exchange (ETDEWEB)

    Ludwig, Peter; Bishop, Shawn; Chernenko, Valentyna; Faestermann, Thomas; Fimiani, Leticia; Gomez, Jose; Hain, Karin; Korschinek, Gunther [Technische Univ. Muenchen, Garching (Germany). Physik-Department; Egli, Ramon [Central Institute for Meteorology and Geodynamics, Vienna (Austria)

    2013-07-01

    The detection of supernova debris on Earth can be achieved by use of accelerator mass spectrometry (AMS) to search for radionuclides like {sup 60}Fe. This long-lived isotope (T{sub 1/2}=2.6 Myr) is produced in massive stars and is expected to be present in the debris of type II supernovae. The discovery of {sup 60}Fe in a ferromanganese crust from the Pacific ocean (Knie et al., 2004) was interpreted as the input of a supernova explosion about 2.2 Myr ago. Currently, several projects are aiming for the confirmation of the signature of {sup 60}Fe in terrestrial and lunar samples. In this talk, the search for this {sup 60}Fe signature in Earth's microfossil record is presented. The sample material for this study is marine sediment from the eastern equatorial Pacific. A specific kind of secondary (formed in situ) magnetite mineral contained in the sample material are magnetofossils, which are the remains of magnetotactic bacteria, which are the target for extraction. The chemical extraction technique used to produce AMS samples has been characterized using newly developed magnetic analysis methods and has been shown to be extremely selective towards secondary magnetite. The AMS samples produced in this way are uniquely suited for the search for supernova {sup 60}Fe. Preliminary AMS results are presented.

  14. The Search for the Companion Star of Tycho Brahe's 1572 Supernova

    Science.gov (United States)

    Mendez, J.

    2005-03-01

    In recent years, type Ia supernovae (SNe Ia) have been used successfully as cosmological probes of the Universe. However, the nature of their progenitors has remained somewhat of a mystery. It is widely accepted that they represent the disruption of a degenerate object, but there are also numerous progenitor models, but most of these have serious theoretical/observational problems or do not appear to produce sufficient numbers to explain the observed frequency of SNe Ia in our Galaxy. Tycho Brahe's supernova (SN 1572) is one of the only two supernovae observed in our Galaxy that are thought to have been of type Ia as revealed by the light curve, radio emission and X-ray spectra. We have conducted a search for the surviving companion star of SN 1572.

  15. Integer programming formulation and variable neighborhood search metaheuristic for the multiproduct pipeline scheduling problem

    Energy Technology Data Exchange (ETDEWEB)

    Souza Filho, Erito M.; Bahiense, Laura; Ferreira Filho, Virgilio J.M. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE); Lima, Leonardo [Centro Federal de Educacao Tecnologica Celso Sukow da Fonseca (CEFET-RJ), Rio de Janeiro, RJ (Brazil)

    2008-07-01

    Pipeline are known as the most reliable and economical mode of transportation for petroleum and its derivatives, especially when large amounts of products have to be pumped for large distances. In this work we address the short-term schedule of a pipeline system comprising the distribution of several petroleum derivatives from a single oil refinery to several depots, connected to local consumer markets, through a single multi-product pipeline. We propose an integer linear programming formulation and a variable neighborhood search meta-heuristic in order to compare the performances of the exact and heuristic approaches to the problem. Computational tests in C language and MOSEL/XPRESS-MP language are performed over a real Brazilian pipeline system. (author)

  16. Revisiting the Lick Observatory Supernova Search Volume-Limited Sample: Updated Classifications and Revised Stripped-envelope Supernova Fractions

    CERN Document Server

    Shivvers, Isaac; Zheng, Weikang; Filippenko, Alexei V; Silverman, Jeffrey M; Liu, Yuqian; Matheson, Thomas; Pastorello, Andrea; Graur, Or; Foley, Ryan J; Chornock, Ryan; Smith, Nathan; Leaman, Jesse; Benetti, Stefano

    2016-01-01

    We re-examine the classifications of supernovae (SNe) presented in the Lick Observatory Supernova Search (LOSS) volume-limited sample with a focus on the stripped-envelope SNe. The LOSS volumetric sample, presented by Leaman et al. (2011) and Li et al. (2011b), was calibrated to provide meaningful measurements of SN rates in the local universe; the results presented therein continue to be used for comparisons to theoretical and modeling efforts. Many of the objects from the LOSS sample were originally classified based upon only a small subset of the data now available, and recent studies have both updated some subtype distinctions and improved our ability to perform robust classifications, especially for stripped-envelope SNe. We re-examine the spectroscopic classifications of all events in the LOSS volumetric sample (180 SNe and SN impostors) and update them if necessary. We discuss the populations of rare objects in our sample including broad-lined Type Ic SNe, Ca-rich SNe, SN 1987A-like events (we identify...

  17. Nearby Supernova Rates from the Lick Observatory Supernova Search. II. The Observed Luminosity Functions and Fractions of Supernovae in a Complete Sample

    CERN Document Server

    Li, Weidong; Chornock, Ryan; Filippenko, Alexei V; Poznanski, Dovi; Ganeshalingam, Mohan; Wang, Xiaofeng; Modjaz, Maryam; Jha, Saurabh; Foley, Ryan J; Smith, Nathan

    2010-01-01

    This is the second paper of a series in which we present new measurements of the observed rates of supernovae (SNe) in the local Universe, determined from the Lick Observatory Supernova Search (LOSS). In this paper, a complete SN sample is constructed, and the observed (uncorrected for host-galaxy extinction) luminosity functions (LFs) of SNe are derived. These LFs solve two issues that have plagued previous rate calculations for nearby SNe: the luminosity distribution of SNe and the host-galaxy extinction. We select a volume-limited sample of 175 SNe, collect photometry for every object, and fit a family of light curves to constrain the peak magnitudes and light-curve shapes. The volume-limited LFs show that they are not well represented by a Gaussian distribution. There are notable differences in the LFs for galaxies of different Hubble types (especially for SNe Ia). We derive the observed fractions for the different subclasses in a complete SN sample, and find significant fractions of SNe II-L (10%), IIb (...

  18. X-Pipeline: An analysis package for autonomous gravitational-wave burst searches

    CERN Document Server

    Sutton, Patrick J; Chatterji, Shourov; Kalmus, Peter Michael; Leonor, Isabel; Poprocki, Stephen; Rollins, Jameson; Searle, Antony; Stein, Leo; Tinto, Massimo; Was, Michal

    2009-01-01

    Autonomous gravitational-wave searches -- fully automated analyses of data that run without human intervention or assistance -- are desirable for a number of reasons. They are necessary for the rapid identification of gravitational-wave burst candidates, which in turn will allow for follow-up observations by other observatories and the maximum exploitation of their scientific potential. A fully automated analysis would also circumvent the traditional "by hand" setup and tuning of burst searches that is both labourious and time consuming. We demonstrate a fully automated search with X-Pipeline, a software package for the coherent analysis of data from networks of interferometers for detecting bursts associated with GRBs and other astrophysical triggers. We discuss the methods X-Pipeline uses for automated running, including background estimation, efficiency studies, unbiased optimal tuning of search thresholds, and prediction of upper limits. These are all done automatically via Monte Carlo with multiple indep...

  19. Near-IR Search for Lensed Supernovae Behind Galaxy Clusters: I. Observations and transient detection efficiency

    CERN Document Server

    Stanishev, V; Paech, K; Amanullah, R; Dahlén, T; Jönsson, J; Kneib, J P; Lidman, C; Limousin, M; Mörtsell, E; Nobili, S; Richard, J; Riehm, T; von Strauss, M

    2009-01-01

    Massive galaxy clusters at intermediate redshift can magnify the flux of distant background sources by several magnitudes and we exploit this effect to search for lensed distant supernovae that may otherwise be too faint to be detected. A supernova search was conducted at near infrared wavelengths using the ISAAC instrument at VLT. The galaxy clusters Abell 1689, Abell 1835 and AC114 were observed at multiple epochs of 2 hours of exposure time, separated by a month. Image subtraction techniques were used to search for transient objects with light curve properties consistent with supernovae, both in our new and archival ISAAC/VLT data. The limiting magnitude of the individual epochs was estimated by adding artificial stars to the subtracted images. Most of the epochs reach 90% detection efficiency at SZ(J) ~= 23.8-24.0 mag (Vega). Two transient objects, both in archival images of Abell 1689 and AC114, were detected. The transient in AC114 coincides - within the position uncertainty - with a X-ray source and is...

  20. Detailed comparison of LIGO and Virgo inspiral pipelines in preparation for a joint search

    Energy Technology Data Exchange (ETDEWEB)

    Beauville, F; Buskulic, D; Grosjean, D [Laboratoire d' Annecy-le-Vieux de Physique des Particules, Chemin de Bellevue, BP 110, 74941 Annecy-le-Vieux Cedex (France); Bizouard, M-A; Cavalier, F; Clapson, A-C; Hello, P [Laboratoire de l' Accelerateur Lineaire, IN2P3/CNRS-Universite de Paris XI, BP 34, 91898 Orsay Cedex (France); Blackburn, L; Katsavounidis, E [LIGO-Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Bosi, L [INFN Sezione di Perugia and/or Universita di Perugia, Via A Pascoli, I-06123 Perugia (Italy); Brocco, L [INFN Sezione di Roma and/or Universita ' La Sapienza' , P.le A Moro 2, I-00185, Roma (Italy); Brown, D A; Chatterji, S [LIGO-California Institute of Technology, Pasadena, CA 91125 (United States); Christensen, N; Knight, M [Carleton College, Northfield, MN 55057 (United States); Fairhurst, S [University of Wisconsin-Milwaukee, Milwaukee, WI 53201 (United States); Guidi, G [INFN Sezione Firenze/Urbino Via G Sansone 1, I-50019 Sesto Fiorentino (Italy) and/or Universita di Firenze, Largo E.Fermi 2, I-50125 Firenze and/or Universita di Urbino, Via S Chiara 27, I-61029 Urbino (Italy); Heng, S; Hewitson, M [University of Glasgow, Glasgow, G12 8QQ (United Kingdom); Klimenko, S [University of Florida-Gainesville, FL 32611 (United States)] (and others)

    2008-02-21

    Presented in this paper is a detailed and direct comparison of the detection pipelines used by LIGO and Virgo in their attempt to observe gravitational waves from binary neutron star systems. In order to test the search programs, numerous inspiral signals were added to 24 h of simulated detector data. The efficiencies of the different pipelines were tested, and found to be very similar. Parameter estimation routines were also tested. We demonstrate that there are definite benefits if LIGO and Virgo conduct a joint coincident analysis; these advantages include increased detection efficiency and information on source sky location.

  1. Object Classification at the Nearby Supernova Factory

    Energy Technology Data Exchange (ETDEWEB)

    Aragon, Cecilia R.; Bailey, Stephen; Aragon, Cecilia R.; Romano, Raquel; Thomas, Rollin C.; Weaver, B. A.; Wong, D.

    2007-12-21

    We present the results of applying new object classification techniques to the supernova search of the Nearby Supernova Factory. In comparison to simple threshold cuts, more sophisticated methods such as boosted decision trees, random forests, and support vector machines provide dramatically better object discrimination: we reduced the number of nonsupernova candidates by a factor of 10 while increasing our supernova identification efficiency. Methods such as these will be crucial for maintaining a reasonable false positive rate in the automated transient alert pipelines of upcoming large optical surveys.

  2. Search for Nonthermal X-Rays from Supernova Remnant Shells

    Science.gov (United States)

    Petre, R.; Keohane, J.; Hwang, U.; Allen, G.; Gotthelf, E.

    The demonstration by ASCA that the nonthermal X-ray emission from the rim of SN1006 is synchrotron emission from TeV electrons, produced in the same environment responsible for cosmic ray protons and nuclei (Koyama et al. 1995, Nature 378, 255), has stimulated a search for nonthermal X-rays from other remnants. Nonthermal emission has subsequently been found to arise in the shells of at least two other remnants, Cas A and IC 443. In Cas A, a hard tail is detected using ASCA, XTE, and OSSE to energies exceeding 100 keV; the shape of the spectrum rules out all mechanisms except synchrotron radiation. In IC 443, the previously known hard emission has been shown using ASCA to be isolated to a small region along the rim of the remnant, where the shock is interacting most strongly with a molecular cloud. Nonthermal X-ray emission is thought to arise here by enhanced cosmic ray production associated with the shock/cloud interaction (Keohane et al. 1997, ApJ in press). We describe the properties of the nonthermal emission in SN1006, Cas A, and IC 443, and discuss the status of our search for nonthermal emission associated with the shocks of other Galactic and LMC SNR's.

  3. Search for supernova-produced {sup 60}Fe in the Earth's fossil record

    Energy Technology Data Exchange (ETDEWEB)

    Bishop, Shawn; Ludwig, Peter; Chernenko, Valentyna; Faestermann, Thomas; Famulok, Nicolai; Fimiani, Leticia; Gomez, Jose; Hain, Karin; Korschinek, Gunther [TU Muenchen, Physik Department (Germany); Egli, Ramon [ZAMG, Wien (Austria); Frederichs, Thomas [Universitaet Bremen, Geowissenschaften (Germany); Hazlik, Marianne [TU Muenchen, Fakultaet fuer Chemie (Germany); Merchel, Silke; Rugel, Georg [HZDR, Dresden (Germany)

    2014-07-01

    Approximately 1.8 to 2.8 Myr before the present our planet was subjected to the debris of a supernova explosion. The terrestrial proxy for this event was the discovery of live atoms of {sup 60}Fe in a deep-sea ferromanganese crust [Knie et al., Phys. Rev. Lett. (2004)]. The signature for this supernova event should also reside in magnetite (Fe{sub 3}O{sub 4}) magnetofossils produced by magnetotactic bacteria extant at the time of the Earth-supernova interaction; these bacteria were and are ubiquitous in all ocean sediments. We have conducted accelerator mass spectrometry (AMS) measurements, searching for live {sup 60}Fe in the magnetofossil component of a Pacific Ocean sediment core (ODP Core 848); additional AMS measurements are now ongoing with a second sediment core (ODP Core 851) in which we expect to find a higher {sup 60}Fe signal. This talk presents the current preliminary status of our {sup 60}Fe search results for both sediment cores.

  4. The Search for Failed Supernovae with the Large Binocular Telescope: Constraints from 7 Years of Data

    CERN Document Server

    Adams, S M; Gerke, J R; Stanek, K Z

    2016-01-01

    We report updated results for the first 7 years of our program to monitor 27 galaxies within 10 Mpc using the Large Binocular Telescope to search for failed supernovae -- core-collapses of massive stars that form black holes without luminous supernovae. In the new data, we identify no new compelling candidates and confirm the existing candidate. Given the 6 successful core-collapse SNe in the sample and one likely failed SN, the implied fraction of core-collapses that result in failed SNe is $f = 0.14^{+0.33}_{-0.10}$ at 90% confidence. If the current candidate is a failed SN, the fraction of failed SN naturally explains the missing high-mass RSG SN progenitors and the black hole mass function. If the current candidate is ultimately rejected, the data implies a 90% confidence upper limit on the failed SN fraction of $f < 0.35$.

  5. An improved pipeline to search for gravitational waves from compact binary coalescence

    CERN Document Server

    Usman, Samantha A; Nitz, Alexander H; Harry, Ian W; Brown, Duncan A; Capano, Collin D; Dent, Thomas; Fairhurst, Stephen; Pfeiffer, Harald P; Biwer, Christopher M; Canton, Tito Dal; Keppel, Drew; Saulson, Peter R; West, Matthew; Willis, Joshua L

    2015-01-01

    The second generation of ground-based gravitational-wave detectors will begin taking data in September 2015. Sensitive and computationally-efficient data analysis methods will be required to maximize what we learn from their observations. We describe improvements made to the offline analysis pipeline searching for gravitational waves from stellar-mass compact binary coalescences, and assess how these improvements affect search sensitivity. Starting with the two-stage ihope pipeline used in S5, S6 and VSR1-3 and using two weeks of S6/VSR3 data as test periods, we first demonstrate a pipeline with a simpler workflow. This single-stage pipeline performs matched filtering and coincidence testing only once. This simplification allows us to reach much lower false-alarm rates for loud candidate events. We then describe an optimized chi-squared test which minimizes computational cost. Next, we compare methods of generating template banks, demonstrating that a fixed bank may be used for extended stretches of time. Fix...

  6. Directed searches for broadband extended gravitational-wave emission in nearby energetic core-collapse supernovae

    CERN Document Server

    Van Putten, Maurice H P M

    2016-01-01

    Core-collapse supernovae are factories of neutron stars and stellar mass black holes. Type Ib/c supernovae stand out as potentially originating in relatively compact stellar binaries and their branching ratio of about 1\\% into long gamma-ray bursts. The most energetic events probably derive from central engines harboring rapidly rotating black holes, wherein accretion of fall-back matter down to the Inner Most Stable Circular Orbit (ISCO) offers a window to {\\em broadband extended gravitational-wave emission} (BEGE). To search for BEGE, we introduce a butterfly filter in time-frequency space by Time Sliced Matched Filtering. To analyze long epochs of data, we propose using coarse grained searches followed by high resolution searches on events of interest. We illustrate our proposed coarse grained search on two weeks of LIGO S6 data prior to SN 2010br $(z=0.002339)$ using a bank of up to 64 thousand templates of one second duration covering a broad range in chirp frequencies and bandwidth. Correlating events w...

  7. The sloan digital sky Survey-II supernova survey: search algorithm and follow-up observations

    Energy Technology Data Exchange (ETDEWEB)

    Sako, Masao [Department of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104 (United States); Bassett, Bruce [Department of Mathematics and Applied Mathematics, University of Cape Town, Rondebosch 7701 (South Africa); Becker, Andrew; Hogan, Craig J. [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); Cinabro, David [Department of Physics, Wayne State University, Detroit, MI 48202 (United States); DeJongh, Fritz; Frieman, Joshua A.; Marriner, John; Miknaitis, Gajus [Center for Particle Astrophysics, Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510 (United States); Depoy, D. L.; Prieto, Jose Luis [Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210-1173 (United States); Dilday, Ben; Kessler, Richard [Kavli Institute for Cosmological Physics, The University of Chicago, 5640 South Ellis Avenue Chicago, IL 60637 (United States); Doi, Mamoru [Institute of Astronomy, Graduate School of Science, University of Tokyo 2-21-1, Osawa, Mitaka, Tokyo 181-0015 (Japan); Garnavich, Peter M. [University of Notre Dame, 225 Nieuwland Science, Notre Dame, IN 46556-5670 (United States); Holtzman, Jon [Department of Astronomy, MSC 4500, New Mexico State University, P.O. Box 30001, Las Cruces, NM 88003 (United States); Jha, Saurabh [Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, P.O. Box 20450, MS29, Stanford, CA 94309 (United States); Konishi, Kohki [Institute for Cosmic Ray Research, University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa, Chiba, 277-8582 (Japan); Lampeitl, Hubert [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Nichol, Robert C. [Institute of Cosmology and Gravitation, Mercantile House, Hampshire Terrace, University of Portsmouth, Portsmouth PO1 2EG (United Kingdom); and others

    2008-01-01

    The Sloan Digital Sky Survey-II Supernova Survey has identified a large number of new transient sources in a 300 deg{sup 2} region along the celestial equator during its first two seasons of a three-season campaign. Multi-band (ugriz) light curves were measured for most of the sources, which include solar system objects, galactic variable stars, active galactic nuclei, supernovae (SNe), and other astronomical transients. The imaging survey is augmented by an extensive spectroscopic follow-up program to identify SNe, measure their redshifts, and study the physical conditions of the explosions and their environment through spectroscopic diagnostics. During the survey, light curves are rapidly evaluated to provide an initial photometric type of the SNe, and a selected sample of sources are targeted for spectroscopic observations. In the first two seasons, 476 sources were selected for spectroscopic observations, of which 403 were identified as SNe. For the type Ia SNe, the main driver for the survey, our photometric typing and targeting efficiency is 90%. Only 6% of the photometric SN Ia candidates were spectroscopically classified as non-SN Ia instead, and the remaining 4% resulted in low signal-to-noise, unclassified spectra. This paper describes the search algorithm and the software, and the real-time processing of the SDSS imaging data. We also present the details of the supernova candidate selection procedures and strategies for follow-up spectroscopic and imaging observations of the discovered sources.

  8. Rates and progenitors of type Ia supernovae

    Energy Technology Data Exchange (ETDEWEB)

    Wood-Vasey, William Michael [Univ. of California, Berkeley, CA (United States)

    2004-01-01

    The remarkable uniformity of Type Ia supernovae has allowed astronomers to use them as distance indicators to measure the properties and expansion history of the Universe. However, Type Ia supernovae exhibit intrinsic variation in both their spectra and observed brightness. The brightness variations have been approximately corrected by various methods, but there remain intrinsic variations that limit the statistical power of current and future observations of distant supernovae for cosmological purposes. There may be systematic effects in this residual variation that evolve with redshift and thus limit the cosmological power of SN Ia luminosity-distance experiments. To reduce these systematic uncertainties, we need a deeper understanding of the observed variations in Type Ia supernovae. Toward this end, the Nearby Supernova Factory has been designed to discover hundreds of Type Ia supernovae in a systematic and automated fashion and study them in detail. This project will observe these supernovae spectrophotometrically to provide the homogeneous high-quality data set necessary to improve the understanding and calibration of these vital cosmological yardsticks. From 1998 to 2003, in collaboration with the Near-Earth Asteroid Tracking group at the Jet Propulsion Laboratory, a systematic and automated searching program was conceived and executed using the computing facilities at Lawrence Berkeley National Laboratory and the National Energy Research Supercomputing Center. An automated search had never been attempted on this scale. A number of planned future large supernovae projects are predicated on the ability to find supernovae quickly, reliably, and efficiently in large datasets. A prototype run of the SNfactory search pipeline conducted from 2002 to 2003 discovered 83 SNe at a final rate of 12 SNe/month. A large, homogeneous search of this scale offers an excellent opportunity to measure the rate of Type Ia supernovae. This thesis presents a new method for

  9. The Nearby Supernova Factory

    CERN Document Server

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

    2004-01-01

    The Nearby Supernova Factory (SNfactory) is an ambitious project to find and study in detail approximately 300 nearby Type Ia supernovae (SNe~Ia) at redshifts 0.03searches. In 2002, 35 SNe were found using our test-bed pipeline for automated SN search and discovery. The pipeline uses images from the asteroid search conducted by the Near Earth Asteroid Tracking group at JPL. Improvements in our subtraction techniques and analysis have allowed us to increase our effective SN discovery rate to ~12 SNe/month in 2003.

  10. Proposed searches for candidate sources of gravitational waves in a nearby core-collapse supernova survey

    CERN Document Server

    Heo, Jeon-Eun; Lee, Dae-Sub; Kong, In-Taek; Lee, Sang-Hoon; van Putten, Maurice H P M; Della Valle, Massimo

    2015-01-01

    Gravitational wave bursts in the formation of neutron stars and black holes in energetic core-collapse supernovae (CC-SNe) are of potential interest to LIGO-Virgo and KAGRA. Events nearby are readily discovered using moderately sized telescopes. CC-SNe are competitive with mergers of neutron stars and black holes, if the fraction producing an energetic output in gravitational waves exceeds about 1\\%. This opportunity motivates the design of a novel Sejong University Core-CollapsE Supernova Survey (SUCCESS), to provide triggers for follow-up searches for gravitational waves. It is based on the 76 cm Sejong University Telescope (SUT) for weekly monitoring of nearby star-forming galaxies, i.e., M51, M81-M82 and Blue Dwarf Galaxies from the Unified Nearby Galaxy Catalog with an expected yield of a few hundred per year. Optical light curves will be resolved for the true time-of-onset for probes of gravitational waves by broadband time-sliced matched filtering.

  11. Prospects for Gravitational Wave Searches for Core-Collapse Supernovae within the Local Universe

    Science.gov (United States)

    Gill, Kiranjyot; Branchesi, Marica; Zanolin, Michele; Szczepanczyk, Marek; LIGO Collaboration

    2017-01-01

    We present an updated estimate of the intrinsic (vs observed) core collapse supernovae (CCSNe) rate within 20 Mpc from Earth, which is roughly the largest distance of interest for the searches for gravitational waves (GWs) from CCSNe with laser interferometers. Recognizing that CCSN galaxy host models are morphologically dependent, we separate the galaxies within 20 Mpc into the local field and Virgo cluster and account for biases, such as galactic plane absorption. The improved estimation of the CCSNe rate within 20 Mpc is 430 +/- 21 CCSNe Century -1 Mpc-1. We also discuss the Feldman-Cousins and GRB methodologies for detecting CCSNe when there are multiple CCSNe optical triggers, as predicted for advanced LIGO data science runs. Illustrative examples of the sensitivity improvement with respect to the single-event current approaches are provided for rapidly rotating semi-analytical models of GW emissions and real (publicly released) LIGO data.

  12. Search for. gamma. rays from the supernova 1987A at energies greater than 100 TeV

    Energy Technology Data Exchange (ETDEWEB)

    Bond, I.A.; Budding, E.; Conway, M.J.; Fenton, K.B.; Fujii, H.; Fujii, Z.; Hasegawa, H.; Hayashida, N.; Honda, M.; Hotta, N.

    1988-03-21

    We searched for ultrahigh-energy ..gamma.. rays emitted by the supernova 1987A with a new cosmic-ray facility installed at the Black Birch Range in New Zealand. The observations from 13 October to 3 December 1987 suggest no clear clustering of events around the direction of the supernova. We conclude that an upper limit on the flux ..gamma.. rays of energies greater than 100 TeV is 1.1 x 10/sup -12/ cm/sup -2/ s/sup -1/ (95% confidence limit) for a differential spectral index ..cap alpha.. = 2.0 and source distance d = 50 kpc. This value gives an upper bound on the ..gamma..-ray luminosity of the supernova of 5.5 x 10/sup 38/ erg s/sup -1/ for 10/sup 14/--10/sup 17/ eV

  13. Methodology of the joint search for Gravitational Wave and Low Energy Neutrino signals from Core-Collapse Supernovae

    Science.gov (United States)

    Casentini, Claudio

    2016-05-01

    Core-Collapse Supernovae (CCSNe) have a neutrino (v) signature confirmed by SN 1987A and are potential sources of Gravitational Waves (GWs). vs and GWs coming from these sources will reach the observer almost simultaneously and without significant interaction with interstellar matter. The expected GW signals are in the range of the upcoming advanced detectors for galactic neighborhood events. However, there are still significant uncertainties on the theoretical model of the emission. A joint search of coincident vs and GWs from these sources would bring valuable information from the inner core of the collapsing star and would enhance the detection of the so-called Silent Supernovae. Recently, a project for a joint search involving GW interferometers and v detectors has started. In this paper we discuss about the principal GW theoretical models of emission, and we present a methodological study of the joint search project between GW and v.

  14. A Search for New Candidate Super-Chandrasekhar-Mass Type Ia Supernovae in the Nearby Supernova Factory Dataset

    CERN Document Server

    Scalzo, The Nearby Supernova Factory: R; Antilogus, P; Aragon, C; Bailey, S; Baltay, C; Bongard, S; Buton, C; Canto, A; Cellier-Holzem, F; Childress, M; Chotard, N; Copin, Y; Fakhouri, H K; Gangler, E; Guy, J; Hsiao, E Y; Kerschhaggl, M; Kowalski, M; Nugent, P; Paech, K; Pain, R; Pecontal, E; Pereira, R; Perlmutter, S; Rabinowitz, D; Rigault, M; Runge, K; Smadja, G; Tao, C; Thomas, R C; Weaver, B A; Wu, C

    2012-01-01

    We present optical photometry and spectroscopy of five type Ia supernovae discovered by the Nearby Supernova Factory selected to be spectroscopic analogues of the candidate super-Chandrasekhar-mass events SN 2003fg and SN 2007if. Their spectra are characterized by hot, highly ionized photospheres near maximum light, for which SN 1991T supplies the best phase coverage among available close spectral templates. Like SN 2007if, these supernovae are overluminous (-19.5 < M_V < -20) and the velocity of the Si II 6355 absorption minimum is consistent with being constant in time from phases as early as a week before, and up to two weeks after, $B$-band maximum light. We interpret the velocity plateaus as evidence for a reverse-shock shell in the ejecta formed by interaction at early times with a compact envelope of surrounding material, as might be expected for SNe resulting from the mergers of two white dwarfs. We use the bolometric light curves and line velocity evolution of these SNe to estimate important pa...

  15. The rate of Supernovae from the combined sample of five searches

    CERN Document Server

    Cappellaro, E; Tsvetkov, D Y; Bartunov, O S; Pollas, C; Evans, R; Hamuy, M

    1996-01-01

    With the purpose to obtain new estimates of the rate of supernovae we joined the logs of five SN searches, namely the Asiago, Crimea, Cal{á}n-Tololo and OCA photographic surveys and the visual search by Evans (the sample counts 110 SNe). We found that the most prolific galaxies are late spirals in which most SNe are of type II (0.88 SNu). SN Ib/c are rarer than SN Ia (0.16 and 0.24 SNu, respectively), ruling out previous claims of a very high rate of SNIb/c. We also found that the rate of SN Ia in ellipticals (0.13 SNu) is smaller than in spirals, supporting the hypothesis of different ages of the progenitor systems in early and late type galaxies. Finally, we estimated that even assuming that separate classes of faint SN Ia and SN II do exist (SNe 1991bg and 1987A could be the respective prototypes) the overall SN rate is raised only by 20-30%, therefore excluding that faint SNe represent the majority of SN explosions. Also, the bright SNIIn are intrinsically very rare (2 to 5% of all SNII in spirals).

  16. A search for \\textit{Fermi} bursts associated to supernovae and their frequency of occurrence

    CERN Document Server

    Kovacevic, M; Wang, Y; Muccino, M; Della Valle, M; Amati, L; Barbarino, C; Enderli, M; Pisani, G B; Li, L

    2014-01-01

    Context: Observations suggest that the major fraction of long duration gamma-ray bursts (GRBs) are connected with broad-lines supernovae Ib/c, (SNe-Ibc). The presence of GRB-SNe is revealed by rebrightenings emerging from the optical GRB afterglow $10$--$15$ days, in the rest-frame of the source, after the prompt GRB emission. Aims: \\textit{Fermi}-GBM has a field of view (FoV) which is about 6.5 times larger than the FoV of \\textit{Swift}, therefore we expect that a number of GRB-SN connections have been missed due to lack of optical and X-ray instruments on board of \\textit{Fermi}, which are essential to reveal SNe associated with GRBs. This fact has motivated our search in the \\textit{Fermi} catalogue for possible GRB-SN events. Methods: The search for possible GRB-SN associations follows two requirements: (1) SN should fall inside the \\textit{Fermi}-GBM error box of the considered long GRB, and (2) this GRB should occur within $20$ days before the SN event. Results: We have found $5$ cases, within $z<0....

  17. A Search for New Candidate Super-Chandrasekhar-mass Type Ia Supernovae in the Nearby Supernova Factory Data Set

    Science.gov (United States)

    Scalzo, R.; Aldering, G.; Antilogus, P.; Aragon, C.; Bailey, S.; Baltay, C.; Bongard, S.; Buton, C.; Canto, A.; Cellier-Holzem, F.; Childress, M.; Chotard, N.; Copin, Y.; Fakhouri, H. K.; Gangler, E.; Guy, J.; Hsiao, E. Y.; Kerschhaggl, M.; Kowalski, M.; Nugent, P.; Paech, K.; Pain, R.; Pecontal, E.; Pereira, R.; Perlmutter, S.; Rabinowitz, D.; Rigault, M.; Runge, K.; Smadja, G.; Tao, C.; Thomas, R. C.; Weaver, B. A.; Wu, C.; Nearby Supernova Factory, The

    2012-09-01

    We present optical photometry and spectroscopy of five Type Ia supernovae discovered by the Nearby Supernova Factory selected to be spectroscopic analogs of the candidate super-Chandrasekhar-mass events SN 2003fg and SN 2007if. Their spectra are characterized by hot, highly ionized photospheres near maximum light, for which SN 1991T supplies the best phase coverage among available close spectral templates. Like SN 2007if, these supernovae are overluminous (-19.5 constant in time from phases as early as a week before, and up to two weeks after, B-band maximum light. We interpret the velocity plateaus as evidence for a reverse-shock shell in the ejecta formed by interaction at early times with a compact envelope of surrounding material, as might be expected for SNe resulting from the mergers of two white dwarfs. We use the bolometric light curves and line velocity evolution of these SNe to estimate important parameters of the progenitor systems, including 56Ni mass, total progenitor mass, and masses of shells and surrounding carbon/oxygen envelopes. We find that the reconstructed total progenitor mass distribution of the events (including SN 2007if) is bounded from below by the Chandrasekhar mass, with SN 2007if being the most massive. We discuss the relationship of these events to the emerging class of super-Chandrasekhar-mass SNe Ia, estimate the relative rates, compare the mass distribution to that expected for double-degenerate SN Ia progenitors from population synthesis, and consider implications for future cosmological Hubble diagrams.

  18. A SEARCH FOR NEW CANDIDATE SUPER-CHANDRASEKHAR-MASS TYPE Ia SUPERNOVAE IN THE NEARBY SUPERNOVA FACTORY DATA SET

    Energy Technology Data Exchange (ETDEWEB)

    Scalzo, R. [Research School of Astronomy and Astrophysics, Australian National University, Mount Stromlo Observatory, Cotter Road, Weston Creek, ACT 2611 (Australia); Aldering, G.; Aragon, C.; Bailey, S.; Childress, M.; Fakhouri, H. K.; Hsiao, E. Y. [Physics Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Antilogus, P.; Bongard, S.; Canto, A.; Cellier-Holzem, F.; Guy, J. [Laboratoire de Physique Nucleaire et des Hautes Energies, Universite Pierre et Marie Curie Paris 6, Universite Paris Diderot Paris 7, CNRS-IN2P3, 4 place Jussieu, F-75252 Paris Cedex 05 (France); Baltay, C. [Department of Physics, Yale University, New Haven, CT 06250-8121 (United States); Buton, C.; Kerschhaggl, M.; Kowalski, M. [Physikalisches Institut, Universitaet Bonn, Nussallee 12, D-53115 Bonn (Germany); Chotard, N.; Copin, Y.; Gangler, E. [Institut de Physique Nucleaire, 43 Boulevard du 11 Novembre 1918, 69622 Villeurbanne Cedex (France); Nugent, P., E-mail: rscalzo@mso.anu.edu.au [Computational Cosmology Center, Computational Research Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road MS 50B-4206, Berkeley, CA 94720 (United States); Collaboration: Nearby Supernova Factory; and others

    2012-09-20

    We present optical photometry and spectroscopy of five Type Ia supernovae discovered by the Nearby Supernova Factory selected to be spectroscopic analogs of the candidate super-Chandrasekhar-mass events SN 2003fg and SN 2007if. Their spectra are characterized by hot, highly ionized photospheres near maximum light, for which SN 1991T supplies the best phase coverage among available close spectral templates. Like SN 2007if, these supernovae are overluminous (-19.5 < M{sub V} < -20) and the velocity of the Si II {lambda}6355 absorption minimum is consistent with being constant in time from phases as early as a week before, and up to two weeks after, B-band maximum light. We interpret the velocity plateaus as evidence for a reverse-shock shell in the ejecta formed by interaction at early times with a compact envelope of surrounding material, as might be expected for SNe resulting from the mergers of two white dwarfs. We use the bolometric light curves and line velocity evolution of these SNe to estimate important parameters of the progenitor systems, including {sup 56}Ni mass, total progenitor mass, and masses of shells and surrounding carbon/oxygen envelopes. We find that the reconstructed total progenitor mass distribution of the events (including SN 2007if) is bounded from below by the Chandrasekhar mass, with SN 2007if being the most massive. We discuss the relationship of these events to the emerging class of super-Chandrasekhar-mass SNe Ia, estimate the relative rates, compare the mass distribution to that expected for double-degenerate SN Ia progenitors from population synthesis, and consider implications for future cosmological Hubble diagrams.

  19. A Deep Search for Prompt Radio Emission from Thermonuclear Supernovae with the Very Large Array

    CERN Document Server

    Chomiuk, Laura; Chevalier, Roger A; Bruzewski, Seth; Foley, Ryan J; Parrent, Jerod; Strader, Jay; Badenes, Carles; Fransson, Claes; Kamble, Atish; Margutti, Raffaella; Rupen, Michael P; Simon, Joshua D

    2015-01-01

    Searches for circumstellar material around Type Ia supernovae (SNe Ia) are one of the most powerful tests of the nature of SN Ia progenitors, and radio observations provide a particularly sensitive probe of this material. Here we report radio observations for SNe Ia and their lower-luminosity thermonuclear cousins. We present the largest, most sensitive, and spectroscopically diverse study of prompt (delta t <~ 1 yr) radio observations of 85 thermonuclear SNe, including 25 obtained by our team with the unprecedented depth of the Karl G. Jansky Very Large Array. With these observations, SN 2012cg joins SN 2011fe and SN 2014J as a SN Ia with remarkably deep radio limits and excellent temporal coverage (six epochs, spanning 5--216 days after explosion, yielding Mdot/v_w <~ 5 x 10^-9 M_sun/yr / (100 km/s), assuming epsilon_B = 0.1 and epsilon_e = 0.1). All observations yield non-detections, placing strong constraints on the presence of circumstellar material. We present analytical models for the temporal an...

  20. Analysis pipeline for the epistasis search – statistical versus biological filtering

    Directory of Open Access Journals (Sweden)

    Xiangqing eSun

    2014-04-01

    Full Text Available Gene-gene interactions may contribute to the genetic variation underlying complex traits but have not always been taken fully into account. Statistical analyses that consider gene-gene interaction may increase the power of detecting associations, especially for low-marginal-effect markers, and may explain in part the missing heritability. Detecting pair-wise and higher-order interactions genome-wide requires enormous computational power. Filtering pipelines increase the computational speed by limiting the number of tests performed. We summarize existing filtering approaches to detect epistasis, after distinguishing the purposes that lead us to search for epistasis. Statistical filtering includes quality control on the basis of single marker statistics to avoid the analysis of bad and least informative data, and limits the search space for finding interactions. Biological filtering includes targeting specific pathways, integrating various databases based on known biological and metabolic pathways, gene function ontology and protein-protein interactions. It is increasingly possible to target single-nucleotide polymorphisms that have defined functions on gene expression, though not belonging to protein-coding genes. Filtering can improve the power of an interaction association study, but also increases the chance of missing important findings.

  1. The Search for Supernova-produced Radionuclides in Terrestrial Deep-sea Archives

    CERN Document Server

    Feige, Jenny; Winkler, Stephan R; Merchel, Silke; Fifield, L Keith; Korschinek, Gunther; Rugel, Georg; Breitschwerdt, Dieter

    2012-01-01

    An enhanced concentration of 60Fe was found in a deep ocean's crust in 2004 in a layer corresponding to an age of ~2 Myr. The confirmation of this signal in terrestrial archives as supernova-induced and detection of other supernova-produced radionuclides is of great interest. We have identified two suitable marine sediment cores from the South Australian Basin and estimated the intensity of a possible signal of the supernova-produced radionuclides 26Al, 53Mn, 60Fe and the pure r-process element 244Pu in these cores. A finding of these radionuclides in a sediment core might allow to improve the time resolution of the signal and thus to link the signal to a supernova event in the solar vicinity ~2 Myr ago. Furthermore, it gives an insight on nucleosynthesis scenarios in massive stars, the condensation into dust grains and transport mechanisms from the supernova shell into the solar system.

  2. MG-Digger: An Automated Pipeline to Search for Giant Virus-Related Sequences in Metagenomes.

    Science.gov (United States)

    Verneau, Jonathan; Levasseur, Anthony; Raoult, Didier; La Scola, Bernard; Colson, Philippe

    2016-01-01

    The number of metagenomic studies conducted each year is growing dramatically. Storage and analysis of such big data is difficult and time-consuming. Interestingly, analysis shows that environmental and human metagenomes include a significant amount of non-annotated sequences, representing a 'dark matter.' We established a bioinformatics pipeline that automatically detects metagenome reads matching query sequences from a given set and applied this tool to the detection of sequences matching large and giant DNA viral members of the proposed order Megavirales or virophages. A total of 1,045 environmental and human metagenomes (≈ 1 Terabase) were collected, processed, and stored on our bioinformatics server. In addition, nucleotide and protein sequences from 93 Megavirales representatives, including 19 giant viruses of amoeba, and 5 virophages, were collected. The pipeline was generated by scripts written in Python language and entitled MG-Digger. Metagenomes previously found to contain megavirus-like sequences were tested as controls. MG-Digger was able to annotate 100s of metagenome sequences as best matching those of giant viruses. These sequences were most often found to be similar to phycodnavirus or mimivirus sequences, but included reads related to recently available pandoraviruses, Pithovirus sibericum, and faustoviruses. Compared to other tools, MG-Digger combined stand-alone use on Linux or Windows operating systems through a user-friendly interface, implementation of ready-to-use customized metagenome databases and query sequence databases, adjustable parameters for BLAST searches, and creation of output files containing selected reads with best match identification. Compared to Metavir 2, a reference tool in viral metagenome analysis, MG-Digger detected 8% more true positive Megavirales-related reads in a control metagenome. The present work shows that massive, automated and recurrent analyses of metagenomes are effective in improving knowledge about the

  3. MG-Digger: an automated pipeline to search for giant virus-related sequences in metagenomes

    Directory of Open Access Journals (Sweden)

    Jonathan eVerneau

    2016-03-01

    Full Text Available The number of metagenomic studies conducted each year is growing dramatically. Storage and analysis of such big data is difficult and time-consuming. Interestingly, analysis shows that environmental and human metagenomes include a significant amount of non-annotated sequences, representing a ‘dark matter’. We established a bioinformatics pipeline that automatically detects metagenome reads matching query sequences from a given set and applied this tool to the detection of sequences matching large and giant DNA viral members of the proposed order Megavirales or virophages. A total of 1,045 environmental and human metagenomes (≈ 1 Terabase pairs were collected, processed and stored on our bioinformatics server. In addition, nucleotide and protein sequences from 93 Megavirales representatives, including 19 giant viruses of amoeba, and five virophages, were collected. The pipeline was generated by scripts written in Python language and entitled MG-Digger. Metagenomes previously found to contain megavirus-like sequences were tested as controls. MG-Digger was able to annotate hundreds of metagenome sequences as best matching those of giant viruses. These sequences were most often found to be similar to phycodnavirus or mimivirus sequences, but included reads related to recently available pandoraviruses, Pithovirus sibericum, and faustoviruses. Compared to other tools, MG-Digger combined stand-alone use on Linux or Windows operating systems through a user-friendly interface, implementation of ready-to-use customized metagenome databases and query sequence databases, adjustable parameters for BLAST searches, and creation of output files containing selected reads with best match identification. Compared to Metavir 2, a reference tool in viral metagenome analysis, MG-Digger detected 8% more true positive Megavirales-related reads in a control metagenome. The present work shows that massive, automated and recurrent analyses of metagenomes are

  4. LOSS Revisited - I: Unraveling correlations between supernova rates and galaxy properties, as measured in a re-analysis of the Lick Observatory Supernova Search

    CERN Document Server

    Graur, Or; Huang, Shan; Modjaz, Maryam; Shivvers, Isaac; Filippenko, Alexei V; Li, Weidong

    2016-01-01

    Most types of supernovae (SNe) have yet to be connected with their progenitor stellar systems. Here, we re-analyze the ten-year 1998-2008 SN sample collected by the Lick Observatory Supernova Search (LOSS) in order to constrain the progenitors of SNe Ia and stripped-envelope SNe (SE SNe; i.e., SNe IIb, Ib, Ic, and broad-lined Ic). We matched the LOSS galaxy sample with spectroscopy from the Sloan Digital Sky Survey and measured SN rates as a function of galaxy stellar mass, specific star-formation rate (sSFR), and oxygen abundance (metallicity). We find significant correlations between the SN rates and all three galaxy properties. The SN Ia correlations are consistent with other measurements, as well as with our previous explanation of these measurements in the form of a combination of the SN Ia delay-time distribution and the correlation between galaxy mass and age. Intriguingly, we measure a deficiency in the SE SN rates, relative to the SN II rates, in galaxies with low stellar masses, high sSFR values, an...

  5. Nearby Supernova Rates from the Lick Observatory Supernova Search. III. The Rate-Size Relation, and the Rates as a Function of Galaxy Hubble Type and Colour

    CERN Document Server

    Li, Weidong; Leaman, Jesse; Filippenko, Alexei V; Poznanski, Dovi; Wang, Xiaofeng; Ganeshalingam, Mohan; Mannucci, Filippo

    2010-01-01

    This is the third paper of a series in which we present new measurements of the observed rates of supernovae (SNe) in the local Universe, determined from the Lick Observatory Supernova Search (LOSS). We have considered a sample of about 1000 SNe and used an optimal subsample of 726 SNe (274 SNe Ia, 116 SNe Ibc, and 324 SNe II) to determine our rates. We study the trend of the rates as a function of a few quantities available for our galaxy sample, such as luminosity in the B and K bands, stellar mass, and morphological class. We discuss different choices (SN samples, input SN luminosity functions, inclination correction factors) and their effect on the rates and their uncertainties. A comparison between our SN rates and the published measurements shows that they are consistent with each other to within uncertainties when the rate calculations are done in the same manner. Nevertheless, our data demonstrate that the rates cannot be adequately described by a single parameter using either galaxy Hubble types or B...

  6. A bioinformatics search pipeline, RNA2DSearch, identifies RNA localization elements in Drosophila retrotransposons.

    Science.gov (United States)

    Hamilton, Russell S; Hartswood, Eve; Vendra, Georgia; Jones, Cheryl; Van De Bor, Veronique; Finnegan, David; Davis, Ilan

    2009-02-01

    mRNA localization is a widespread mode of delivering proteins to their site of function. The embryonic axes in Drosophila are determined in the oocyte, through Dynein-dependent transport of gurken/TGF-alpha mRNA, containing a small localization signal that assigns its destination. A signal with a similar secondary structure, but lacking significant sequence similarity, is present in the I factor retrotransposon mRNA, also transported by Dynein. It is currently unclear whether other mRNAs exist that are localized to the same site using similar signals. Moreover, searches for other genes containing similar elements have not been possible due to a lack of suitable bioinformatics methods for searches of secondary structure elements and the difficulty of experimentally testing all the possible candidates. We have developed a bioinformatics approach for searching across the genome for small RNA elements that are similar to the secondary structures of particular localization signals. We have uncovered 48 candidates, of which we were able to test 22 for their localization potential using injection assays for Dynein mediated RNA localization. We found that G2 and Jockey transposons each contain a gurken/I factor-like RNA stem-loop required for Dynein-dependent localization to the anterior and dorso-anterior corner of the oocyte. We conclude that I factor, G2, and Jockey are members of a "family" of transposable elements sharing a gurken-like mRNA localization signal and Dynein-dependent mechanism of transport. The bioinformatics pipeline we have developed will have broader utility in fields where small RNA signals play important roles.

  7. Overview of the nearby supernova factory

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-07-29

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

  8. The IceCube Neutrino Observatory VI: Neutrino Oscillations, Supernova Searches, Ice Properties

    OpenAIRE

    The IceCube Collaboration

    2011-01-01

    Atmospheric neutrino oscillations with DeepCore; Supernova detection with IceCube and beyond; Study of South Pole ice transparency with IceCube flashers; Submitted papers to the 32nd International Cosmic Ray Conference, Beijing 2011.

  9. A Blind Search Pipeline for Dark Satellites of the Milky Way in Gamma Rays

    Science.gov (United States)

    Sandford, Nathan Ross; Charles, Eric; Di Mauro, Mattia; Fermi-LAT Collaboration

    2017-01-01

    According to current cosmological dark matter simulations, the Milky Way’s halo should host several thousand dark matter subhalos, many of which are not massive enough to accrete considerable baryonic content and form stars. Because these “dark satellites” are completely dark matter dominated and contain few if any astrophysical sources, the only possibility of finding them is through observations of gamma rays from dark matter annihilation in them. The sensitivity and all-sky coverage of the Fermi Large Area Telescope (Fermi-LAT) make it uniquely capable to detect this population of dark satellites. In preparation for an all-sky blind search for dark satellites we have performed systematic studies of simulated data to establish robust choices for the energy and spatial binning used in the analysis. We have also applied a preliminary version of the analysis pipeline in the directions of confirmed and candidate dwarf spheroidal satellite galaxies using seven years of Fermi-LAT data and confirmed that our methodology gives upper limits compatible with previous work on these satellites.

  10. An Expanded HST/WFC3 Survey of M83: Project Overview and Targeted Supernova Remnant Search

    CERN Document Server

    Blair, William P; Dopita, Michael A; Ghavamian, Parviz; Hammer, Derek; Kuntz, K D; Long, Knox S; Soria, Roberto; Whitmore, Bradley C; Winkler, P Frank

    2014-01-01

    We present an optical/NIR imaging survey of the face-on spiral galaxy M83, using data from the Hubble Space Telescope Wide Field Camera 3 (WFC3). Seven fields are used to cover a large fraction of the inner disk, with observations in nine broadband and narrowband filters. In conjunction with a deep Chandra survey and other new radio and optical ground-based work, these data enable a broad range of science projects to be pursued. We provide an overview of the WFC3 data and processing and then delve into one topic, the population of young supernova remnants. We used a search method targeted toward soft X-ray sources to identify 26 new supernova remnants. Many compact emission nebulae detected in [Fe II] 1.644 micron align with known remnants and this diagnostic has also been used to identify many new remnants, some of which are hard to find with optical images. We include 37 previously identified supernova remnants that the data reveal to be <0.5'' in angular size and thus are difficult to characterize from ...

  11. The Sloan Digital Sky Survey-II Supernova Survey:Search Algorithm and Follow-up Observations

    Energy Technology Data Exchange (ETDEWEB)

    Sako, Masao; /Pennsylvania U. /KIPAC, Menlo Park; Bassett, Bruce; /Cape Town U. /South African Astron. Observ.; Becker, Andrew; /Washington U., Seattle, Astron. Dept.; Cinabro, David; /Wayne State U.; DeJongh, Don Frederic; /Fermilab; Depoy, D.L.; /Ohio State U.; Doi, Mamoru; /Tokyo U.; Garnavich, Peter M.; /Notre Dame U.; Craig, Hogan, J.; /Washington U., Seattle, Astron. Dept.; Holtzman, Jon; /New Mexico State U.; Jha, Saurabh; /Stanford U., Phys. Dept.; Konishi, Kohki; /Tokyo U.; Lampeitl, Hubert; /Baltimore, Space; Marriner, John; /Fermilab; Miknaitis, Gajus; /Fermilab; Nichol, Robert C.; /Portsmouth U.; Prieto, Jose Luis; /Ohio State U.; Richmond, Michael W.; /Rochester Inst.; Schneider, Donald P.; /Penn State U., Astron. Astrophys.; Smith, Mathew; /Portsmouth U.; SubbaRao, Mark; /Chicago U. /Tokyo U. /Tokyo U. /South African Astron. Observ. /Tokyo

    2007-09-14

    The Sloan Digital Sky Survey-II Supernova Survey has identified a large number of new transient sources in a 300 deg2 region along the celestial equator during its first two seasons of a three-season campaign. Multi-band (ugriz) light curves were measured for most of the sources, which include solar system objects, Galactic variable stars, active galactic nuclei, supernovae (SNe), and other astronomical transients. The imaging survey is augmented by an extensive spectroscopic follow-up program to identify SNe, measure their redshifts, and study the physical conditions of the explosions and their environment through spectroscopic diagnostics. During the survey, light curves are rapidly evaluated to provide an initial photometric type of the SNe, and a selected sample of sources are targeted for spectroscopic observations. In the first two seasons, 476 sources were selected for spectroscopic observations, of which 403 were identified as SNe. For the Type Ia SNe, the main driver for the Survey, our photometric typing and targeting efficiency is 90%. Only 6% of the photometric SN Ia candidates were spectroscopically classified as non-SN Ia instead, and the remaining 4% resulted in low signal-to-noise, unclassified spectra. This paper describes the search algorithm and the software, and the real-time processing of the SDSS imaging data. We also present the details of the supernova candidate selection procedures and strategies for follow-up spectroscopic and imaging observations of the discovered sources.

  12. Prospects of the search for neutrino bursts from Supernovae with Baksan Large Volume Scintillation Detector

    CERN Document Server

    Petkov, V B

    2015-01-01

    Observing a high-statistics neutrino signal from the supernova explosions in the Galaxy is a major goal of low-energy neutrino astronomy. The prospects for detecting all flavors of neutrinos and antineutrinos from the core-collapse supernova (ccSN) in operating and forthcoming large liquid scintillation detectors (LLSD) are widely discussed now. One of proposed LLSD is Baksan Large Volume Scintillation Detector (BLVSD). This detector will be installed at the Baksan Neutrino Observatory (BNO) of the Institute for Nuclear Research, Russian Academy of Sciences, at a depth of 4800 m.w.e. Low-energy neutrino astronomy is one of the main lines of research of the BLVSD.

  13. Star Trek: The Search for the First Alleged Crab Supernova Rock Art

    Science.gov (United States)

    Krupp, E. C.

    2014-01-01

    Since the 1950s, star/crescent combinations in prehistoric rock art in the American Southwest have become broadly accepted as eyewitness records of the Crab supernova explosion, a spectacular event visible in 1054 A.D. For more than three decades, images of this "supernova" rock art have routinely appeared in astronomy textbooks, in popular articles, on websites, and in television programs. As this Crab supernova interpretation became more fashionable, Griffith Observatory Director E.C. Krupp began a long-term effort to inspect each of these sites in person. His field work eventually led him, in 2008, to the two sites in northern Arizona that started this cottage industry in supernova rock art, sites that had been lost and had not been revisited for 50 years. Developments in the study of rock art, Pueblo Indian iconography, and Pueblo ceremonialism have permitted a greater appreciation of the role of the sky in the ancient Southwest. The best known star/crescent sites are surveyed to clarify the discipline required for cross-disciplinary research. Through this exploration of an aspect of the relationship between astronomy and culture, the presentation acknowledges the intent of American Institute of Physics Andrew Gemant Award.

  14. X-ray Emission from Supernovae in Dense Circumstellar Matter Environments: a Search for Collisionless Shocks

    Science.gov (United States)

    Ofek, E. O.; Fox, D.; Cenko, Stephen B.; Sullivan, M; Gnat, O.; Frail, D. A.; Horesh, A.; Corsi, A.; Quimby, R. M.; Gehrels, N.; Kulkarni, S. R.; Gal-Yam, A.; Nugent, P. E.; Yaron, O.; Fillippenko, A. V; Kasliwal, M. M.; Bildsten, L.; Bloom, J. S.; Poznanski, D.; Arcavi, I.; Laher, R. R.; Levitan, D.; Sesar, B.; Surace, J..

    2013-01-01

    The optical light curve of some supernovae (SNe) may be powered by the outward diffusion of the energy deposited by the explosion shock (the so-called shock breakout) in optically thick (Tau approx > 30) circumstellar matter (CSM). Recently, it was shown that the radiation-mediated and radiation-dominated shock in an optically thick wind must transform into a collisionless shock and can produce hard X-rays. The X-rays are expected to peak at late times, relative to maximum visible light. Here we report on a search, using Swift/XRT and Chandra, for X-ray emission from 28 SNe that belong to classes whose progenitors are suspected to be embedded in dense CSM. Our sample includes 19 Type IIn SNe, one Type Ibn SN, and eight hydrogen-poor superluminous SNe (SLSN-I such as SN 2005ap). Two SNe (SN 2006jc and SN 2010jl) have X-ray properties that are roughly consistent with the expectation for X-rays from a collisionless shock in optically thick CSM. However, the X-ray emission from SN 2006jc can also be explained as originating in an optically thin region. Thus, we propose that the optical light curve of SN 2010jl is powered by shock breakout in CSM. We suggest that two other events (SN 2010al and SN 2011ht) were too X-ray bright during the SN maximum optical light to be explained by the shock-breakout model.We conclude that the light curves of some, but not all, SNe IIn/Ibn are powered by shock breakout in CSM. For the rest of the SNe in our sample, including all of the SLSN-I events, our X-ray limits are not deep enough and were typically obtained too early (i.e., near the SN maximum light) for definitive conclusions about their nature. Late-time X-ray observations are required in order to further test whether these SNe are indeed embedded in dense CSM. We review the conditions required for a shock breakout in a wind profile. We argue that the timescale, relative to maximum light, for the SN to peak in X-rays is a probe of the column density and the density profile above

  15. A HIGH-RESOLUTION SPECTROSCOPIC SEARCH FOR THE REMAINING DONOR FOR TYCHO'S SUPERNOVA

    Energy Technology Data Exchange (ETDEWEB)

    Kerzendorf, Wolfgang E.; Yong, David; Schmidt, Brian P.; Murphy, Simon J.; Bessell, Michael S. [Research School of Astronomy and Astrophysics, Mount Stromlo Observatory, Cotter Road, Weston Creek, ACT 2611 (Australia); Simon, Joshua D. [Observatories of the Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Jeffery, C. Simon [Armagh Observatory, College Hill, Armagh BT61 9DG (United Kingdom); Anderson, Jay [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Podsiadlowski, Philipp [Department of Astrophysics, University of Oxford, Oxford, OX1 3RH (United Kingdom); Gal-Yam, Avishay [Benoziyo Center for Astrophysics, Faculty of Physics, Weizmann Institute of Science, Rehovot 76100 (Israel); Silverman, Jeffrey M.; Filippenko, Alexei V. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Nomoto, Ken' ichi [Kavli Institute for the Physics and Mathematics of the Universe, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583 (Japan); Venn, Kim A. [Department of Physics and Astronomy, University of Victoria, Elliott Building, 3800 Finnerty Road, Victoria, BC V8P 5C2 (Canada); Foley, Ryan J., E-mail: wkerzend@mso.anu.edu.au [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

    2013-09-10

    In this paper, we report on our analysis using Hubble Space Telescope astrometry and Keck-I HIRES spectroscopy of the central six stars of Tycho's supernova remnant (SN 1572). With these data, we measured the proper motions, radial velocities, rotational velocities, and chemical abundances of these objects. Regarding the chemical abundances, we do not confirm the unusually high [Ni/Fe] ratio previously reported for Tycho-G. Rather, we find that for all metrics in all stars, none exhibit the characteristics expected from traditional Type Ia supernova single-degenerate-scenario calculations. The only possible exception is Tycho-B, a rare, metal-poor A-type star; however, we are unable to find a suitable scenario for it. Thus, we suggest that SN 1572 cannot be explained by the standard single-degenerate model.

  16. First targeted search for gravitational-wave bursts from core-collapse supernovae in data of first-generation laser interferometer detectors

    Science.gov (United States)

    Abbott, B. P.; Abbott, R.; Abbott, T. D.; Abernathy, M. R.; Acernese, F.; Ackley, K.; Adams, C.; Adams, T.; Addesso, P.; Adhikari, R. X.; Adya, V. B.; Affeldt, C.; Agathos, M.; Agatsuma, K.; Aggarwal, N.; Aguiar, O. D.; Aiello, L.; Ain, A.; Ajith, P.; Allen, B.; Allocca, A.; Altin, P. A.; Anderson, S. B.; Anderson, W. G.; Arai, K.; Araya, M. C.; Arceneaux, C. C.; Areeda, J. S.; Arnaud, N.; Arun, K. G.; Ascenzi, S.; Ashton, G.; Ast, M.; Aston, S. M.; Astone, P.; Aufmuth, P.; Aulbert, C.; Babak, S.; Bacon, P.; Bader, M. K. M.; Baker, P. T.; Baldaccini, F.; Ballardin, G.; Ballmer, S. W.; Barayoga, J. C.; Barclay, S. E.; Barish, B. C.; Barker, D.; Barone, F.; Barr, B.; Barsotti, L.; Barsuglia, M.; Barta, D.; Bartlett, J.; Bartos, I.; Bassiri, R.; Basti, A.; Batch, J. C.; Baune, C.; Bavigadda, V.; Bazzan, M.; Behnke, B.; Bejger, M.; Bell, A. S.; Bell, C. J.; Berger, B. K.; Bergman, J.; Bergmann, G.; Berry, C. P. L.; Bersanetti, D.; Bertolini, A.; Betzwieser, J.; Bhagwat, S.; Bhandare, R.; Bilenko, I. A.; Billingsley, G.; Birch, J.; Birney, R.; Biscans, S.; Bisht, A.; Bitossi, M.; Biwer, C.; Bizouard, M. A.; Blackburn, J. K.; Blair, C. D.; Blair, D. G.; Blair, R. M.; Bloemen, S.; Bock, O.; Bodiya, T. P.; Boer, M.; Bogaert, G.; Bogan, C.; Bohe, A.; Bojtos, P.; Bond, C.; Bondu, F.; Bonnand, R.; Boom, B. A.; Bork, R.; Boschi, V.; Bose, S.; Bouffanais, Y.; Bozzi, A.; Bradaschia, C.; Brady, P. R.; Braginsky, V. B.; Branchesi, M.; Brau, J. E.; Briant, T.; Brillet, A.; Brinkmann, M.; Brisson, V.; Brockill, P.; Brooks, A. F.; Brown, D. A.; Brown, D. D.; Brown, N. M.; Buchanan, C. C.; Buikema, A.; Bulik, T.; Bulten, H. J.; Buonanno, A.; Buskulic, D.; Buy, C.; Byer, R. L.; Cadonati, L.; Cagnoli, G.; Cahillane, C.; Calderón Bustillo, J.; Callister, T.; Calloni, E.; Camp, J. B.; Cannon, K. C.; Cao, J.; Capano, C. D.; Capocasa, E.; Carbognani, F.; Caride, S.; Casanueva Diaz, J.; Casentini, C.; Caudill, S.; Cavaglià, M.; Cavalier, F.; Cavalieri, R.; Cella, G.; Cepeda, C. B.; Cerboni Baiardi, L.; Cerretani, G.; Cesarini, E.; Chakraborty, R.; Chalermsongsak, T.; Chamberlin, S. J.; Chan, M.; Chao, S.; Charlton, P.; Chassande-Mottin, E.; Chen, H. Y.; Chen, Y.; Cheng, C.; Chincarini, A.; Chiummo, A.; Cho, H. S.; Cho, M.; Chow, J. H.; Christensen, N.; Chu, Q.; Chua, S.; Chung, S.; Ciani, G.; Clara, F.; Clark, J. A.; Cleva, F.; Coccia, E.; Cohadon, P.-F.; Colla, A.; Collette, C. G.; Cominsky, L.; Constancio, M.; Conte, A.; Conti, L.; Cook, D.; Corbitt, T. R.; Cornish, N.; Corpuz, A.; Corsi, A.; Cortese, S.; Costa, C. A.; Coughlin, M. W.; Coughlin, S. B.; Coulon, J.-P.; Countryman, S. T.; Couvares, P.; Coward, D. M.; Cowart, M. J.; Coyne, D. C.; Coyne, R.; Craig, K.; Creighton, J. D. E.; Cripe, J.; Crowder, S. G.; Cumming, A.; Cunningham, L.; Cuoco, E.; Dal Canton, T.; Danilishin, S. L.; D'Antonio, S.; Danzmann, K.; Darman, N. S.; Dattilo, V.; Dave, I.; Daveloza, H. P.; Davier, M.; Davies, G. S.; Daw, E. J.; Day, R.; DeBra, D.; Debreczeni, G.; Degallaix, J.; De Laurentis, M.; Deléglise, S.; Del Pozzo, W.; Denker, T.; Dent, T.; Dergachev, V.; De Rosa, R.; DeRosa, R. T.; DeSalvo, R.; Dhurandhar, S.; Díaz, M. C.; Di Fiore, L.; Di Giovanni, M.; Di Girolamo, T.; Di Lieto, A.; Di Pace, S.; Di Palma, I.; Di Virgilio, A.; Dojcinoski, G.; Dolique, V.; Donovan, F.; Dooley, K. L.; Doravari, S.; Douglas, R.; Downes, T. P.; Drago, M.; Drever, R. W. P.; Driggers, J. C.; Du, Z.; Ducrot, M.; Dwyer, S. E.; Edo, T. B.; Edwards, M. C.; Effler, A.; Eggenstein, H.-B.; Ehrens, P.; Eichholz, J.; Eikenberry, S. S.; Engels, W.; Essick, R. C.; Etzel, T.; Evans, M.; Evans, T. M.; Everett, R.; Factourovich, M.; Fafone, V.; Fair, H.; Fairhurst, S.; Fan, X.; Fang, Q.; Farinon, S.; Farr, B.; Farr, W. M.; Favata, M.; Fays, M.; Fehrmann, H.; Fejer, M. M.; Ferrante, I.; Ferreira, E. C.; Ferrini, F.; Fidecaro, F.; Fiori, I.; Fiorucci, D.; Fisher, R. P.; Flaminio, R.; Fletcher, M.; Fournier, J.-D.; Frasca, S.; Frasconi, F.; Frei, Z.; Freise, A.; Frey, R.; Frey, V.; Fricke, T. T.; Fritschel, P.; Frolov, V. V.; Fulda, P.; Fyffe, M.; Gabbard, H. A. G.; Gair, J. R.; Gammaitoni, L.; Gaonkar, S. G.; Garufi, F.; Gaur, G.; Gehrels, N.; Gemme, G.; Genin, E.; Gennai, A.; George, J.; Gergely, L.; Germain, V.; Ghosh, Archisman; Ghosh, S.; Giaime, J. A.; Giardina, K. D.; Giazotto, A.; Gill, K.; Glaefke, A.; Goetz, E.; Goetz, R.; Gondan, L.; González, G.; Gonzalez Castro, J. M.; Gopakumar, A.; Gordon, N. A.; Gorodetsky, M. L.; Gossan, S. E.; Gosselin, M.; Gouaty, R.; Grado, A.; Graef, C.; Graff, P. B.; Granata, M.; Grant, A.; Gras, S.; Gray, C.; Greco, G.; Green, A. C.; Groot, P.; Grote, H.; Grunewald, S.; Guidi, G. M.; Guo, X.; Gupta, A.; Gupta, M. K.; Gushwa, K. E.; Gustafson, E. K.; Gustafson, R.; Hacker, J. J.; Hall, B. R.; Hall, E. D.; Hammond, G.; Haney, M.; Hanke, M. M.; Hanks, J.; Hanna, C.; Hannam, M. D.; Hanson, J.; Hardwick, T.; Harms, J.; Harry, G. M.; Harry, I. W.; Hart, M. J.; Hartman, M. T.; Haster, C.-J.; Haughian, K.; Heidmann, A.; Heintze, M. C.; Heitmann, H.; Hello, P.; Hemming, G.; Hendry, M.; Heng, I. S.; Hennig, J.; Heptonstall, A. W.; Heurs, M.; Hild, S.; Hoak, D.; Hodge, K. A.; Hofman, D.; Hollitt, S. E.; Holt, K.; Holz, D. E.; Hopkins, P.; Hosken, D. J.; Hough, J.; Houston, E. A.; Howell, E. J.; Hu, Y. M.; Huang, S.; Huerta, E. A.; Huet, D.; Hughey, B.; Husa, S.; Huttner, S. H.; Huynh-Dinh, T.; Idrisy, A.; Indik, N.; Ingram, D. R.; Inta, R.; Isa, H. N.; Isac, J.-M.; Isi, M.; Islas, G.; Isogai, T.; Iyer, B. R.; Izumi, K.; Jacqmin, T.; Jang, H.; Jani, K.; Jaranowski, P.; Jawahar, S.; Jiménez-Forteza, F.; Johnson, W. W.; Jones, D. I.; Jones, R.; Jonker, R. J. G.; Ju, L.; Haris, K.; Kalaghatgi, C. V.; Kalmus, P.; Kalogera, V.; Kamaretsos, I.; Kandhasamy, S.; Kang, G.; Kanner, J. B.; Karki, S.; Kasprzack, M.; Katsavounidis, E.; Katzman, W.; Kaufer, S.; Kaur, T.; Kawabe, K.; Kawazoe, F.; Kéfélian, F.; Kehl, M. S.; Keitel, D.; Kelley, D. B.; Kells, W.; Kennedy, R.; Key, J. S.; Khalaidovski, A.; Khalili, F. Y.; Khan, I.; Khan, S.; Khan, Z.; Khazanov, E. A.; Kijbunchoo, N.; Kim, Chunglee; Kim, J.; Kim, K.; Kim, Nam-Gyu; Kim, Namjun; Kim, Y.-M.; King, E. J.; King, P. J.; Kinzel, D. L.; Kissel, J. S.; Kleybolte, L.; Klimenko, S.; Koehlenbeck, S. M.; Kokeyama, K.; Koley, S.; Kondrashov, V.; Kontos, A.; Korobko, M.; Korth, W. Z.; Kowalska, I.; Kozak, D. B.; Kringel, V.; Krishnan, B.; Królak, A.; Krueger, C.; Kuehn, G.; Kumar, P.; Kuo, L.; Kutynia, A.; Lackey, B. D.; Landry, M.; Lange, J.; Lantz, B.; Lasky, P. D.; Lazzarini, A.; Lazzaro, C.; Leaci, P.; Leavey, S.; Lebigot, E. O.; Lee, C. H.; Lee, H. K.; Lee, H. M.; Lee, K.; Lenon, A.; Leonardi, M.; Leong, J. R.; Leroy, N.; Letendre, N.; Levin, Y.; Levine, B. M.; Li, T. G. F.; Libson, A.; Littenberg, T. B.; Lockerbie, N. A.; Loew, K.; Logue, J.; Lombardi, A. L.; Lord, J. E.; Lorenzini, M.; Loriette, V.; Lormand, M.; Losurdo, G.; Lough, J. D.; Lück, H.; Lundgren, A. P.; Luo, J.; Lynch, R.; Ma, Y.; MacDonald, T.; Machenschalk, B.; MacInnis, M.; Macleod, D. M.; Magaña-Sandoval, F.; Magee, R. M.; Mageswaran, M.; Majorana, E.; Maksimovic, I.; Malvezzi, V.; Man, N.; Mandel, I.; Mandic, V.; Mangano, V.; Mansell, G. L.; Manske, M.; Mantovani, M.; Marchesoni, F.; Marion, F.; Márka, S.; Márka, Z.; Markosyan, A. S.; Maros, E.; Martelli, F.; Martellini, L.; Martin, I. W.; Martin, R. M.; Martynov, D. V.; Marx, J. N.; Mason, K.; Masserot, A.; Massinger, T. J.; Masso-Reid, M.; Mastrogiovanni, S.; Matichard, F.; Matone, L.; Mavalvala, N.; Mazumder, N.; Mazzolo, G.; McCarthy, R.; McClelland, D. E.; McCormick, S.; McGuire, S. C.; McIntyre, G.; McIver, J.; McManus, D. J.; McWilliams, S. T.; Meacher, D.; Meadors, G. D.; Meidam, J.; Melatos, A.; Mendell, G.; Mendoza-Gandara, D.; Mercer, R. A.; Merilh, E. L.; Merzougui, M.; Meshkov, S.; Messenger, C.; Messick, C.; Metzdorff, R.; Meyers, P. M.; Mezzani, F.; Miao, H.; Michel, C.; Middleton, H.; Mikhailov, E. E.; Milano, L.; Miller, A. L.; Miller, J.; Millhouse, M.; Minenkov, Y.; Ming, J.; Mirshekari, S.; Mishra, C.; Mitra, S.; Mitrofanov, V. P.; Mitselmakher, G.; Mittleman, R.; Moggi, A.; Mohan, M.; Mohapatra, S. R. P.; Montani, M.; Moore, B. C.; Moore, C. J.; Moraru, D.; Moreno, G.; Morriss, S. R.; Mossavi, K.; Mours, B.; Mow-Lowry, C. M.; Mueller, C. L.; Mueller, G.; Muir, A. W.; Mukherjee, Arunava; Mukherjee, D.; Mukherjee, S.; Mukund, K. N.; Mullavey, A.; Munch, J.; Murphy, D. J.; Murray, P. G.; Mytidis, A.; Nardecchia, I.; Naticchioni, L.; Nayak, R. K.; Necula, V.; Nedkova, K.; Nelemans, G.; Neri, M.; Neunzert, A.; Newton, G.; Nguyen, T. T.; Nielsen, A. B.; Nissanke, S.; Nitz, A.; Nocera, F.; Nolting, D.; Normandin, M. E. N.; Nuttall, L. K.; Oberling, J.; Ochsner, E.; O'Dell, J.; Oelker, E.; Ogin, G. H.; Oh, J. J.; Oh, S. H.; Ohme, F.; Oliver, M.; Oppermann, P.; Oram, Richard J.; O'Reilly, B.; O'Shaughnessy, R.; Ott, C. D.; Ottaway, D. J.; Ottens, R. S.; Overmier, H.; Owen, B. J.; Pai, A.; Pai, S. A.; Palamos, J. R.; Palashov, O.; Palomba, C.; Pal-Singh, A.; Pan, H.; Pankow, C.; Pannarale, F.; Pant, B. C.; Paoletti, F.; Paoli, A.; Papa, M. A.; Paris, H. R.; Parker, W.; Pascucci, D.; Pasqualetti, A.; Passaquieti, R.; Passuello, D.; Patricelli, B.; Patrick, Z.; Pearlstone, B. L.; Pedraza, M.; Pedurand, R.; Pekowsky, L.; Pele, A.; Penn, S.; Pereira, R.; Perreca, A.; Phelps, M.; Piccinni, O. J.; Pichot, M.; Piergiovanni, F.; Pierro, V.; Pillant, G.; Pinard, L.; Pinto, I. M.; Pitkin, M.; Poggiani, R.; Popolizio, P.; Post, A.; Powell, J.; Prasad, J.; Predoi, V.; Premachandra, S. S.; Prestegard, T.; Price, L. R.; Prijatelj, M.; Principe, M.; Privitera, S.; Prix, R.; Prodi, G. A.; Prokhorov, L.; Puncken, O.; Punturo, M.; Puppo, P.; Pürrer, M.; Qi, H.; Qin, J.; Quetschke, V.; Quintero, E. A.; Quitzow-James, R.; Raab, F. J.; Rabeling, D. S.; Radkins, H.; Raffai, P.; Raja, S.; Rakhmanov, M.; Rapagnani, P.; Raymond, V.; Razzano, M.; Re, V.; Read, J.; Reed, C. M.; Regimbau, T.; Rei, L.; Reid, S.; Reitze, D. H.; Rew, H.; Ricci, F.; Riles, K.; Robertson, N. A.; Robie, R.; Robinet, F.; Rocchi, A.; Rolland, L.; Rollins, J. G.; Roma, V. J.; Romano, J. D.; Romano, R.; Romanov, G.; Romie, J. H.; Rosińska, D.; Rowan, S.; Rüdiger, A.; Ruggi, P.; Ryan, K.; Sachdev, S.; Sadecki, T.; Sadeghian, L.; Salconi, L.; Saleem, M.; Salemi, F.; Samajdar, A.; Sammut, L.; Sanchez, E. J.; Sandberg, V.; Sandeen, B.; Sanders, J. R.; Santamaria, L.; Sassolas, B.; Sathyaprakash, B. S.; Saulson, P. R.; Sauter, O. E. S.; Savage, R. L.; Sawadsky, A.; Schale, P.; Schilling, R.; Schmidt, J.; Schmidt, P.; Schnabel, R.; Schofield, R. M. S.; Schönbeck, A.; Schreiber, E.; Schuette, D.; Schutz, B. F.; Scott, J.; Scott, S. M.; Sellers, D.; Sentenac, D.; Sequino, V.; Sergeev, A.; Serna, G.; Setyawati, Y.; Sevigny, A.; Shaddock, D. A.; Shahriar, M. S.; Shaltev, M.; Shao, Z.; Shapiro, B.; Shawhan, P.; Sheperd, A.; Shoemaker, D. H.; Shoemaker, D. M.; Siellez, K.; Siemens, X.; Sieniawska, M.; Sigg, D.; Silva, A. D.; Simakov, D.; Singer, A.; Singer, L. P.; Singh, A.; Singh, R.; Singhal, A.; Sintes, A. M.; Slagmolen, B. J. J.; Smith, J. R.; Smith, N. D.; Smith, R. J. E.; Son, E. J.; Sorazu, B.; Sorrentino, F.; Souradeep, T.; Srivastava, A. K.; Staley, A.; Steinke, M.; Steinlechner, J.; Steinlechner, S.; Steinmeyer, D.; Stephens, B. C.; Stone, R.; Strain, K. A.; Straniero, N.; Stratta, G.; Strauss, N. A.; Strigin, S.; Sturani, R.; Stuver, A. L.; Summerscales, T. Z.; Sun, L.; Sutton, P. J.; Swinkels, B. L.; Szczepańczyk, M. J.; Tacca, M.; Talukder, D.; Tanner, D. B.; Tápai, M.; Tarabrin, S. P.; Taracchini, A.; Taylor, R.; Theeg, T.; Thirugnanasambandam, M. P.; Thomas, E. G.; Thomas, M.; Thomas, P.; Thorne, K. A.; Thorne, K. S.; Thrane, E.; Tiwari, S.; Tiwari, V.; Tokmakov, K. V.; Tomlinson, C.; Tonelli, M.; Torres, C. V.; Torrie, C. I.; Töyrä, D.; Travasso, F.; Traylor, G.; Trifirò, D.; Tringali, M. C.; Trozzo, L.; Tse, M.; Turconi, M.; Tuyenbayev, D.; Ugolini, D.; Unnikrishnan, C. S.; Urban, A. L.; Usman, S. A.; Vahlbruch, H.; Vajente, G.; Valdes, G.; van Bakel, N.; van Beuzekom, M.; van den Brand, J. F. J.; Van Den Broeck, C.; Vander-Hyde, D. C.; van der Schaaf, L.; van Heijningen, J. V.; van Veggel, A. A.; Vardaro, M.; Vass, S.; Vasúth, M.; Vaulin, R.; Vecchio, A.; Vedovato, G.; Veitch, J.; Veitch, P. J.; Venkateswara, K.; Verkindt, D.; Vetrano, F.; Viceré, A.; Vinciguerra, S.; Vine, D. J.; Vinet, J.-Y.; Vitale, S.; Vo, T.; Vocca, H.; Vorvick, C.; Voss, D. V.; Vousden, W. D.; Vyatchanin, S. P.; Wade, A. R.; Wade, L. E.; Wade, M.; Walker, M.; Wallace, L.; Walsh, S.; Wang, G.; Wang, H.; Wang, M.; Wang, X.; Wang, Y.; Ward, R. L.; Warner, J.; Was, M.; Weaver, B.; Wei, L.-W.; Weinert, M.; Weinstein, A. J.; Weiss, R.; Welborn, T.; Wen, L.; Weßels, P.; Westphal, T.; Wette, K.; Whelan, J. T.; Whitcomb, S. E.; White, D. J.; Whiting, B. F.; Williams, R. D.; Williamson, A. R.; Willis, J. L.; Willke, B.; Wimmer, M. H.; Winkler, W.; Wipf, C. C.; Wittel, H.; Woan, G.; Worden, J.; Wright, J. L.; Wu, G.; Yablon, J.; Yam, W.; Yamamoto, H.; Yancey, C. C.; Yap, M. J.; Yu, H.; Yvert, M.; ZadroŻny, A.; Zangrando, L.; Zanolin, M.; Zendri, J.-P.; Zevin, M.; Zhang, F.; Zhang, L.; Zhang, M.; Zhang, Y.; Zhao, C.; Zhou, M.; Zhou, Z.; Zhu, X. J.; Zucker, M. E.; Zuraw, S. E.; Zweizig, J.; LIGO Scientific Collaboration; Virgo Collaboration

    2016-11-01

    We present results from a search for gravitational-wave bursts coincident with two core-collapse supernovae observed optically in 2007 and 2011. We employ data from the Laser Interferometer Gravitational-wave Observatory (LIGO), the Virgo gravitational-wave observatory, and the GEO 600 gravitational-wave observatory. The targeted core-collapse supernovae were selected on the basis of (1) proximity (within approximately 15 Mpc), (2) tightness of observational constraints on the time of core collapse that defines the gravitational-wave search window, and (3) coincident operation of at least two interferometers at the time of core collapse. We find no plausible gravitational-wave candidates. We present the probability of detecting signals from both astrophysically well-motivated and more speculative gravitational-wave emission mechanisms as a function of distance from Earth, and discuss the implications for the detection of gravitational waves from core-collapse supernovae by the upgraded Advanced LIGO and Virgo detectors.

  17. A First Targeted Search for Gravitational-Wave Bursts from Core-Collapse Supernovae in Data of First-Generation Laser Interferometer Detectors

    CERN Document Server

    Abbott, B P; Abbott, T D; Abernathy, M R; Acernese, F; Ackley, K; Adams, C; Adams, T; Addesso, P; Adhikari, R X; Adya, V B; Affeldt, C; Agathos, M; Agatsuma, K; Aggarwal, N; Aguiar, O D; Aiello, L; Ain, A; Ajith, P; Allen, B; Allocca, A; Altin, P A; Anderson, S B; Anderson, W G; Arai, K; Araya, M C; Arceneaux, C C; Areeda, J S; Arnaud, N; Arun, K G; Ascenzi, S; Ashton, G; Ast, M; Aston, S M; Astone, P; Aufmuth, P; Aulbert, C; Babak, S; Bacon, P; Bader, M K M; Baker, P T; Baldaccini, F; Ballardin, G; Ballmer, S W; Barayoga, J C; Barclay, S E; Barish, B C; Barker, D; Barone, F; Barr, B; Barsotti, L; Barsuglia, M; Barta, D; Bartlett, J; Bartos, I; Bassiri, R; Basti, A; Batch, J C; Baune, C; Bavigadda, V; Bazzan, M; Behnke, B; Bejger, M; Bell, A S; Bell, C J; Berger, B K; Bergman, J; Bergmann, G; Berry, C P L; Bersanetti, D; Bertolini, A; Betzwieser, J; Bhagwat, S; Bhandare, R; Bilenko, I A; Billingsley, G; Birch, J; Birney, R; Biscans, S; Bisht, A; Bitossi, M; Biwer, C; Bizouard, M A; Blackburn, J K; Blair, C D; Blair, D G; Blair, R M; Bloemen, S; Bock, O; Bodiya, T P; Boer, M; Bogaert, G; Bogan, C; Bohe, A; Bojtos, P; Bond, C; Bondu, F; Bonnand, R; Boom, B A; Bork, R; Boschi, V; Bose, S; Bouffanais, Y; Bozzi, A; Bradaschia, C; Brady, P R; Braginsky, V B; Branchesi, M; Brau, J E; Briant, T; Brillet, A; Brinkmann, M; Brisson, V; Brockill, P; Brooks, A F; Brown, D A; Brown, D D; Brown, N M; Buchanan, C C; Buikema, A; Bulik, T; Bulten, H J; Buonanno, A; Buskulic, D; Buy, C; Byer, R L; Cadonati, L; Cagnoli, G; Cahillane, C; Bustillo, J Calder'on; Callister, T; Calloni, E; Camp, J B; Cannon, K C; Cao, J; Capano, C D; Capocasa, E; Carbognani, F; Caride, S; Diaz, J Casanueva; Casentini, C; Caudill, S; Cavagli`a, M; Cavalier, F; Cavalieri, R; Cella, G; Cepeda, C B; Baiardi, L Cerboni; Cerretani, G; Cesarini, E; Chakraborty, R; Chalermsongsak, T; Chamberlin, S J; Chan, M; Chao, S; Charlton, P; Chassande-Mottin, E; Chen, H Y; Chen, Y; Cheng, C; Chincarini, A; Chiummo, A; Cho, H S; Cho, M; Chow, J H; Christensen, N; Chu, Q; Chua, S; Chung, S; Ciani, G; Clara, F; Clark, J A; Cleva, F; Coccia, E; Cohadon, P -F; Colla, A; Collette, C G; Cominsky, L; Constancio, M; Conte, A; Conti, L; Cook, D; Corbitt, T R; Cornish, N; Corpuz, A; Corsi, A; Cortese, S; Costa, C A; Coughlin, M W; Coughlin, S B; Coulon, J -P; Countryman, S T; Couvares, P; Coward, D M; Cowart, M J; Coyne, D C; Coyne, R; Craig, K; Creighton, J D E; Cripe, J; Crowder, S G; Cumming, A; Cunningham, L; Cuoco, E; Canton, T Dal; Danilishin, S L; D'Antonio, S; Danzmann, K; Darman, N S; Dattilo, V; Dave, I; Daveloza, H P; Davier, M; Davies, G S; Daw, E J; Day, R; DeBra, D; Debreczeni, G; Degallaix, J; De Laurentis, M; Del'eglise, S; Del Pozzo, W; Denker, T; Dent, T; Dergachev, V; De Rosa, R; DeRosa, R T; DeSalvo, R; Dhurandhar, S; D'iaz, M C; Di Fiore, L; Di Giovanni, M; Di Girolamo, T; Di Lieto, A; Di Pace, S; Di Palma, I; Di Virgilio, A; Dojcinoski, G; Dolique, V; Donovan, F; Dooley, K L; Doravari, S; Douglas, R; Downes, T P; Drago, M; Drever, R W P; Driggers, J C; Du, Z; Ducrot, M; Dwyer, S E; Edo, T B; Edwards, M C; Effler, A; Eggenstein, H -B; Ehrens, P; Eichholz, J; Eikenberry, S S; Engels, W; Essick, R C; Etzel, T; Evans, M; Evans, T M; Everett, R; Factourovich, M; Fafone, V; Fair, H; Fairhurst, S; Fan, X; Fang, Q; Farinon, S; Farr, B; Farr, W M; Favata, M; Fays, M; Fehrmann, H; Fejer, M M; Ferrante, I; Ferreira, E C; Ferrini, F; Fidecaro, F; Fiori, I; Fiorucci, D; Fisher, R P; Flaminio, R; Fletcher, M; Fournier, J -D; Frasca, S; Frasconi, F; Frei, Z; Freise, A; Frey, R; Frey, V; Fricke, T T; Fritschel, P; Frolov, V V; Fulda, P; Fyffe, M; Gabbard, H A G; Gair, J R; Gammaitoni, L; Gaonkar, S G; Garufi, F; Gaur, G; Gehrels, N; Gemme, G; Genin, E; Gennai, A; George, J; Gergely, L; Germain, V; Ghosh, Archisman; Ghosh, S; Giaime, J A; Giardina, K D; Giazotto, A; Gill, K; Glaefke, A; Goetz, E; Goetz, R; Gondan, L; Gonz'alez, G; Castro, J M Gonzalez; Gopakumar, A; Gordon, N A; Gorodetsky, M L; Gossan, S E; Gosselin, M; Gouaty, R; Grado, A; Graef, C; Graff, P B; Granata, M; Grant, A; Gras, S; Gray, C; Greco, G; Green, A C; Groot, P; Grote, H; Grunewald, S; Guidi, G M; Guo, X; Gupta, A; Gupta, M K; Gushwa, K E; Gustafson, E K; Gustafson, R; Hacker, J J; Hall, B R; Hall, E D; Hammond, G; Haney, M; Hanke, M M; Hanks, J; Hanna, C; Hannam, M D; Hanson, J; Hardwick, T; Harms, J; Harry, G M; Harry, I W; Hart, M J; Hartman, M T; Haster, C -J; Haughian, K; Heidmann, A; Heintze, M C; Heitmann, H; Hello, P; Hemming, G; Hendry, M; Heng, I S; Hennig, J; Heptonstall, A W; Heurs, M; Hild, S; Hoak, D; Hodge, K A; Hofman, D; Hollitt, S E; Holt, K; Holz, D E; Hopkins, P; Hosken, D J; Hough, J; Houston, E A; Howell, E J; Hu, Y M; Huang, S; Huerta, E A; Huet, D; Hughey, B; Husa, S; Huttner, S H; Huynh-Dinh, T; Idrisy, A; Indik, N; Ingram, D R; Inta, R; Isa, H N; Isac, J -M; Isi, M; Islas, G; Isogai, T; Iyer, B R; Izumi, K; Jacqmin, T; Jang, H; Jani, K; Jaranowski, P; Jawahar, S; Jim'enez-Forteza, F; Johnson, W W; Jones, D I; Jones, R; Jonker, R J G; Ju, L; K, Haris; Kalaghatgi, C V; Kalmus, P; Kalogera, V; Kamaretsos, I; Kandhasamy, S; Kang, G; Kanner, J B; Karki, S; Kasprzack, M; Katsavounidis, E; Katzman, W; Kaufer, S; Kaur, T; Kawabe, K; Kawazoe, F; K'ef'elian, F; Kehl, M S; Keitel, D; Kelley, D B; Kells, W; Kennedy, R; Key, J S; Khalaidovski, A; Khalili, F Y; Khan, I; Khan, S; Khan, Z; Khazanov, E A; Kijbunchoo, N; Kim, Chunglee; Kim, J; Kim, K; Kim, Nam-Gyu; Kim, Namjun; Kim, Y -M; King, E J; King, P J; Kinzel, D L; Kissel, J S; Kleybolte, L; Klimenko, S; Koehlenbeck, S M; Kokeyama, K; Koley, S; Kondrashov, V; Kontos, A; Korobko, M; Korth, W Z; Kowalska, I; Kozak, D B; Kringel, V; Krishnan, B; Kr'olak, A; Krueger, C; Kuehn, G; Kumar, P; Kuo, L; Kutynia, A; Lackey, B D; Landry, M; Lange, J; Lantz, B; Lasky, P D; Lazzarini, A; Lazzaro, C; Leaci, P; Leavey, S; Lebigot, E O; Lee, C H; Lee, H K; Lee, H M; Lee, K; Lenon, A; Leonardi, M; Leong, J R; Leroy, N; Letendre, N; Levin, Y; Levine, B M; Li, T G F; Libson, A; Littenberg, T B; Lockerbie, N A; Loew, K; Logue, J; Lombardi, A L; Lord, J E; Lorenzini, M; Loriette, V; Lormand, M; Losurdo, G; Lough, J D; L"uck, H; Lundgren, A P; Luo, J; Lynch, R; Ma, Y; MacDonald, T; Machenschalk, B; MacInnis, M; Macleod, D M; na-Sandoval, F Maga; Magee, R M; Mageswaran, M; Majorana, E; Maksimovic, I; Malvezzi, V; Man, N; Mandel, I; Mandic, V; Mangano, V; Mansell, G L; Manske, M; Mantovani, M; Marchesoni, F; Marion, F; M'arka, S; M'arka, Z; Markosyan, A S; Maros, E; Martelli, F; Martellini, L; Martin, I W; Martin, R M; Martynov, D V; Marx, J N; Mason, K; Masserot, A; Massinger, T J; Masso-Reid, M; Mastrogiovanni, S; Matichard, F; Matone, L; Mavalvala, N; Mazumder, N; Mazzolo, G; McCarthy, R; McClelland, D E; McCormick, S; McGuire, S C; McIntyre, G; McIver, J; McManus, D J; McWilliams, S T; Meacher, D; Meadors, G D; Meidam, J; Melatos, A; Mendell, G; Mendoza-Gandara, D; Mercer, R A; Merilh, E L; Merzougui, M; Meshkov, S; Messenger, C; Messick, C; Metzdorff, R; Meyers, P M; Mezzani, F; Miao, H; Michel, C; Middleton, H; Mikhailov, E E; Milano, L; Miller, A L; Miller, J; Millhouse, M; Minenkov, Y; Ming, J; Mirshekari, S; Mishra, C; Mitra, S; Mitrofanov, V P; Mitselmakher, G; Mittleman, R; Moggi, A; Mohan, M; Mohapatra, S R P; Montani, M; Moore, B C; Moore, C J; Moraru, D; Moreno, G; Morriss, S R; Mossavi, K; Mours, B; Mow-Lowry, C M; Mueller, C L; Mueller, G; Muir, A W; Mukherjee, Arunava; Mukherjee, D; Mukherjee, S; Mukund, K N; Mullavey, A; Munch, J; Murphy, D J; Murray, P G; Mytidis, A; Nardecchia, I; Naticchioni, L; Nayak, R K; Necula, V; Nedkova, K; Nelemans, G; Neri, M; Neunzert, A; Newton, G; Nguyen, T T; Nielsen, A B; Nissanke, S; Nitz, A; Nocera, F; Nolting, D; Normandin, M E N; Nuttall, L K; Oberling, J; Ochsner, E; O'Dell, J; Oelker, E; Ogin, G H; Oh, J J; Oh, S H; Ohme, F; Oliver, M; Oppermann, P; Oram, Richard J; O'Reilly, B; O'Shaughnessy, R; Ott, C D; Ottaway, D J; Ottens, R S; Overmier, H; Owen, B J; Pai, A; Pai, S A; Palamos, J R; Palashov, O; Palomba, C; Pal-Singh, A; Pan, H; Pankow, C; Pannarale, F; Pant, B C; Paoletti, F; Paoli, A; Papa, M A; Paris, H R; Parker, W; Pascucci, D; Pasqualetti, A; Passaquieti, R; Passuello, D; Patricelli, B; Patrick, Z; Pearlstone, B L; Pedraza, M; Pedurand, R; Pekowsky, L; Pele, A; Penn, S; Pereira, R; Perreca, A; Phelps, M; Piccinni, O J; Pichot, M; Piergiovanni, F; Pierro, V; Pillant, G; Pinard, L; Pinto, I M; Pitkin, M; Poggiani, R; Popolizio, P; Post, A; Powell, J; Prasad, J; Predoi, V; Premachandra, S S; Prestegard, T; Price, L R; Prijatelj, M; Principe, M; Privitera, S; Prix, R; Prodi, G A; Prokhorov, L; Puncken, O; Punturo, M; Puppo, P; P"urrer, M; Qi, H; Qin, J; Quetschke, V; Quintero, E A; Quitzow-James, R; Raab, F J; Rabeling, D S; Radkins, H; Raffai, P; Raja, S; Rakhmanov, M; Rapagnani, P; Raymond, V; Razzano, M; Re, V; Read, J; Reed, C M; Regimbau, T; Rei, L; Reid, S; Reitze, D H; Rew, H; Ricci, F; Riles, K; Robertson, N A; Robie, R; Robinet, F; Rocchi, A; Rolland, L; Rollins, J G; Roma, V J; Romano, J D; Romano, R; Romanov, G; Romie, J H; Rosi'nska, D; Rowan, S; R"udiger, A; Ruggi, P; Ryan, K; Sachdev, S; Sadecki, T; Sadeghian, L; Salconi, L; Saleem, M; Salemi, F; Samajdar, A; Sammut, L; Sanchez, E J; Sandberg, V; Sandeen, B; Sanders, J R; Santamaria, L; Sassolas, B; Sathyaprakash, B S; Saulson, P R; Sauter, O E S; Savage, R L; Sawadsky, A; Schale, P; Schilling, R; Schmidt, J; Schmidt, P; Schnabel, R; Schofield, R M S; Sch"onbeck, A; Schreiber, E; Schuette, D; Schutz, B F; Scott, J; Scott, S M; Sellers, D; Sentenac, D; Sequino, V; Sergeev, A; Serna, G; Setyawati, Y; Sevigny, A; Shaddock, D A; Shahriar, M S; Shaltev, M; Shao, Z; Shapiro, B; Shawhan, P; Sheperd, A; Shoemaker, D H; Shoemaker, D M; Siellez, K; Siemens, X; Sieniawska, M; Sigg, D; Silva, A D; Simakov, D; Singer, A; Singer, L P; Singh, A; Singh, R; Singhal, A; Sintes, A M; Slagmolen, B J J; Smith, J R; Smith, N D; Smith, R J E; Son, E J; Sorazu, B; Sorrentino, F; Souradeep, T; Srivastava, A K; Staley, A; Steinke, M; Steinlechner, J; Steinlechner, S; Steinmeyer, D; Stephens, B C; Stone, R; Strain, K A; Straniero, N; Stratta, G; Strauss, N A; Strigin, S; Sturani, R; Stuver, A L; Summerscales, T Z; Sun, L; Sutton, P J; Swinkels, B L; Szczepa'nczyk, M J; Tacca, M; Talukder, D; Tanner, D B; T'apai, M; Tarabrin, S P; Taracchini, A; Taylor, R; Theeg, T; Thirugnanasambandam, M P; Thomas, E G; Thomas, M; Thomas, P; Thorne, K A; Thorne, K S; Thrane, E; Tiwari, S; Tiwari, V; Tokmakov, K V; Tomlinson, C; Tonelli, M; Torres, C V; Torrie, C I; T"oyr"a, D; Travasso, F; Traylor, G; Trifir`o, D; Tringali, M C; Trozzo, L; Tse, M; Turconi, M; Tuyenbayev, D; Ugolini, D; Unnikrishnan, C S; Urban, A L; Usman, S A; Vahlbruch, H; Vajente, G; Valdes, G; van Bakel, N; van Beuzekom, M; Brand, J F J van den; Broeck, C Van Den; Vander-Hyde, D C; van der Schaaf, L; van Heijningen, J V; van Veggel, A A; Vardaro, M; Vass, S; Vas'uth, M; Vaulin, R; Vecchio, A; Vedovato, G; Veitch, J; Veitch, P J; Venkateswara, K; Verkindt, D; Vetrano, F; Vicer'e, A; Vinciguerra, S; Vine, D J; Vinet, J -Y; Vitale, S; Vo, T; Vocca, H; Vorvick, C; Voss, D V; Vousden, W D; Vyatchanin, S P; Wade, A R; Wade, L E; Wade, M; Walker, M; Wallace, L; Walsh, S; Wang, G; Wang, H; Wang, M; Wang, X; Wang, Y; Ward, R L; Warner, J; Was, M; Weaver, B; Wei, L -W; Weinert, M; Weinstein, A J; Weiss, R; Welborn, T; Wen, L; Wessels, P; Westphal, T; Wette, K; Whelan, J T; Whitcomb, S E; White, D J; Whiting, B F; Williams, R D; Williamson, A R; Willis, J L; Willke, B; Wimmer, M H; Winkler, W; Wipf, C C; Wittel, H; Woan, G; Worden, J; Wright, J L; Wu, G; Yablon, J; Yam, W; Yamamoto, H; Yancey, C C; Yap, M J; Yu, H; Yvert, M; zny, A Zadro; Zangrando, L; Zanolin, M; Zendri, J -P; Zevin, M; Zhang, F; Zhang, L; Zhang, M; Zhang, Y; Zhao, C; Zhou, M; Zhou, Z; Zhu, X J; Zucker, M E; Zuraw, S E; Zweizig, J

    2016-01-01

    We present results from a search for gravitational-wave bursts coincident with a set of two core-collapse supernovae observed between 2007 and 2011. We employ data from the Laser Interferometer Gravitational-wave Observatory (LIGO), the Virgo gravitational-wave observatory, and the GEO 600 gravitational-wave observatory. The targeted core-collapse supernovae were selected on the basis of (1) proximity (within approximately 15 Mpc), (2) tightness of observational constraints on the time of core collapse that defines the gravitational-wave search window, and (3) coincident operation of at least two interferometers at the time of core collapse. We find no plausible gravitational-wave candidates. We present the probability of detecting signals from both astrophysically well-motivated and more speculative gravitational-wave emission mechanisms as a function of distance from Earth, and discuss the implications for the detection of gravitational waves from core-collapse supernovae by the upgraded Advanced LIGO and V...

  18. Integrated Proteomic Pipeline Using Multiple Search Engines for a Proteogenomic Study with a Controlled Protein False Discovery Rate.

    Science.gov (United States)

    Park, Gun Wook; Hwang, Heeyoun; Kim, Kwang Hoe; Lee, Ju Yeon; Lee, Hyun Kyoung; Park, Ji Yeong; Ji, Eun Sun; Park, Sung-Kyu Robin; Yates, John R; Kwon, Kyung-Hoon; Park, Young Mok; Lee, Hyoung-Joo; Paik, Young-Ki; Kim, Jin Young; Yoo, Jong Shin

    2016-11-04

    In the Chromosome-Centric Human Proteome Project (C-HPP), false-positive identification by peptide spectrum matches (PSMs) after database searches is a major issue for proteogenomic studies using liquid-chromatography and mass-spectrometry-based large proteomic profiling. Here we developed a simple strategy for protein identification, with a controlled false discovery rate (FDR) at the protein level, using an integrated proteomic pipeline (IPP) that consists of four engrailed steps as follows. First, using three different search engines, SEQUEST, MASCOT, and MS-GF+, individual proteomic searches were performed against the neXtProt database. Second, the search results from the PSMs were combined using statistical evaluation tools including DTASelect and Percolator. Third, the peptide search scores were converted into E-scores normalized using an in-house program. Last, ProteinInferencer was used to filter the proteins containing two or more peptides with a controlled FDR of 1.0% at the protein level. Finally, we compared the performance of the IPP to a conventional proteomic pipeline (CPP) for protein identification using a controlled FDR of <1% at the protein level. Using the IPP, a total of 5756 proteins (vs 4453 using the CPP) including 477 alternative splicing variants (vs 182 using the CPP) were identified from human hippocampal tissue. In addition, a total of 10 missing proteins (vs 7 using the CPP) were identified with two or more unique peptides, and their tryptic peptides were validated using MS/MS spectral pattern from a repository database or their corresponding synthetic peptides. This study shows that the IPP effectively improved the identification of proteins, including alternative splicing variants and missing proteins, in human hippocampal tissues for the C-HPP. All RAW files used in this study were deposited in ProteomeXchange (PXD000395).

  19. A search for thermal X-ray signatures in Gamma-Ray Bursts I: Swift bursts with optical supernovae

    CERN Document Server

    Starling, R L C; Pe'er, A; Beardmore, A P; Osborne, J P

    2012-01-01

    The X-ray spectra of Gamma-Ray Bursts can generally be described by an absorbed power law. The landmark discovery of thermal X-ray emission in addition to the power law in the unusual GRB 060218, followed by a similar discovery in GRB 100316D, showed that during the first thousand seconds after trigger the soft X-ray spectra can be complex. Both the origin and prevalence of such spectral components still evades understanding, particularly after the discovery of thermal X-ray emission in the classical GRB 090618. Possibly most importantly, these three objects are all associated with optical supernovae, begging the question of whether the thermal X-ray components could be a result of the GRB-SN connection, possibly in the shock breakout. We therefore performed a search for blackbody components in the early Swift X-ray spectra of 11 GRBs that have or may have associated optical supernovae, accurately recovering the thermal components reported in the literature for GRBs 060218, 090618 and 100316D. We present the ...

  20. SEARCH FOR GAMMA-RAY EMISSION FROM THE SUPERNOVA REMNANT IC 443 WITH THE MAGIC TELESCOPE

    Directory of Open Access Journals (Sweden)

    R. J. García López

    2009-01-01

    Full Text Available TeV observations of Supernova remnants (SNRs and, in particular, of SNRs which appear to be physically related to EGRET sources are a prime target for the MAGIC telescope. MAGIC's spatial resolution and sensi- tivity can probe the main mechanism responsible for producing high energy photons in the SNR neighbourhood. Based on a recent systematical analysis of the molecular environment of the vicinity of all SNR-EGRET source pairs, the IC 443 remnant was chosen for observations with MAGIC. We brie y describe the observational strategy which provided the detection of a new very-high energy gamma-ray source: MAGIC 0616+225.

  1. A search for supernova remnants in NGC 6946 using the [Fe II] 1.64 μm line

    Energy Technology Data Exchange (ETDEWEB)

    Bruursema, Justice; Meixner, Margaret [Department of Physics and Astronomy, The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Long, Knox S.; Otsuka, Masaaki, E-mail: justiceb@pha.jhu.edu [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)

    2014-09-01

    Shock models indicate and observations show that in the infrared (IR), supernova remnants (SNRs) emit strongly in [Fe II] at 1.64 μm. Here, we report the results of a search for SNRs in NGC 6946 relying on [Fe II] 1.64 μm line emission, where we employed an adjacent [Fe II]{sub Off} filter to accurately assess the local continuum levels. For this study, we used the WIYN High Resolution Infrared Camera on the WIYN 3.5 m telescope to image NGC 6946 in broadbands J and H and narrowbands [Fe II], [Fe II]{sub Off}, Paβ, and Paβ{sub Off}. From our search, we have identified 48 SNR candidates (SNRcs), 6 of which are coincident with sources found in prior radio, optical, and/or X-ray studies. The measured [Fe II] fluxes of our SNRcs range from 1.5 × 10{sup –16} to 4.2 × 10{sup –15} erg s{sup –1} cm{sup –2} and are among the highest of previously published extragalactic SNR [Fe II] fluxes. All of the candidates now need to be confirmed spectroscopically. However, the fact that we detect as many objects as we did suggests that [Fe II] can be used as an effective search tool to find extragalactic SNRs.

  2. The Search for Faint Radio Supernova Remnants in the Outer Galaxy: Five New Discoveries

    CERN Document Server

    Gerbrandt, Stephanie; Kothes, Roland; Geisbuesch, Joern; Tung, Albert

    2014-01-01

    High resolution and sensitivity large-scale radio surveys of the Milky Way are critical in the discovery of very low surface brightness supernova remnants (SNRs), which may constitute a significant portion of the Galactic SNRs still unaccounted for (ostensibly the Missing SNR problem). The overall purpose here is to present the results of a systematic, deep data-mining of the Canadian Galactic Plane Survey (CGPS) for faint, extended non-thermal and polarized emission structures that are likely the shells of uncatalogued supernova remnants. We examine 5$\\times$5 degree mosaics from the entire 1420 MHz continuum and polarization dataset of the CGPS after removing unresolved point sources and subsequently smoothing them. Newly revealed extended emission objects are compared to similarly-prepared CGPS 408 MHz continuum mosaics, as well as to source-removed mosaics from various existing radio surveys at 4.8 GHz, 2.7 GHz, and 327 MHz, to identify candidates with non-thermal emission characteristics. We integrate fl...

  3. The search for failed supernovae with the Large Binocular Telescope: confirmation of a disappearing star

    CERN Document Server

    Adams, S M; Gerke, J R; Stanek, K Z; Dai, X

    2016-01-01

    We present Hubble Space Telescope imaging confirming the optical disappearance of the failed supernova candidate identified by Gerke et al. (2015). This $\\sim 25~M_{\\odot}$ red supergiant experienced a weak $\\sim 10^{6}~L_{\\odot}$ optical outburst in 2009 and is now at least 5 magnitudes fainter than the progenitor in the optical. The mid-IR flux has slowly decreased to the lowest levels since the first measurements in 2004. There is faint ($2000-3000~L_{\\odot}$) near-IR emission likely associated with the source. We find the late-time evolution of the source to be inconsistent with obscuration from an ejected, dusty shell. Models of the spectral energy distribution indicate that the remaining bolometric luminosity is $>6$ times fainter than that of the progenitor and is decreasing as $\\sim t^{-4/3}$. We conclude that the transient is unlikely to be a SN impostor or stellar merger. The event is consistent with the ejection of the envelope of a red supergiant in a failed supernova and the late-time emission co...

  4. Search for supernova-produced {sup 60}Fe in the microfossil record

    Energy Technology Data Exchange (ETDEWEB)

    Ludwig, Peter; Bishop, Shawn; Chernenko, Valentyna; Faestermann, Thomas; Famulok, Nicolai; Fimiani, Leticia; Gomez, Jose; Hain, Karin; Korschinek, Gunther [TU Muenchen, Physik Department (Germany); Egli, Ramon [ZAMG, Wien (Austria); Frederichs, Thomas [Universitaet Bremen, Geowissenschaften (Germany); Hanzlik, Marianne [TU Muenchen, Fakultaet fuer Chemie (Germany); Merchel, Silke; Rugel, Georg [HZDR, Dresden (Germany)

    2014-07-01

    Material distributed into the interstellar medium by supernova explosions can be incorporated into terrestrial archives. After the discovery of live {sup 60}Fe atoms in 2-3 Myr old layers of a Pacific Ocean ferromanganese crust, a confirmation of this signal, as well as a mapping of the signal with high time-resolution is desirable. Another reservoir in which the {sup 60}Fe signature should have been incorporated are the fossils of magnetotactic bacteria in ocean sediment. To this end, two sediment cores from the Eastern Equatorial Pacific were obtained, iron was chemically extracted with high selectivity towards biogenic magnetite, and the extraction procedure was characterized using novel magnetic measurements. The {sup 60}Fe/Fe concentration in the samples was then measured with accelerator mass spectrometry at the GAMS setup in Garching. Preliminary results for both sediment cores are reported.

  5. A High-Resolution Spectroscopic Search for the Remaining Donor for Tycho's Supernova

    CERN Document Server

    Kerzendorf, Wolfgang E; Schmidt, Brian P; Simon, Joshua D; Jeffery, C Simon; Anderson, Jay; Podsiadlowski, Philipp; Gal-Yam, Avishay; Silverman, Jeffrey M; Filippenko, Alexei V; Nomoto, Ken'ichi; Murphy, Simon J; Bessell, Michael S; Venn, Kim A; Foley, Ryan J

    2012-01-01

    In this paper, we report on our analysis using Hubble Space Telescope astrometry and Keck-I HIRES spectroscopy of the central six stars of Tycho's supernova remnant (SN 1572). With these data, we measured the proper motions, radial velocities, rotational velocities, and chemical abundances of these objects. Regarding the chemical abundances, we do not confirm the unusu- ally high [Ni/Fe] ratio previously reported for Tycho-G. Rather, we find that for all metrics in all stars, none exhibit the characteristics expected from traditional SN Ia single-degenerate-scenario calculations. The only possible exception is Tycho-B, a rare, metal-poor A-type star; however, we are unable to find a suitable scenario for it. Thus, we suggest that SN 1572 cannot be explained by the standard single-degenerate model.

  6. Searching for the Time Variation in Supernova Remnant RX J1713.7-3946

    CERN Document Server

    Sezer, Aytap; Cui, Xiaohong; Bamba, Aya; Ohira, Yutaka

    2016-01-01

    Supernova Remnant RX J1713.7-3946 emits synchrotron X-rays and very high energy $\\gamma$-rays. Recently, thermal X-ray line emission is detected from ejecta plasma. CO and HI observations indicate that a highly inhomogeneous medium surrounding the SNR. It is interacting with dense molecular clouds in the northwest and the southwest of the remnant. The origin of the $\\gamma$-ray emission from RX J1713.7-3946 is still uncertain. Detection of rapid variability in X-ray emission from RX J1713.7-3946 indicates the magnetic field $B$ $\\sim$ mG. In this work, we investigate the time variation in X-ray flux, luminosity and photon index of RX J1713.7-3946. For this investigation, we study the northwest part of the remnant using Suzaku data in 2006 and 2010. We present preliminary results based on our analysis and interpretations about these X-ray time variability.

  7. Search for Early Gamma-ray Production in Supernovae Located in a Dense Circumstellar Medium with the Fermi LAT

    CERN Document Server

    ,

    2015-01-01

    Supernovae (SNe) exploding in a dense circumstellar medium (CSM) are hypothesized to accelerate cosmic rays in collisionless shocks and emit GeV gamma rays and TeV neutrinos on a time scale of several months. We perform the first systematic search for gamma-ray emission in Fermi LAT data in the energy range from 100 MeV to 300 GeV from the ensemble of 147 SNe Type IIn exploding in dense CSM. We search for a gamma-ray excess at each SNe location in a one year time window. In order to enhance a possible weak signal, we simultaneously study the closest and optically brightest sources of our sample in a joint-likelihood analysis in three different time windows (1 year, 6 months and 3 months). For the most promising source of the sample, SN 2010jl (PTF10aaxf), we repeat the analysis with an extended time window lasting 4.5 years. We do not find a significant excess in gamma rays for any individual source nor for the combined sources and provide model-independent flux upper limits for both cases. In addition, we de...

  8. A Search for Neutrinos from the Solar hep Reaction and the Diffuse Supernova Neutrino Background with the Sudbury Neutrino Observatory

    CERN Document Server

    Ahmed, S N; Beier, E W; Bellerive, A; Bergevin, M; Biller, S D; Boulay, M G; Chan, Y D; Chen, M; Chen, X; Cleveland, B T; Cox, G A; Currat, C A; Dai, X; Dalnoki-Veress, F; Deng, H; Detwiler, J; Di Marco, M; Doe, P J; Doucas, G; Drouin, P L; Duncan, F A; Dunford, M; Dunmore, J A; Earle, E D; Evans, H C; Ewan, G T; Farine, J; Fergani, H; Fleurot, F; Ford, R J; Formaggio, J A; Gagnon, N; Goon, J TM; Graham, K; Guillian, E; Hahn, R L; Hallin, A L; Hallman, E D; Harvey, P J; Hazama, R; Heeger, K M; Heintzelman, W J; Heise, J; Helmer, R L; Hemingway, R J; Henning, R; Hime, A; Howard, C; Howe, M A; Huang, M; Jagam, P; Jelley, N A; Klein, J R; Kormos, L L; Kos, M; Krüger, A; Kraus, C V; Krauss, C B; Kutter, T; Kyba, C C M; Labranche, H; Lange, R; Law, J; Lawson, I T; Lesko, K T; Leslie, J R; Loach, J C; Luoma, S; MacLellan, R; Majerus, S; Mak, H B; Maneira, J; Marino, A D; Martin, R; McCauley, N; McDonald, A B; McGee, S; Miin, C; Miknaitis, K K S; Miller, M L; Monreal, B; Nickel, B G; Noble, A J; Norman, E B; Oblath, N S; Okada, C E; O'Keeffe, H M; Orebi-Gann, G D; Oser, S M; Ott, R; Peeters, S J M; Poon, A W P; Prior, G; Rielage, K; Robertson, B C; Robertson, R G H; Rollin, E; Schwendener, M H; Secrest, J A; Seibert, S R; Simard, O; Sims, C J; Sinclair, D; Skensved, P; Stokstad, R G; Stonehill, L C; Tesic, G; Tolich, N; Tsui, T; Van Berg, R; Van de Water, R G; Van Devender, B A; Virtue, C J; Walker, T J; Wall, B L; Waller, D; Wan Chan Tseung, H; Wark, D L; Wendland, J; West, N; Wilkerson, J F; Wilson, J R; Wouters, J M; Wright, A; Yeh, M; Zhang, F; Zuber, K

    2006-01-01

    A search has been made for neutrinos from the hep reaction in the Sun and from the diffuse supernova neutrino background (DSNB) using data collected during the first operational phase of the Sudbury Neutrino Observatory. For the hep neutrino search, two events are observed in the effective electron energy range of 14.3 MeV

  9. Transformation of an uncertain video search pipeline to a sketch-based visual analytics loop.

    Science.gov (United States)

    Legg, Philip A; Chung, David H S; Parry, Matthew L; Bown, Rhodri; Jones, Mark W; Griffiths, Iwan W; Chen, Min

    2013-12-01

    Traditional sketch-based image or video search systems rely on machine learning concepts as their core technology. However, in many applications, machine learning alone is impractical since videos may not be semantically annotated sufficiently, there may be a lack of suitable training data, and the search requirements of the user may frequently change for different tasks. In this work, we develop a visual analytics systems that overcomes the shortcomings of the traditional approach. We make use of a sketch-based interface to enable users to specify search requirement in a flexible manner without depending on semantic annotation. We employ active machine learning to train different analytical models for different types of search requirements. We use visualization to facilitate knowledge discovery at the different stages of visual analytics. This includes visualizing the parameter space of the trained model, visualizing the search space to support interactive browsing, visualizing candidature search results to support rapid interaction for active learning while minimizing watching videos, and visualizing aggregated information of the search results. We demonstrate the system for searching spatiotemporal attributes from sports video to identify key instances of the team and player performance.

  10. How to Find More Supernovae with Less Work: Object ClassificationTechniques for Difference Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, Stephen; Aragon, Cecilia; Romano, Raquel; Thomas, RollinC.; Weaver, Benjamin A.; Wong, Daniel

    2007-05-02

    We present the results of applying new object classificationtechniques to difference images in the context of the Nearby SupernovaFactory supernova search. Most current supernova searches subtractreference images from new images, identify objects in these differenceimages, and apply simple threshold cuts on parameters such as statisticalsignificance, shape, and motionto reject objects such as cosmic rays,asteroids, and subtraction artifacts. Although most static objectssubtract cleanly, even a very low false positive detection rate can leadto hundreds of non-supernova candidates which must be vetted by humaninspection before triggering additional followup. In comparison to simplethreshold cuts, more sophisticated methods such as Boosted DecisionTrees, Random Forests, and Support Vector Machines provide dramaticallybetter object discrimination. At the Nearby Supernova Factory, we reducedthe number of non-supernova candidates by a factor of 10 while increasingour supernova identification efficiency. Methods such as these will becrucial for maintaining a reasonable false positive rate in the automatedtransient alert pipelines of upcoming projects such as PanSTARRS andLSST.

  11. The historical supernovae

    CERN Document Server

    Clark, David H

    1977-01-01

    The Historical Supernovae is an interdisciplinary study of the historical records of supernova. This book is composed of 12 chapters that particularly highlight the history of the Far East. The opening chapter briefly describes the features of nova and supernova, stars which spontaneously explode with a spectacular and rapid increase in brightness. The succeeding chapter deals with the search for the historical records of supernova from Medieval European monastic chronicles, Arabic chronicles, astrological works etc., post renaissance European scientific writings, and Far Eastern histories and

  12. Systematic search for gamma-ray emitting molecular clouds in the vicinity of supernova remnants

    CERN Document Server

    Häffner, Stephanie; Stegmann, Christian

    2013-01-01

    Observations of very-high-energy (VHE) gamma-ray emission from supernova remnants (SNR) established them as sources of accelerated particles up to energies of 100 TeV. The dominant process - leptonic or hadronic - responsible for the VHE emission is still not proven for most of the SNRs. Molecular clouds (MCs) in the vicinity of SNRs provide increased amount of target material for accelerated particles escaping the SNRs, thus making MCs potential gamma-ray sources. The predicted gamma-ray flux for MCs offset from the SNR shock depends on the applied diffusion model for VHE particles and the SNR and MC properties, which encounter large uncertainties. While the the average galactic diffusion coefficient is estimated, the spatially resolved propagation properties of VHE cosmic rays are unknown. gamma-ray emitting MCs provide a unique possibility to derive new information on the propagation of VHE particles through the ISM and on the acceleration of hadrons at SNRs. We present in this paper a strategy and first r...

  13. Search for new supernova remnant shells in the Galactic plane with H.E.S.S

    CERN Document Server

    Pühlhofer, G; Capasso, M; Chaves, R C G; Deil, C; Djannati-Ataï, A; Donath, A; Eger, P; Gottschall, D; Laffon, H; Marandon, V; Oakes, L; Renaud, M; Sasaki, M; Terrier, R; Vink, J; Bamba, A

    2015-01-01

    Amongst the population of TeV gamma-ray sources detected with the High Energy Stereoscopic System (H.E.S.S.) in the Galactic plane, clearly identified supernova remnant (SNR) shells constitute a small but precious source class. TeV-selected SNRs are prime candidates for sources of efficient cosmic-ray acceleration. In this work, we present new SNR candidates that have been identified in the entire H.E.S.S. phase I data set of the Galactic plane recorded over the past ten years. Identification with a known SNR shell candidate was successful for one new source, HESS J1534-571. In other cases, TeV-only shell candidates are challenging to firmly identify as SNRs due to their lack of detected non-thermal emission in lower energy bands. We will discuss how these objects may present an important link between young and evolved SNRs, since their shell emission may be dominated by hadronic processes.

  14. Supernova rates from the SUDARE VST-Omegacam search II. Rates in a galaxy sample

    CERN Document Server

    Botticella, M T; Greggio, L; Pignata, G; Della Valle, M; Grado, A; Limatola, L; Baruffolo, A; Benetti, S; Bufano, F; Capaccioli, M; Cascone, E; Covone, G; De Cicco, D; Falocco, S; Haeussler, B; Harutyunyan, V; Jarvis, M; Marchetti, L; Napolitano, N R; Paolillo, M; Pastorello, A; Radovich, M; Schipani, P; Tomasella, L; Turatto, M; Vaccari, M

    2016-01-01

    This is the second paper of a series in which we present measurements of the Supernova (SN) rates from the SUDARE survey. In this paper, we study the trend of the SN rates with the intrinsic colours, the star formation activity and the mass of the parent galaxies. We have considered a sample of about 130000 galaxies and a SN sample of about 50 events. We found that the SN Ia rate per unit mass is higher by a factor of six in the star-forming galaxies with respect to the passive galaxies. The SN Ia rate per unit mass is also higher in the less massive galaxies that are also younger. These results suggest a distribution of the delay times (DTD) less populated at long delay times than at short delays. The CC SN rate per unit mass is proportional to both the sSFR and the galaxy mass. The trends of the Type Ia and CC SN rates as a function of the sSFR and the galaxy mass that we observed from SUDARE data are in agreement with literature results at different redshifts. The expected number of SNe Ia is in agreement ...

  15. Searching for soft relativistic jets in Core-collapse Supernovae with the IceCube Optical Follow-up Program

    CERN Document Server

    Abbasi, R; Abu-Zayyad, T; Ackermann, M; Adams, J; Aguilar, J A; Ahlers, M; Allen, M M; Altmann, D; Andeen, K; Auffenberg, J; Bai, X; Baker, M; Barwick, S W; Bay, R; Alba, J L Bazo; Beattie, K; Beatty, J J; Bechet, S; Becker, J K; Becker, K -H; Benabderrahmane, M L; BenZvi, S; Berdermann, J; Berghaus, P; Berley, D; Bernardini, E; Bertrand, D; Besson, D Z; Bindig, D; Bissok, M; Blaufuss, E; Blumenthal, J; Boersma, D J; Bohm, C; Bose, D; Böser, S; Botner, O; Brown, A M; Buitink, S; Caballero-Mora, K S; Carson, M; Chirkin, D; Christy, B; Clevermann, F; Cohen, S; Colnard, C; Cowen, D F; Silva, A H Cruz; D'Agostino, M V; Danninger, M; Daughhetee, J; Davis, J C; De Clercq, C; Degner, T; Demirörs, L; Descamps, F; Desiati, P; de Vries-Uiterweerd, G; DeYoung, T; Díaz-Vélez, J C; Dierckxsens, M; Dreyer, J; Dumm, J P; Dunkman, M; Eisch, J; Ellsworth, R W; Engdegård, O; Euler, S; Evenson, P A; Fadiran, O; Fazely, A R; Fedynitch, A; Feintzeig, J; Feusels, T; Filimonov, K; Finley, C; Fischer-Wasels, T; Fox, B D; Franckowiak, A; Franke, R; Gaisser, T K; Gallagher, J; Gerhardt, L; Gladstone, L; Glüsenkamp, T; Goldschmidt, A; Goodman, J A; Góra, D; Grant, D; Griesel, T; Groß, A; Grullon, S; Gurtner, M; Ha, C; Ismail, A Haj; Hallgren, A; Halzen, F; Han, K; Hanson, K; Heinen, D; Helbing, K; Hellauer, R; Herquet, P; Hickford, S; Hill, G C; Hoffman, K D; Hoffmann, B; Homeier, A; Hoshina, K; Huelsnitz, W; Hülß, J -P; Hulth, P O; Hultqvist, K; Hussain, S; Ishihara, A; Jacobi, E; Jacobsen, J; Japaridze, G S; Johansson, H; Kampert, K -H; Kappes, A; Karg, T; Karle, A; Kenny, P; Kiryluk, J; Kislat, F; Klein, S R; Köhne, J -H; Kohnen, G; Kolanoski, H; Köpke, L; Kopper, S; Koskinen, D J; Kowalski, M; Kowarik, T; Krasberg, M; Kroll, G; Kurahashi, N; Kuwabara, T; Labare, M; Laihem, K; Landsman, H; Larson, M J; Lauer, R; Lünemann, J; Madsen, J; Marotta, A; Maruyama, R; Mase, K; Matis, H S; Meagher, K; Merck, M; Mészáros, P; Meures, T; Miarecki, S; Middell, E; Milke, N; Miller, J; Montaruli, T; Morse, R; Movit, S M; Nahnhauer, R; Nam, J W; Naumann, U; Nygren, D R; Odrowski, S; Olivas, A; Olivo, M; O'Murchadha, A; Panknin, S; Paul, L; Heros, C Pérez de los; Petrovic, J; Piegsa, A; Pieloth, D; Porrata, R; Posselt, J; Price, P B; Przybylski, G T; Rawlins, K; Redl, P; Resconi, E; Rhode, W; Ribordy, M; Richman, M; Rodrigues, J P; Rothmaier, F; Rott, C; Ruhe, T; Rutledge, D; Ruzybayev, B; Ryckbosch, D; Sander, H -G; Santander, M; Sarkar, S; Schatto, K; Schmidt, T; Schönwald, A; Schukraft, A; Schultes, A; Schulz, O; Schunck, M; Seckel, D; Semburg, B; Seo, S H; Sestayo, Y; Seunarine, S; Silvestri, A; Spiczak, G M; Spiering, C; Stamatikos, M; Stanev, T; Stezelberger, T; Stokstad, R G; Stössl, A; Strahler, E A; Ström, R; Stüer, M; Sullivan, G W; Swillens, Q; Taavola, H; Taboada, I; Tamburro, A; Ter-Antonyan, S; Tilav, S; Toale, P A; Toscano, S; Tosi, D; van Eijndhoven, N; Vandenbroucke, J; Van Overloop, A; van Santen, J; Vehring, M; Voge, M; Walck, C; Waldenmaier, T; Wallraff, M; Walter, M; Weaver, Ch; Wendt, C; Westerhoff, S; Whitehorn, N; Wiebe, K; Wiebusch, C H; Williams, D R; Wischnewski, R; Wissing, H; Wolf, M; Wood, T R; Woschnagg, K; Xu, C; Xu, D L; Xu, X W; Yanez, J P; Yodh, G; Yoshida, S; Zarzhitsky, P; Akerlof, C W; Pandey, S B; Yuan, F; Zheng, W

    2011-01-01

    Context. Transient neutrino sources such as Gamma-Ray Bursts (GRBs) and Supernovae (SNe) are hypothesized to emit bursts of high-energy neutrinos on a time-scale of \\lesssim 100 s. While GRB neutrinos would be produced in high relativistic jets, core-collapse SNe might host soft-relativistic jets, which become stalled in the outer layers of the progenitor star leading to an efficient production of high-energy neutrinos. Aims. To increase the sensitivity to these neutrinos and identify their sources, a low-threshold optical follow-up program for neutrino multiplets detected with the IceCube observatory has been implemented. Methods. If a neutrino multiplet, i.e. two or more neutrinos from the same direction within 100 s, is found by IceCube a trigger is sent to the Robotic Optical Transient Search Experiment, ROTSE. The 4 ROTSE telescopes immediately start an observation program of the corresponding region of the sky in order to detect an optical counterpart to the neutrino events. Results. No statistically si...

  16. Searching for soft relativistic jets in core-collapse supernovae with the IceCube optical follow-up program

    Science.gov (United States)

    Abbasi, R.; Abdou, Y.; Abu-Zayyad, T.; Ackermann, M.; Adams, J.; Aguilar, J. A.; Ahlers, M.; Allen, M. M.; Altmann, D.; Andeen, K.; Auffenberg, J.; Bai, X.; Baker, M.; Barwick, S. W.; Bay, R.; Bazo Alba, J. L.; Beattie, K.; Beatty, J. J.; Bechet, S.; Becker, J. K.; Becker, K.-H.; Benabderrahmane, M. L.; Benzvi, S.; Berdermann, J.; Berghaus, P.; Berley, D.; Bernardini, E.; Bertrand, D.; Besson, D. Z.; Bindig, D.; Bissok, M.; Blaufuss, E.; Blumenthal, J.; Boersma, D. J.; Bohm, C.; Bose, D.; Böser, S.; Botner, O.; Brown, A. M.; Buitink, S.; Caballero-Mora, K. S.; Carson, M.; Chirkin, D.; Christy, B.; Clevermann, F.; Cohen, S.; Colnard, C.; Cowen, D. F.; Cruz Silva, A. H.; D'Agostino, M. V.; Danninger, M.; Daughhetee, J.; Davis, J. C.; de Clercq, C.; Degner, T.; Demirörs, L.; Descamps, F.; Desiati, P.; de Vries-Uiterweerd, G.; Deyoung, T.; Díaz-Vélez, J. C.; Dierckxsens, M.; Dreyer, J.; Dumm, J. P.; Dunkman, M.; Eisch, J.; Ellsworth, R. W.; Engdegård, O.; Euler, S.; Evenson, P. A.; Fadiran, O.; Fazely, A. R.; Fedynitch, A.; Feintzeig, J.; Feusels, T.; Filimonov, K.; Finley, C.; Fischer-Wasels, T.; Fox, B. D.; Franckowiak, A.; Franke, R.; Gaisser, T. K.; Gallagher, J.; Gerhardt, L.; Gladstone, L.; Glüsenkamp, T.; Goldschmidt, A.; Goodman, J. A.; Góra, D.; Grant, D.; Griesel, T.; Groß, A.; Grullon, S.; Gurtner, M.; Ha, C.; Haj Ismail, A.; Hallgren, A.; Halzen, F.; Han, K.; Hanson, K.; Heinen, D.; Helbing, K.; Hellauer, R.; Herquet, P.; Hickford, S.; Hill, G. C.; Hoffman, K. D.; Hoffmann, B.; Homeier, A.; Hoshina, K.; Huelsnitz, W.; Hülß, J.-P.; Hulth, P. O.; Hultqvist, K.; Hussain, S.; Ishihara, A.; Jacobi, E.; Jacobsen, J.; Japaridze, G. S.; Johansson, H.; Kampert, K.-H.; Kappes, A.; Karg, T.; Karle, A.; Kenny, P.; Kiryluk, J.; Kislat, F.; Klein, S. R.; Köhne, J.-H.; Kohnen, G.; Kolanoski, H.; Köpke, L.; Kopper, S.; Koskinen, D. J.; Kowalski, M.; Kowarik, T.; Krasberg, M.; Kroll, G.; Kurahashi, N.; Kuwabara, T.; Labare, M.; Laihem, K.; Landsman, H.; Larson, M. J.; Lauer, R.; Lünemann, J.; Madsen, J.; Marotta, A.; Maruyama, R.; Mase, K.; Matis, H. S.; Meagher, K.; Merck, M.; Mészáros, P.; Meures, T.; Miarecki, S.; Middell, E.; Milke, N.; Miller, J.; Montaruli, T.; Morse, R.; Movit, S. M.; Nahnhauer, R.; Nam, J. W.; Naumann, U.; Nygren, D. R.; Odrowski, S.; Olivas, A.; Olivo, M.; O'Murchadha, A.; Panknin, S.; Paul, L.; Pérez de Los Heros, C.; Petrovic, J.; Piegsa, A.; Pieloth, D.; Porrata, R.; Posselt, J.; Price, P. B.; Przybylski, G. T.; Rawlins, K.; Redl, P.; Resconi, E.; Rhode, W.; Ribordy, M.; Richman, M.; Rodrigues, J. P.; Rothmaier, F.; Rott, C.; Ruhe, T.; Rutledge, D.; Ruzybayev, B.; Ryckbosch, D.; Sander, H.-G.; Santander, M.; Sarkar, S.; Schatto, K.; Schmidt, T.; Schönwald, A.; Schukraft, A.; Schultes, A.; Schulz, O.; Schunck, M.; Seckel, D.; Semburg, B.; Seo, S. H.; Sestayo, Y.; Seunarine, S.; Silvestri, A.; Spiczak, G. M.; Spiering, C.; Stamatikos, M.; Stanev, T.; Stezelberger, T.; Stokstad, R. G.; Stössl, A.; Strahler, E. A.; Ström, R.; Stüer, M.; Sullivan, G. W.; Swillens, Q.; Taavola, H.; Taboada, I.; Tamburro, A.; Ter-Antonyan, S.; Tilav, S.; Toale, P. A.; Toscano, S.; Tosi, D.; van Eijndhoven, N.; Vandenbroucke, J.; van Overloop, A.; van Santen, J.; Vehring, M.; Voge, M.; Walck, C.; Waldenmaier, T.; Wallraff, M.; Walter, M.; Weaver, Ch.; Wendt, C.; Westerhoff, S.; Whitehorn, N.; Wiebe, K.; Wiebusch, C. H.; Williams, D. R.; Wischnewski, R.; Wissing, H.; Wolf, M.; Wood, T. R.; Woschnagg, K.; Xu, C.; Xu, D. L.; Xu, X. W.; Yanez, J. P.; Yodh, G.; Yoshida, S.; Zarzhitsky, P.; Zoll, M.; IceCube Collaboration; Akerlof, C. W.; Pandey, S. B.; Yuan, F.; Zheng, W.; ROTSE Collaboration

    2012-03-01

    Context. Transient neutrino sources such as gamma-ray bursts (GRBs) and supernovae (SNe) are hypothesized to emit bursts of high-energy neutrinos on a time-scale of ≲100 s. While GRB neutrinos would be produced in high relativistic jets, core-collapse SNe might host soft-relativistic jets, which become stalled in the outer layers of the progenitor star leading to an efficient production of high-energy neutrinos. Aims: To increase the sensitivity to these neutrinos and identify their sources, a low-threshold optical follow-up program for neutrino multiplets detected with the IceCube observatory has been implemented. Methods: If a neutrino multiplet, i.e. two or more neutrinos from the same direction within 100 s, is found by IceCube a trigger is sent to the Robotic Optical Transient Search Experiment, ROTSE. The 4 ROTSE telescopes immediately start an observation program of the corresponding region of the sky in order to detect an optical counterpart to the neutrino events. Results: No statistically significant excess in the rate of neutrino multiplets has been observed and furthermore no coincidence with an optical counterpart was found. Conclusions: The search allows, for the first time, to set stringent limits on current models predicting a high-energy neutrino flux from soft relativistic hadronic jets in core-collapse SNe. We conclude that a sub-population of SNe with typical Lorentz boost factor and jet energy of 10 and 3 × 1051 erg, respectively, does not exceed 4.2% at 90% confidence.

  17. Supernova rates from the SUDARE VST-Omegacam search II. Rates in a galaxy sample

    Science.gov (United States)

    Botticella, M. T.; Cappellaro, E.; Greggio, L.; Pignata, G.; Della Valle, M.; Grado, A.; Limatola, L.; Baruffolo, A.; Benetti, S.; Bufano, F.; Capaccioli, M.; Cascone, E.; Covone, G.; De Cicco, D.; Falocco, S.; Haeussler, B.; Harutyunyan, V.; Jarvis, M.; Marchetti, L.; Napolitano, N. R.; Paolillo, M.; Pastorello, A.; Radovich, M.; Schipani, P.; Tomasella, L.; Turatto, M.; Vaccari, M.

    2017-02-01

    Aims: This is the second paper of a series in which we present measurements of the supernova (SN) rates from the SUDARE survey. The aim of this survey is to constrain the core collapse (CC) and Type Ia SN progenitors by analysing the dependence of their explosion rate on the properties of the parent stellar population averaging over a population of galaxies with different ages in a cosmic volume and in a galaxy sample. In this paper, we study the trend of the SN rates with the intrinsic colours, the star formation activity and the masses of the parent galaxies. To constrain the SN progenitors we compare the observed rates with model predictions assuming four progenitor models for SNe Ia with different distribution functions of the time intervals between the formation of the progenitor and the explosion, and a mass range of 8-40 M⊙ for CC SN progenitors. Methods: We considered a galaxy sample of approximately 130 000 galaxies and a SN sample of approximately 50 events. The wealth of photometric information for our galaxy sample allows us to apply the spectral energy distribution (SED) fitting technique to estimate the intrinsic rest frame colours, the stellar mass and star formation rate (SFR) for each galaxy in the sample. The galaxies have been separated into star-forming and quiescent galaxies, exploiting both the rest frame U-V vs. V-J colour-colour diagram and the best fit values of the specific star formation rate (sSFR) from the SED fitting. Results: We found that the SN Ia rate per unit mass is higher by a factor of six in the star-forming galaxies with respect to the passive galaxies, identified as such both on the U-V vs. V-J colour-colour diagram and for their sSFR. The SN Ia rate per unit mass is also higher in the less massive galaxies that are also younger. These results suggest a distribution of the delay times (DTD) less populated at long delay times than at short delays. The CC SN rate per unit mass is proportional to both the sSFR and the galaxy

  18. GRASP (Greedy Randomized Adaptive Search Procedures) applied to optimization of petroleum products distribution in pipeline networks; GRASP (Greedy Randomized Adaptative Search Procedures) aplicado ao 'scheduling' de redes de distribuicao de petroleo e derivados

    Energy Technology Data Exchange (ETDEWEB)

    Conte, Viviane Cristhyne Bini; Arruda, Lucia Valeria Ramos de; Yamamoto, Lia [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil)

    2008-07-01

    Planning and scheduling of the pipeline network operations aim the most efficient use of the resources resulting in a better performance of the network. A petroleum distribution pipeline network is composed by refineries, sources and/or storage parks, connected by a set of pipelines, which operate the transportation of petroleum and derivatives among adjacent areas. In real scenes, this problem is considered a combinatorial problem, which has difficult solution, which makes necessary methodologies of the resolution that present low computational time. This work aims to get solutions that attempt the demands and minimize the number of batch fragmentations on the sent operations of products for the pipelines in a simplified model of a real network, through by application of the local search metaheuristic GRASP. GRASP does not depend of solutions of previous iterations and works in a random way so it allows the search for the solution in an ampler and diversified search space. GRASP utilization does not demand complex calculation, even the construction stage that requires more computational effort, which provides relative rapidity in the attainment of good solutions. GRASP application on the scheduling of the operations of this network presented feasible solutions in a low computational time. (author)

  19. Search for isotopic signatures of a supernova explosion close to the solar system in marine sediments; Recherche de signatures isotopiques dans les sediments marins de l'explosion d'une supernova proche du systeme solaire

    Energy Technology Data Exchange (ETDEWEB)

    Fitoussi, Caroline [Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse, (CSNSM) IN2P3/CNRS, Campus d' Orsay, Bat 108, 91405 Orsay (France)

    2006-06-15

    The recent observation of a {sup 60}Fe peak in a deep-sea ferro-manganese crust has been interpreted as due to a supernova explosion relatively close to the solar system 2.8 {+-} 0.4 Myr ago. To confirm this interpretation with better time-resolved measurements, and the simultaneous access, on the same sample, to other isotopes and geochemical phases, marine sediments seem to be a tool of choice. The objective of this work was to search for isotopic anomalies which would be characteristic for residues of this supernova. More specifically, {sup 129}I, {sup 60}Fe, and {sup 26}Al have been investigated, being measured by Accelerator Mass Spectrometry (AMS). Quantifying these nuclides' fluxes would help constrain stellar nucleosynthesis models. These residues are isotopes initially produced during hydrostatic and/or explosive nucleosynthesis. The physical conditions during the explosion (temperature, neutron density) are such that supernovae are thought to be good candidates for the astrophysical site of the r-process. The {sup 129}I study showed that measurement of pre-anthropogenic {sup 129}I/{sup 127}I ratios need a very strict control of the various potential {sup 129}I sources, especially when working with small quantities (micrograms) of iodine. This study revealed that the expected pre-anthropogenic {sup 129}I/{sup 127}I ratio for pre-nuclear samples in the marine environment shows a large discrepancy between theoretical calculations and experimental measurements. {sup 60}Fe and {sup 26}Al measurements allow us to conclude that, in the authigenic phase of the marine sediments, there is no {sup 60}Fe anomaly in the time interval defined by the signal found on the Fe-Mn crust (from 2.4 to 3.2 Myr), and no {sup 26}Al anomaly from 2.6 to 3.2 Myr. (author)

  20. Supernova detection

    Energy Technology Data Exchange (ETDEWEB)

    Nakahata, Masayuki [Kamioka Observatory, Institute for Cosmic Ray research, University of Tokyo, Higashi-Mozumi, Kamioka-cho, Hida-shi, Gifu, Japan, 506-1205 (Japan)], E-mail: nakahata@suketto.icrr.u-tokyo.ac.jp

    2008-11-01

    The detection of supernova neutrinos is reviewed, focusing on the current status of experiments to detect supernova burst neutrinos and supernova relic neutrinos. The capabilities of each detector currently operating and in development are assessed and the likely neutrino yield for a future supernova is estimated. It is expected that much more information will be obtained if a supernova burst were to occur in our Galaxy than was obtained for supernova SN1987A. The detection of supernova relic neutrinos is considered and it is concluded that a large volume detector with a neutron tagging technique is necessary.

  1. HomBlocks: A multiple-alignment construction pipeline for organelle phylogenomics based on locally collinear block searching.

    Science.gov (United States)

    Bi, Guiqi; Mao, Yunxiang; Xing, Qikun; Cao, Min

    2017-08-03

    Organelle phylogenomic analysis requires precisely constructed multi-gene alignment matrices concatenated by pre-aligned single gene datasets. For non-bioinformaticians, it can take days to weeks to manually create high-quality multi-gene alignments comprising tens or hundreds of homologous genes. Here, we describe a new and highly efficient pipeline, HomBlocks, which uses a homologous block searching method to construct multiple sequence alignment. This approach can automatically recognize locally collinear blocks among organelle genomes and excavate phylogenetically informative regions to construct multiple sequence alignment in a few hours. In addition, HomBlocks supports organelle genomes without annotation and makes adjustment to different taxon datasets, thereby enabling the inclusion of as many common genes as possible. Topology comparison of trees built by conventional multi-gene and HomBlocks alignments implemented in different taxon categories shows that the same efficiency can be achieved by HomBlocks as when using the traditional method. The availability of Homblocks makes organelle phylogenetic analyses more accessible to non-bioinformaticians, thereby promising to lead to a better understanding of phylogenic relationships at an organelle genome level. HomBlocks is implemented in Perl and is supported by Unix-like operative systems, including Linux and macOS. The Perl source code is freely available for download from https://github.com/fenghen360/HomBlocks.git, and documentation and tutorials are available at https://github.com/fenghen360/HomBlocks. yxmao@ouc.edu.cn or fenghen360@126.com. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Matching Supernovae to Galaxies

    Science.gov (United States)

    Kohler, Susanna

    2016-12-01

    One of the major challenges for modern supernova surveys is identifying the galaxy that hosted each explosion. Is there an accurate and efficient way to do this that avoids investing significant human resources?Why Identify Hosts?One problem in host galaxy identification. Here, the supernova lies between two galaxies but though the centroid of the galaxy on the right is closer in angular separation, this may be a distant background galaxy that is not actually near the supernova. [Gupta et al. 2016]Supernovae are a critical tool for making cosmological predictions that help us to understand our universe. But supernova cosmology relies on accurately identifying the properties of the supernovae including their redshifts. Since spectroscopic followup of supernova detections often isnt possible, we rely on observations of the supernova host galaxies to obtain redshifts.But how do we identify which galaxy hosted a supernova? This seems like a simple problem, but there are many complicating factors a seemingly nearby galaxy could be a distant background galaxy, for instance, or a supernovas host could be too faint to spot.The authors algorithm takes into account confusion, a measure of how likely the supernova is to be mismatched. In these illustrations of low (left) and high (right) confusion, the supernova is represented by a blue star, and the green circles represent possible host galaxies. [Gupta et al. 2016]Turning to AutomationBefore the era of large supernovae surveys, searching for host galaxies was done primarily by visual inspection. But current projects like the Dark Energy Surveys Supernova Program is finding supernovae by the thousands, and the upcoming Large Synoptic Survey Telescope will likely discover hundreds of thousands. Visual inspection will not be possible in the face of this volume of data so an accurate and efficient automated method is clearly needed!To this end, a team of scientists led by Ravi Gupta (Argonne National Laboratory) has recently

  3. A fast contour descriptor algorithm for supernova imageclassification

    Energy Technology Data Exchange (ETDEWEB)

    Aragon, Cecilia R.; Aragon, David Bradburn

    2006-07-16

    We describe a fast contour descriptor algorithm and its application to a distributed supernova detection system (the Nearby Supernova Factory) that processes 600,000 candidate objects in 80 GB of image data per night. Our shape-detection algorithm reduced the number of false positives generated by the supernova search pipeline by 41% while producing no measurable impact on running time. Fourier descriptors are an established method of numerically describing the shapes of object contours, but transform-based techniques are ordinarily avoided in this type of application due to their computational cost. We devised a fast contour descriptor implementation for supernova candidates that meets the tight processing budget of the application. Using the lowest-order descriptors (F{sub 1} and F{sub -1}) and the total variance in the contour, we obtain one feature representing the eccentricity of the object and another denoting its irregularity. Because the number of Fourier terms to be calculated is fixed and small, the algorithm runs in linear time, rather than the O(n log n) time of an FFT. Constraints on object size allow further optimizations so that the total cost of producing the required contour descriptors is about 4n addition/subtraction operations, where n is the length of the contour.

  4. Pipeline engineering

    CERN Document Server

    Liu, Henry

    2003-01-01

    PART I: PIPE FLOWSINTRODUCTIONDefinition and Scope Brief History of PipelinesExisting Major PipelinesImportance of PipelinesFreight (Solids) Transport by PipelinesTypes of PipelinesComponents of PipelinesAdvantages of PipelinesReferencesSINGLE-PHASE INCOMPRESSIBLE NEWTONIAN FLUIDIntroductionFlow RegimesLocal Mean Velocity and Its Distribution (Velocity Profile)Flow Equations for One-Dimensional AnalysisHydraulic and Energy Grade LinesCavitation in Pipeline SystemsPipe in Series and ParallelInterconnected ReservoirsPipe NetworkUnsteady Flow in PipeSINGLE-PHASE COMPRESSIBLE FLOW IN PIPEFlow Ana

  5. Galaxy Zoo Supernovae

    Science.gov (United States)

    Smith, A. M.; Lynn, S.; Sullivan, M.; Lintott, C. J.; Nugent, P. E.; Botyanszki, J.; Kasliwal, M.; Quimby, R.; Bamford, S. P.; Fortson, L. F.; Schawinski, K.; Hook, I.; Blake, S.; Podsiadlowski, P.; Jönsson, J.; Gal-Yam, A.; Arcavi, I.; Howell, D. A.; Bloom, J. S.; Jacobsen, J.; Kulkarni, S. R.; Law, N. M.; Ofek, E. O.; Walters, R.

    2011-04-01

    This paper presents the first results from a new citizen science project: Galaxy Zoo Supernovae. This proof-of-concept project uses members of the public to identify supernova candidates from the latest generation of wide-field imaging transient surveys. We describe the Galaxy Zoo Supernovae operations and scoring model, and demonstrate the effectiveness of this novel method using imaging data and transients from the Palomar Transient Factory (PTF). We examine the results collected over the period 2010 April-July, during which nearly 14 000 supernova candidates from the PTF were classified by more than 2500 individuals within a few hours of data collection. We compare the transients selected by the citizen scientists to those identified by experienced PTF scanners and find the agreement to be remarkable - Galaxy Zoo Supernovae performs comparably to the PTF scanners and identified as transients 93 per cent of the ˜130 spectroscopically confirmed supernovae (SNe) that the PTF located during the trial period (with no false positive identifications). Further analysis shows that only a small fraction of the lowest signal-to-noise ratio detections (r > 19.5) are given low scores: Galaxy Zoo Supernovae correctly identifies all SNe with ≥8σ detections in the PTF imaging data. The Galaxy Zoo Supernovae project has direct applicability to future transient searches, such as the Large Synoptic Survey Telescope, by both rapidly identifying candidate transient events and via the training and improvement of existing machine classifier algorithms. This publication has been made possible by the participation of more than 10 000 volunteers in the Galaxy Zoo Supernovae project ().

  6. Ultrasound monitoring of pipelines; Ultraschallueberwachung an Pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Kircher, W.; Skerra, B.; Kobitsch-Meyer, S. [SONOTEC Ultraschallsensorik, Halle GmbH (Germany)

    2007-01-15

    Pipelines are the most modern, effective and safest transport system, which is world widely spread in a network of millions km length and is annually enlarged about thousands of km. It is sure that these systems, if they should stay save and effective, must be maintained adequately. A technique, which provides accurate and reliable measurement data without interrupting the pipeline operation, ''through the wall'', is the ultrasonic technology. This non-intrusive technology provides data for pig detection as well as it is used for recognising products in pipelines, detecting levels or full/empty states and accomplishment of sediment measurement, distance measurements, position detections and leak search. The article gives a review and describes some applications of ultrasonic technology in pipeline technique. (orig.)

  7. Supernova VLBI

    Science.gov (United States)

    Bartel, N.

    2009-08-01

    We review VLBI observations of supernovae over the last quarter century and discuss the prospect of imaging future supernovae with space VLBI in the context of VSOP-2. From thousands of discovered supernovae, most of them at cosmological distances, ˜50 have been detected at radio wavelengths, most of them in relatively nearby galaxies. All of the radio supernovae are Type II or Ib/c, which originate from the explosion of massive progenitor stars. Of these, 12 were observed with VLBI and four of them, SN 1979C, SN 1986J, SN 1993J, and SN 1987A, could be imaged in detail, the former three with VLBI. In addition, supernovae or young supernova remnants were discovered at radio wavelengths in highly dust-obscured galaxies, such as M82, Arp 299, and Arp 220, and some of them could also be imaged in detail. Four of the supernovae so far observed were sufficiently bright to be detectable with VSOP-2. With VSOP-2 the expansion of supernovae can be monitored and investigated with unsurpassed angular resolution, starting as early as the time of the supernova's transition from its opaque to transparent stage. Such studies can reveal, in a movie, the aftermath of a supernova explosion shortly after shock break out.

  8. Supernova explosions

    CERN Document Server

    Branch, David

    2017-01-01

    Targeting advanced students of astronomy and physics, as well as astronomers and physicists contemplating research on supernovae or related fields, David Branch and J. Craig Wheeler offer a modern account of the nature, causes and consequences of supernovae, as well as of issues that remain to be resolved. Owing especially to (1) the appearance of supernova 1987A in the nearby Large Magellanic Cloud, (2) the spectacularly successful use of supernovae as distance indicators for cosmology, (3) the association of some supernovae with the enigmatic cosmic gamma-ray bursts, and (4) the discovery of a class of superluminous supernovae, the pace of supernova research has been increasing sharply. This monograph serves as a broad survey of modern supernova research and a guide to the current literature. The book’s emphasis is on the explosive phases of supernovae. Part 1 is devoted to a survey of the kinds of observations that inform us about supernovae, some basic interpreta tions of such data, and an overview of t...

  9. Aspherical supernovae

    Energy Technology Data Exchange (ETDEWEB)

    Kasen, Daniel Nathan [Univ. of California, Berkeley, CA (United States)

    2004-01-01

    Although we know that many supernovae are aspherical, the exact nature of their geometry is undetermined. Because all the supernovae we observe are too distant to be resolved, the ejecta structure can't be directly imaged, and asymmetry must be inferred from signatures in the spectral features and polarization of the supernova light. The empirical interpretation of this data, however, is rather limited--to learn more about the detailed supernova geometry, theoretical modeling must been undertaken. One expects the geometry to be closely tied to the explosion mechanism and the progenitor star system, both of which are still under debate. Studying the 3-dimensional structure of supernovae should therefore provide new break throughs in our understanding. The goal of this thesis is to advance new techniques for calculating radiative transfer in 3-dimensional expanding atmospheres, and use them to study the flux and polarization signatures of aspherical supernovae. We develop a 3-D Monte Carlo transfer code and use it to directly fit recent spectropolarimetric observations, as well as calculate the observable properties of detailed multi-dimensional hydrodynamical explosion simulations. While previous theoretical efforts have been restricted to ellipsoidal models, we study several more complicated configurations that are tied to specific physical scenarios. We explore clumpy and toroidal geometries in fitting the spectropolarimetry of the Type Ia supernova SN 2001el. We then calculate the observable consequences of a supernova that has been rendered asymmetric by crashing into a nearby companion star. Finally, we fit the spectrum of a peculiar and extraordinarily luminous Type Ic supernova. The results are brought to bear on three broader astrophysical questions: (1) What are the progenitors and the explosion processes of Type Ia supernovae? (2) What effect does asymmetry have on the observational diversity of Type Ia supernovae, and hence their use in cosmology? (3

  10. Aspherical supernovae

    Energy Technology Data Exchange (ETDEWEB)

    Kasen, Daniel Nathan

    2004-05-21

    Although we know that many supernovae are aspherical, the exact nature of their geometry is undetermined. Because all the supernovae we observe are too distant to be resolved, the ejecta structure can't be directly imaged, and asymmetry must be inferred from signatures in the spectral features and polarization of the supernova light. The empirical interpretation of this data, however, is rather limited--to learn more about the detailed supernova geometry, theoretical modeling must been undertaken. One expects the geometry to be closely tied to the explosion mechanism and the progenitor star system, both of which are still under debate. Studying the 3-dimensional structure of supernovae should therefore provide new break throughs in our understanding. The goal of this thesis is to advance new techniques for calculating radiative transfer in 3-dimensional expanding atmospheres, and use them to study the flux and polarization signatures of aspherical supernovae. We develop a 3-D Monte Carlo transfer code and use it to directly fit recent spectropolarimetric observations, as well as calculate the observable properties of detailed multi-dimensional hydrodynamical explosion simulations. While previous theoretical efforts have been restricted to ellipsoidal models, we study several more complicated configurations that are tied to specific physical scenarios. We explore clumpy and toroidal geometries in fitting the spectropolarimetry of the Type Ia supernova SN 2001el. We then calculate the observable consequences of a supernova that has been rendered asymmetric by crashing into a nearby companion star. Finally, we fit the spectrum of a peculiar and extraordinarily luminous Type Ic supernova. The results are brought to bear on three broader astrophysical questions: (1) What are the progenitors and the explosion processes of Type Ia supernovae? (2) What effect does asymmetry have on the observational diversity of Type Ia supernovae, and hence their use in cosmology? (3

  11. Type Ia Supernova Rate Measurements to Redshift 2.5 from Candles: Searching for Prompt Explosions in the Early Universe

    Science.gov (United States)

    Rodney, Steven A.; Riess, Adam G.; Strogler, Louis-Gregory; Dahlen, Tomas; Graur, Or; Casertano, Stefano; Dickinson, Mark E.; Ferguson, Henry C.; Garnavich, Peter; Cenko, Stephen Bradley

    2014-01-01

    The Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) was a multi-cycle treasury program on the Hubble Space Telescope(HST) that surveyed a total area of approx. 0.25 deg(sup 2) with approx.900 HST orbits spread across five fields over three years. Within these survey images we discovered 65 supernovae (SNe) of all types, out to z approx. 2.5. We classify approx. 24 of these as Type Ia SNe (SNe Ia) based on host galaxy redshifts and SN photometry (supplemented by grism spectroscopy of six SNe). Here we present a measurement of the volumetric SN Ia rate as a function of redshift, reaching for the first time beyond z = 2 and putting new constraints on SN Ia progenitor models. Our highest redshift bin includes detections of SNe that exploded when the universe was only approx. 3 Gyr old and near the peak of the cosmic star formation history. This gives the CANDELS high redshift sample unique leverage for evaluating the fraction of SNe Ia that explode promptly after formation (500 Myr). Combining the CANDELS rates with all available SN Ia rate measurements in the literature we find that this prompt SN Ia fraction isfP0.530.09stat0.100.10sys0.26, consistent with a delay time distribution that follows a simplet1power law for all timest40 Myr. However, mild tension is apparent between ground-based low-z surveys and space-based high-z surveys. In both CANDELS and the sister HST program CLASH (Cluster Lensing And Supernova Survey with Hubble), we find a low rate of SNe Ia at z > 1. This could be a hint that prompt progenitors are in fact relatively rare, accounting for only 20 of all SN Ia explosions though further analysis and larger samples will be needed to examine that suggestion.

  12. A search for metal-poor stars pre-enriched by pair-instability supernovae I.A pilot study for target selection from Sloan Digital Sky Survey

    Institute of Scientific and Technical Information of China (English)

    Jing Ren; Norbert Christlieb; Gang Zhao

    2012-01-01

    We report on a pilot study on identifying metal-poor stars pre-enriched by Pair-Instability Supernovae (PISNe).Very massive,first generation (Population Ⅲ) stars (140 M⊙ ≤ M ≤ 260 M⊙) end their lives as PISNe,which have been predicted by theories,but no relics of PISNe have been observed yet.Among the distinct characteristics of the yields of PISNe,as predicted by theoretical calculations,are a strong odd-even effect,and a strong overabundance of Ca with respect to iron and the solar ratio.We use the latter characteristic to identify metal-poor stars in the Galactic halo that have been pre-enriched by PISNe,by comparing metallicites derived from strong,co-added Fe lines detected in low-resolution (i.e.,R = λ/Δλ ~ 2000) spectra of the Sloan Digital Sky Survey (SDSS),with metallicities determined by the SDSS Stellar Parameters Pipeline (SSPP).The latter are based on the strength of the Ca Ⅱ K line and assumptions on the Ca/Fe abundance ratio.Stars are selected as candidates if their metallicity derived from Fe lines is significantly lower than the SSPP metallicities.In a sample of 12 300 stars for which SDSS spectroscopy is available,we have identified 18 candidate stars.Higher resolution and signal-to-noise ratio spectra of these candidates are being obtained with the Very Large Telescope of the European Southern Observatory and the XSHOOTER spectrograph,to determine their abundance patterns,and to verify our selection method.We plan to apply our method to the database of several million stellar spectra to be acquired with the Guo Shou Jing Telescope (LAMOST) in the next five years.

  13. A Search for Neutrinos from the Solar hep Reaction and the DiffuseSupernova Neutrino Background with the Sudbury Neutrino Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Aharmim, B.; Ahmed, S.N.; Anthony, A.E.; Beier, E.W.; Bellerive,A.; Bergevin, M.; Biller, S.D.; Boulay, M.G.; Chan, Y.D.; Chen, M.; Chen,X.; Cleveland, B.T.; Cox, G.A.; Currat, C.A.; Dai, X.; Dalnoki-Veress,F.; Deng, H.; Detwiler, J.; DiMarco, M.; Doe, P.J.; Doucas, G.; Drouin,P.-L.; Duncan, F.A.; Dunford, M.; Dunmore, J.A.; Earle, E.D.; Evans,H.C.; Ewan, G.T.; Farine, J.; Fergani, H.; Fleurot, F.; Ford, R.J.; Formaggio, J.A.; Gagnon, N.; Goon, J.T.M.; Graham, K.; Guillian, E.; Hahn, R.L.; Hallin, A.L.; Hallman, E.D.; Harvey, P.J.; Hazama, R.; Heeger, K.M.; Heintzelman, W.J.; Heise, J.; Helmer, R.L.; Hemingway,R.J.; Henning, R.; Hime, A.; Howard, C.; Howe, M.A.; Huang, M.; Jagam,P.; Jelley, N.A.; Klein, J.R.; Kormos, L.L.; Kos, M.; Krueger, A.; Kraus,C.; Krauss, C.B.; Kutter, T.; Kyba, C.C.M.; Labranche, H.; Lange, R.; Law, J.Lawson.I.T.; Lesko, K.T.; Leslie, J.R.; Loach, J.C.; Luoma, S.; MacLellan, R.; Majerus, S.; Mak, H.B.; Maneira, J.; Marino, A.D.; Martin,R.; McCauley, N.; McDonald, A.B.; McGee, S.; Mifflin, C.; Miknaitis,K.K.S.; Miller, M.L.; Monreal, B.; Nickel, B.G.; Noble, A.J.; Norman,E.B.; Oblath, N.S.; Okada, C.E.; O' Keeffe, H.M.; Orebi Gann, G.D.; Oser,S.M.; Ott, R.; Peeters, S.J.M.; Poon, A.W.P.; Prior, G.; Rielage, K.; Robertson, B.C.; Robertson, R.G.H.; Rollin, E.; Schwendener, M.H.; Secrest, J.A.; Seibert, S.R.; Simard, O.; Sims, C.J.; Sinclair, D.; Skensved, P.; Stokstad, R.G.; Stonehill, L.C.; Tesic, G.; Tolich, N.; Tsui, T.; Van Berg, R.; Van de Water, R.G.; VanDevender, B.A.; Virtue,C.J.; Walker, T.J.; Wall, B.L.; Waller, D.; Wan Chan Tseung, H.; Wark,D.L.; Wendland, J.; West, N.; Wilkerson, J.F.; Wilson, J.R.; Wouters,J.M.; Wright, A.; Yeh, M.; Zhang, F.; Zuber, K.

    2006-08-01

    A search has been made for neutrinos from the hep reactionin the Sun and from the diffuse supernova neutrino background (DSNB)using data collected during the first operational phase of the SudburyNeutrino Observatory, with an exposure of 0.65 kilotonne-years. For thehep neutrino search, two events are observed in the effective electronenergy range of 14.3 MeV

  14. Cosmology with Superluminous Supernovae

    CERN Document Server

    Scovacricchi, Dario; Bacon, David; Sullivan, Mark; Prajs, Szymon

    2015-01-01

    We predict cosmological constraints for forthcoming surveys using Superluminous Supernovae (SLSNe) as standardisable candles. Due to their high peak luminosity, these events can be observed to high redshift (z~3), opening up new possibilities to probe the Universe in the deceleration epoch. We describe our methodology for creating mock Hubble diagrams for the Dark Energy Survey (DES), the "Search Using DECam for Superluminous Supernovae" (SUDSS) and a sample of SLSNe possible from the Large Synoptic Survey Telescope (LSST), exploring a range of standardisation values for SLSNe. We include uncertainties due to gravitational lensing and marginalise over possible uncertainties in the magnitude scale of the observations (e.g. uncertain absolute peak magnitude, calibration errors). We find that the addition of only ~100 SLSNe from SUDSS to 3800 Type Ia Supernovae (SNe Ia) from DES can improve the constraints on w and Omega_m by at least 20% (assuming a flat wCDM universe). Moreover, the combination of DES SNe Ia a...

  15. Type Ia Supernova Rate Measurements to Redshift 2.5 from CANDELS : Searching for Prompt Explosions in the Early Universe

    CERN Document Server

    Rodney, Steven A; Strolger, Louis-Gregory; Dahlen, Tomas; Graur, Or; Casertano, Stefano; Dickinson, Mark E; Ferguson, Henry C; Garnavich, Peter; Hayden, Brian; Jha, Saurabh W; Jones, David O; Kirshner, Robert P; Koekemoer, Anton M; McCully, Curtis; Mobasher, Bahram; Patel, Brandon; Weiner, Benjamin J; Cenko, Bradley S; Clubb, Kelsey I; Cooper, Michael; Filippenko, Alexei V; Frederiksen, Teddy F; Hjorth, Jens; Leibundgut, Bruno; Matheson, Thomas; Nayyeri, Hooshang; Penner, Kyle; Trump, Jonathan; Silverman, Jeffrey M; U, Vivian; Bostroem, K Azalee; Challis, Peter; Rajan, Abhijith; Wolff, Schuyler; Faber, S M; Grogin, Norman A; Kocevski, Dale

    2014-01-01

    The Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) was a multi-cycle treasury program on the Hubble Space Telescope (HST) that surveyed a total area of ~0.25 deg^2 with ~900 HST orbits spread across 5 fields over 3 years. Within these survey images we discovered 65 supernovae (SN) of all types, out to z~2.5. We classify ~24 of these as Type Ia SN (SN Ia) based on host galaxy redshifts and SN photometry (supplemented by grism spectroscopy of 6 SN). Here we present a measurement of the volumetric SN Ia rate as a function of redshift, reaching for the first time beyond z=2 and putting new constraints on SN Ia progenitor models. Our highest redshift bin includes detections of SN that exploded when the universe was only ~3 Gyr old and near the peak of the cosmic star formation history. This gives the CANDELS high redshift sample unique leverage for evaluating the fraction of SN Ia that explode promptly after formation (40 Myr. However, a mild tension is apparent between ground-based low-z...

  16. Searching for swept-up Hydrogen and Helium in the late-time spectra of 11 nearby Type Ia supernovae

    CERN Document Server

    Maguire, Kate; Sullivan, Mark; Mazzali, Paolo A

    2015-01-01

    The direct detection of a stellar system that explodes as a Type Ia supernova (SN Ia) has not yet been successful. Various indirect methods have been used to investigate SN Ia progenitor systems but none have produced conclusive results. A prediction of single-degenerate models is that H- (or He-) rich material from the envelope of the companion star should be swept up by the SN ejecta in the explosion. Seven SNe Ia have been analysed to date looking for signs of H-rich material in their late-time spectra and none were detected. We present results from new late-time spectra of 11 SNe Ia obtained at the VLT using XShooter and FORS2. We present the tentative detection of H-alpha emission for SN 2013ct, corresponding to ~0.007 Msun of stripped/ablated companion star material (under the assumptions of the spectral modelling). This mass is significantly lower than expected for single-degenerate scenarios, suggesting that >0.1 Msun of H-rich is present but not observed. We do not detect H-alpha emission in the othe...

  17. Radio Supernovae in the Local Universe

    CERN Document Server

    Kamble, Atish; Berger, Edo; Zauderer, Ashley; Chakraborti, Sayan; Williams, Peter

    2014-01-01

    In the last three decades, about 50 radio supernovae have been detected as a result of targeted searches of optically discovered supernovae in the local universe. Despite this relatively small number some diversity among them has already been identified which is an indication of the underlying richness of radio supernovae waiting to be discovered. For example, comparison of star formation and supernova discovery rate imply that as many as half of the supernovae remain undetected in the traditional optical searches, either because of intrinsic dimness or due to dust obscuration. This has far reaching consequences to the models of stellar and galaxy evolution. A radio sky survey would be ideal to uncover larger supernova population. Transient radio sky would benefit significantly from such a survey. With the advent of advanced gravitational wave detectors a new window is set to open on the local Universe. Localization of these gravitational detectors is poor to identify electromagnetic counterparts of the gravi...

  18. The ESSENCE Supernova Survey: Survey Optimization, Observations, and Supernova Photometry

    Energy Technology Data Exchange (ETDEWEB)

    Miknaitis, Gajus; Pignata, G.; Rest, A.; Wood-Vasey, W.M.; Blondin, S.; Challis, P.; Smith, R.C.; Stubbs, C.W.; Suntzeff, N.B.; Foley, R.J.; Matheson, T.; Tonry, J.L.; Aguilera, C.; Blackman, J.W.; Becker, A.C.; Clocchiatti, A.; Covarrubias, R.; Davis, T.M.; Filippenko, A.V.; Garg, A.; Garnavich, P.M.; /Fermilab /Chile U., Catolica /Cerro-Tololo

    2007-01-08

    We describe the implementation and optimization of the ESSENCE supernova survey, which we have undertaken to measure the equation of state parameter of the dark energy. We present a method for optimizing the survey exposure times and cadence to maximize our sensitivity to the dark energy equation of state parameter w = P/{rho}c{sup 2} for a given fixed amount of telescope time. For our survey on the CTIO 4m telescope, measuring the luminosity distances and redshifts for supernovae at modest redshifts (z {approx} 0.5 {+-} 0.2) is optimal for determining w. We describe the data analysis pipeline based on using reliable and robust image subtraction to find supernovae automatically and in near real-time. Since making cosmological inferences with supernovae relies crucially on accurate measurement of their brightnesses, we describe our efforts to establish a thorough calibration of the CTIO 4m natural photometric system. In its first four years, ESSENCE has discovered and spectroscopically confirmed 102 type Ia SNe, at redshifts from 0.10 to 0.78, identified through an impartial, effective methodology for spectroscopic classification and redshift determination. We present the resulting light curves for the all type Ia supernovae found by ESSENCE and used in our measurement of w, presented in Wood-Vasey et al. (2007).

  19. The search for gamma radiation from supernova 1987A in an experiment aboard the Salut-7/Cosmos-1686 complex

    Science.gov (United States)

    Bachilova, R. N.; Bloch, G. M.; Pankov, V. M.; Prohin, V. L.; Rutkovsky, A. I.; Rumin, S. P.

    1988-07-01

    Gamma-quanta flux measurements were carried out during February-October 1987 in a search for radiation from SN 1987A. The time dependence of the mean monthly gamma-quanta flux measured with the Nega telescope at an altitude of 500 km in the equatorial region is analyzed. The upper limit of the gamma-quanta flux is determined to be 1.5 x 10 to the -6th/sq cm s keV on the 3-sigma level for the 1.5-4.4 MeV energy interval.

  20. Leadership Pipeline

    DEFF Research Database (Denmark)

    Elmholdt, Claus Westergård

    2012-01-01

    Artiklen analyserer grundlaget for Leadership Pipeline modellen med henblik på en vurdering af substansen bag modellen, og perspektiverne for generalisering af modellen til en dansk organisatorisk kontekst.......Artiklen analyserer grundlaget for Leadership Pipeline modellen med henblik på en vurdering af substansen bag modellen, og perspektiverne for generalisering af modellen til en dansk organisatorisk kontekst....

  1. Photometric Supernova Classification With Machine Learning

    CERN Document Server

    Lochner, Michelle; Peiris, Hiranya V; Lahav, Ofer; Winter, Max K

    2016-01-01

    Automated photometric supernova classification has become an active area of research in recent years in light of current and upcoming imaging surveys such as the Dark Energy Survey (DES) and the Large Synoptic Telescope (LSST), given that spectroscopic confirmation of type for all supernovae discovered with these surveys will be impossible. Here, we develop a multi-faceted classification pipeline, combining existing and new approaches. Our pipeline consists of two stages: extracting descriptive features from the light curves and classification using a machine learning algorithm. Our feature extraction methods vary from model-dependent techniques, namely SALT2 fits, to more independent techniques fitting parametric models to curves, to a completely model-independent wavelet approach. We cover a range of representative machine learning algorithms, including naive Bayes, k-nearest neighbors, support vector machines, artificial neural networks and boosted decision trees. We test the pipeline on simulated multi-ba...

  2. Smoking Supernovae

    CERN Document Server

    Gomez, H L; Dunne, L

    2007-01-01

    The question "Are supernovae important sources of dust?" is a contentious one. Observations with the Infrared Astronomical Satellite (IRAS) and the Infrared Space Observatory (ISO) only detected very small amounts of hot dust in supernova remnants. Here, we review observations of two young Galactic remnants with the Submillimetre Common User Bolometer Array (SCUBA), which imply that large quantities of dust are produced by supernovae. The association of dust with the Cassiopeia A remnant is in question due to the contamination of foreground material. In this article, we compare the emission from cold dust with CO emission towards Kepler's supernova remnant. We detect very little CO at the location of the submillimetre peaks. A comparison of masses from the CO and the dust clouds are made, and we estimate the 3 sigma upper limit on the gas-to-dust ratios to range from 25 - 65 suggesting that we cannot yet rule out freshly-formed or swept up circumstellar dust in Kepler's supernova remnant.

  3. Search for Orbital Motion of the Pulsar 4U 1626-67: Candidate for a Neutron Star with a Supernova Fall-back Accretion Disk

    Indian Academy of Sciences (India)

    Chetana Jain; Biswajit Paul; Kaustubh Joshi; Anjan Dutta; Harsha Raichur

    2007-12-01

    We report here results from a new search for orbital motion of the accretion powered X-ray pulsar 4U 1626-67 using two different analysis techniques. X-ray light curve obtained with the Proportional Counter Array of the Rossi X-ray Timing Explorer during a long observation carried out in February 1996, was used in this work. The spin period and the local period derivative were first determined from the broad 2–60 keV energy band light curve and these were used for all subsequent timing analysis. In the first technique, the orbital phase dependent pulse arrival times were determined for different trial orbital periods in the range of 500 to 10,000 s. We have determined a 3 upper limit of 13 lt-ms on the projected semimajor axis of the orbit of the neutron star for most of the orbital period range, while in some narrow orbital period ranges, covering about 10% of the total orbital period range, it is 20 lt-ms. In the second method, we have measured the pulse arrival times at intervals of 100 s over the entire duration of the observation. The pulse arrival time data were used to put an upper limit on any periodic arrival time delay using the Lomb–Scargle periodogram. We have obtained a similar upper limit of 10 lt-ms using the second method over the orbital period range of 500–10,000 s. This puts very stringent upper limits for the mass of the compact object except for the unlikely case of a complete face-on orientation of the binary system with respect to our line-of-sight. In the light of this measurement and the earlier reports, we discuss the possibility of this system being a neutron star with a supernovae fall-back accretion disk.

  4. Automated Supernova Discovery (Abstract)

    Science.gov (United States)

    Post, R. S.

    2015-12-01

    (Abstract only) We are developing a system of robotic telescopes for automatic recognition of Supernovas as well as other transient events in collaboration with the Puckett Supernova Search Team. At the SAS2014 meeting, the discovery program, SNARE, was first described. Since then, it has been continuously improved to handle searches under a wide variety of atmospheric conditions. Currently, two telescopes are used to build a reference library while searching for PSN with a partial library. Since data is taken every night without clouds, we must deal with varying atmospheric and high background illumination from the moon. Software is configured to identify a PSN, reshoot for verification with options to change the run plan to acquire photometric or spectrographic data. The telescopes are 24-inch CDK24, with Alta U230 cameras, one in CA and one in NM. Images and run plans are sent between sites so the CA telescope can search while photometry is done in NM. Our goal is to find bright PSNs with magnitude 17.5 or less which is the limit of our planned spectroscopy. We present results from our first automated PSN discoveries and plans for PSN data acquisition.

  5. Supernova 1987A: The Supernova of a Lifetime

    Science.gov (United States)

    Kirshner, Robert

    2017-01-01

    Supernova 1987A, the brightest supernova since Kepler's in 1604, was detected 30 years ago at a distance of 160 000 light years in the Large Magellanic Cloud, a satellite galaxy of the Milky Way. Visible with the naked eye and detected with the full range of technology constructed since Kepler's time, SN 1987A has continued to be a rich source of empirical information to help understand supernova explosions and their evolution into supernova remnants. While the light output has faded by a factor of 10 000 000 over those 30 years, instrumentation, like the Hubble Space Telescope, the Chandra X-ray Observatory, and the Atacama Large Millimeter Array has continued to improve so that this supernova continues to be visible in X-rays, ultraviolet light, visible light, infrared light and in radio emission. In this review, I will sketch what has been learned from these observations about the pre-supernova star and its final stages of evolution, the explosion physics, the energy sources for emission, and the shock physics as the expanding debris encounters the circumstellar ring that was created about 20 000 years before the explosion. Today, SN 1987A is making the transition to a supernova remnant- the energetics are no longer dominated by the radioactive elements produced in the explosion, but by the interaction of the expanding debris with the surrounding gas. While we are confident that the supernova explosion had its origin in gravitational collapse, careful searches for a compact object at the center of the remnant place upper limits of a few solar luminosities on that relic. Support for HST GO programs 13401 and 13405 was provided by NASA through grants from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

  6. SOUSA's Swift Supernova Siblings

    CERN Document Server

    Brown, Peter J

    2015-01-01

    Swift has observed over three hundred supernovae in its first ten years. Photometry from the Ultra-Violet Optical Telescope (UVOT) is being compiled in the Swift Optical/Ultraviolet Supernovae Archive (SOUSA). The diversity of supernovae leads to a wide dynamic range of intrinsic properties. The intrinsic UV brightness of supernovae as a function of type and epoch allows one to understand the distance ranges at which Swift can reliably detect supernovae. The large Swift sample also includes supernovae from the same galaxy as other Swift supernovae. Through the first ten years, these families include 34 supernovae from 16 host galaxies (two galaxies have each hosted three Swift supernovae).

  7. Simulating Supernova Light Curves

    Energy Technology Data Exchange (ETDEWEB)

    Even, Wesley Paul [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dolence, Joshua C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-05-05

    This report discusses supernova light simulations. A brief review of supernovae, basics of supernova light curves, simulation tools used at LANL, and supernova results are included. Further, it happens that many of the same methods used to generate simulated supernova light curves can also be used to model the emission from fireballs generated by explosions in the earth’s atmosphere.

  8. Photometric classification of type Ia supernovae in the SuperNova Legacy Survey with supervised learning

    CERN Document Server

    Möller, A; Leloup, C; Neveu, J; Palanque-Delabrouille, N; Rich, J; Carlberg, R; Lidman, C; Pritchet, C

    2016-01-01

    In the era of large astronomical surveys, photometric classification of supernovae (SNe) has become an important research field due to limited spectroscopic resources for candidate follow-up and classification. In this work, we present a method to photometrically classify type Ia supernovae based on machine learning with redshifts that are derived from the SN light-curves. This method is implemented on real data from the SNLS deferred pipeline, a purely photometric pipeline that identifies SNe Ia at high-redshifts ($0.2Supernova Legacy Survey (SNLS), which contains large spectroscopically and photometrically classified type Ia sa...

  9. The dark energy survey Y1 supernova search: Survey strategy compared to forecasts and the photometric type Is SN volumetric rate

    Science.gov (United States)

    Fischer, John Arthur

    For 70 years, the physics community operated under the assumption that the expansion of the Universe must be slowing due to gravitational attraction. Then, in 1998, two teams of scientists used Type Ia supernovae to discover that cosmic expansion was actually acceler- ating due to a mysterious "dark energy." As a result, Type Ia supernovae have become the most cosmologically important transient events in the last 20 years, with a large amount of effort going into their discovery as well as understanding their progenitor systems. One such probe for understanding Type Ia supernovae is to use rate measurements to de- termine the time delay between star formation and supernova explosion. For the last 30 years, the discovery of individual Type Ia supernova events has been accelerating. How- ever, those discoveries were happening in time-domain surveys that probed only a portion of the redshift range where expansion was impacted by dark energy. The Dark Energy Survey (DES) is the first project in the "next generation" of time-domain surveys that will discovery thousands of Type Ia supernovae out to a redshift of 1.2 (where dark energy be- comes subdominant) and DES will have better systematic uncertainties over that redshift range than any survey to date. In order to gauge the discovery effectiveness of this survey, we will use the first season's 469 photometrically typed supernovee and compare it with simulations in order to update the full survey Type Ia projections from 3500 to 2250. We will then use 165 of the 469 supernovae out to a redshift of 0.6 to measure the supernovae rate both as a function of comoving volume and of the star formation rate as it evolves with redshift. We find the most statistically significant prompt fraction of any survey to date (with a 3.9? prompt fraction detection). We will also reinforce the already existing tension in the measurement of the delayed fraction between high (z > 1.2) and low red- shift rate measurements, where we find no

  10. A unified explanation for the supernova rate-galaxy mass dependency based on supernovae discovered in Sloan galaxy spectra

    CERN Document Server

    Graur, Or; Modjaz, Maryam

    2014-01-01

    Using a method to discover and classify supernovae (SNe) in galaxy spectra, we detect 91 Type Ia SNe (SNe Ia) and 16 Type II SNe (SNe II) among ~740,000 galaxies of all types and ~215,000 star-forming galaxies without active galactic nuclei, respectively, in Data Release 9 of the Sloan Digital Sky Survey. Of these SNe, 22 SNe Ia and 8 SNe II are new discoveries reported here for the first time. We use our SN samples to measure SN rates per unit mass as a function of galaxy stellar mass, star-formation rate (SFR), and specific SFR (sSFR), as derived by the MPA-JHU Galspec pipeline. We confirm the rate-mass correlations, first discovered by the Lick Observatory Supernova Search, for both SNe Ia and SNe II at median redshifts of ~0.1 and ~0.075, respectively. The mass-normalized SN Ia and SN II rates, averaged over all masses and redshifts in their respective galaxy samples, are 0.10 +/- 0.01 (stat) +/- 0.01 (sys) X 10^-12 Msol^-1 yr^-1 and 0.52 +0.16 -0.13 (stat) +0.02 -0.05 (sys) X 10^-12 Msol^-1 yr^-1, respec...

  11. X-Ray Supernovae

    CERN Document Server

    Immler, S; Immler, Stefan; Lewin, Walter H.G.

    2002-01-01

    We present a review of X-ray observations of supernovae (SNe). By observing the (~0.1--100 keV) X-ray emission from young SNe, physical key parameters such as the circumstellar matter (CSM) density, mass-loss rate of the progenitor and temperature of the outgoing and reverse shock can be derived as a function of time. Despite intensive search over the last ~25 years, only 15 SNe have been detected in X-rays. We review the individual X-ray observations of these SNe and discuss their implications as to our understanding of the physical processes giving rise to the X-ray emission.

  12. Leadership Pipeline

    DEFF Research Database (Denmark)

    Elmholdt, Claus Westergård

    2013-01-01

    I artiklen undersøges det empiriske grundlag for Leader- ship Pipeline. Først beskrives Leadership Pipeline modellen om le- delsesbaner og skilleveje i opadgående transitioner mellem orga- nisatoriske ledelsesniveauer (Freedman, 1998; Charan, Drotter and Noel, 2001). Dernæst sættes fokus på det...... forholdet mellem kontinuitet- og diskontinuitet i ledel- seskompetencer på tværs af organisatoriske niveauer præsenteres og diskuteres. Afslutningsvis diskuteres begrænsningerne i en kompetencebaseret tilgang til Leadership Pipeline, og det foreslås, at succesfuld ledelse i ligeså høj grad afhænger af...

  13. Leadership Pipeline

    DEFF Research Database (Denmark)

    Elmholdt, Claus Westergård

    2013-01-01

    I artiklen undersøges det empiriske grundlag for Leader- ship Pipeline. Først beskrives Leadership Pipeline modellen om le- delsesbaner og skilleveje i opadgående transitioner mellem orga- nisatoriske ledelsesniveauer (Freedman, 1998; Charan, Drotter and Noel, 2001). Dernæst sættes fokus på det...... forholdet mellem kontinuitet- og diskontinuitet i ledel- seskompetencer på tværs af organisatoriske niveauer præsenteres og diskuteres. Afslutningsvis diskuteres begrænsningerne i en kompetencebaseret tilgang til Leadership Pipeline, og det foreslås, at succesfuld ledelse i ligeså høj grad afhænger af...

  14. Supernova Forensics

    Science.gov (United States)

    Soderberg, Alicia M.

    2014-01-01

    For decades, the study of stellar explosions -- supernovae -- have focused almost exclusively on the strong optical emission that dominates the bolometric luminosity in the days following the ultimate demise of the star. Yet many of the leading breakthroughs in our understanding of stellar death have been enabled by obtaining data at other wavelengths. For example, I have shown that 1% of all supernovae give rise to powerful relativistic jets, representing the biggest bangs in the Universe since the Big Bang. My recent serendipitous X-ray discovery of a supernova in the act of exploding (“in flagrante delicto”) revealed a novel technique to discover new events and provide clues on the shock physics at the heart of the explosion. With the advent of sensitive new radio telescopes, my research group combines clues from across the electromagnetic spectrum (radio to gamma-ray), leading us to a holistic study of stellar death, the physics of the explosions, and their role in fertilizing the Universe with new elements, by providing the community with cosmic autopsy reports.

  15. Matter mixing in aspherical core-collapse supernovae: a search for possible conditions for conveying $^{56}$Ni into high velocity regions

    CERN Document Server

    Ono, Masaomi; Ito, Hirotaka; Lee, Shiu-Hang; Mao, Jirong; Hashimoto, Masa-aki; Tolstov, Alexey

    2013-01-01

    We perform two-dimensional axisymmetric hydrodynamic simulations of matter mixing in aspherical core-collapse supernova explosions of a 16.3 $M_{\\odot}$ star with a compact hydrogen envelope. Observations of SN 1987A have provided evidence that $^{56}$Ni synthesized by explosive nucleosynthesis is mixed into fast moving matter ($\\gtrsim$ 3,500 km s$^{-1}$) in the exploding star. In order to clarify the key conditions for reproducing such high velocity of $^{56}$Ni, we revisit matter mixing in aspherical core-collapse supernova explosions. Explosions are initiated artificially by injecting thermal and kinetic energies around the interface between the iron core and the silicon-rich layer. Perturbations of 5% or 30% amplitude in the radial velocities are introduced at several points in time. We found that no high velocity $^{56}$Ni can be obtained if we consider bipolar explosions with perturbations (5% amplitude) of pre-supernova origins. If large perturbations (30% amplitude) are introduced or exist due to som...

  16. Anchor Loads on Pipelines

    OpenAIRE

    Wei, Ying

    2015-01-01

    Anchor hooking on a subsea pipeline has been investigated in this thesis. Anchor loads on pipelines is in general a rarely occurring event, however, the severity when it occurs could easily jeopardize the integrity of any pipeline. It is considered as an accidental load in the design of pipelines. Pipeline Loads, limit state criteria and anchor categories are defined by the DNV standards. For pipeline, DNV-OS-F101 (08.2012), Submarine Pipeline Systems is adopted. Offshore standard DNV-RP...

  17. Echoes from Ancient supernovae in the Large Magellanic Cloud

    Energy Technology Data Exchange (ETDEWEB)

    Rest, A; Suntzeff, N B; Olsen, K; Prieto, J L; Smith, R C; Welch, D L; Becker, A; Bergmann, M; Clocchiatti, A; Cook, K; Garg, A; Huber, M; Miknaitis, G; Minniti, D; Nikolaev, S; Stubbs, C

    2005-06-15

    In principle, historical supernovae could still be visible as scattered-light echoes even centuries later [1, 2]. Searches for surface brightness variations using photographic plates have not recovered any echoes in the regions of historical Galactic supernovae [3]. Using differenced images, our SuperMACHO collaboration has discovered three faint new variable surface brightness complexes with high apparent proper motion pointing back to well-defined positions in the Large Magellanic Cloud (LMC). These correspond to three of the six smallest (and likely youngest) supernova remnants believed to be due to thermonuclear (Type Ia) supernovae [4]. A lower limit to the age of these remnants and echoes is 200 years given the lack of any reported LMC supernovae until 1987. The discovery of historical supernova echoes in the LMC suggests that similar echoes for Galactic supernovae such as Tycho, Kepler, Cas A, or SN1006 could be visible using standard image differencing techniques.

  18. Detection of Supernova Neutrinos

    OpenAIRE

    Bekman, B.; Holeczek, J.; Kisiel, J4

    2004-01-01

    Matter effects on neutrino oscillations in both, a supernova and the Earth, change the observed supernova neutrino spectra. We calculate the expected number of supernova neutrino interactions for ICARUS, SK and SNO detectors as a function of the distance which they traveled in the Earth. Calculations are performed for supernova type II at 10kpc from the Earth, using standard supernova neutrino fluxes described by thermal Fermi--Dirac distributions and the PREM I Earth matter density profile.

  19. Type Ia supernova rate at $z \\sim 0.1$

    CERN Document Server

    Hardin, D P; Alard, C; Albert, J N; Amadon, A; Andersen, J; Ansari, R; Aubourg, E; Bareyre, P; Bauer, F; Beaulieu, J P; Blanc, G; Bouquet, A; Char, S; Charlot, X; Couchot, F; Coutures, C; Derue, F; Ferlet, R; Glicenstein, J F; Goldman, B; Gould, A; Graff, D; Gros, M H; Haïssinski, J; Hamilton, J C; Kat, J; Kim, A; Lasserre, T; Lesquoy, E; Loup, C; Magneville, C; Mansoux, B; Marquette, J B; Maurice, E; Milshtein, A I; Moniez, M; Palanque-Delabrouille, Nathalie; Perdereau, O; Prévôt, L; Regnault, N; Rich, J; Spiro, Michel; Vidal-Madjar, A; Vigroux, L; Zylberajch, S

    2000-01-01

    We present the EROS nearby supernova ($z \\sim 0.02 - 0.2$) search and the analysis of the first year of data (1997). A total of 80 square degrees were surveyed. Eight supernov{\\ae} were detected, four of which were spectroscopically identified as type Ia supernov{\\ae}. The search efficiency was determined with a Monte-Carlo simulation taking into account the efficiencies for both supernova detection and host galaxy identification. Assuming that for a given galaxy the supernova rate is proportional to the galactic luminosity, we compute a type Ia supernova explosion rate of: ${\\cal R} = 0.44 {}_{-0.21}^{+0.35} {}_{-0.07}^{+0.13} h^2: / 10^{10} \\lbsun / 100 {\\rm yrs}$ at an average redshift of $\\sim 0.1$ where the errors are respectively statistical and systematic (type misidentification included).

  20. Cosmology with superluminous supernovae

    Science.gov (United States)

    Scovacricchi, D.; Nichol, R. C.; Bacon, D.; Sullivan, M.; Prajs, S.

    2016-02-01

    We predict cosmological constraints for forthcoming surveys using superluminous supernovae (SLSNe) as standardizable candles. Due to their high peak luminosity, these events can be observed to high redshift (z ˜ 3), opening up new possibilities to probe the Universe in the deceleration epoch. We describe our methodology for creating mock Hubble diagrams for the Dark Energy Survey (DES), the `Search Using DECam for Superluminous Supernovae' (SUDSS) and a sample of SLSNe possible from the Large Synoptic Survey Telescope (LSST), exploring a range of standardization values for SLSNe. We include uncertainties due to gravitational lensing and marginalize over possible uncertainties in the magnitude scale of the observations (e.g. uncertain absolute peak magnitude, calibration errors). We find that the addition of only ≃100 SLSNe from SUDSS to 3800 Type Ia Supernovae (SNe Ia) from DES can improve the constraints on w and Ωm by at least 20 per cent (assuming a flat wCDM universe). Moreover, the combination of DES SNe Ia and 10 000 LSST-like SLSNe can measure Ωm and w to 2 and 4 per cent, respectively. The real power of SLSNe becomes evident when we consider possible temporal variations in w(a), giving possible uncertainties of only 2, 5 and 14 per cent on Ωm, w0 and wa, respectively, from the combination of DES SNe Ia, LSST-like SLSNe and Planck. These errors are competitive with predicted Euclid constraints, indicating a future role for SLSNe for probing the high-redshift Universe.

  1. Intermediate Palomar Transient Factory: Realtime Image Subtraction Pipeline

    CERN Document Server

    Cao, Yi; Kasliwal, Mansi M

    2016-01-01

    A fast-turnaround pipeline for realtime data reduction plays an essential role in discovering and permitting follow-up observations to young supernovae and fast-evolving transients in modern time-domain surveys. In this paper, we present the realtime image subtraction pipeline in the intermediate Palomar Transient Factory. By using high-performance computing, efficient database, and machine learning algorithms, this pipeline manages to reliably deliver transient candidates within ten minutes of images being taken. Our experience in using high performance computing resources to process big data in astronomy serves as a trailblazer to dealing with data from large-scale time-domain facilities in near future.

  2. Search for broad absorption lines in spectra of stars in the field of supernova remnant RX J0852.0-4622 (Vela Jr.)

    CERN Document Server

    Iyudin, A F; Chugai, N N; Greiner, J; Axelsson, M; Larsson, S; Ryabchikova, T A

    2010-01-01

    Supernova remnant (SNR) RX J0852.0-4622 is one of the youngest and is most likely the closest among known galactic supernova remnants (SNRs). It was detected in X-rays, the 44Ti gamma-line, and radio. We obtain and analyze medium-resolution spectra of 14 stars in the direction towards the SNR RX J0852.0-4622 in an attempt to detect broad absorption lines of unshocked ejecta against background stars. Spectral synthesis is performed for all the stars in the wavelength range of 3740-4020AA to extract the broad absorption lines of Ca II related to the SNR RX J0852.0-4622. We do not detect any broad absorption line and place a 3-sigma upper limit on the relative depths of <0.04 for the broad Ca II absorption produced by the SNR. We detect narrow low and high velocity absorption components of Ca II. High velocity |V(LSR)|=100-140 km/s components are attributed to radiative shocks in clouds engulfed by the old Vela SNR. The upper limit to the absorption line strength combined with the width and flux of the 44Ti g...

  3. Diffuse supernova neutrinos at underground laboratories

    Science.gov (United States)

    Lunardini, Cecilia

    2016-06-01

    I review the physics of the Diffuse Supernova Neutrino flux (or Background, DSNB), in the context of future searches at the next generation of neutrino observatories. The theory of the DSNB is discussed in its fundamental elements, namely the cosmological rate of supernovae, neutrino production inside a core collapse supernova, redshift, and flavor oscillation effects. The current upper limits are also reviewed, and results are shown for the rates and energy distributions of the events expected at future liquid argon and liquid scintillator detectors of O(10) kt mass, and water Cherenkov detectors up to a 0.5 Mt mass. Perspectives are given on the significance of future observations of the DSNB, both at the discovery and precision phases, for the investigation of the physics of supernovae and of the properties of the neutrino.

  4. Luminous Supernovae

    CERN Document Server

    Gal-Yam, Avishay

    2012-01-01

    Supernovae (SNe), the luminous explosions of stars, were observed since antiquity, with typical peak luminosity not exceeding 1.2x10^{43} erg/s (absolute magnitude >-19.5 mag). It is only in the last dozen years that numerous examples of SNe that are substantially super-luminous (>7x10^{43} erg/s; <-21 mag absolute) were well-documented. Reviewing the accumulated evidence, we define three broad classes of super-luminous SN events (SLSNe). Hydrogen-rich events (SLSN-II) radiate photons diffusing out from thick hydrogen layers where they have been deposited by strong shocks, and often show signs of interaction with circumstellar material. SLSN-R, a rare class of hydrogen-poor events, are powered by very large amounts of radioactive 56Ni and arguably result from explosions of very massive stars due to the pair instability. A third, distinct group of hydrogen-poor events emits photons from rapidly-expanding hydrogen-poor material distributed over large radii, and are not powered by radioactivity (SLSN-I). Thes...

  5. More Supernova Surprises

    Science.gov (United States)

    2010-09-24

    SEP 2010 2. REPORT TYPE 3. DATES COVERED 00-00-2010 to 00-00-2010 4. TITLE AND SUBTITLE More Supernova Surprises 5a. CONTRACT NUMBER 5b. GRANT...PERSPECTIVES More Supernova Surprises ASTRONOMY J. Martin Laming Spectroscopic observations of the supernova SN1987A are providing a new window into high...a core-collapse supernova ) have stretched and motivated research that has expanded our knowledge of astrophysics. The brightest such event in

  6. SNO and Supernovae

    CERN Document Server

    Virtue, C J

    2001-01-01

    The Sudbury Neutrino Observatory (SNO) has unique capabilities as a supernova detector. In the event of a galactic supernova there are opportunities, with the data that SNO would collect, to constrain certain intrinsic neutrino properties significantly, to test details of the various models of supernova dynamics, and to provide prompt notification to the astronomical community through the Supernova Early Warning System (SNEWS). This paper consists of a discussion of these opportunities illustrated by some preliminary Monte Carlo results.

  7. Spectroscopic observations of eight supernovae at intermediate redshift

    CERN Document Server

    Balland, C; Amanullah, R; Astier, Pierre; Fabbro, S; Folatelli, G; Garavini, G; Goobar, A; Hardin, D; Irwin, M J; McMahon, R G; Mourão, A M; Nobili, S; Pain, R; Pascoal, R; Raux, J; Sainton, G; Schahmaneche, K; Walton, N A

    2007-01-01

    We present spectra of six Type Ia and two Type II supernovae obtained in June 2002 at the William Herschel Telescope during a search for Type Ia supernovae (SNIa) at intermediate redshift. Supernova type identification and phase determination are performed using a fitting technique based on a Xi2 minimization against a series of model templates. The spectra range from z=0.033 to z=0.328, including one spectroscopically underluminous SNIa at z=0.033. This set of spectra significantly increases the sample of well-observed type SNIa supernovae available in the range 0.15< z <0.35. Together with the twelve supernovae observed by our team in 1999 in the same redshift range, they form an homogeneous sample of seventeen type Ia supernovae with comparable signal-to-noise ratio and regular phase sampling in a still largely unexplored region of the redshift space.

  8. A Comprehensive Investigation Into Modeling Supernovae Spectra

    Science.gov (United States)

    Hillier, Desmond

    Supernovae are a rich source of information. By studying their light curves and spectra we gain insights into stellar evolution, the nature of the progenitor star, surface abundances at the time of the explosion, whether previous mass-loss episodes have occurred, the physics of the explosion including the amount and type of elements synthesized, and whether the explosion has produced significant mixing between shells of different chemical composition. To maximize the information that can be gleaned from observations of supernovae it is essential that we have the necessary spectroscopic tools. To this end, we are developing a code, CMFGEN, capable of modeling supernova light curves and spectra. The code is currently being used, to study core-collapse supernovae as well as those arising from the nuclear detonation of a White Dwarf star. We wish to extend CMFGEN's capabilities by developing a procedure to handle non-monotonic velocity flows so that we can treat shock breakout and the interaction of supernova ejecta with circumstellar material. We will also investigate magnetar-powered SNe, and explore the connection between Type Ib and Type Ic supernovae and those supernovae associated with long-duration gamma-ray bursters. Through detailed studies of individual supernova, and through the construction of model grids, we are able to infer deficiencies in our modeling, in our atomic data, and in the progenitor models, and hence make refinements so that we can improve our understanding of all SNe classes. Previous (IUE), current (HST, Chandra, GALEX), and future NASA missions (James Webb Telescope) do/will provide a wealth of data on supernovae. The proposed research is related to strategic subgoal 3D: "Discover the origin, structure, evolution, and destiny of the universe, and search for Earth-like planets." Supernovae are inherently coupled to the evolution of the universe and life: They can trigger star formation and they provide the raw materials (e.g., oxygen

  9. Underground pipeline corrosion

    CERN Document Server

    Orazem, Mark

    2014-01-01

    Underground pipelines transporting liquid petroleum products and natural gas are critical components of civil infrastructure, making corrosion prevention an essential part of asset-protection strategy. Underground Pipeline Corrosion provides a basic understanding of the problems associated with corrosion detection and mitigation, and of the state of the art in corrosion prevention. The topics covered in part one include: basic principles for corrosion in underground pipelines, AC-induced corrosion of underground pipelines, significance of corrosion in onshore oil and gas pipelines, n

  10. Photometric selection of Type Ia supernovae in the Supernova Legacy Survey

    CERN Document Server

    Bazin, G; Palanque-Delabrouille, N; Rich, J; Aubourg, E; Astier, P; Balland, C; Basa, S; Carlberg, R G; Conley, A; Fouchez, D; Guy, J; Hardin, D; Hook, I M; Howell, D A; Pain, R; Perrett, K; Pritchet, C J; Regnault, N; Sullivan, M; Fourmanoit, N; Gonzalez-Gaitan, S; Lidman, C; Perlmutter, S; Ripoche, P; Walker, E S

    2011-01-01

    We present a sample of 485 photometrically identified Type Ia supernova candidates mined from the first three years of data of the CFHT SuperNova Legacy Survey (SNLS). The images were submitted to a deferred processing independent of the SNLS real-time detection pipeline. Light curves of all transient events were reconstructed in the g_M, r_M, i_M and z_M filters and submitted to automated sequential cuts in order to identify possible supernovae. Pure noise and long-term variable events were rejected by light curve shape criteria. Type Ia supernova identification relied on event characteristics fitted to their light curves assuming the events to be normal SNe Ia. The light curve fitter SALT2 was used for this purpose, assigning host galaxy photometric redshifts to the tested events. The selected sample of 485 candidates is one magnitude deeper than that allowed by the SNLS spectroscopic identification. The contamination by supernovae of other types is estimated to be 4%. Testing Hubble diagram residuals with ...

  11. 77 FR 70543 - Pipeline Safety: Meeting of the Gas Pipeline Advisory Committee and the Liquid Pipeline Advisory...

    Science.gov (United States)

    2012-11-26

    ... for natural gas pipelines and for hazardous liquid pipelines. Both committees were established under... TRANSPORTATION Pipeline and Hazardous Materials Safety Administration Pipeline Safety: Meeting of the Gas Pipeline Advisory Committee and the Liquid Pipeline Advisory Committee AGENCY: Pipeline and...

  12. The LOFAR Known Pulsar Data Pipeline

    CERN Document Server

    Alexov, A; Mol, J D; Stappers, B; van Leeuwen, J

    2010-01-01

    Transient radio phenomena and pulsars are one of six LOFAR Key Science Projects (KSPs). As part of the Transients KSP, the Pulsar Working Group (PWG) has been developing the LOFAR Pulsar Data Pipelines to both study known pulsars as well as search for new ones. The pipelines are being developed for the Blue Gene/P (BG/P) supercomputer and a large Linux cluster in order to utilize enormous amounts of computational capabilities (50Tflops) to process data streams of up to 23TB/hour. The LOFAR pipeline output will be using the Hierarchical Data Format 5 (HDF5) to efficiently store large amounts of numerical data, and to manage complex data encompassing a variety of data types, across distributed storage and processing architectures. We present the LOFAR Known Pulsar Data Pipeline overview, the pulsar beam-formed data format, the status of the pipeline processing as well as our future plans for developing the LOFAR Pulsar Search Pipeline. These LOFAR pipelines and software tools are being developed as the next gen...

  13. Photometric Supernova Classification with Machine Learning

    Science.gov (United States)

    Lochner, Michelle; McEwen, Jason D.; Peiris, Hiranya V.; Lahav, Ofer; Winter, Max K.

    2016-08-01

    Automated photometric supernova classification has become an active area of research in recent years in light of current and upcoming imaging surveys such as the Dark Energy Survey (DES) and the Large Synoptic Survey Telescope, given that spectroscopic confirmation of type for all supernovae discovered will be impossible. Here, we develop a multi-faceted classification pipeline, combining existing and new approaches. Our pipeline consists of two stages: extracting descriptive features from the light curves and classification using a machine learning algorithm. Our feature extraction methods vary from model-dependent techniques, namely SALT2 fits, to more independent techniques that fit parametric models to curves, to a completely model-independent wavelet approach. We cover a range of representative machine learning algorithms, including naive Bayes, k-nearest neighbors, support vector machines, artificial neural networks, and boosted decision trees (BDTs). We test the pipeline on simulated multi-band DES light curves from the Supernova Photometric Classification Challenge. Using the commonly used area under the curve (AUC) of the Receiver Operating Characteristic as a metric, we find that the SALT2 fits and the wavelet approach, with the BDTs algorithm, each achieve an AUC of 0.98, where 1 represents perfect classification. We find that a representative training set is essential for good classification, whatever the feature set or algorithm, with implications for spectroscopic follow-up. Importantly, we find that by using either the SALT2 or the wavelet feature sets with a BDT algorithm, accurate classification is possible purely from light curve data, without the need for any redshift information.

  14. Type Ia supernova rate studies from the SDSS-II Supernova Study

    Energy Technology Data Exchange (ETDEWEB)

    Dilday, Benjamin [Univ. of Chicago, IL (United States)

    2008-08-01

    The author presents new measurements of the type Ia SN rate from the SDSS-II Supernova Survey. The SDSS-II Supernova Survey was carried out during the Fall months (Sept.-Nov.) of 2005-2007 and discovered ~ 500 spectroscopically confirmed SNe Ia with densely sampled (once every ~ 4 days), multi-color light curves. Additionally, the SDSS-II Supernova Survey has discovered several hundred SNe Ia candidates with well-measured light curves, but without spectroscopic confirmation of type. This total, achieved in 9 months of observing, represents ~ 15-20% of the total SNe Ia discovered worldwide since 1885. The author describes some technical details of the SN Survey observations and SN search algorithms that contributed to the extremely high-yield of discovered SNe and that are important as context for the SDSS-II Supernova Survey SN Ia rate measurements.

  15. OH Masers and Supernova Remnants

    CERN Document Server

    Wardle, Mark

    2012-01-01

    OH(1720 MHz) masers are created by the interaction of supernova remnants with molecular clouds. These masers are pumped by collisions in warm, shocked molecular gas with OH column densities in the range 10^{16}--10^{17} cm^{-2}. Excitation calculations suggest that inversion of the 6049 MHz OH line may occur at the higher column densities that have been inferred from main-line absorption studies of supernova remnants with the Green Bank Telescope. OH(6049 MHz) masers have therefore been proposed as a complementary indicator of remnant-cloud interaction. This motivated searches for 6049 MHz maser emission from supernova remnants using the Parkes 63 m and Effelsberg 100 m telescopes, and the Australia Telescope Compact Array. A total of forty-one remnants have been examined by one or more of these surveys, but without success. To check the accuracy of the OH column densities inferred from the single-dish observations we modelled OH absorption at 1667 MHz observed with the Very Large Array towards three supernov...

  16. Supernovae neutrino pasta interaction

    Science.gov (United States)

    Lin, Zidu; Horowitz, Charles; Caplan, Matthew; Berry, Donald; Roberts, Luke

    2017-01-01

    In core-collapse supernovae, the neutron rich matter is believed to have complex structures, such as spherical, slablike, and rodlike shapes. They are collectively called ``nuclear pasta''. Supernovae neutrinos may scatter coherently on the ``nuclear pasta'' since the wavelength of the supernovae neutrinos are comparable to the nuclear pasta scale. Consequently, the neutrino pasta scattering is important to understand the neutrino opacity in the supernovae. In this work we simulated the ``nuclear pasta'' at different temperatures and densities using our semi-classical molecular dynamics and calculated the corresponding static structure factor that describes ν-pasta scattering. We found the neutrino opacities are greatly modified when the ``pasta'' exist and may have influence on the supernovae neutrino flux and average energy. Our neutrino-pasta scattering effect can finally be involved in the current supernovae simulations and we present preliminary proto neutron star cooling simulations including our pasta opacities.

  17. Supernova Neutrino Detection

    Energy Technology Data Exchange (ETDEWEB)

    Gil-Botella, Ines, E-mail: ines.gil@ciemat.es [CIEMAT, Basic Research Department, Avenida Complutense, 22, 28040 Madrid (Spain)

    2011-07-25

    The neutrino burst from a core collapse supernova can provide information about the explosion mechanism and the mechanisms of proto neutron star cooling but also about the intrinsic properties of the neutrino such as flavor oscillations. One important question is to understand to which extend can the supernova and the neutrino physics be decoupled in the observation of a single supernova. The possibility to probe the neutrino mixing angle {theta}{sub 13} and the type of mass hierarchy from the detection of supernova neutrinos with liquid argon detectors is discussed in this paper. Moreover, a quantitatively study about the possibility to constrain the supernova parameters is presented. A very massive liquid argon detector ({approx} 100 kton) is needed to perform accurate measurements of these parameters. Finally the possible detection of the diffuse supernova neutrino background in liquid argon detectors is also described.

  18. The Frequency of Supernovae in the Early Universe

    Science.gov (United States)

    Melinder, Jens

    Supernovae are cosmic explosions of cataclysmic proportion that signify the death of a star. While being interesting phenomena in their own right, their brightness also make them excellent probes of the early universe. Depending on the type of the progenitor star and the origin of the explosion different subjects can be investigated. In this dissertation the work I have done on the detection, characterisation and rate measurements of supernovae in the Stockholm VIMOS Supernova Search is presented. We have discovered 16 supernovae that exploded billions of years ago (or, equivalently, at high redshift, z). The observed brightness and colour evolution have been used to classify the supernovae into either thermonuclear (type Ia) or core collapse (type II) supernovae. The accuracy of the classification code is high, only about 5% of the supernovae are mistyped, similar to other codes of the same kind. By comparing the observed frequency of supernovae to simulations the underlying supernova rate at these high redshifts have been measured. The main result reported in this thesis is that the core collapse supernova rate at high redshift matches the rates estimated from looking at the star formation history of the universe, and agree well with previous studies. The rate of Ia supernovae at high redshift have been investigated by several projects, our results show a somewhat higher rate of Ia supernovae than expected. Proper estimates of the systematic errors of rate measurements are found to be very important. Furthermore, by using novel techniques for reducing and stacking images, we have obtained a galaxy sample containing approximately 50,000 galaxies. Photometric redshifts have been obtained for most of the galaxies, the resulting accuracy below z=1 is on the order of 10%. The galaxy sample has also been used to find high redshift sources, so called Lyman Break Galaxies, at z=3-5.

  19. Atomic and molecular supernovae

    Energy Technology Data Exchange (ETDEWEB)

    Liu, W.

    1997-12-01

    Atomic and molecular physics of supernovae is discussed with an emphasis on the importance of detailed treatments of the critical atomic and molecular processes with the best available atomic and molecular data. The observations of molecules in SN 1987A are interpreted through a combination of spectral and chemical modelings, leading to strong constraints on the mixing and nucleosynthesis of the supernova. The non-equilibrium chemistry is used to argue that carbon dust can form in the oxygen-rich clumps where the efficient molecular cooling makes the nucleation of dust grains possible. For Type Ia supernovae, the analyses of their nebular spectra lead to strong constraints on the supernova explosion models.

  20. Photometric classification of type Ia supernovae in the SuperNova Legacy Survey with supervised learning

    Science.gov (United States)

    Möller, A.; Ruhlmann-Kleider, V.; Leloup, C.; Neveu, J.; Palanque-Delabrouille, N.; Rich, J.; Carlberg, R.; Lidman, C.; Pritchet, C.

    2016-12-01

    In the era of large astronomical surveys, photometric classification of supernovae (SNe) has become an important research field due to limited spectroscopic resources for candidate follow-up and classification. In this work, we present a method to photometrically classify type Ia supernovae based on machine learning with redshifts that are derived from the SN light-curves. This method is implemented on real data from the SNLS deferred pipeline, a purely photometric pipeline that identifies SNe Ia at high-redshifts (0.2 Random Forest and Boosted Decision Trees. We evaluate the performance using SN simulations and real data from the first 3 years of the Supernova Legacy Survey (SNLS), which contains large spectroscopically and photometrically classified type Ia samples. Using the Area Under the Curve (AUC) metric, where perfect classification is given by 1, we find that our best-performing classifier (Extreme Gradient Boosting Decision Tree) has an AUC of 0.98.We show that it is possible to obtain a large photometrically selected type Ia SN sample with an estimated contamination of less than 5%. When applied to data from the first three years of SNLS, we obtain 529 events. We investigate the differences between classifying simulated SNe, and real SN survey data. In particular, we find that applying a thorough set of selection cuts to the SN sample is essential for good classification. This work demonstrates for the first time the feasibility of machine learning classification in a high-z SN survey with application to real SN data.

  1. Neutrinos from Supernovae

    CERN Document Server

    Choubey, S; Choubey, Sandhya; Kar, Kamales

    2002-01-01

    In this review, the effect of flavor oscillations on the neutrinos released during supernova explosion after core collapse is described. In some scenarios there are large enhancement of the number of events compared to the no oscillation case. Various other features associated with supernova neutrinos are also discussed.

  2. Galaxy Zoo Supernovae

    CERN Document Server

    Smith, A M; Sullivan, M; Lintott, C J; Nugent, P E; Botyanszki, J; Kasliwal, M; Quimby, R; Bamford, S P; Fortson, L F; Schawinski, K; Hook, I; Blake, S; Podsiadlowski, P; Joensson, J; Gal-Yam, A; Arcavi, I; Howell, D A; Bloom, J S; Jacobsen, J; Kulkarni, S R; Law, N M; Ofek, E O; Walters, R

    2010-01-01

    This paper presents the first results from a new citizen science project: Galaxy Zoo Supernovae. This proof of concept project uses members of the public to identify supernova candidates from the latest generation of wide-field imaging transient surveys. We describe the Galaxy Zoo Supernovae operations and scoring model, and demonstrate the effectiveness of this novel method using imaging data and transients from the Palomar Transient Factory (PTF). We examine the results collected over the period April-July 2010, during which nearly 14,000 supernova candidates from PTF were classified by more than 2,500 individuals within a few hours of data collection. We compare the transients selected by the citizen scientists to those identified by experienced PTF scanners, and find the agreement to be remarkable - Galaxy Zoo Supernovae performs comparably to the PTF scanners, and identified as transients 93% of the ~130 spectroscopically confirmed SNe that PTF located during the trial period (with no false positive iden...

  3. Molecules in supernova ejecta

    CERN Document Server

    Cherchneff, Isabelle

    2011-01-01

    The first molecules detected at infrared wavelengths in the ejecta of a Type II supernova, namely SN1987A, consisted of CO and SiO. Since then, confirmation of the formation of these two species in several other supernovae a few hundred days after explosion has been obtained. However, supernova environments appear to hamper the synthesis of large, complex species due to the lack of microscopically-mixed hydrogen deep in supernova cores. Because these environments also form carbon and silicate dust, it is of importance to understand the role played by molecules in the depletion of elements and how chemical species get incorporated into dust grains. In the present paper, we review our current knowledge of the molecular component of supernova ejecta, and present new trends and results on the synthesis of molecules in these harsh, explosive events.

  4. Trace Software Pipelining

    Institute of Scientific and Technical Information of China (English)

    王剑; AndreasKrall; 等

    1995-01-01

    Global software pipelining is a complex but efficient compilation technique to exploit instruction-level parallelism for loops with branches.This paper presents a novel global software pipelining technique,called Trace Software Pipelining,targeted to the instruction-level parallel processors such as Very Long Instruction Word (VLIW) and superscalar machines.Trace software pipelining applies a global code scheduling technique to compact the original loop body.The resulting loop is called a trace software pipelined (TSP) code.The trace softwrae pipelined code can be directly executed with special architectural support or can be transformed into a globally software pipelined loop for the current VLIW and superscalar processors.Thus,exploiting parallelism across all iterations of a loop can be completed through compacting the original loop body with any global code scheduling technique.This makes our new technique very promising in practical compilers.Finally,we also present the preliminary experimental results to support our new approach.

  5. Stripped-envelope supernova rates and host-galaxy properties

    CERN Document Server

    Graur, Or; Modjaz, Maryam; Maoz, Dan; Shivvers, Isaac; Filippenko, Alexei V; Li, Weidong

    2015-01-01

    The progenitors of stripped-envelope supernovae (SNe Ibc) remain to be conclsuively identified, but correlations between SN rates and host-galaxy properties can constrain progenitor models. Here, we present one result from a re-analysis of the rates from the Lick Observatory Supernova Search. Galaxies with stellar masses less than $\\sim 10^{10}~{\\rm M_\\odot}$ are less efficient at producing SNe Ibc than more massive galaxies. Any progenitor scenario must seek to explain this new observation.

  6. Green pipeline dreams; Gruene Pipeline-Traeume

    Energy Technology Data Exchange (ETDEWEB)

    Wiedemann, Karsten

    2010-11-15

    In theory, Germany and the other EU states would be able to cover their natural gas demand completely with pipeline-supplied biomethane. But will this be really possible in practice? The contribution takes a closer look. (orig.)

  7. ALMA Pipeline: Current Status

    Science.gov (United States)

    Shinnaga, H.; Humphreys, E.; Indebetouw, R.; Villard, E.; Kern, J.; Davis, L.; Miura, R. E.; Nakazato, T.; Sugimoto, K.; Kosugi, G.; Akiyama, E.; Muders, D.; Wyrowski, F.; Williams, S.; Lightfoot, J.; Kent, B.; Momjian, E.; Hunter, T.; ALMA Pipeline Team

    2015-12-01

    The ALMA Pipeline is the automated data reduction tool that runs on ALMA data. Current version of the ALMA pipeline produces science quality data products for standard interferometric observing modes up to calibration process. The ALMA Pipeline is comprised of (1) heuristics in the form of Python scripts that select the best processing parameters, and (2) contexts that are given for book-keeping purpose of data processes. The ALMA Pipeline produces a "weblog" that showcases detailed plots for users to judge how each step of calibration processes are treated. The ALMA Interferometric Pipeline was conditionally accepted in March 2014 by processing Cycle 0 and Cycle 1 data sets. From Cycle 2, ALMA Pipeline is used for ALMA data reduction and quality assurance for the projects whose observing modes are supported by the ALMA Pipeline. Pipeline tasks are available based on CASA version 4.2.2, and the first public pipeline release called CASA 4.2.2-pipe has been available since October 2014. One can reduce ALMA data both by CASA tasks as well as by pipeline tasks by using CASA version 4.2.2-pipe.

  8. VNS (Variable Neighbourhood Search) applied to batch sequencing in operational scheduling of pipeline network; VNS (Variable Neighbourhood Search) aplicado ao sequenciamento de bateladas do 'scheduling' de operacoes de uma malha dutoviaria

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Lia; Arruda, Lucia Valeria Ramos de; Libert, Nikolas [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil)

    2008-07-01

    This work presents the VNS heuristic technique applied on batches ordering in a real network of petroleum derivatives distribution. These ordering have great influence in operational scheduling of a pipeline network. The operational scheduling purposes the efficient utilization of the resources, resulting on a better performance. Due to the great complexity of the real network problem and the necessity of its resolution in little computational time, it was adopted a problem subdivision in assignment of resources, sequencing and timing. In the resources assignment stage, it is considered the production/consumption functions and the products tankages to determine the total batches, including its volume, flow rate and the time-windows to satisfy the demand. These data are used in the sequencing stage, where a VNS based model determines the batches ordering. In a final step, the last block, realize the temporisation considering the network operational constraints. This work shows the results from the optimization of the sequencing stage which aims the improvement of the solution quality of scheduling. (author)

  9. Optical Spectra and Light Curves of Supernovae

    CERN Document Server

    Filippenko, A V

    2003-01-01

    I review recent optical observations of supernovae (SNe) conducted by my group. The Lick Observatory Supernova Search with the 0.76-m Katzman Automatic Imaging Telescope is currently the world's most successful search for nearby SNe. We also use this telescope to obtain multicolor light curves of SNe. One of the more interesting SNe we discovered is SN 2000cx, which differs from all previously observed SNe Ia. Another very strange SN Ia that we studied is SN 2002cx, many of whose properties are opposite those of SN 2000cx. Extensive data on SNe II-P 1999em and 1999gi were used to derive distances with the expanding photosphere method. Results from spectropolarimetry suggest that the deeper we peer into the ejecta of core-collapse SNe, the greater the asphericity. We are using Hubble Space Telescope data to identify, or set limits on, the progenitors of core-collapse SNe.

  10. Supernova electron capture rates

    CERN Document Server

    Martínez-Pinedo, G

    1999-01-01

    We have calculated the Gamow-Teller strength distributions for the ground states and low lying states of several nuclei that play an important role in the precollapse evolution of supernova. The calculations reproduce the experimental GT distributions nicely. The GT distribution are used to calculate electron capture rates for typical presupernova conditions. The computed rates are noticeably smaller than the presently adopted rates. The possible implications for the supernova evolution are discussed.

  11. Reconstructing core-collapse supernovae waveforms with advanced era interferometers

    Science.gov (United States)

    McIver, Jessica; LIGO Scientific Collaboration

    2015-04-01

    Among of the wide range of potentially interesting astrophysical sources for Advanced LIGO and Advanced Virgo are galactic core-collapse supernovae. Although detectable core-collapse supernovae have a low expected rate (a few per century, or less) these signals would yield a wealth of new physics in the form of many messengers. Of particular interest is the insight into the explosion mechanism driving core-collapse supernovae that can be gleaned from the reconstructed gravitational wave signal. A well-reconstructed waveform will allow us to assess the likelihood of different explosion models, perform model selection, and potentially map unexpected features to new physics. This talk will present a study evaluating the current performance of the reconstruction of core-collapse supernovae gravitational wave signals. We used simulated waveforms modeled after different explosion mechanisms that we first injected into fake strain data re-colored to the expected Advanced LIGO/Virgo noise curves and then reconstructed using the pipelines Coherent Waveburst 2G and BayesWave. We will discuss the impact of these results on our ability to accurately reconstruct core-collapse supernovae signals, and by extension, other potential astrophysical generators of rich, complex waveforms.

  12. Possible use of the dedicated MARLY one meter telescope for intensive supernovae studies

    CERN Document Server

    Moniez, M

    2001-01-01

    The EROS2 microlensing search will end at the end of 2002. Apart of this microlensing search, EROS has discovered ~70 supernovae during 8 periods partially dedicated to a SN search. In this document, we investigated a new way of using the EROS telescope (The MARLY) after this date, as a dedicated nearby supernovae photometer. The performance of a set-up with two cameras allowing to simultaneously perform BVRI and U photometry have been estimated. Each year, of order of 100 type Ia supernovae at z ~0.05 should be photometrically followed-up during 80 days with a precision of 2% in BVRI and ~3,5% in U.

  13. The ESO/VLT 3rd year Type Ia supernova data set from the Supernova Legacy Survey

    CERN Document Server

    Balland, C; Basa, S; Mouchet, M; Howell, D A; Astier, P; Carlberg, R G; Conley, A; Fouchez, D; Guy, J; Hardin, D; Hook, I M; Pain, R; Perrett, K; Pritchet, C J; Regnault, N; Rich, J; Sullivan, M; Antilogus, P; Arsenijevic, V; Du, J Le; Fabbro, S; Lidman, C; Mourao, A; Palanque-Delabrouille, Nathalie; Pécontal, E; Ruhlmann-Kleider, V

    2009-01-01

    We present 139 spectra of 124 Type Ia supernovae (SNeIa) that were observed at the ESO/VLT during the first three years of the Canada-France-Hawai Telescope (CFHT) Supernova Legacy Survey (SNLS). This homogeneous data set is used to test for redshift evolution of SNeIa spectra, and will be used in the SNLS 3rd year cosmological analyses. Spectra have been reduced and extracted with a dedicated pipeline that uses photometric information from deep CFHT Legacy Survey (CFHT-LS) reference images to trace, at sub-pixel accuracy, the position of the supernova on the spectrogram as a function of wavelength. It also separates the supernova and its host light in 60% of cases. The identification of the supernova candidates is performed using a spectrophotometric SNIa model. A total of 124 SNeIa, roughly 50% of the overall SNLS spectroscopic sample, have been identified using the ESO/VLT during the first three years of the survey. Their redshifts range from z=0.149 to z=1.031. The average redshift of the sample is z=0.63...

  14. Holdup Measurement of Pipeline

    Institute of Scientific and Technical Information of China (English)

    LU; Wen-guang; XU; Zheng

    2015-01-01

    This research mainly adopts gamma spectroscopy to detect the pipeline retention.The calculation of retention of uranium has been obtained based on the intensity of gamma rays of 185.715 keV emitted by 235U,and the analysis method for the pipeline retention has been established.

  15. Supernova Simulations and Strategies For the Dark Energy Survey

    CERN Document Server

    Bernstein, J P; Kuhlmann, S; Biswas, R; Kovacs, E; Aldering, G; Crane, I; Finley, D A; Frieman, J A; Hufford, T; Jarvis, M J; Kim, A G; Marriner, J; Mukherjee, P; Nichol, R C; Nugent, P; Parkinson, D; Reis, R R R; Sako, M; Spinka, H; Sullivan, M

    2011-01-01

    We present an analysis of supernova light curves simulated for the upcoming Dark Energy Survey (DES) supernova search. The simulations employ a code suite that generates and fits realistic light curves in order to obtain distance modulus/redshift pairs that are passed to a cosmology fitter. We investigated several different survey strategies including field selection, supernova selection biases, and photometric redshift measurements. Using the results of this study, we chose a 30 square degree search area in the griz filter set. We forecast 1) that this survey will provide a homogeneous sample of up to 4000 Type Ia supernovae in the redshift range 0.05supernova with an identified host galaxy will be obtained from spectroscopic observations of the host. A supernova spectrum will be obtained for a subset of the sample, which will be utilized for control studi...

  16. Slurry pipeline hydrostatic testing

    Energy Technology Data Exchange (ETDEWEB)

    Betinol, Roy G.; Navarro Rojas, Luis Alejandro [BRASS Chile S.A., Santiago (Chile)

    2009-07-01

    The transportation of concentrates and tailings through long distance pipeline has been proven in recent years to be the most economic, environmentally friendly and secure means of transporting of mine products. This success has led to an increase in the demand for long distance pipeline throughout the mining industry. In year 2007 alone, a total of over 500 km of pipeline has been installed in South America alone and over 800 km are in the planning stages. As more pipelines are being installed, the need to ensure its operating integrity is ever increasing. Hydrostatic testing of long distance pipeline is one of the most economical and expeditious way to proving the operational integrity of the pipe. The intent of this paper is to show the sound reasoning behind construction hydro testing and the economic benefit it presents. It will show how hydro test pressures are determined based on ASME B31.11 criteria. (author)

  17. Slurry pipeline design approach

    Energy Technology Data Exchange (ETDEWEB)

    Betinol, Roy; Navarro R, Luis [Brass Chile S.A., Santiago (Chile)

    2009-12-19

    Compared to other engineering technologies, the design of a commercial long distance Slurry Pipeline design is a relatively new engineering concept which gained more recognition in the mid 1960 's. Slurry pipeline was first introduced to reduce cost in transporting coal to power generating units. Since then this technology has caught-up worldwide to transport other minerals such as limestone, copper, zinc and iron. In South America, the use of pipeline is commonly practiced in the transport of Copper (Chile, Peru and Argentina), Iron (Chile and Brazil), Zinc (Peru) and Bauxite (Brazil). As more mining operations expand and new mine facilities are opened, the design of the long distance slurry pipeline will continuously present a commercially viable option. The intent of this paper is to present the design process and discuss any new techniques and approach used today to ensure a better, safer and economical slurry pipeline. (author)

  18. EVOLUTION OF THE CRAB NEBULA IN A LOW ENERGY SUPERNOVA

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Haifeng; Chevalier, Roger A., E-mail: hy4px@virginia.edu, E-mail: rac5x@virginia.edu [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904 (United States)

    2015-06-20

    The nature of the supernova leading to the Crab Nebula has long been controversial because of the low energy that is present in the observed nebula. One possibility is that there is significant energy in extended fast material around the Crab but searches for such material have not led to detections. An electron capture supernova model can plausibly account for the low energy and the observed abundances in the Crab. Here, we examine the evolution of the Crab pulsar wind nebula inside a freely expanding supernova and find that the observed properties are most consistent with a low energy event. Both the velocity and radius of the shell material, and the amount of gas swept up by the pulsar wind point to a low explosion energy (∼10{sup 50} erg). We do not favor a model in which circumstellar interaction powers the supernova luminosity near maximum light because the required mass would limit the freely expanding ejecta.

  19. Evolution of the Crab nebula in a low energy supernova

    CERN Document Server

    Yang, Haifeng

    2015-01-01

    The nature of the supernova leading to the Crab Nebula has long been controversial because of the low energy that is present in the observed nebula. One possibility is that there is significant energy in extended fast material around the Crab but searches for such material have not led to detections. An electron capture supernova model can plausibly account for the low energy and the observed abundances in the Crab. Here, we examine the evolution of the Crab pulsar wind nebula inside a freely expanding supernova and find that the observed properties are most consistent with a low energy event. Both the velocity and radius of the shell material, and the amount of gas swept up by the pulsar wind point to a low explosion energy ($\\sim 10^{50}$ ergs). We do not favor a model in which circumstellar interaction powers the supernova luminosity near maximum light because the required mass would limit the freely expanding ejecta.

  20. Pre-Supernova Evolution of Massive Single and Binary Stars

    CERN Document Server

    Langer, N

    2012-01-01

    Massive stars are essential to understand a variety of branches of astronomy including galaxy and star cluster evolution, nucleosynthesis and supernovae, pulsars and black holes. It has become evident that massive star evolution is very diverse, being sensitive to metallicity, binarity, rotation, and possibly magnetic fields. While the problem to obtain a good statistical observational database is alleviated by current large spectroscopic surveys, it remains a challenge to model these diverse paths of massive stars towards their violent end stage. We show that the main sequence stage offers the best opportunity to gauge the relevance of the various possible evolutionary scenarios. This also allows to sketch the post-main sequence evolution of massive stars, for which observations of Wolf-Rayet stars give essential clues. Recent supernova discoveries due to the current boost in transient searches allow tentative mappings of progenitor models with supernova types, including pair instability supernovae and gamma...

  1. Prospective Type Ia Supernova Surveys From Dome A

    Energy Technology Data Exchange (ETDEWEB)

    Kim, A.; /LBL, Berkeley; Bonissent, A.; /Marseille, CPPM; Christiansen, J.L.; /Cal. Poly.; Ealet, A.; /Marseille, CPPM; Faccioli, L.; /UC, Berkeley; Gladney, L.; /Pennsylvania U.; Kushner, G.; /LBL, Berkeley; Linder, E.; /UC, Berkeley; Stoughton, C.; /Fermilab; Wang, L.; /Texas A-M /Purple Mountain Observ.

    2010-02-01

    Dome A, the highest plateau in Antarctica, is being developed as a site for an astronomical observatory. The planned telescopes and instrumentation and the unique site characteristics are conducive toward Type Ia supernova surveys for cosmology. A self-contained search and survey over five years can yield a spectro-photometric time series of {approx}1000 z < 0.08 supernovae. These can serve to anchor the Hubble diagram and quantify the relationship between luminosities and heterogeneities within the Type Ia supernova class, reducing systematics. Larger aperture ({approx}>4-m) telescopes are capable of discovering supernovae shortly after explosion out to z {approx} 3. These can be fed to space telescopes, and can isolate systematics and extend the redshift range over which we measure the expansion history of the universe.

  2. Prospective Type Ia supernova surveys from Dome A

    Energy Technology Data Exchange (ETDEWEB)

    Kim, A.; Bonissent, A.; Christiansen, J. L.; Ealet, A.; Faccioli, L.; Gladney, L.; Kushner, G.; Linder, E.; Stoughton, C.; Wang, L.

    2010-03-10

    Dome A, the highest plateau in Antarctica, is being developed as a site for an astronomical observatory. The planned telescopes and instrumentation and the unique site characteristics are conducive toward Type Ia supernova surveys for cosmology. A self-contained search and survey over 5 years can yield a spectro-photometric time series of ~;; 1000 z< 0:08 supernovae. These can serve to anchor the Hubble diagram and quantify the relationship between luminosities and heterogeneities within the Type Ia supernova class, reducing systematics. Larger aperture (>=4-m) telescopes are capable of discovering supernovae shortly after explosion out to z ~;; 3. These can be fed to space telescopes, and can isolate systematics and extend the redshift range over which we measure the expansion history of the universe.

  3. Cosmic Supernova Rate History and Type Ia Supernova Progenitors

    OpenAIRE

    Kobayashi, Chiaki; Nomoto, Ken'ichi; Tsujimoto, Takuji

    2001-01-01

    Adopting a single degenerate scenario for Type Ia supernova progenitors with the metallicity effect, we make a prediction of the cosmic supernova rate history as a composite of the supernova rates in spiral and elliptical galaxies, and compare with the recent observational data up to z ~ 0.55.

  4. Modeling Core Collapse Supernovae

    Science.gov (United States)

    Mezzacappa, Anthony

    2017-01-01

    Core collapse supernovae, or the death throes of massive stars, are general relativistic, neutrino-magneto-hydrodynamic events. The core collapse supernova mechanism is still not in hand, though key components have been illuminated, and the potential for multiple mechanisms for different progenitors exists. Core collapse supernovae are the single most important source of elements in the Universe, and serve other critical roles in galactic chemical and thermal evolution, the birth of neutron stars, pulsars, and stellar mass black holes, the production of a subclass of gamma-ray bursts, and as potential cosmic laboratories for fundamental nuclear and particle physics. Given this, the so called ``supernova problem'' is one of the most important unsolved problems in astrophysics. It has been fifty years since the first numerical simulations of core collapse supernovae were performed. Progress in the past decade, and especially within the past five years, has been exponential, yet much work remains. Spherically symmetric simulations over nearly four decades laid the foundation for this progress. Two-dimensional modeling that assumes axial symmetry is maturing. And three-dimensional modeling, while in its infancy, has begun in earnest. I will present some of the recent work from the ``Oak Ridge'' group, and will discuss this work in the context of the broader work by other researchers in the field. I will then point to future requirements and challenges. Connections with other experimental, observational, and theoretical efforts will be discussed, as well.

  5. The Most Luminous Supernovae

    Science.gov (United States)

    Sukhbold, Tuguldur; Woosley, S. E.

    2016-04-01

    Recent observations have revealed a stunning diversity of extremely luminous supernovae, seemingly increasing in radiant energy without bound. We consider simple approximate limits for what existing models can provide for the peak luminosity and total radiated energy for non-relativistic, isotropic stellar explosions. The brightest possible supernova is a Type I explosion powered by a sub-millisecond magnetar with field strength B ∼ few × {10}13 G. In extreme cases, such models might reach a peak luminosity of 2× {10}46 {erg} {{{s}}}-1 and radiate a total energy of up to 4× {10}52 {erg}. Other less luminous models are also explored, including prompt hyper-energetic explosions in red supergiants, pulsational-pair instability supernovae, pair-instability supernovae, and colliding shells. Approximate analytic expressions and limits are given for each case. Excluding magnetars, the peak luminosity is near 3× {10}44 {erg} {{{s}}}-1 for the brightest models and the corresponding limit on total radiated energy is 3× {10}51 {erg}. Barring new physics, supernovae with a light output over 3× {10}51 erg must be rotationally powered, either during the explosion itself or after, the most obvious candidate being a rapidly rotating magnetar. A magnetar-based model for the recent transient event, ASASSN-15lh is presented that strains, but does not exceed the limits of what the model can provide.

  6. Physics of supernovae

    Energy Technology Data Exchange (ETDEWEB)

    Woosley, S.E.; Weaver, T.A.

    1985-12-13

    Presupernova models of massive stars are presented and their explosion by ''delayed neutrino transport'' examined. A new form of long duration Type II supernova model is also explored based upon repeated encounter with the electron-positron pair instability in stars heavier than about 60 Msub solar. Carbon deflagration in white dwarfs is discussed as the probable explanation of Type I supernovae and special attention is paid to the physical processes whereby a nuclear flame propagates through degenerate carbon. 89 refs., 12 figs.

  7. Demonstrating Supernova Remnant Evolution

    Science.gov (United States)

    Leahy, Denis A.; Williams, Jacqueline

    2017-01-01

    We have created a software tool to calculate at display supernova remnant evolution which includes all stages from early ejecta dominated phase to late-time merging with the interstellar medium. The software was created using Python, and can be distributed as Python code, or as an executable file. The purpose of the software is to demonstrate the different phases and transitions that a supernova remnant undergoes, and will be used in upper level undergraduate astrophysics courses as a teaching tool. The usage of the software and its graphical user interface will be demonstrated.

  8. BVRI Photometry of Supernovae

    OpenAIRE

    Ho, Wynn C. G.; Van Dyk, Schuyler D.; Peng, Chien Y.; Filippenko, Alexei V.; Leonard, Douglas C.; Matheson, Thomas; Treffers, Richard R.; Richmond, Michael W.

    2001-01-01

    We present optical photometry of one Type IIn supernova (1994Y) and nine Type Ia supernovae (1993Y, 1993Z, 1993ae, 1994B, 1994C, 1994M, 1994Q, 1994ae, and 1995D). SN 1993Y and SN 1993Z appear to be normal SN Ia events with similar rates of decline, but we do not have data near maximum brightness. The colors of SN 1994C suggest that it suffers from significant reddening or is intrinsically red. The light curves of SN 1994Y are complicated; they show a slow rise and gradual decline near maximum...

  9. The supernova cosmology cookbook: Bayesian numerical recipes

    CERN Document Server

    Karpenka, N V

    2015-01-01

    Theoretical and observational cosmology have enjoyed a number of significant successes over the last two decades. Cosmic microwave background measurements from the Wilkinson Microwave Anisotropy Probe and Planck, together with large-scale structure and supernova (SN) searches, have put very tight constraints on cosmological parameters. Type Ia supernovae (SNIa) played a central role in the discovery of the accelerated expansion of the Universe, recognised by the Nobel Prize in Physics in 2011. The last decade has seen an enormous increase in the amount of high quality SN observations, with SN catalogues now containing hundreds of objects. This number is expected to increase to thousands in the next few years, as data from next-generation missions, such as the Dark Energy Survey and Large Synoptic Survey Telescope become available. In order to exploit the vast amount of forthcoming high quality data, it is extremely important to develop robust and efficient statistical analysis methods to answer cosmological q...

  10. Supernova constraints on decaying vacuum cosmology

    CERN Document Server

    Carneiro, S; Borges, H A; Alcaniz, J S

    2006-01-01

    There is mounting observational evidence that the expansion of our Universe is undergoing a late-time acceleration. Among many proposals to describe this phenomenon, the cosmological constant seems to be the simplest and the most natural explanation. However, despite its observational successes, such a possibility exacerbates the well known cosmological constant problem, requiring a natural explanation for its small, but nonzero, value. In this paper we consider a cosmological scenario driven by a varying cosmological term, in which the vacuum energy density decays linearly with the Hubble parameter. We show that this model is indistinguishable from the standard one in that the early radiation phase is followed by a long dust-dominated era, and only recently the varying cosmological term becomes dominant, accelerating the cosmic expansion. In order to test the viability of this scenario we have used the most recent type Ia supernova data, i.e., the High-Z SN Search (HZS) Team and the Supernova Legacy Survey (...

  11. Planck intermediate results XXXI. Microwave survey of Galactic supernova remnants

    DEFF Research Database (Denmark)

    Arnaud, M.; Ashdown, M.; Atrio-Barandela, F.

    2016-01-01

    The all-sky Planck survey in 9 frequency bands was used to search for emission from all 274 known Galactic supernova remnants. Of these, 16 were detected in at least two Planck frequencies. The radio-through-microwave spectral energy distributions were compiled to determine the mechanism for micr......The all-sky Planck survey in 9 frequency bands was used to search for emission from all 274 known Galactic supernova remnants. Of these, 16 were detected in at least two Planck frequencies. The radio-through-microwave spectral energy distributions were compiled to determine the mechanism...... for microwave emission. In only one case, IC 443, is there high-frequency emission clearly from dust associated with the supernova remnant. In all cases, the low-frequency emission is from synchrotron radiation. As predicted for a population of relativistic particles with energy distribution that extends...

  12. Natural Gas Liquid Pipelines

    Data.gov (United States)

    Department of Homeland Security — Natural gas interstate and intrastate pipelines in the United States. Based on a variety of sources with varying scales and levels of accuracy and therefore accuracy...

  13. BSEE_Pacific_Pipelines

    Data.gov (United States)

    Bureau of Ocean Energy Management, Department of the Interior — This data set contains the locations of oil and gas pipelines in the Bureau of Safety and Environmental Enforcement Pacific OCS Region

  14. Central oxygen pipeline failure

    African Journals Online (AJOL)

    Anaesthetic and critical care staff play a governing role in the comprehension of a ... complete central oxygen pipeline failure occurred throughout. Tygerberg Hospital. ..... emergency stations and at plant room emergency supply manifolds.

  15. Nearshore Pipeline Installation Methods.

    Science.gov (United States)

    1981-08-01

    179. 5. Aldridge, R. G., and Bomba , J. G., "Deep Water Pipelines - Interdependence of Design and Construction", ASCE Paper. 6. American Society Civil...October 13, 1967. 24. Bomba , J. G. and Seeds, K. J., "Pipelining in 600 feet of water .... A Case Study of Washington Natural Gas Company’s Puget Sound...Crossing", Offshore Technology Conference, paper OTC 1188, 1970. 25. Bomba , J., "Submarine Pipe Construction Methods", Petroleum Engineer, Vol. 32

  16. Theoretical models for supernovae

    Energy Technology Data Exchange (ETDEWEB)

    Woosley, S.E.; Weaver, T.A.

    1981-09-21

    The results of recent numerical simulations of supernova explosions are presented and a variety of topics discussed. Particular emphasis is given to (i) the nucleosynthesis expected from intermediate mass (10sub solar less than or equal to M less than or equal to 100 Msub solar) Type II supernovae and detonating white dwarf models for Type I supernovae, (ii) a realistic estimate of the ..gamma..-line fluxes expected from this nucleosynthesis, (iii) the continued evolution, in one and two dimensions, of intermediate mass stars wherein iron core collapse does not lead to a strong, mass-ejecting shock wave, and (iv) the evolution and explosion of vary massive stars (M greater than or equal to 100 Msub solar of both Population I and III. In one dimension, nuclear burning following a failed core bounce does not appear likely to lead to a supernova explosion although, in two dimensions, a combination of rotation and nuclear burning may do so. Near solar proportions of elements from neon to calcium and very brilliant optical displays may be created by hypernovae, the explosions of stars in the mass range 100 M/sub solar/ to 300 M/sub solar/. Above approx. 300 M/sub solar/ a black hole is created by stellar collapse following carbon ignition. Still more massive stars may be copious producers of /sup 4/He and /sup 14/N prior to their collapse on the pair instability.

  17. Supernova 2013by

    DEFF Research Database (Denmark)

    Valenti, S.; Sand, D.; Stritzinger, M.

    2015-01-01

    We present multiband ultraviolet and optical light curves, as well as visual-wavelength and near-infrared spectroscopy of the Type II linear (IIL) supernova (SN) 2013by. We show that SN 2013by and other SNe IIL in the literature, after their linear decline phase that start after maximum, have...

  18. QCD and Supernovas

    Science.gov (United States)

    Barnes, T.

    2005-12-01

    In this contribution we briefly summarize aspects of the physics of QCD which are relevant to the supernova problem. The topic of greatest importance is the equation of state (EOS) of nuclear and strongly-interacting matter, which is required to describe the physics of the proto-neutron star (PNS) and the neutron star remnant (NSR) formed during a supernova event. Evaluation of the EOS in the regime of relevance for these systems, especially the NSR, requires detailed knowledge of the spectrum and strong interactions of hadrons of the accessible hadronic species, as well as other possible phases of strongly interacting matter, such as the quark-gluon plasma (QGP). The forces between pairs of baryons (both nonstrange and strange) are especially important in determining the EOS at NSR densities. Predictions for these forces are unfortunately rather model dependent where not constrained by data, and there are several suggestions for the QCD mechanism underlying these short-range hadronic interactions. The models most often employed for determining these strong interactions are broadly of two types, 1) meson exchange models (usually assumed in the existing neutron star and supernova literature), and 2) quark-gluon models (mainly encountered in the hadron, nuclear and heavy-ion literature). Here we will discuss the assumptions made in these models, and discuss how they are applied to the determination of hadronic forces that are relevant to the supernova problem.

  19. The Most Luminous Supernovae

    CERN Document Server

    Sukhbold, Tuguldur

    2016-01-01

    Recent observations have revealed an amazing diversity of extremely luminous supernovae, seemingly increasing in radiant energy without bound. We consider here the physical limits of what existing models can provide for the peak luminosity and total radiated energy for non-relativistic, isotropic stellar explosions. The brightest possible supernova is a Type I explosion powered by a sub-millisecond magnetar. Such models can reach a peak luminosity of $\\rm 2\\times10^{46}\\ erg\\ s^{-1}$ and radiate a total energy of $\\rm 4 \\times10^{52}\\ erg$. Other less luminous models are also explored, including prompt hyper-energetic explosions in red supergiants, pulsational-pair instability supernovae, and pair-instability supernovae. Approximate analytic expressions and limits are given for each case. Excluding magnetars, the peak luminosity is near $\\rm 1\\times10^{44}\\ erg\\ s^{-1}$ for the brightest models. The corresponding limits on total radiated power are $\\rm3 \\times 10^{51}\\ erg$ (Type I) and $\\rm1 \\times 10^{51}\\ ...

  20. Supernovae and Dark Energy

    Science.gov (United States)

    Domínguez, I.; Bravo, E.; Piersanti, L.; Straniero, O.; Tornambé, A.

    2009-08-01

    A decade ago the observations of thermonuclear supernovae at high-redhifts showed that the expansion rate of the Universe is accelerating and since then, the evidence for cosmic acceleration has gotten stronger. This acceleration requires that the Universe is dominated by dark energy, an exotic component characterized by its negative pressure. Nowadays all the available astronomical data (i.e. thermonuclear supernovae, cosmic microwave background, barionic acoustic oscillations, large scale structure, etc.) agree that our Universe is made of about 70% of dark energy, 25% of cold dark matter and only 5% of known, familiar matter. This Universe is geometrically flat, older than previously thought, its destiny is no longer linked to its geometry but to dark energy, and we ignore about 95% of its components. To understand the nature of dark energy is probably the most fundamental problem in physics today. Current astronomical observations are compatible with dark energy being the vacuum energy. Supernovae have played a fundamental role in modern Cosmology and it is expected that they will contribute to unveil the dark energy. In order to do that it is mandatory to understand the limits of supernovae as cosmological distance indicators, improving their precision by a factor 10.

  1. Pipeline coating comparison methods for northern pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Singh, P. [Shaw Pipe Protection, Calgary, AB (Canada); Purves, G.A. [Cimarron Engineering Ltd., Calgary, AB (Canada)

    2004-07-01

    Two high-quality pipe coatings designed for northern environments were compared for their relative costs and suitability for the conditions that will be encountered in the field. Coating selection should consider local conditions to achieve the optimum life-cycle costs for the system. Some of the key factors affecting the integrity of the protective coating on a pipe include the effects of cold temperature and soil types. In this study, both Fusion Bonded Epoxy (FBE) and High Performance Composite Coatings (HPCC) were evaluated for an entire pipeline installation in a northern environment, from the coating plant to the pipe trench. The evaluation focused on the advantages of better abrasion resistance of the HPCC coating. This was compared against the incremental cost of HPCC coating over FBE on large diameter NPS 30 to NPS 48 pipelines. The following parameters influenced the choice of coating: storage, transportation and handling; bending ability under cold weather conditions; pipe installation and backfilling; weld joint coatings; coating repair and cathodic protection and pipeline integrity. Some of the construction costs that are indirectly affected by the choice of pipe coating include right-of-way preparation and restoration; trenching; supervision, service and downtime and specialist crossings. It was concluded that HPCC has better resistance to abrasion than FBE and is more flexible in extremely cold temperatures. Standard FBE is about 10 per cent less expensive than HPCC. In general HPCC will require less coating protection than FBE, depending on site conditions. 3 refs., 18 tabs., 8 figs.

  2. The Core-collapse rate from the Supernova Legacy Survey

    CERN Document Server

    Bazin, G; Rich, J; Ruhlmann-Kleider, V; Aubourg, E; Guillou, L Le; Astier, P; Balland, C; Basa, S; Carlberg, R G; Conley, A; Fouchez, D; Guy, J; Hardin, D; Hook, I M; Howell, D A; Pain, R; Perrett, K; Pritchet, C J; Regnault, N; Sullivan, M; Antilogus, P; Arsenijevic, V; Baumont, S; Fabbro, S; Du, J Le; Lidman, C; Mouchet, M; Mourão, A; Walker, E S

    2009-01-01

    We use three years of data from the Supernova Legacy Survey (SNLS) to study the general properties of core-collapse and type Ia supernovae. This is the first such study using the "rolling search" technique which guarantees well-sampled SNLS light curves and good efficiency for supernovae brighter than $i^\\prime\\sim24$. Using host photometric redshifts, we measure the supernova absolute magnitude distribution down to luminosities $4.5 {\\rm mag}$ fainter than normal SNIa. Using spectroscopy and light-curve fitting to discriminate against SNIa, we find a sample of 117 core-collapse supernova candidates with redshifts $z<0.4$ (median redshift of 0.29) and measure their rate to be larger than the type Ia supernova rate by a factor $4.5\\pm0.8(stat.) \\pm0.6 (sys.)$. This corresponds to a core-collapse rate at $z=0.3$ of $[1.42\\pm 0.3(stat.) \\pm0.3(sys.)]\\times10^{-4}\\yr^{-1}(h_{70}^{-1}\\Mpc)^{-3}$.

  3. Planck intermediate results XXXI. Microwave survey of Galactic supernova remnants

    DEFF Research Database (Denmark)

    Arnaud, M.; Ashdown, M.; Atrio-Barandela, F.;

    2016-01-01

    The all-sky Planck survey in 9 frequency bands was used to search for emission from all 274 known Galactic supernova remnants. Of these, 16 were detected in at least two Planck frequencies. The radio-through-microwave spectral energy distributions were compiled to determine the mechanism for micr...

  4. 77 FR 2126 - Pipeline Safety: Implementation of the National Registry of Pipeline and Liquefied Natural Gas...

    Science.gov (United States)

    2012-01-13

    ... Registry of Pipeline and Liquefied Natural Gas Operators AGENCY: Pipeline and Hazardous Materials Safety... registry of pipeline and liquefied natural gas operators. FOR FURTHER INFORMATION CONTACT: Jamerson Pender... 72878), titled: ``Pipeline Safety: Updates to Pipeline and Liquefied Natural Gas Reporting...

  5. Pipeliners go regulator shopping

    Energy Technology Data Exchange (ETDEWEB)

    Byfield, M.

    1996-12-09

    The weakening of Alberta`s regulatory grip on gas pipelines was discussed. Palliser Pipeline Limited has challenged Nova Corp`s monopoly by applying to the National Energy Board (NEB) for permission to build a 150-mile pipeline from Calgary to the Saskatchewan border. If the $350 million project proceeds, it would mean that gas would be flowing out of Alberta for the first time through a line that is not operated by Nova Corp. Palliser would operate with a lower shipping toll, set by the NEB rather than Alberta`s Energy and Utilities Board. Alliance Pipeline Ltd. will also apply to the NEB to build a 1850-mile pipeline that would originate in British Columbia, cross Alberta and terminate in Chicago. Nova Corp has implied that it might have to consider charging distance-based tolls if the Palliser bypass line proceeds. However, Palliser countered that it should not be necessary to change the postage stamp system for that small a fraction. Palliser suggested that Nova was simply reacting because it was facing competition for the first time. Final decision is in the hands of the federal government.

  6. Protecting a pipeline

    Energy Technology Data Exchange (ETDEWEB)

    Gray, D.H (Univ. of Michigan, Ann Arbor, MI (United States)); Garcia-Lopez, M. (Ingenieria y Geotecnia Ltda., Santafe de Bogota (Colombia))

    1994-12-01

    This article describes some of the difficulties in constructing an oil pipeline in Colombia across a forested mountain range that has erosion-prone slopes. Engineers are finding ways to protect the pipeline against slope failures and severe erosion problems while contending with threats of guerrilla attacks. Torrential rainfall, precipitous slopes, unstable soils, unfavorable geology and difficult access make construction of an oil pipeline in Colombia a formidable undertaking. Add the threat of guerrilla attacks, and the project takes on a new dimension. In the country's central uplands, a 76 cm pipeline traverses some of the most daunting and formidable terrain in the world. The right-of-way crosses rugged mountains with vertical elevations ranging from 300 m to 2,000 mm above sea level over a distance of some 30 km. The pipeline snakes up and down steep forested inclines in some spots and crosses streams and faults in others, carrying the country's major export--petroleum--from the Cusiana oil field, located in Colombia's lowland interior, to the coast.

  7. Pipelines. Economy's veins; Pipelines. Adern der Wirtschaft

    Energy Technology Data Exchange (ETDEWEB)

    Feizlmayr, Adolf; Goestl, Stefan [ILF Beratende Ingenieure, Muenchen (Germany)

    2011-02-15

    According to the existing prognoses more than 1 million km of gas pipelines, oil pipelines and water pipelines are built up to the year 2030. The predominant portion is from gas pipelines. The safe continued utilization of the aging pipelines is a large challenge. In addition, the diagnostic technology, the evaluation and risk assessment have to be developed further. With the design of new oil pipelines and gas pipelines, aspects of environmental protection, the energy efficiency of transport and thus the emission reduction of carbon dioxide, the public acceptance and the market strategy of the exporters gain in importance. With the offshore pipelines one soon will exceed the present border of 2,000 m depth of water and penetrate into larger sea depths.

  8. 77 FR 31827 - Pipeline Safety: Pipeline Damage Prevention Programs

    Science.gov (United States)

    2012-05-30

    ... Safety: Pipeline Damage Prevention Programs AGENCY: Pipeline and Hazardous Materials Safety... excavation damage prevention law enforcement programs; establish an administrative process for making... excavation damage prevention law enforcement programs; and establish the adjudication process...

  9. Supernova-Remnant Origin of Cosmic Rays?

    CERN Document Server

    Butt, Y M; Romero, G E; Dame, T M; Combi, J A; Butt, Yousaf M.; Torres, Diego F.; Romero, Gustavo E.; Dame, Thomas M.; Combi, Jorge A.

    2002-01-01

    It is thought that Galactic cosmic ray (CR) nuclei are gradually accelerated to high energies (up to ~300 TeV/nucleon, where 1TeV=10^12eV) in the expanding shock-waves connected with the remnants of powerful supernova explosions. However, this conjecture has eluded direct observational confirmation^1,2 since it was first proposed in 1953 (ref. 3). Enomoto et al.^4 claim to have finally found definitive evidence that corroborates this model, proposing that the very-high-energy, TeV-range, gamma-rays from the supernova remnant (SNR) RX J1713.7-3946 are due to the interactions of energetic nuclei in this region. Here we argue that their claim is not supported by the existing multiwavelength spectrum of this source. The search for the origin(s) of Galactic cosmic ray nuclei may be closing in on the long-suspected supernova-remnant sources, but it is not yet over.

  10. Scheduled discoveries of 7+ high-Redshift supernovae: First cosmology results and bounds on q{sub 0}

    Energy Technology Data Exchange (ETDEWEB)

    Perlmutter, S., FNAL

    1998-09-01

    Our search for high-redshift Type Ia supernovae discovered, in its first years, a sample of seven supernovae. Using a ``batch`` search strategy, almost all were discovered before maximum light and were observed over the peak of their light curves. The spectra and light curves indicate that almost all were Type Ia supernovae at redshifts z = 0.35 - 0.5. These high-redshift supernovae can provide a distance indicator and ``standard clock`` to study the cosmological parameters q{sub 0} , {Lambda}, {Omega}{sub 0} , and H{sub 0}. This presentation and the following presentations of Kim et al. (1996), Goldhaber et al. (1996), and Pain et al. (1996) will discuss observation strategies and rates, analysis and calibration issues, the sources of measurement uncertainty, and the cosmological implications, including bounds on q{sub 0} , of these first high-redshift supernovae from our ongoing search.

  11. CPL: Common Pipeline Library

    Science.gov (United States)

    ESO CPL Development Team

    2014-02-01

    The Common Pipeline Library (CPL) is a set of ISO-C libraries that provide a comprehensive, efficient and robust software toolkit to create automated astronomical data reduction pipelines. Though initially developed as a standardized way to build VLT instrument pipelines, the CPL may be more generally applied to any similar application. The code also provides a variety of general purpose image- and signal-processing functions, making it an excellent framework for the creation of more generic data handling packages. The CPL handles low-level data types (images, tables, matrices, strings, property lists, etc.) and medium-level data access methods (a simple data abstraction layer for FITS files). It also provides table organization and manipulation, keyword/value handling and management, and support for dynamic loading of recipe modules using programs such as EsoRex (ascl:1504.003).

  12. Pipeline rehabilitation planning

    Energy Technology Data Exchange (ETDEWEB)

    Palmer-Jones, Roland; Hopkins, Phil; Eyre, David [PENSPEN (United Kingdom)

    2005-07-01

    An operator faced with an onshore pipeline that has extensive damage must consider the need for rehabilitation, the sort of rehabilitation to be used, and the rehabilitation schedule. This paper will consider pipeline rehabilitation based on the authors' experiences from recent projects, and recommend a simple strategy for planning pipeline rehabilitation. It will also consider rehabilitation options: external re-coating; internal lining; internal painting; programmed repairs. The main focus will be external re-coating. Consideration will be given to rehabilitation coating types, including tape wraps, epoxy, and polyurethane. Finally it will discuss different options for scheduling the rehabilitation of corrosion damage including: the statistical comparison of signals from inspection pigs; statistical comparison of selected measurements from inspection pigs and other inspections; the use of corrosion rates estimated for the mechanisms and conditions; expert judgement. (author)

  13. Supernova Photometric Classification Challenge

    CERN Document Server

    Kessler, Richard; Jha, Saurabh; Kuhlmann, Stephen

    2010-01-01

    We have publicly released a blinded mix of simulated SNe, with types (Ia, Ib, Ic, II) selected in proportion to their expected rate. The simulation is realized in the griz filters of the Dark Energy Survey (DES) with realistic observing conditions (sky noise, point spread function and atmospheric transparency) based on years of recorded conditions at the DES site. Simulations of non-Ia type SNe are based on spectroscopically confirmed light curves that include unpublished non-Ia samples donated from the Carnegie Supernova Project (CSP), the Supernova Legacy Survey (SNLS), and the Sloan Digital Sky Survey-II (SDSS-II). We challenge scientists to run their classification algorithms and report a type for each SN. A spectroscopically confirmed subset is provided for training. The goals of this challenge are to (1) learn the relative strengths and weaknesses of the different classification algorithms, (2) use the results to improve classification algorithms, and (3) understand what spectroscopically confirmed sub-...

  14. Collective supernova neutrino oscillations

    Energy Technology Data Exchange (ETDEWEB)

    Mirizzi, Alessandro [Max Planck Institute for Physics, Munich (Germany)

    2009-07-01

    Neutrinos emitted by core-collapse supernovae (SNe) represent an important laboratory for both particle physics and astrophysics. While propagating in the dense SN environment, they can feel not only the presence of background matter (via ordinary Mikheev-Smirnov-Wolfenstein effects) but also of the gas of neutrinos and antineutrinos (via neutrino-neutrino interaction effects). The neutrino-neutrino interactions appear to modify the flavor evolution of SN neutrinos in a collective way, completely different from the ordinary matter effects. In these conditions, the flavor evolution equations become highly nonlinear, sometimes resulting in surprising phenomena when the entire neutrino system oscillates coherently as a single collective mode. In this talk, I present the recent results on collective supernova neutrino flavor conversions and I discuss about the sensitivity of these effects to the ordering of the neutrino mass spectrum.

  15. ADIDAS SUPERNOVA CTR10

    Institute of Scientific and Technical Information of China (English)

    刘楠

    2008-01-01

    ADIDAS SUPERNOVA CTR10作为ADIDAS控制型跑鞋中的佼佼者,鞋款结合了如立体FORMOTION,大面积的PRO-MODERATOR特殊材质,以及强化型的07款鞋模(EL-07),前脚掌大块ADIPRENE+等诸多ADIDAS的当家技术,但在实际的跑步过程中,这些技术点能否真正为跑步者带来明显的感受?请随我们进入到ADIDAS SUPERNOVA CONTROL10评测环节。

  16. Galaxy Outflows Without Supernovae

    CERN Document Server

    Sur, Sharanya; Ostriker, Eve C

    2016-01-01

    High surface density, rapidly star-forming galaxies are observed to have $\\approx 50-100\\,{\\rm km\\,s^{-1}}$ line-of-sight velocity dispersions, which are much higher than expected from supernova driving alone, but may arise from large-scale gravitational instabilities. Using three-dimensional simulations of local regions of the interstellar medium, we explore the impact of high velocity dispersions that arise from these disk instabilities. Parametrizing disks by their surface densities and epicyclic frequencies, we conduct a series of simulations that probe a broad range of conditions. Turbulence is driven purely horizontally and on large scales, neglecting any energy input from supernovae. We find that such motions lead to strong global outflows in the highly-compact disks that were common at high redshifts, but weak or negligible mass loss in the more diffuse disks that are prevalent today. Substantial outflows are generated if the one-dimensional horizontal velocity dispersion exceeds $\\approx 35\\,{\\rm km\\...

  17. Supernova Science Center

    Energy Technology Data Exchange (ETDEWEB)

    S. E. Woosley

    2008-05-05

    The Supernova Science Center (SNSC) was founded in 2001 to carry out theoretical and computational research leading to a better understanding of supernovae and related transients. The SNSC, a four-institutional collaboration, included scientists from LANL, LLNL, the University of Arizona (UA), and the University of California at Santa Cruz (UCSC). Intitially, the SNSC was funded for three years of operation, but in 2004 an opportunity was provided to submit a renewal proposal for two years. That proposal was funded and subsequently, at UCSC, a one year no-cost extension was granted. The total operational time of the SNSC was thus July 15, 2001 - July 15, 2007. This document summarizes the research and findings of the SNSC and provides a cummulative publication list.

  18. Nurseries of Supernovae

    DEFF Research Database (Denmark)

    Frederiksen, Teddy

    Type Ia supernovae (SNe) have long been the gold standard for precision cosmology and after several decades of intense research the supernova (SN) community was in 2011 honored by giving the Nobel Prize in physics for the discovery of Dark Energy to the leaders of the two big SN collaborations...... the gasphase metallicity, stellar mass and stellar age for this z = 1.55 host galaxy. I am also able to rule out the presence of any AGN though emission-line ratios. The host is classified as a highly star forming, low mass, low metallicity galaxy. It is a clear outlier in star formation and stellar mass...... compared to most low redshift (z 1) redshift SNe. This is mainly due to the change in specific star-formation rate as a function of redshift. This can potentially impact the use of high redshift SN Ia as standard candels...

  19. 78 FR 70623 - Pipeline Safety: Meeting of the Gas Pipeline Advisory Committee and the Liquid Pipeline Advisory...

    Science.gov (United States)

    2013-11-26

    ... gas pipelines and for hazardous liquid pipelines. Both committees were established under the Federal... Administration [Docket No. PHMSA-2009-0203] Pipeline Safety: Meeting of the Gas Pipeline Advisory Committee and the Liquid Pipeline Advisory Committee AGENCY: Pipeline and Hazardous Materials Safety...

  20. The Remnant of Supernova 1987A

    Science.gov (United States)

    McCray, Richard; Fransson, Claes

    2016-09-01

    Although it has faded by a factor of ˜107, SN 1987A is still bright enough to be observed in almost every band of the electromagnetic spectrum. Today, the bolometric luminosity of the debris is dominated by a far-infrared (˜200μm) continuum from ˜0.5 M⊙ of dust grains in the interior debris. The dust is heated by UV, optical, and near-infrared (NIR) emission resulting from radioactive energy deposition by 44Ti. The optical light of the supernova debris is now dominated by illumination of the debris by X-rays resulting from the impact of the outer supernova envelope with an equatorial ring (ER) of gas that was expelled some 20,000 years before the supernova explosion. X-ray and optical observations trace a complex system of shocks resulting from this impact, whereas radio observations trace synchrotron radiation from relativistic electrons accelerated by these shocks. The luminosity of the remnant is dominated by an NIR (˜20μm) continuum from dust grains in the ER heated by collisions with ions in the X-ray emitting gas. With the Atacama Large Millimeter Array (ALMA), we can observe the interior debris at millimeter/submillimeter wavelengths, which are not absorbed by the interior dust. The ALMA observations reveal bright emission lines from rotational transitions of CO and SiO lines that provide a new window into the interior structure of the supernova debris. Optical, NIR, and ALMA observations all indicate strongly asymmetric ejecta. Intensive searches have failed to yield any evidence for the compact object expected to reside at the center of the remnant. The current upper limit to the luminosity of such an object is a few tens of solar luminosities.

  1. The TROBAR pipeline

    Science.gov (United States)

    Stefanon, Mauro

    TROBAR is a 60cm robotic telescope installed at the Observatrio de Aras de los Olmos (OAO), approximately 100km north-west of Valencia (Spain). It is currently equipped with a 4K×4K optical camera covering a FoV of 30×30 arcmin^2. We are now implementing a pipeline for the automatic reduction of its data. In this paper we will present the main features of the pipeline, with particular care to some of the algorithms implemented to assess the quality of the produced data and showing their application to synthetic images.

  2. Coherent pipeline for biomarker discovery using mass spectrometry and bioinformatics

    Directory of Open Access Journals (Sweden)

    Al-Shahib Ali

    2010-08-01

    Full Text Available Abstract Background Robust biomarkers are needed to improve microbial identification and diagnostics. Proteomics methods based on mass spectrometry can be used for the discovery of novel biomarkers through their high sensitivity and specificity. However, there has been a lack of a coherent pipeline connecting biomarker discovery with established approaches for evaluation and validation. We propose such a pipeline that uses in silico methods for refined biomarker discovery and confirmation. Results The pipeline has four main stages: Sample preparation, mass spectrometry analysis, database searching and biomarker validation. Using the pathogen Clostridium botulinum as a model, we show that the robustness of candidate biomarkers increases with each stage of the pipeline. This is enhanced by the concordance shown between various database search algorithms for peptide identification. Further validation was done by focusing on the peptides that are unique to C. botulinum strains and absent in phylogenetically related Clostridium species. From a list of 143 peptides, 8 candidate biomarkers were reliably identified as conserved across C. botulinum strains. To avoid discarding other unique peptides, a confidence scale has been implemented in the pipeline giving priority to unique peptides that are identified by a union of algorithms. Conclusions This study demonstrates that implementing a coherent pipeline which includes intensive bioinformatics validation steps is vital for discovery of robust biomarkers. It also emphasises the importance of proteomics based methods in biomarker discovery.

  3. The Acceleration of the Universe in the Light of Supernovae: The Key Role of CTIO

    Science.gov (United States)

    Hamuy, M.; Suntzeff, N. B.

    2015-05-01

    The discovery of acceleration and dark energy arguably constitutes the most revolutionary discovery in astrophysics in recent years. The Cerro Tololo Inter-American Observatory (CTIO) played a key role in this amazing discovery through three systematic surveys organized by staff astronomers: the “Tololo Supernova Program“ (1986-2000), the Calán/Tololo Project (1989-1993), and the “High-Z Supernova Search Team” (1994-1998). CTIO's state of the art instruments also were fundamental in the independent discovery of acceleration by the “Supernova Cosmology Project” (1992-1999). Here I summarize the work on supernovae carried out from CTIO that led to the discovery of acceleration and dark energy and provide a brief historical summary on the use of Type Ia supernovae in cosmology in order to provide context for the CTIO contribution.

  4. Sinopec: Pipeline Goes Ahead

    Institute of Scientific and Technical Information of China (English)

    Xie Ye

    2002-01-01

    @@ Asia's largest refinery, Sinopec Corp, will proceed with a 1,600-kilometre oil pipeline across southern provinces of China, although speculation continues to linger that the company will scrap the plan due to a postponement of the multi-million-dollar project.

  5. Selection bias in the reported performances of AD classification pipelines.

    Science.gov (United States)

    Mendelson, Alex F; Zuluaga, Maria A; Lorenzi, Marco; Hutton, Brian F; Ourselin, Sébastien

    2017-01-01

    The last decade has seen a great proliferation of supervised learning pipelines for individual diagnosis and prognosis in Alzheimer's disease. As more pipelines are developed and evaluated in the search for greater performance, only those results that are relatively impressive will be selected for publication. We present an empirical study to evaluate the potential for optimistic bias in classification performance results as a result of this selection. This is achieved using a novel, resampling-based experiment design that effectively simulates the optimisation of pipeline specifications by individuals or collectives of researchers using cross validation with limited data. Our findings indicate that bias can plausibly account for an appreciable fraction (often greater than half) of the apparent performance improvement associated with the pipeline optimisation, particularly in small samples. We discuss the consistency of our findings with patterns observed in the literature and consider strategies for bias reduction and mitigation.

  6. Observations and Theory of Supernovae

    CERN Document Server

    Wheeler, J C

    2003-01-01

    This Resource Letter provides a guide to the literature on the observations of supernovae and the theory of their explosion mechanisms. Journal articles and books are cited for the following topics: observations of the spectra, spectropolarimetry, and light curves of supernovae of various types, theory of thermonuclear explosions, core collapse, and radioactive decay, applications to cosmology, and possible connections to gamma-ray bursts.

  7. Collective neutrino oscillations in supernovae

    Energy Technology Data Exchange (ETDEWEB)

    Duan, Huaiyu [Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM 87131 (United States)

    2014-06-24

    In a dense neutrino medium neutrinos can experience collective flavor transformation through the neutrino-neutrino forward scattering. In this talk we present some basic features of collective neutrino flavor transformation in the context in core-collapse supernovae. We also give some qualitative arguments for why and when this interesting phenomenon may occur and how it may affect supernova nucleosynthesis.

  8. Mass Varying Neutrinos in Supernovae

    CERN Document Server

    Rossi-Torres, F; de Holanda, P C; Peres, O L G

    2010-01-01

    We study limits for the mass varying neutrino model, using constrains from supernova neutrinos placed by the r-process condition, $Y_e<0.5$. Also, we use this model in a supernova environment to study the regions of survival probability in the oscillation space parameter ($\\tan^2\\theta$ and $\\Delta m^2_0$), considering the channel $\

  9. Kepler Science Operations Center Pipeline Framework

    Science.gov (United States)

    Klaus, Todd C.; McCauliff, Sean; Cote, Miles T.; Girouard, Forrest R.; Wohler, Bill; Allen, Christopher; Middour, Christopher; Caldwell, Douglas A.; Jenkins, Jon M.

    2010-01-01

    The Kepler mission is designed to continuously monitor up to 170,000 stars at a 30 minute cadence for 3.5 years searching for Earth-size planets. The data are processed at the Science Operations Center (SOC) at NASA Ames Research Center. Because of the large volume of data and the memory and CPU-intensive nature of the analysis, significant computing hardware is required. We have developed generic pipeline framework software that is used to distribute and synchronize the processing across a cluster of CPUs and to manage the resulting products. The framework is written in Java and is therefore platform-independent, and scales from a single, standalone workstation (for development and research on small data sets) to a full cluster of homogeneous or heterogeneous hardware with minimal configuration changes. A plug-in architecture provides customized control of the unit of work without the need to modify the framework itself. Distributed transaction services provide for atomic storage of pipeline products for a unit of work across a relational database and the custom Kepler DB. Generic parameter management and data accountability services are provided to record the parameter values, software versions, and other meta-data used for each pipeline execution. A graphical console allows for the configuration, execution, and monitoring of pipelines. An alert and metrics subsystem is used to monitor the health and performance of the pipeline. The framework was developed for the Kepler project based on Kepler requirements, but the framework itself is generic and could be used for a variety of applications where these features are needed.

  10. Fixing the U-band photometry of Type Ia supernovae

    CERN Document Server

    Krisciunas, Kevin; Espinoza, Juan; Gonzalez, David; Gonzalez, Luis; Gonzalez, Sergio; Hamuy, Mario; Hsiao, Eric Y; Morrell, Nidia; Phillips, Mark M; Suntzeff, Nicholas B

    2012-01-01

    We present previously unpublished photometry of supernovae 2003gs and 2003hv. Using spectroscopically-derived corrections to the U-band photometry, we reconcile U-band light curves made from imagery with the Cerro Tololo 0.9-m, 1.3-m and Las Campanas 1-m telescopes. Previously, such light curves showed a 0.4 mag spread at one month after maximum light. This gives us hope that a set of corrected ultraviolet light curves of nearby objects can contribute to the full utilization of rest frame U-band data of supernovae at redshift ~0.3 to 0.8. As pointed out recently by Kessler et al. in the context of the Sloan Digital Sky Survey supernova search, if we take the published U-band photometry of nearby Type Ia supernovae at face value, there is a 0.12 mag U-band anomaly in the distance moduli of higher redshift objects. This anomaly led the Sloan survey to eliminate from their analyses all photometry obtained in the rest frame U-band. The Supernova Legacy Survey eliminated observer frame U-band photometry, which is ...

  11. Current pipelines for neglected diseases.

    Directory of Open Access Journals (Sweden)

    Paolo di Procolo

    2014-09-01

    Full Text Available This paper scrutinises pipelines for Neglected Diseases (NDs, through freely accessible and at-least-weekly updated trials databases. It updates to 2012 data provided by recent publications, and integrates these analyses with information on location of trials coordinators and patients recruitment status. Additionally, it provides (i disease-specific information to better understand the rational of investments in NDs, (ii yearly data, to understand the investment trends. The search identified 650 clinical studies. Leishmaniasis, Arbovirus infection, and Dengue are the top three diseases by number of clinical studies. Disease diffusion risk seems to be the most important driver of the clinical trials target choice, whereas the role played by disease prevalence and unmet need is controversial. Number of trials is stable between 2005 and 2010, with an increase in the last two years. Patient recruitment was completed for most studies (57.6%, and Phases II and III account for 35% and 28% of trials, respectively. The primary purpose of clinical investigations is prevention (49.3%, especially for infectious diseases with mosquitoes and sand flies as the vector, and treatment (43.2%, which is the primary target for parasitic diseases Research centres and public organisations are the most important clinical studies sponsors (58.9%, followed by the pharmaceutical industry (24.1%, foundations and non-governmental organisations (9.3%. Many coordinator centres are located in less affluent countries (43.7%, whereas OECD countries and BRICS account for 34.7% and 17.5% of trials, respectively. Information was partially missing for some parameters. Notwithstanding, and despite its descriptive nature, this research has enhanced the evidence of the literature on pipelines for NDs. Future contributions may further investigate whether trials metrics are consistent with the characteristics of the interested countries and the explicative variables of trials location

  12. Current pipelines for neglected diseases.

    Science.gov (United States)

    di Procolo, Paolo; Jommi, Claudio

    2014-09-01

    This paper scrutinises pipelines for Neglected Diseases (NDs), through freely accessible and at-least-weekly updated trials databases. It updates to 2012 data provided by recent publications, and integrates these analyses with information on location of trials coordinators and patients recruitment status. Additionally, it provides (i) disease-specific information to better understand the rational of investments in NDs, (ii) yearly data, to understand the investment trends. The search identified 650 clinical studies. Leishmaniasis, Arbovirus infection, and Dengue are the top three diseases by number of clinical studies. Disease diffusion risk seems to be the most important driver of the clinical trials target choice, whereas the role played by disease prevalence and unmet need is controversial. Number of trials is stable between 2005 and 2010, with an increase in the last two years. Patient recruitment was completed for most studies (57.6%), and Phases II and III account for 35% and 28% of trials, respectively. The primary purpose of clinical investigations is prevention (49.3%), especially for infectious diseases with mosquitoes and sand flies as the vector, and treatment (43.2%), which is the primary target for parasitic diseases Research centres and public organisations are the most important clinical studies sponsors (58.9%), followed by the pharmaceutical industry (24.1%), foundations and non-governmental organisations (9.3%). Many coordinator centres are located in less affluent countries (43.7%), whereas OECD countries and BRICS account for 34.7% and 17.5% of trials, respectively. Information was partially missing for some parameters. Notwithstanding, and despite its descriptive nature, this research has enhanced the evidence of the literature on pipelines for NDs. Future contributions may further investigate whether trials metrics are consistent with the characteristics of the interested countries and the explicative variables of trials location, target

  13. The NOAO Pipeline Data Manager

    Science.gov (United States)

    Hiriart, R.; Valdes, F.; Pierfederici, F.; Smith, C.; Miller, M.

    2004-07-01

    The Data Manager for NOAO Pipeline system is a set of interrelated components that are being developed to fulfill the pipeline system data needs. It includes: (1) management of calibration files (flat, bias, bad pixel mask and xtalk calibration data.); (2) management of the pipeline stages' configuration parameters; and (3) management of the pipeline processing historic information, for each of the data products generated by the pipeline. The Data Manager components uses a distributed, CORBA based architecture, providing a flexible and extensible object oriented framework, capable of accommodating the present and future pipeline data requirements. The Data Manager communicates with the pipeline modules, with internal and external databases, and with other NOAO systems such as the NOAO Archive and the NOAO Data Transport System.

  14. Cosmological and supernova neutrinos

    Energy Technology Data Exchange (ETDEWEB)

    Kajino, T. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan Department of Astronomy, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033 (Japan); Aoki, W. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Balantekin, A. B. [Department of Physics, University of Wisconsin - Madison, Wisconsin 53706 (United States); Cheoun, M.-K. [Department of Physics, Soongsil University, Seoul 156-743 (Korea, Republic of); Hayakawa, T. [Japan Atomic Energy Agency, Shirakara-Shirane 2-4, Tokai-mura, Ibaraki 319-1195 (Japan); Hidaka, J. [National Astronomical Observatory, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Hirai, Y.; Shibagaki, S. [National Astronomical Observatory, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan and Department of Astronomy, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033 (Japan); Kusakabe, M. [School of Liberal Arts and Science, Korea Aerospace University, Goyang 412-791 (Korea, Republic of); Mathews, G. J. [Department of Physics, University of Notre Dame, IN 46556 (United States); Nakamura, K. [Waseda University, Ohkubo 3-4-1, Shinjuku, Tokyo 169-8555 (Japan); Pehlivan, Y. [Mimar Sinan GSÜ, Department of Physics, Şişli, İstanbul 34380 (Turkey); Suzuki, T. [Nihon University, Sakurajosui 3-25-40, Setagaya-ku, Tokyo 156-8550 (Japan)

    2014-06-24

    The Big Bang nucleosynthesis (BBN) and the cosmic microwave background (CMB) anisotropies are the pillars of modern cosmology. It has recently been suggested that axion which is a dark matter candidate in the framework of the standard model could condensate in the early universe and induce photon cooling before the epoch of the photon last scattering. Although this may render a solution to the overproduction problem of primordial {sup 7}Li abundance, there arises another serious difficulty of overproducing D abundance. We propose a hybrid dark matter model with both axions and relic supersymmetric (SUSY) particles to solve both overproduction problems of the primordial D and {sup 7}Li abundances simultaneously. The BBN also serves to constrain the nature of neutrinos. Considering non-thermal photons produced in the decay of the heavy sterile neutrinos due to the magnetic moment, we explore the cosmological constraint on the strength of neutrino magnetic moment consistent with the observed light element abundances. Core-collapse supernovae eject huge flux of energetic neutrinos which affect explosive nucleosynthesis of rare isotopes like {sup 7}Li, {sup 11}B, {sup 92}Nb, {sup 138}La and {sup 180}Ta and r-process elements. Several isotopes depend strongly on the neutrino flavor oscillation due to the Mikheyev-Smirnov-Wolfenstein (MSW) effect. Combining the recent experimental constraints on θ{sub 13} with predicted and observed supernova-produced abundance ratio {sup 11}B/{sup 7}Li encapsulated in the presolar grains from the Murchison meteorite, we show a marginal preference for an inverted neutrino mass hierarchy. We also discuss supernova relic neutrinos (SRN) that may indicate the softness of the equation of state (EoS) of nuclear matter and adiabatic conditions of the neutrino oscillation.

  15. GALAXY OUTFLOWS WITHOUT SUPERNOVAE

    Energy Technology Data Exchange (ETDEWEB)

    Sur, Sharanya [Indian Institute of Astrophysics, 2nd Block, Koramangala, Bangalore 560034 (India); Scannapieco, Evan [School of Earth and Space Exploration, Arizona State University, P.O. Box 876004, Tempe-85287 (United States); Ostriker, Eve C., E-mail: sharanya.sur@iiap.res.in, E-mail: sharanya.sur@asu.edu [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States)

    2016-02-10

    High surface density, rapidly star-forming galaxies are observed to have ≈50–100 km s{sup −1} line of sight velocity dispersions, which are much higher than expected from supernova driving alone, but may arise from large-scale gravitational instabilities. Using three-dimensional simulations of local regions of the interstellar medium, we explore the impact of high velocity dispersions that arise from these disk instabilities. Parametrizing disks by their surface densities and epicyclic frequencies, we conduct a series of simulations that probe a broad range of conditions. Turbulence is driven purely horizontally and on large scales, neglecting any energy input from supernovae. We find that such motions lead to strong global outflows in the highly compact disks that were common at high redshifts, but weak or negligible mass loss in the more diffuse disks that are prevalent today. Substantial outflows are generated if the one-dimensional horizontal velocity dispersion exceeds ≈35 km s{sup −1}, as occurs in the dense disks that have star-formation rate (SFR) densities above ≈0.1 M{sub ⊙} yr{sup −1} kpc{sup −2}. These outflows are triggered by a thermal runaway, arising from the inefficient cooling of hot material coupled with successive heating from turbulent driving. Thus, even in the absence of stellar feedback, a critical value of the SFR density for outflow generation can arise due to a turbulent heating instability. This suggests that in strongly self-gravitating disks, outflows may be enhanced by, but need not caused by, energy input from supernovae.

  16. New Galactic supernova remnants discovered with IPHAS

    CERN Document Server

    Sabin, L; Contreras, M E; Olguín, L; Frew, D J; Stupar, M; Vázquez, R; Wright, N J; Corradi, R L M; Morris, R A H

    2013-01-01

    As part of a systematic search programme of a 10-degree wide strip of the Northern Galactic plane we present preliminary evidence for the discovery of four (and possibly five) new supernova remnants (SNRs). The pilot search area covered the 19-20 hour right ascension zone sampling from +20 to +55 degrees in declination using binned mosaic images from the INT Photometric H-alpha Survey (IPHAS). The optical identification of the candidate SNRs was based mainly on their filamentary and arc-like emission morphologies, their apparently coherent, even if fractured structure and clear disconnection from any diffuse neighbouring HII region type nebulosity. Follow-up optical spectroscopy was undertaken, sampling carefully across prominent features of these faint sources. The resulting spectra revealed typical emission line ratios for shock excited nebulae which are characteristic of SNRs, which, along with the latest diagnostic diagrams, strongly support the likely SNR nature of these sources: G038.7-1.3 (IPHASX J1906...

  17. Supernovae anisotropy power spectrum

    CERN Document Server

    Ghodsi, Hoda; Habibi, Farhang

    2016-01-01

    We contribute another anisotropy study to this field of research using Supernovae Type Ia (SNe Ia). In this work, we utilise the power spectrum calculation method and apply it to both the current SNe Ia data and simulation. Our simulations are constructed with the characteristics of the upcoming survey of the Large Synoptic Survey Telescope (LSST), which shall bring us the largest SNe Ia collection to date. We make predictions for the amplitude of a possible dipole anisotropy or anisotropy in higher multipole moments that would be detectable by the LSST.

  18. Detection strategies for a supernova gravitational wave burst in a network of interferometric detectors

    CERN Document Server

    Arnaud, N; Bizouard, M A; Brisson, V; Cavalier, F; Davier, M; Hello, P; Kreckelberg, S; Porter, E K; Arnaud, Nicolas; Barsuglia, Matteo; Bizouard, Marie-Anne; Brisson, Violette; Cavalier, Fabien; Davier, Michel; Hello, Patrice; Kreckelberg, Stephane; Porter, Edward K.

    2003-01-01

    Trying to detect the gravitational wave (GW) signal emitted by a type II supernova is a main challenge for the GW community. Indeed, the corresponding waveform is not accurately modeled as the supernova physics is very complex; in addition, all the existing numerical simulations agree on the weakness of the GW emission, thus restraining the number of sources potentially detectable. Consequently, triggering the GW signal with a confidence level high enough to conclude directly to a detection is very difficult, even with the use of a network of interferometric detectors. On the other hand, one can hope to take benefit from the neutrino and optical emissions associated to the supernova explosion, in order to discover and study GW radiation in an event already detected independently. This article aims at presenting some realistic scenarii for the search of the supernova GW bursts, based on the present knowledge of the emitted signals and on the results of network data analysis simulations. Both the direct search ...

  19. Vulnerability of pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2006-07-01

    Although pipelines may be damaged due to natural sources such as stress corrosion cracking (SCC) or hydrogen-induced cracking (HIC), most pipeline damages are a result of third-party interference, such as unauthorized construction in a right of way. Pipelines are also among the prime targets for sabotage because interruptions in energy distribution can render large segments of a population debilitated. The importance of protecting critical infrastructure was emphasized in this theme issue which disseminated information on vulnerability of pipelines due to third-party intrusions, both intentional and unintentional. It summarized the 10 presentations that were delivered at a pipelines security forum in Calgary, Alberta, addressing Canadian and U.S. government and industry approaches to oil and natural gas pipeline security. The opening keynote address remarked on the evolution of international terror networks, the targeting of the energy sector, and the terrorist threat and presence in Canada. Policies towards critical energy infrastructure protection (CIP) were then examined in light of these threats. A policy shift away from traditional defensive protective security towards an offensive intelligence-led strategy to forestall terrorist threats was advocated. Energy sector representatives agreed that Canada needs an effective national lead agency to provide threat assessments, alert notification, and coordination of information pertaining to CIP. It was agreed that early warning information must come from Canadian as well as U.S. sources in order to be pertinent. The conference session on information collection concentrated on defining what sort of threat information is needed by the energy sector, who should collect it and how should it be shared. It was emphasized that government leadership should coordinate threat reporting and disseminate information, set standards, and address the issues of terrorism risk insurance. Concern was raised about the lack of

  20. Instrumented Pipeline Initiative

    Energy Technology Data Exchange (ETDEWEB)

    Thomas Piro; Michael Ream

    2010-07-31

    This report summarizes technical progress achieved during the cooperative agreement between Concurrent Technologies Corporation (CTC) and U.S. Department of Energy to address the need for a for low-cost monitoring and inspection sensor system as identified in the Department of Energy (DOE) National Gas Infrastructure Research & Development (R&D) Delivery Reliability Program Roadmap.. The Instrumented Pipeline Initiative (IPI) achieved the objective by researching technologies for the monitoring of pipeline delivery integrity, through a ubiquitous network of sensors and controllers to detect and diagnose incipient defects, leaks, and failures. This report is organized by tasks as detailed in the Statement of Project Objectives (SOPO). The sections all state the objective and approach before detailing results of work.

  1. Pipeline ADC Design Methodology

    OpenAIRE

    Zhao, Hui

    2012-01-01

    Demand for high-performance analog-to-digital converter (ADC) integrated circuits (ICs) with optimal combined specifications of resolution, sampling rate and power consumption becomes dominant due to emerging applications in wireless communications, broad band transceivers, digital-intermediate frequency (IF) receivers and countless of digital devices. This research is dedicated to develop a pipeline ADC design methodology with minimum power dissipation, while keeping relatively high speed an...

  2. Pipeline ADC Design Methodology

    OpenAIRE

    Zhao, Hui

    2012-01-01

    Demand for high-performance analog-to-digital converter (ADC) integrated circuits (ICs) with optimal combined specifications of resolution, sampling rate and power consumption becomes dominant due to emerging applications in wireless communications, broad band transceivers, digital-intermediate frequency (IF) receivers and countless of digital devices. This research is dedicated to develop a pipeline ADC design methodology with minimum power dissipation, while keeping relatively high speed an...

  3. The MIS Pipeline Toolkit

    Science.gov (United States)

    Teuben, Peter J.; Pound, M. W.; Storm, S.; Mundy, L. G.; Salter, D. M.; Lee, K.; Kwon, W.; Fernandez Lopez, M.; Plunkett, A.

    2013-01-01

    A pipeline toolkit was developed to help organizing, reducing and analyzing a large number of near-identical datasets. This is a very general problem, for which many different solutions have been implemented. In this poster we present one such solution that lends itself to users of the Unix command line, using the Unix "make" utility, and adapts itself easily to observational as well as theoretical projects. Two examples are given, one from the CARMA CLASSy survey, and another from a simulated kinematic survey of early galaxy forming disks. The CLASSy survey (discussed in more detail in three accompanying posters) consists of 5 different star forming regions, observed with CARMA, each containing roughly 10-20 datasets in continuum and 3 different molecular lines, that need to be combined in final data cubes and maps. The strength of such a pipeline toolkit shows itself as new data are accumulated, the data reduction steps are improved and easily re-applied to previously taken data. For this we employed a master script that was run nightly, and collaborators submitted improved script and/or pipeline parameters that control these scripts. MIS is freely available for download.

  4. ALMA Pipeline Heuristics

    Science.gov (United States)

    Muders, D.; Boone, F.; Wyrowski, F.; Lightfoot, J.; Kosugi, G.; Wilson, C.; Davis, L.; Shepherd, D.

    2007-10-01

    The Atacama Large Millimeter Array / Atacama Compact Array (ALMA / ACA) Pipeline Heuristics system is being developed to automatically reduce data taken with the standard observing modes such as single fields, mosaics or on-the-fly maps. The goal is to make ALMA user-friendly to astronomers who are not experts in radio interferometry. The Pipeline Heuristics must capture the expert knowledge required to provide data products that can be used without further processing. The Pipeline Heuristics system is being developed as a set of Python scripts using as the data processing engines the Common Astronomy Software Applications (CASA[PY]) libraries and the ATNF Spectral Analysis Package (ASAP). The interferometry heuristics scripts currently provide an end-to-end process for the single field mode comprising flagging, initial calibration, re-flagging, re-calibration, and imaging of the target data. A Java browser provides user-friendly access to the heuristics results. The initial single-dish heuristics scripts implement automatic spectral line detection, baseline fitting and image gridding. The resulting data cubes are analyzed to detect source emission spectrally and spatially in order to calculate signal-to-noise ratios for comparison against the science goals specified by the observer.

  5. ALMA Pipeline Heuristics

    Science.gov (United States)

    Lightfoot, J.; Wyrowski, F.; Muders, D.; Boone, F.; Davis, L.; Shepherd, D.; Wilson, C.

    2006-07-01

    The ALMA (Atacama Large Millimeter Array) Pipeline Heuristics system is being developed to automatically reduce data taken with the standard observing modes. The goal is to make ALMA user-friendly to astronomers who are not experts in radio interferometry. The Pipeline Heuristics system must capture the expert knowledge required to provide data products that can be used without further processing. Observing modes to be processed by the system include single field interferometry, mosaics and single dish `on-the-fly' maps, and combinations of these modes. The data will be produced by the main ALMA array, the ALMA Compact Array (ACA) and single dish antennas. The Pipeline Heuristics system is being developed as a set of Python scripts. For interferometry these use as data processing engines the CASA/AIPS++ libraries and their bindings as CORBA objects within the ALMA Common Software (ACS). Initial development has used VLA and Plateau de Bure data sets to build and test a heuristic script capable of reducing single field data. In this paper we describe the reduction datapath and the algorithms used at each stage. Test results are presented. The path for future development is outlined.

  6. The inverse electroencephalography pipeline

    Science.gov (United States)

    Weinstein, David Michael

    The inverse electroencephalography (EEG) problem is defined as determining which regions of the brain are active based on remote measurements recorded with scalp EEG electrodes. An accurate solution to this problem would benefit both fundamental neuroscience research and clinical neuroscience applications. However, constructing accurate patient-specific inverse EEG solutions requires complex modeling, simulation, and visualization algorithms, and to date only a few systems have been developed that provide such capabilities. In this dissertation, a computational system for generating and investigating patient-specific inverse EEG solutions is introduced, and the requirements for each stage of this Inverse EEG Pipeline are defined and discussed. While the requirements of many of the stages are satisfied with existing algorithms, others have motivated research into novel modeling and simulation methods. The principal technical results of this work include novel surface-based volume modeling techniques, an efficient construction for the EEG lead field, and the Open Source release of the Inverse EEG Pipeline software for use by the bioelectric field research community. In this work, the Inverse EEG Pipeline is applied to three research problems in neurology: comparing focal and distributed source imaging algorithms; separating measurements into independent activation components for multifocal epilepsy; and localizing the cortical activity that produces the P300 effect in schizophrenia.

  7. Spectroscopic confirmation of high-redshift supernovae with the ESO VLT

    CERN Document Server

    Lidman, C E; Folatelli, G; Garavini, G; Nobili, S; Aldering, G; Amanullah, R; Antilogus, P; Astier, Pierre; Blanc, G; Burns, M S; Conley, A; Deustua, S E; Doi, M; Ellis, R; Fabbro, S; Fadeev, V; Gibbons, R; Goldhaber, G; Goobar, A; Groom, D E; Hook, I; Kashikawa, N; Kim, A G; Knop, R A; Lee Byung Cheol; Méndez, J; Morokuma, T; Motohara, K; Nugent, P; Pain, R; Perlmutter, S; Prasad, V; Quimby, R; Raux, J; Regnault, N; Ruiz-Lapuente, P; Sainton, G; Schaefer, B E; Schahmaneche, K; Smith, E; Spadafora, A L; Stanishev, V; Walton, N A; Wang, L; Wood-Vasey, W M; Yasuda, N

    2004-01-01

    We present VLT FORS1 and FORS2 spectra of 39 candidate high-redshift supernovae that were discovered as part of a cosmological study using Type Ia supernovae (SNe Ia) over a wide range of redshifts. From the spectra alone, 20 candidates are spectrally classified as SNe Ia with redshifts ranging from z=0.212 to z=1.181. Of the remaining 19 candidates, 1 might be a Type II supernova and 11 exhibit broad supernova-like spectral features and/or have supernova-like light curves. The candidates were discovered in 8 separate ground-based searches. In those searches in which SNe Ia at z ~ 0.5 were targeted, over 80% of the observed candidates were spectrally classified as SNe Ia. In those searches in which SNe Ia with z > 1 were targeted, 4 candidates with z > 1 were spectrally classified as SNe Ia and later followed with ground and space based observatories. We present the spectra of all candidates, including those that could not be spectrally classified as supernova.

  8. Supernova olivine from cometary dust

    Science.gov (United States)

    Messenger, Scott; Keller, Lindsay P.; Lauretta, Dante S.

    2005-01-01

    An interplanetary dust particle contains a submicrometer crystalline silicate aggregate of probable supernova origin. The grain has a pronounced enrichment in 18O/16O (13 times the solar value) and depletions in 17O/16O (one-third solar) and 29Si/28Si (olivine (forsterite 83) grains olivine grain could have formed by equilibrium condensation from cooling supernova ejecta if several different nucleosynthetic zones mixed in the proper proportions. The supernova grain is also partially encased in nitrogen-15-rich organic matter that likely formed in a presolar cold molecular cloud.

  9. Supernova Acceleration Probe: Studying Dark Energy with Type Ia Supernovae

    CERN Document Server

    Albert, J; Allam, S; Althouse, W E; Amanullah, R; Annis, J; Astier, Pierre; Aumeunier, M; Bailey, S; Baltay, C; Barrelet, E; Basa, S; Bebek, C; Bergström, L; Bernstein, G; Bester, M; Besuner, B; Bigelow, B; Blandford, R; Bohlin, R; Bonissent, A; Bower, C; Brown, M; Campbell, M; Carithers, W; Cole, D; Commins, Eugene D; Craig, W; Davis, T; Dawson, K; Day, C; De Harveng, M; De Jongh, F; Deustua, S; Diehl, H; Dobson, T; Dodelson, S; Ealet, A; Ellis, R; Emmet, W; Figer, D; Fouchez, D; Frerking, M; Frieman, J A; Fruchter, A; Gerdes, D; Gladney, L; Goldhaber, G; Goobar, A; Groom, D; Heetderks, H; Hoff, M; Holland, S; Huffer, M; Hui, L; Huterer, D; Jain, B; Jelinsky, P; Juramy, C; Karcher, A; Kent, S; Kahn, S; Kim, A; Kolbe, W; Krieger, B; Kushner, G; Kuznetsova, N; Lafever, R; Lamoureux, J; Lampton, M; Lefèvre, O; Lebrun, V; Levi, M; Limon, P; Lin, H; Linder, E; Loken, S; Lorenzon, W; Malina, R; Marian, L; Marriner, J P; Marshall, P; Massey, R; Mazure, A; McGinnis, B; McKay, T; McKee, S; Miquel, R; Mobasher, B; Morgan, N; Mortsell, E; Mostek, N; Mufson, S; Musser, J; Nakajima, R; Nugent, P; Olus, H; Pain, R; Palaio, N; Pankow, D; Peoples, John; Perlmutter, S; Peterson, D; Prieto, E; Rabinowitz, D; Réfrégier, A; Rhodes, J; Roe, N; Rusin, D; Scarpine, V; Schubnell, M; Seiffert, M; Sholl, M; Shukla, H; Smadja, G; Smith, R M; Smoot, George F; Snyder, J; Spadafora, A; Stabenau, F; Stebbins, A; Stoughton, C; Szymkowiak, A; Tarle, G; Taylor, K; Tilquin, A; Tomasch, A; Tucker, D; Vincent, D; Von der Lippe, H; Walder, J P; Wang, G; Weinstein, A; Wester, W; White, M

    2005-01-01

    The Supernova Acceleration Probe (SNAP) will use Type Ia supernovae (SNe Ia) as distance indicators to measure the effect of dark energy on the expansion history of the Universe. (SNAP's weak-lensing program is described in a companion White Paper.) The experiment exploits supernova distance measurements up to their fundamental systematic limit; strict requirements on the monitoring of each supernova's properties lead to the need for a space-based mission. Results from pre-SNAP experiments, which characterize fundamental SN Ia properties, will be used to optimize the SNAP observing strategy to yield data, which minimize both systematic and statistical uncertainties. SNAP has achieved technological readiness and the collaboration is poised to begin construction.

  10. Photometric redshifts for supernovae Ia in the Supernova Legacy Survey

    CERN Document Server

    Palanque-Delabrouille, Nathalie; Pascal, S; Rich, J; Guy, J; Bazin, G; Astier, P; Balland, C; Basa, S; Carlberg, R G; Conley, A; Fouchez, D; Hardin, D; Hook, I M; Howell, D A; Pain, R; Perrett, K; Pritchet, C J; Regnault, N; Sullivan, M

    2009-01-01

    We present a method using the SALT2 light curve fitter to determine the redshift of Type Ia supernovae in the Supernova Legacy Survey (SNLS) based on their photometry in g', r', i' and z'. On 289 supernovae of the first three years of SNLS data, we obtain a precision $\\sigma_{\\Delta z/(1+z)} = 0.022$ on average up to a redshift of 1.0, with a higher precision of 0.016 for z0.45. The rate of events with $|\\Delta z|/(1+z)>0.15$ (catastrophic errors) is 1.4%. Both the precision and the rate of catastrophic errors are better than what can be currently obtained using host galaxy photometric redshifts. Photometric redshifts of this precision may be useful for future experiments which aim to discover up to millions of supernovae Ia but without spectroscopy for most of them.

  11. Pipeline integrity : control by coatings

    Energy Technology Data Exchange (ETDEWEB)

    Khanna, A.S. [Indian Inst. of Technology, Bombay (India)

    2008-07-01

    This presentation provided background information on the history of cross-country pipelines in India. It discussed the major use of gas. The key users were described as being the power and fertilizer industries, followed by vehicles using compressed natural gas to replace liquid fuels and thereby reduce pollution. The presentation also addressed the integrity of pipelines in terms of high production, safety, and monitoring. Integrity issues of pipelines were discussed with reference to basic design, control of corrosion, and periodic health monitoring. Other topics that were outlined included integrity by corrosion control; integrity by health monitoring; coatings requirements; classification of UCC pipeline coatings; and how the pipeline integrity approach can help to achieve coatings which give design life without any failure. Surface cleanliness, coating conditions, and the relationship between temperature of Epoxy coating and the time of adhesive coating were also discussed. Last, the presentation provided the results of an audit of the HBJ pipeline conducted from 1999 to 2000. tabs., figs.

  12. Magnetar-Powered Supernovae in Two Dimensions. I. Superluminous Supernovae

    OpenAIRE

    Chen, Ke-Jung; Woosley, S. E.; Sukhbold, Tuguldur

    2016-01-01

    Previous studies have shown that the radiation emitted by a rapidly rotating magnetar embedded in a young supernova can greatly amplify its luminosity. These one-dimensional studies have also revealed the existence of an instability arising from the piling up of radiatively accelerated matter in a thin dense shell deep inside the supernova. Here we examine the problem in two dimensions and find that, while instabilities cause mixing and fracture this shell into filamentary structures that red...

  13. Slurry pipeline technology: an overview

    Energy Technology Data Exchange (ETDEWEB)

    Chapman, Jay P. [Pipeline Systems Incorporated (PSI), Belo Horizonte, MG (Brazil); Lima, Rafael; Pinto, Daniel; Vidal, Alisson [Ausenco do Brasil Engenharia Ltda., Nova Lima, MG (Brazil). PSI Div.

    2009-12-19

    Slurry pipelines represent an economical and environmentally friendly transportation means for many solid materials. This paper provides an over-view of the technology, its evolution and current Brazilian activity. Mineral resources are increasingly moving farther away from ports, processing plants and end use points, and slurry pipelines are an important mode of solids transport. Application guidelines are discussed. State-of-the-Art technical solutions such as pipeline system simulation, pipe materials, pumps, valves, automation, telecommunications, and construction techniques that have made the technology successful are presented. A discussion of where long distant slurry pipelines fit in a picture that also includes thickened and paste materials pipe lining is included. (author)

  14. The Vela Supernova Remnant

    Science.gov (United States)

    Raymond, John C.

    We wish to obtain both emission and absorption line observations of the Vela Supernova remnant. The filament we wish to study in emission is the brightest filament in the SNR, so it will provide a spectrum twice the quality of any in existence. It is also located at the edge of an unusual bulge in the SNR, and it can be used to test the level of departure from pressure equilibrium in the remnant, which is useful as a test of evaporative models of SNR evolution. The absorption line studies will look for evidence of the drastically unstable behavior of shocks above 150 km/s predicted by Innes and Giddings. Four of the stars studied by Jenkins, Silk and Wallerstein showed marginal evidence for two positive or two negative high velocity components. If these multiple velocity components are confirmed, they support the secondary shock predictions of Innes and Giddings.

  15. Neutrinos and nucleosynthesis in supernova

    Energy Technology Data Exchange (ETDEWEB)

    Solis, U [Instituto de Ciencias Nucleares, Departamento de Fisica de Altas EnergIas, Universidad Nacional Autonoma de Mexico (ICN-UNAM). Apartado Postal 70-543, 04510 Mexico, D.F. (Mexico); D' Olivo, J C [Instituto de Ciencias Nucleares, Departamento de Fisica de Altas EnergIas, Universidad Nacional Autonoma de Mexico (ICN-UNAM). Apartado Postal 70-543, 04510 Mexico, D.F. (Mexico); Cabral-Rosetti, L G [Departamento de Posgrado, Centro Interdisciplinario de Investigacion y Docencia en Educacion Tecnica (CIIDET), Av. Universidad 282 Pte., Col. Centro, A. Postal 752, C.P. 76000, Santiago de Queretaro, Qro. (Mexico)

    2006-05-15

    The type II supernova is considered as a candidate site for the production of heavy elements. The nucleosynthesis occurs in an intense neutrino flux, we calculate the electron fraction in this environment.

  16. The Diffuse Supernova Neutrino Background

    CERN Document Server

    Beacom, John F

    2010-01-01

    The Diffuse Supernova Neutrino Background (DSNB) is the weak glow of MeV neutrinos and antineutrinos from distant core-collapse supernovae. The DSNB has not been detected yet, but the Super-Kamiokande (SK) 2003 upper limit on the electron antineutrino flux is close to predictions, now quite precise, based on astrophysical data. If SK is modified with dissolved gadolinium to reduce detector backgrounds and increase the energy range for analysis, then it should detect the DSNB at a rate of a few events per year, providing a new probe of supernova neutrino emission and the cosmic core-collapse rate. If the DSNB is not detected, then new physics will be required. Neutrino astronomy, while uniquely powerful, has proven extremely difficult -- only the Sun and the nearby Supernova 1987A have been detected to date -- so the promise of detecting new sources soon is exciting indeed.

  17. Toward a Standard Model of Core Collapse Supernovae

    OpenAIRE

    Mezzacappa, A.

    2000-01-01

    In this paper, we discuss the current status of core collapse supernova models and the future developments needed to achieve significant advances in understanding the supernova mechanism and supernova phenomenology, i.e., in developing a supernova standard model.

  18. [SKLOF: a new algorithm to reduce the range of supernova candidates].

    Science.gov (United States)

    Tu, Liang-ping; Wei, Hui-ming; Wei, Peng; Pan, Jing-chang; Luo, A-li; Zhao, Yong-heng

    2015-01-01

    Supernova (SN) is called the "standard candles" in the cosmology, the probability of outbreak in the galaxy is very low and is a kind of special, rare astronomical objects. Only in a large number of galaxies, we have a chance to find the supernova. The supernova which is in the midst of explosion will illuminate the entire galaxy, so the spectra of galaxies we obtained have obvious features of supernova. But the number of supernova have been found is very small relative to the large number of astronomical objects. The time computation that search the supernova be the key to weather the follow-up observations, therefore it needs to look for an efficient method. The time complexity of the density-based outlier detecting algorithm (LOF) is not ideal, which effects its application in large datasets. Through the improvement of LOF algorithm, a new algorithm that reduces the searching range of supernova candidates in a flood of spectra of galaxies is introduced and named SKLOF. Firstly, the spectra datasets are pruned and we can get rid of most objects are impossible to be the outliers. Secondly, we use the improved LOF algorithm to calculate the local outlier factors (LOF) of the spectra datasets remained and all LOFs are arranged in descending order. Finally, we can get the smaller searching range of the supernova candidates for the subsequent identification. The experimental results show that the algorithm is very effective, not only improved in accuracy, but also reduce the operation time compared with LOF algorithm with the guarantee of the accuracy of detection.

  19. Supernovae and Gamma Ray Bursts

    Directory of Open Access Journals (Sweden)

    M. Della Valle

    2007-01-01

    Full Text Available Se revisa el estatus observacional de la conexi on Supernova (SN/Estallido de Rayos-Gamma (GRB. Recientes (y no tan recientes observaciones de GRBs largos sugieren que una fracci on signi cativa de ellos (pero no todos est an asociados con supernovas brillantes del tipo Ib/c. Estimaciones actuales de las tasas de producci on de GRBs y SNs dan una raz on para GRB/SNe-Ibc en el rango 0:4%

  20. INTERNAL REPAIR OF PIPELINES

    Energy Technology Data Exchange (ETDEWEB)

    Bill Bruce; Nancy Porter; George Ritter; Matt Boring; Mark Lozev; Ian Harris; Bill Mohr; Dennis Harwig; Robin Gordon; Chris Neary; Mike Sullivan

    2005-07-20

    The two broad categories of fiber-reinforced composite liner repair and deposited weld metal repair technologies were reviewed and evaluated for potential application for internal repair of gas transmission pipelines. Both are used to some extent for other applications and could be further developed for internal, local, structural repair of gas transmission pipelines. Principal conclusions from a survey of natural gas transmission industry pipeline operators can be summarized in terms of the following performance requirements for internal repair: (1) Use of internal repair is most attractive for river crossings, under other bodies of water, in difficult soil conditions, under highways, under congested intersections, and under railway crossings. (2) Internal pipe repair offers a strong potential advantage to the high cost of horizontal direct drilling when a new bore must be created to solve a leak or other problem. (3) Typical travel distances can be divided into three distinct groups: up to 305 m (1,000 ft.); between 305 m and 610 m (1,000 ft. and 2,000 ft.); and beyond 914 m (3,000 ft.). All three groups require pig-based systems. A despooled umbilical system would suffice for the first two groups which represents 81% of survey respondents. The third group would require an onboard self-contained power unit for propulsion and welding/liner repair energy needs. (4) The most common size range for 80% to 90% of operators surveyed is 508 mm (20 in.) to 762 mm (30 in.), with 95% using 558.8 mm (22 in.) pipe. Evaluation trials were conducted on pipe sections with simulated corrosion damage repaired with glass fiber-reinforced composite liners, carbon fiber-reinforced composite liners, and weld deposition. Additional un-repaired pipe sections were evaluated in the virgin condition and with simulated damage. Hydrostatic failure pressures for pipe sections repaired with glass fiber-reinforced composite liner were only marginally greater than that of pipe sections without

  1. A New Determination of the High Redshift Type Ia Supernova Rateswith the Hubble Space Telescope Advanced Camera for Surveys

    Energy Technology Data Exchange (ETDEWEB)

    Kuznetsova, N.; Barbary, K.; Connolly, B.; Kim, A.G.; Pain, R.; Roe, N.A.; Aldering, G.; Amanullah, R.; Dawson, K.; Doi, M.; Fadeyev, V.; Fruchter, A.S.; Gibbons, R.; Goldhaber, G.; Goober, A.; Gude, A.; Knop,R.A.; Kowalski, M.; Lidman, C.; Morokuma, T.; Meyers, J.; Perlmutter, S.; Rubin, D.; Schlegel, D.J.; Spadafora, A.L.; Stanishev, V.; Strovink, M.; Suzuki, N.; Wang, L.; Yasuda, N.

    2007-10-01

    We present a new measurement of the volumetric rate of Type Ia supernova up to a redshift of 1.7, using the Hubble Space Telescope (HST) GOODS data combined with an additional HST dataset covering the North GOODS field collected in 2004. We employ a novel technique that does not require spectroscopic data for identifying Type Ia supernovae (although spectroscopic measurements of redshifts are used for over half the sample); instead we employ a Bayesian approach using only photometric data to calculate the probability that an object is a Type Ia supernova. This Bayesian technique can easily be modified to incorporate improved priors on supernova properties, and it is well-suited for future high-statistics supernovae searches in which spectroscopic follow up of all candidates will be impractical. Here, the method is validated on both ground- and space-based supernova data having some spectroscopic follow up. We combine our volumetric rate measurements with low redshift supernova data, and fit to a number of possible models for the evolution of the Type Ia supernova rate as a function of redshift. The data do not distinguish between a flat rate at redshift > 0.5 and a previously proposed model, in which the Type Ia rate peaks at redshift {approx} 1 due to a significant delay from star-formation to the supernova explosion. Except for the highest redshifts, where the signal to noise ratio is generally too low to apply this technique, this approach yields smaller or comparable uncertainties than previous work.

  2. Ozone Depletion from Nearby Supernovae

    CERN Document Server

    Gehrels, N; Jackman, C H; Cannizzo, J K; Mattson, B J; Chen, W; Gehrels, Neil; Laird, Claude M.; Jackman, Charles H.; Cannizzo, John K.; Mattson, Barbara J.; Chen, Wan

    2003-01-01

    Estimates made in the 1970's indicated that a supernova occurring within tens of parsecs of Earth could have significant effects on the ozone layer. Since that time, improved tools for detailed modeling of atmospheric chemistry have been developed to calculate ozone depletion, and advances have been made in theoretical modeling of supernovae and of the resultant gamma-ray spectra. In addition, one now has better knowledge of the occurrence rate of supernovae in the galaxy, and of the spatial distribution of progenitors to core-collapse supernovae. We report here the results of two-dimensional atmospheric model calculations that take as input the spectral energy distribution of a supernova, adopting various distances from Earth and various latitude impact angles. In separate simulations we calculate the ozone depletion due to both gamma-rays and cosmic rays. We find that for the combined ozone depletion roughly to double the ``biologically active'' UV flux received at the surface of the Earth, the supernova mu...

  3. Ozone Depletion from Nearby Supernovae

    Science.gov (United States)

    Gehrels, Neil; Laird, Claude M.; Jackman, Charles H.; Cannizzo, John K.; Mattson, Barbara J.; Chen, Wan; Bhartia, P. K. (Technical Monitor)

    2002-01-01

    Estimates made in the 1970's indicated that a supernova occurring within tens of parsecs of Earth could have significant effects on the ozone layer. Since that time improved tools for detailed modeling of atmospheric chemistry have been developed to calculate ozone depletion, and advances have been made also in theoretical modeling of supernovae and of the resultant gamma ray spectra. In addition, one now has better knowledge of the occurrence rate of supernovae in the galaxy, and of the spatial distribution of progenitors to core-collapse supernovae. We report here the results of two-dimensional atmospheric model calculations that take as input the spectral energy distribution of a supernova, adopting various distances from Earth and various latitude impact angles. In separate simulations we calculate the ozone depletion due to both gamma rays and cosmic rays. We find that for the combined ozone depletion from these effects roughly to double the 'biologically active' UV flux received at the surface of the Earth, the supernova must occur at approximately or less than 8 parsecs.

  4. First supernova companion star found

    Science.gov (United States)

    2004-01-01

    Supernova 1993J exploding hi-res Size hi-res: 222 kb Credits: ESA and Justyn R. Maund (University of Cambridge) Supernova 1993J exploding (artist’s impression) New observations with the Hubble Space Telescope allow a look into a supernova explosion under development. In this artist’s view the red supergiant supernova progenitor star (left) is exploding after having transferred about 10 solar masses of hydrogen gas to the blue companion star (right). This interaction process happened over about 250 years and affected the supernova explosion to such an extent that SN 1993J was later known as one of the most peculiar supernovae ever seen. Supernova 1993J exploding hi-res Size hi-res: 4200 kb Credits: ESA and Justyn R. Maund (University of Cambridge) The site of the Supernova 1993J explosion A virtual journey into one of the spiral arms of the grand spiral Messier 81 (imaged with the Isaac Newton Telescope on La Palma, left) reveals the superb razor-sharp imaging power of the NASA/ESA Hubble Space Telescope (Hubble’s WFPC2 instrument, below). The close-up (with Hubble’s ACS, to the right) is centred on the newly discovered companion star to Supernova 1993J that itself is no longer visible. The quarter-circle around the supernova companion is a so-called light echo originating from sheets of dust in the galaxy reflecting light from the original supernova explosion. Supernova 1993J explosing site hi-res Size hi-res: 1502 kb Credits: ESA and Justyn R. Maund (University of Cambridge) Close-up of the Supernova 1993J explosion site (ACS/HRC image) This NASA/ESA Hubble Space Telescope image shows the area in Messier 81 where Supernova 1993J exploded. The companion to the supernova ‘mother star’ that remains after the explosion is seen in the centre of the image. The image is taken with Hubble’s Advanced Camera for Surveys and is a combination of four exposures taken with ACS’ High Resolution Camera. The exposures were taken through two near-UV filters (250W

  5. Kvitebjoern gas pipeline repair - baptism of remote pipeline repair system

    Energy Technology Data Exchange (ETDEWEB)

    Gjertveit, Erling

    2010-07-01

    On the 1st of November 2007, severe anchor damage was discovered on the 30 inch Kvitebjoern gas export pipeline. The damage constituted a localised dent and a 17deg buckle, but no leakage. Statoil has invested in building an effective repair contingency structure for the large pipeline network on the Norwegian Continental shelf, with particular focus on the large gas export pipelines. The repair method for the Kvitebjoern pipeline was remotely operated using two Morgrip couplings and a spool. The installation used the purpose built Pipeline Repair System stored at Killingoey and couplings produced and tested back in 2005. This presentation will cover the initial damage investigations, the temporary operational phase, the repair preparations, the actual repair and lessons learned. (Author)

  6. A mildly relativistic radio jet from the otherwise normal type Ic supernova 2007gr.

    Science.gov (United States)

    Paragi, Z; Taylor, G B; Kouveliotou, C; Granot, J; Ramirez-Ruiz, E; Bietenholz, M; van der Horst, A J; Pidopryhora, Y; van Langevelde, H J; Garrett, M A; Szomoru, A; Argo, M K; Bourke, S; Paczyński, B

    2010-01-28

    The class of type Ic supernovae have drawn increasing attention since 1998 owing to their sparse association (only four so far) with long duration gamma-ray bursts (GRBs). Although both phenomena originate from the core collapse of a massive star, supernovae emit mostly at optical wavelengths, whereas GRBs emit mostly in soft gamma-rays or hard X-rays. Though the GRB central engine generates ultra-relativistic jets, which beam the early emission into a narrow cone, no relativistic outflows have hitherto been found in type Ib/c supernovae explosions, despite theoretical expectations and searches. Here we report radio (interferometric) observations that reveal a mildly relativistic expansion in a nearby type Ic supernova, SN 2007gr. Using two observational epochs 60 days apart, we detect expansion of the source and establish a conservative lower limit for the average apparent expansion velocity of 0.6c. Independently, a second mildly relativistic supernova has been reported. Contrary to the radio data, optical observations of SN 2007gr indicate a typical type Ic supernova with ejecta velocities approximately 6,000 km s(-1), much lower than in GRB-associated supernovae. We conclude that in SN 2007gr a small fraction of the ejecta produced a low-energy mildly relativistic bipolar radio jet, while the bulk of the ejecta were slower and, as shown by optical spectropolarimetry, mildly aspherical.

  7. Transportation of coal by pipeline

    Energy Technology Data Exchange (ETDEWEB)

    Round, G.F.

    1982-01-01

    Discusses Canada's coal resources, technology of long distance coal slurry pipelines, existing and planned coal slurry pipelines, their economics, liquid carbon dioxide, methanol and crude oil instead of water as carrier fluid, and coal slurry research in Canada.

  8. SAND: Automated VLBI imaging and analyzing pipeline

    Science.gov (United States)

    Zhang, Ming

    2016-05-01

    The Search And Non-Destroy (SAND) is a VLBI data reduction pipeline composed of a set of Python programs based on the AIPS interface provided by ObitTalk. It is designed for the massive data reduction of multi-epoch VLBI monitoring research. It can automatically investigate calibrated visibility data, search all the radio emissions above a given noise floor and do the model fitting either on the CLEANed image or directly on the uv data. It then digests the model-fitting results, intelligently identifies the multi-epoch jet component correspondence, and recognizes the linear or non-linear proper motion patterns. The outputs including CLEANed image catalogue with polarization maps, animation cube, proper motion fitting and core light curves. For uncalibrated data, a user can easily add inline modules to do the calibration and self-calibration in a batch for a specific array.

  9. Twin Supernova Studies with SNe Ia from SNfactory

    Science.gov (United States)

    Fakhouri, Hannah; Aldering, G.; Aragon, C.; Hsiao, E.; Loken, S.; Nugent, P.; Perlmutter, S.; Runge, K.; Thomas, R. C.; Antilogous, P.; Bongard, S.; Canto, A.; Pain, R.; Wu, C.; Chotard, N.; Copin, Y.; Gangler, E.; Pereira, R.; Smadja, G.; Pecontal, E.; Baltay, C.; Rabinowitz, D.; Scalzo, R.; Buton, C.; Kerschhaggl, M.; Kowalski, M.; Paech, K.; Tao, C.

    2011-01-01

    We present a study of twin supernovae with spectrophotometric timeseries of nearby Type Ia supernova from the Nearby Supernova Factory (Aldering, et al. 2002). One advantage of "twins” is they offer the best opportunity for having objects with the same intrinsic luminosities and colors, ostensibly leaving only extrinsic factors such as dust to explain any observed differences in brightness and color. Using well-sampled timeseries data for over 100 nearby Hubble-flow SNe Ia, we study the impact of dust on the brightness differences of SN Ia twins in order to improve the standardization of these standardizable candles that have been and will continue to be a primary tool in the determination of cosmological parameters. Specifically we are able to solve for the relative extinction and RV needed to bring the twins into near-perfect agreement. We will present a study of the resulting distribution of RV. In searching for twin supernovae we have found groups of SNe, again differing only by a dust law that accounts for the brightness differences. These groups allow us to look for similarities in subsets of SNe and explore spectrophotometric differences from group to group.

  10. How Bright Can Supernovae Get?

    Science.gov (United States)

    Kohler, Susanna

    2016-04-01

    Supernovae enormous explosions associated with the end of a stars life come in a variety of types with different origins. A new study has examined how the brightest supernovae in the Universe are produced, and what limits might be set on their brightness.Ultra-Luminous ObservationsRecent observations have revealed many ultra-luminous supernovae, which haveenergies that challenge our abilities to explain them usingcurrent supernova models. An especially extreme example is the 2015 discovery of the supernova ASASSN-15lh, which shone with a peak luminosity of ~2*1045 erg/s, nearly a trillion times brighter than the Sun. ASASSN-15lh radiated a whopping ~2*1052 erg in the first four months after its detection.How could a supernova that bright be produced? To explore the answer to that question, Tuguldur Sukhbold and Stan Woosley at University of California, Santa Cruz, have examined the different sources that could produce supernovae and calculated upper limits on the potential luminosities ofeach of these supernova varieties.Explosive ModelsSukhbold and Woosley explore multiple different models for core-collapse supernova explosions, including:Prompt explosionA stars core collapses and immediately explodes.Pair instabilityElectron/positron pair production at a massive stars center leads to core collapse. For high masses, radioactivity can contribute to delayed energy output.Colliding shellsPreviously expelled shells of material around a star collide after the initial explosion, providing additional energy release.MagnetarThe collapsing star forms a magnetar a rapidly rotating neutron star with an incredibly strong magnetic field at its core, which then dumps energy into the supernova ejecta, further brightening the explosion.They then apply these models to different types of stars.Setting the LimitThe authors show that the light curve of ASASSN-15lh (plotted in orange) can be described by a model (black curve) in which a magnetar with an initial spin period of 0.7 ms

  11. Nurseries of Supernovae

    DEFF Research Database (Denmark)

    Frederiksen, Teddy

    mechanisms that governs the SN explosions. In the first of three papers I investigate the host galaxy of the first SN Ia found in the Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey (CANDELS) SN search. From long slit spectroscopy using the Xshooter spectrograph and broadband photometry I determine....... In the second paper I investigate one of the high redshift SN Ia hosts found in the Subaru Deep Field (SDF) SN search. The SDF SN search relies heavily on photometric redshifts and transients previously identified as active galactic nuclei (AGN) to reproduce the cosmic SN rate. Due to the small number statistic...... activity. I found a young host galaxy with high star-formation rate and sub-solar metallicity. In the last paper I analyze the full high redshift (z > 1) SN host sample from the CANDELS and CLASH SN search. I determine the stellar properties of each host by fitting the broad-band photometry using the Gal...

  12. Type II Supernovae as Probes of Cosmology

    CERN Document Server

    Poznanski, Dovi; Blondin, Stephane; Bloom, Joshua S; D'Andrea, Christopher B; Della Valle, Massimo; Dessart, Luc; Ellis, Richard S; Gal-Yam, Avishay; Goobar, Ariel; Hamuy, Mario; Hicken, Malcolm; Kasen, Daniel N; Krisciunas, Kevin L; Leonard, Douglas C; Li, Weidong; Livio, Mario; Marion, Howie; Matheson, Thomas; Neill, James D; Nomoto, Ken'ichi; Nugent, Peter E; Quimby, Robert; Sako, Masao; Sullivan, Mark; Thomas, Rollin C; Turatto, Massimo; Van Dyk, Schuyler D; Wood-Vasey, W Michael

    2009-01-01

    - Constraining the cosmological parameters and understanding Dark Energy have tremendous implications for the nature of the Universe and its physical laws. - The pervasive limit of systematic uncertainties reached by cosmography based on Cepheids and Type Ia supernovae (SNe Ia) warrants a search for complementary approaches. - Type II SNe have been shown to offer such a path. Their distances can be well constrained by luminosity-based or geometric methods. Competing, complementary, and concerted efforts are underway, to explore and exploit those objects that are extremely well matched to next generation facilities. Spectroscopic follow-up will be enabled by space- based and 20-40 meter class telescopes. - Some systematic uncertainties of Type II SNe, such as reddening by dust and metallicity effects, are bound to be different from those of SNe Ia. Their stellar progenitors are known, promising better leverage on cosmic evolution. In addition, their rate - which closely tracks the ongoing star formation rate -...

  13. The Nearby Supernova Factory: Toward A High-Precision Spectro-Photometry

    Energy Technology Data Exchange (ETDEWEB)

    Nearby Supernova Factory; Copin, Y.; Buton, C.; Gangler, E.; Smadja, G.; Pecontal, E.; Rigaudier, G.; Antilogus, P.; Bailey, S.; Pain, R.; Pereira, R.; Wu, C.; Aldering, G.; Aragon, C.; Bongard, S.; Childress, M.; Loken, S.; Nugent, P.; Perlmutter, S.; Runge, K.; Thomas, R.; Weaver, B.; Baltay, C.; Bauer, A.; Rabinowitz, D.; Scalzo, R.

    2007-07-01

    The Nearby Supernova Factory (SNfactory) is an international project to discover and study a large sample of type Ia supernovae in the redshift range 0.03 < z < 0.08. Follow-up spectro-photometric observations are performed using the dedicated Supernovae Integral-Field Spectrograph, mounted since 2004 on 2.2 m UH telescope. The goal is to acquire for each supernova and over its full life-time (more than 10 epochs) high spectro-photometric quality spectra over the extended optical range (320-1000 nm).I will present the current status of the SNfactory project, from search efficiency to first scientific results, with an emphasis on the spectro-photometric calibration issues and achievements.

  14. Type Ia supernova rate at a redshift of ~ 0.1

    CERN Document Server

    Blanc, G; Alard, C; Albert, J N; Aldering, G; Amadon, A; Andersen, J; Ansari, R; Aubourg, E; Balland, C; Bareyre, P; Beaulieu, J P; Charlot, X; Conley, A; Coutures, C; Dahlen, T; Derue, F; Fan, X; Ferlet, R; Folatelli, G; Fouqué, P; Garavini, G; Glicenstein, J F; Goldman, B; Goobar, A; Gould, A; Graff, D; Gros, M; Haïssinski, J; Hamadache, C; Hardin, D; Hook, I M; De Kat, J; Kent, S; Kim, A; Lasserre, T; Le Guillou, Laurent; Lesquoy, E; Loup, C; Magneville, C; Marquette, J B; Maurice, E; Maury, A; Milsztajn, A; Moniez, M; Mouchet, M; Newberg, H; Nobili, S; Palanque-Delabrouille, Nathalie; Perdereau, O; Prévôt, L; Rahal, Y R; Regnault, N; Rich, J; Ruiz-Lapuente, P; Spiro, M; Tisserand, P; Vidal-Madjar, A; Vigroux, L; Walton, N A; Zylberajch, S

    2004-01-01

    We present the type Ia rate measurement based on two EROS supernova search campaigns (in 1999 and 2000). Sixteen supernovae identified as type Ia were discovered. The measurement of the detection efficiency, using a Monte Carlo simulation, provides the type Ia supernova explosion rate at a redshift ~ 0.13. The result is $0.125^{+0.044+0.028}_{-0.034-0.028} h_{70}^2$ SNu where 1 SNu = 1 SN / $10^{10} L_{sun}^B$ / century. This value is compatible with the previous EROS measurement (Hardin et al. 2000), done with a much smaller sample, at a similar redshift. Comparison with other values at different redshifts suggests an evolution of the type Ia supernova rate.

  15. Can supernova remnants accelerate protons up to PeV energies?

    CERN Document Server

    Gabici, S; Zandanel, F

    2016-01-01

    Supernova remnants are believed to be the sources of galactic cosmic rays. Within this framework, diffusive shock acceleration must operate in these objects and accelerate protons all the way up to PeV energies. To do so, significant amplification of the magnetic field at the shock is required. The goal of this paper is to investigate the capability of supernova remnants to accelerate PeV protons. We present analytic estimates of the maximum energy of accelerated protons under various assumptions about the field amplification at supernova remnant shocks. We show that acceleration up to PeV energies is problematic in all the scenarios considered. This implies that either a different (more efficient) mechanism of field amplification operates at supernova remnant shocks, or that the sources of galactic cosmic rays in the PeV energy range should be searched somewhere else.

  16. Type Ia supernova rate at a redshift of ~;0.1

    Energy Technology Data Exchange (ETDEWEB)

    Blanc, G.; Afonso, C.; Alard, C.; Albert, J.N.; Aldering, G.; Amadon, A.; Andersen, J.; Ansari, R.; Aubourg, E.; Balland, C.; Bareyre,P.; Beaulieu, J.P.; Charlot, X.; Conley, A.; Coutures, C.; Dahlen, T.; Derue, F.; Fan, X.; Ferlet, R.; Folatelli, G.; Fouque, P.; Garavini, G.; Glicenstein, J.F.; Goldman, B.; Goobar, A.; Gould, A.; Graff, D.; Gros,M.; Haissinski, J.; Hamadache, C.; Hardin, D.; Hook, I.M.; deKat, J.; Kent, S.; Kim, A.; Lasserre, T.; LeGuillou, L.; Lesquoy, E.; Loup, C.; Magneville, C.; Marquette, J.B.; Maurice, E.; Maury, A.; Milsztajn, A.; Moniez, M.; Mouchet, M.; Newberg, H.; Nobili, S.; Palanque-Delabrouille,N.; Perdereau, O.; Prevot, L.; Rahal, Y.R.; Regnault, N.; Rich, J.; Ruiz-Lapuente, P.; Spiro, M.; Tisserand, P.; Vidal-Madjar, A.; Vigroux,L.; Walton, N.A.; Zylberajch, S.

    2004-05-11

    We present the type Ia rate measurement based on two EROS supernova search campaigns (in 1999 and 2000). Sixteen supernovae identified as type Ia were discovered. The measurement of the detection efficiency, using a Monte Carlo simulation, provides the type Ia supernova explosion rate at a redshift {approx} 0.13. The result is 0.125{sub -0.034-0.028}{sup +0.044+0.028} h{sub 70}{sup 2} SNu where 1 SNu = 1 SN/10{sup 10} L{sub {circle_dot}}{sup B}/century. This value is compatible with the previous EROS measurement (Hardin et al. 2000), done with a much smaller sample, at a similar redshift. Comparison with other values at different redshifts suggests an evolution of the type Ia supernova rate.

  17. Light-echo spectroscopy of historic Supernovae

    Science.gov (United States)

    Krause, Oliver

    Young Galactic supernova remnants are unique laboratories for supernova physics. Due to their proximity they provide us with the most detailed view of the outcome of a supernova. However, the exact spectroscopic types of their original explosions have been undetermined so far -hindering to link the wealth of multi-wavelength knowledge about their remnants with the diverse population of supernovae. Light echoes, reflektions of the brilliant supernova burst of light by interstellar dust, provide a unique opportunity to reobserve today -with powerful scientific instruments of the 21st century -historic supernova exlosions even after hundreds of years and to conclude on their nature. We report on optical light-echo spectroscopy of two famous Galactic supernovae: Tycho Brahe's SN 1572 and the supernova that created the Cassiopeia A remnant around the year 1680. These observations finally recovered the missing spectroscopic classifications and provide new constraints on explosion models for future studies.

  18. Coal log pipeline research at the University of Missouri

    Energy Technology Data Exchange (ETDEWEB)

    Liu, H.

    1992-03-01

    Project tasks: Perform the necessary testing and development to demonstrate that the amount of binder in coal logs can be reduced to 8% or lower to produce logs with adequate strength to eliminate breakage during pipeline transportation, under conditions experienced in long distance pipeline systems. Prior to conducting any testing and demonstration, grantee shall perform an information search and make full determination of all previous attempts to extrude or briquette coal, upon which the testing and demonstration shall be based. Perform the necessary development to demonstrate a small model of the most promising injection system for coal-logs, and test the logs produced from Task 1. Conduct economic analysis of coal-log pipeline, based upon the work to date. Refine and complete the economic model. Prepare a final report for DOE.

  19. Supernova Physics at DUNE

    CERN Document Server

    Ankowski, Artur; Benhar, Omar; Chen, Sun; Cherry, John; Cui, Yanou; Friedland, Alexander; Gil-Botella, Ines; Haghighat, Alireza; Horiuchi, Shunsaku; Huber, Patrick; Kneller, James; Laha, Ranjan; Li, Shirley; Link, Jonathan; Lovato, Alessandro; Macias, Oscar; Mariani, Camillo; Mezzacappa, Anthony; O'Connor, Evan; O'Sullivan, Erin; Rubbia, Andre; Scholberg, Kate; Takeuchi, Tatsu

    2016-01-01

    The DUNE/LBNF program aims to address key questions in neutrino physics and astroparticle physics. Realizing DUNE's potential to reconstruct low-energy particles in the 10-100 MeV energy range will bring significant benefits for all DUNE's science goals. In neutrino physics, low-energy sensitivity will improve neutrino energy reconstruction in the GeV range relevant for the kinematics of DUNE's long-baseline oscillation program. In astroparticle physics, low-energy capabilities will make DUNE's far detectors the world's best apparatus for studying the electron-neutrino flux from a supernova. This will open a new window to unrivaled studies of the dynamics and neutronization of a star's central core in real time, the potential discovery of the neutrino mass hierarchy, provide new sensitivity to physics beyond the Standard Model, and evidence of neutrino quantum-coherence effects. The same capabilities will also provide new sensitivity to `boosted dark matter' models that are not observable in traditional direc...

  20. A Supernova's Shockwaves

    Science.gov (United States)

    2007-01-01

    Supernovae are the explosive deaths of the universe's most massive stars. In death, these volatile creatures blast tons of energetic waves into the cosmos, destroying much of the dust surrounding them. This false-color composite from NASA's Spitzer Space Telescope and NASA's Chandra X-ray Observatory shows the remnant of one such explosion. The remnant, called N132D, is the wispy pink shell of gas at the center of this image. The pinkish color reveals a clash between the explosion's high-energy shockwaves and surrounding dust grains. In the background, small organic molecules called polycyclic aromatic hydrocarbons are shown as tints of green. The blue spots represent stars in our galaxy along this line of sight. N132D is located 163,000 light-years away in a neighboring galaxy called, the Large Magellanic Cloud. In this image, infrared light at 4.5 microns is mapped to blue, 8.0 microns to green and 24 microns to red. Broadband X-ray light is mapped purple. The infrared data were taken by Spitzer's infrared array camera and multiband imaging photometer, while the X-ray data were captured by Chandra.

  1. The Shape of Superluminous Supernovae

    Science.gov (United States)

    Kohler, Susanna

    2016-11-01

    What causes the tremendous explosions of superluminous supernovae? New observations reveal the geometry of one such explosion, SN 2015bn, providing clues as to its source.A New Class of ExplosionsImage of a type Ia supernova in the galaxy NGC 4526. [NASA/ESA]Supernovae are powerful explosions that can briefly outshine the galaxies that host them. There are several different classifications of supernovae, each with a different physical source such as thermonuclear instability in a white dwarf, caused by accretion of too much mass, or the exhaustion of fuel in the core of a massive star, leading to the cores collapse and expulsion of its outer layers.In recent years, however, weve detected another type of supernovae, referred to as superluminous supernovae. These particularly energetic explosions last longer months instead of weeks and are brighter at their peaks than normal supernovae by factors of tens to hundreds.The physical cause of these unusual explosions is still a topic of debate. Recently, however, a team of scientists led by Cosimo Inserra (Queens University Belfast) has obtained new observations of a superluminous supernova that might help address this question.The flux and the polarization level (black lines) along the dominant axis of SN 2015bn, 24 days before peak flux (left) and 28 days after peak flux (right). Blue lines show the authors best-fitting model. [Inserra et al. 2016]Probing GeometryInserra and collaborators obtained two sets of observations of SN 2015bn one roughly a month before and one a month after the superluminous supernovas peak brightness using a spectrograph on the Very Large Telescope in Chile. These observations mark the first spectropolarimetric data for a superluminous supernova.Spectropolarimetry is the practice of obtaining information about the polarization of radiation from an objects spectrum. Polarization carries information about broken spatial symmetries in the object: only if the object is perfectly symmetric can it

  2. INTERNAL REPAIR OF PIPELINES

    Energy Technology Data Exchange (ETDEWEB)

    Robin Gordon; Bill Bruce; Ian Harris; Dennis Harwig; George Ritter; Bill Mohr; Matt Boring; Nancy Porter; Mike Sullivan; Chris Neary

    2004-08-17

    The two broad categories of fiber-reinforced composite liner repair and deposited weld metal repair technologies were reviewed and evaluated for potential application for internal repair of gas transmission pipelines. Both are used to some extent for other applications and could be further developed for internal, local, structural repair of gas transmission pipelines. Principal conclusions from a survey of natural gas transmission industry pipeline operators can be summarized in terms of the following performance requirements for internal repair: (1) Use of internal repair is most attractive for river crossings, under other bodies of water, in difficult soil conditions, under highways, under congested intersections, and under railway. (2) Internal pipe repair offers a strong potential advantage to the high cost of horizontal direct drilling when a new bore must be created to solve a leak or other problem. (3) Typical travel distances can be divided into three distinct groups: up to 305 m (1,000 ft.); between 305 m and 610 m (1,000 ft. and 2,000 ft.); and beyond 914 m (3,000 ft.). All three groups require pig-based systems. A despooled umbilical system would suffice for the first two groups which represents 81% of survey respondents. The third group would require an onboard self-contained power unit for propulsion and welding/liner repair energy needs. (4) The most common size range for 80% to 90% of operators surveyed is 508 mm (20 in.) to 762 mm (30 in.), with 95% using 558.8 mm (22 in.) pipe. Evaluation trials were conducted on pipe sections with simulated corrosion damage repaired with glass fiber-reinforced composite liners, carbon fiber-reinforced composite liners, and weld deposition. Additional un-repaired pipe sections were evaluated in the virgin condition and with simulated damage. Hydrostatic failure pressures for pipe sections repaired with glass fiber-reinforced composite liner were only marginally greater than that of pipe sections without liners

  3. INTERNAL REPAIR OF PIPELINES

    Energy Technology Data Exchange (ETDEWEB)

    Robin Gordon; Bill Bruce; Ian Harris; Dennis Harwig; George Ritter; Bill Mohr; Matt Boring; Nancy Porter; Mike Sullivan; Chris Neary

    2004-12-31

    The two broad categories of fiber-reinforced composite liner repair and deposited weld metal repair technologies were reviewed and evaluated for potential application for internal repair of gas transmission pipelines. Both are used to some extent for other applications and could be further developed for internal, local, structural repair of gas transmission pipelines. Principal conclusions from a survey of natural gas transmission industry pipeline operators can be summarized in terms of the following performance requirements for internal repair: (1) Use of internal repair is most attractive for river crossings, under other bodies of water, in difficult soil conditions, under highways, under congested intersections, and under railway crossings. (2) Internal pipe repair offers a strong potential advantage to the high cost of horizontal direct drilling when a new bore must be created to solve a leak or other problem. (3) Typical travel distances can be divided into three distinct groups: up to 305 m (1,000 ft.); between 305 m and 610 m (1,000 ft. and 2,000 ft.); and beyond 914 m (3,000 ft.). All three groups require pig-based systems. A despooled umbilical system would suffice for the first two groups which represents 81% of survey respondents. The third group would require an onboard self-contained power unit for propulsion and welding/liner repair energy needs. (4) The most common size range for 80% to 90% of operators surveyed is 508 mm (20 in.) to 762 mm (30 in.), with 95% using 558.8 mm (22 in.) pipe. Evaluation trials were conducted on pipe sections with simulated corrosion damage repaired with glass fiber-reinforced composite liners, carbon fiber-reinforced composite liners, and weld deposition. Additional un-repaired pipe sections were evaluated in the virgin condition and with simulated damage. Hydrostatic failure pressures for pipe sections repaired with glass fiber-reinforced composite liner were only marginally greater than that of pipe sections without

  4. INTERNAL REPAIR OF PIPELINES

    Energy Technology Data Exchange (ETDEWEB)

    Robin Gordon; Bill Bruce; Ian Harris; Dennis Harwig; Nancy Porter; Mike Sullivan; Chris Neary

    2004-04-12

    The two broad categories of deposited weld metal repair and fiber-reinforced composite liner repair technologies were reviewed for potential application for internal repair of gas transmission pipelines. Both are used to some extent for other applications and could be further developed for internal, local, structural repair of gas transmission pipelines. Preliminary test programs were developed for both deposited weld metal repair and for fiber-reinforced composite liner repair. Evaluation trials have been conducted using a modified fiber-reinforced composite liner provided by RolaTube and pipe sections without liners. All pipe section specimens failed in areas of simulated damage. Pipe sections containing fiber-reinforced composite liners failed at pressures marginally greater than the pipe sections without liners. The next step is to evaluate a liner material with a modulus of elasticity approximately 95% of the modulus of elasticity for steel. Preliminary welding parameters were developed for deposited weld metal repair in preparation of the receipt of Pacific Gas & Electric's internal pipeline welding repair system (that was designed specifically for 559 mm (22 in.) diameter pipe) and the receipt of 559 mm (22 in.) pipe sections from Panhandle Eastern. The next steps are to transfer welding parameters to the PG&E system and to pressure test repaired pipe sections to failure. A survey of pipeline operators was conducted to better understand the needs and performance requirements of the natural gas transmission industry regarding internal repair. Completed surveys contained the following principal conclusions: (1) Use of internal weld repair is most attractive for river crossings, under other bodies of water, in difficult soil conditions, under highways, under congested intersections, and under railway crossings. (2) Internal pipe repair offers a strong potential advantage to the high cost of horizontal direct drilling (HDD) when a new bore must be created

  5. Pipeline risk assessment

    Energy Technology Data Exchange (ETDEWEB)

    Kariyawasam, S. [TransCanada PipeLines Ltd., Calgary, AB (Canada); Weir, D. [Enbridge Pipelines Inc., Calgary, AB (Canada)] (comps.)

    2009-07-01

    Risk assessments and risk analysis are system-wide activities that include site-specific risk and reliability-based decision-making, implementation, and monitoring. This working group discussed the risk management process in the pipeline industry, including reliability-based integrity management and risk control processes. Attendants at the group discussed reliability-based decision support and performance measurements designed to support corporate risk management policies. New developments and technologies designed to optimize risk management procedures were also presented. The group was divided into 3 sessions: (1) current practice, strengths and limitations of system-wide risk assessments for facility assets; (2) accounting for uncertainties to assure safety; and (3) reliability based excavation repair criteria and removing potentially unsafe corrosion defects. Presentations of risk assessment procedures used at various companies were given. The role of regulators, best practices, and effective networking environments in ensuring the success of risk assessment policies was discussed. Risk assessment models were also reviewed.

  6. Maglev crude oil pipeline

    Science.gov (United States)

    Knolle, Ernst G.

    1994-05-01

    This maglev crude oil pipeline consists of two conduits guiding an endless stream of long containers. One conduit carries loaded containers and the other empty returns. The containers are levitated by permanent magnets in repulsion and propelled by stationary linear induction motors. The containers are linked to each other in a manner that allows them, while in continuous motion, to be folded into side by side position at loading and unloading points. This folding causes a speed reduction in proportion to the ratio of container diameter to container length. While in side by side position, containers are opened at their ends to be filled or emptied. Container size and speed are elected to produce a desired carrying capacity.

  7. Northern pipelines : challenges and needs

    Energy Technology Data Exchange (ETDEWEB)

    Dean, D.; Brownie, D. [ProLog Canada Inc., Calgary, AB (Canada); Fafara, R. [TransCanada PipeLines Ltd., Calgary, AB (Canada)

    2007-07-01

    Working Group 10 presented experiences acquired from the operation of pipeline systems in a northern environment. There are currently 3 pipelines operating north of 60, notably the Shiha gas pipeline near Fort Liard, the Ikhil gas pipeline in Inuvik and the Norman Wells oil pipeline. Each has its unique commissioning, operating and maintenance challenges, as well as specific training and logistical support requirements for the use of in-line inspection tools and other forms of integrity assessment. The effectiveness of cathodic protection systems in a permafrost northern environment was also discussed. It was noted that the delay of the Mackenzie Gas Pipeline Project by two to three years due to joint regulatory review may lead to resource constraints for the project as well as competition for already scarce human resources. The issue of a potential timing conflict with the Alaskan Pipeline Project was also addressed as well as land use issues for routing of supply roads. Integrity monitoring and assessment issues were outlined with reference to pipe soil interaction monitoring in discontinuous permafrost; south facing denuded slope stability; base lining projects; and reclamation issues. It was noted that automatic welding and inspection will increase productivity, while reducing the need for manual labour. In response to anticipated training needs, companies are planning to involve and train Aboriginal labour and will provide camp living conditions that will attract labour. tabs., figs.

  8. High-throughput bioinformatics with the Cyrille2 pipeline system

    Directory of Open Access Journals (Sweden)

    de Groot Joost CW

    2008-02-01

    Full Text Available Abstract Background Modern omics research involves the application of high-throughput technologies that generate vast volumes of data. These data need to be pre-processed, analyzed and integrated with existing knowledge through the use of diverse sets of software tools, models and databases. The analyses are often interdependent and chained together to form complex workflows or pipelines. Given the volume of the data used and the multitude of computational resources available, specialized pipeline software is required to make high-throughput analysis of large-scale omics datasets feasible. Results We have developed a generic pipeline system called Cyrille2. The system is modular in design and consists of three functionally distinct parts: 1 a web based, graphical user interface (GUI that enables a pipeline operator to manage the system; 2 the Scheduler, which forms the functional core of the system and which tracks what data enters the system and determines what jobs must be scheduled for execution, and; 3 the Executor, which searches for scheduled jobs and executes these on a compute cluster. Conclusion The Cyrille2 system is an extensible, modular system, implementing the stated requirements. Cyrille2 enables easy creation and execution of high throughput, flexible bioinformatics pipelines.

  9. Nurseries of Supernovae

    DEFF Research Database (Denmark)

    Frederiksen, Teddy

    . In the second paper I investigate one of the high redshift SN Ia hosts found in the Subaru Deep Field (SDF) SN search. The SDF SN search relies heavily on photometric redshifts and transients previously identified as active galactic nuclei (AGN) to reproduce the cosmic SN rate. Due to the small number statistic......, especially at high redshift, catastrophic redshift outliers and miss-identified transients can bias the inferred SN rate. The host galaxy of the SDF transient was observed with the Xshooter spectrograph. I confirm the photometric redshift of z = 1.55 and from emission-line ratios I can also rule out AGN...

  10. Pipeline clean-up : speed, environment drive pipelining equipment

    Energy Technology Data Exchange (ETDEWEB)

    Budd, G.

    2004-08-01

    Horizontal drilling technology is the single most important enhanced oil recovery technology which has resulted in a significant increase in pipeline utilization. Pipeline operators such as Calgary-based Denim Pipeline Construction Ltd. are responding by using the latest equipment, including excavation equipment, to avoid maintenance delays and downtime. The sales of Denim's horizontal pipe bending equipment have increased due to their attention to worker safety. Denim's horizontal bending machine does not require as much technical support, plus it is faster to install and speeds up production. The machine consists of 3 hydraulic jacks that move on a horizontal plate. Curved dies can be modified to accommodate various diameters of pipe. The bending operation is performed very near to the ground, thereby significantly reducing the risk of pipe injury. Environmental damage is minimized through the use of mechanized mulching which has replaced burning of unwanted trees and brush to clean for pipelines. 1 fig.

  11. Characterising Dark Energy through supernovae

    CERN Document Server

    Davis, Tamara M

    2016-01-01

    Type Ia supernovae are a powerful cosmological probe, that gave the first strong evidence that the expansion of the universe is accelerating. Here we provide an overview of how supernovae can go further to reveal information about what is causing the acceleration, be it dark energy or some modification to our laws of gravity. We first summarise the many different approaches used to explain or test the acceleration, including parametric models (like the standard model, LambdaCDM), non-parametric models, dark fluid models such as quintessence, and extensions to standard gravity. We also show how supernova data can be used beyond the Hubble diagram, to give information on gravitational lensing and peculiar velocities that can be used to distinguish between models that predict the same expansion history. Finally, we review the methods of statistical inference that are commonly used, making a point of separating parameter estimation from model selection.

  12. Featured Image: Modeling Supernova Remnants

    Science.gov (United States)

    Kohler, Susanna

    2016-05-01

    This image shows a computer simulation of the hydrodynamics within a supernova remnant. The mixing between the outer layers (where color represents the log of density) is caused by turbulence from the Rayleigh-Taylor instability, an effect that arises when the expanding core gas of the supernova is accelerated into denser shell gas. The past standard for supernova-evolution simulations was to perform them in one dimension and then, in post-processing, manually smooth out regions that undergo Rayleigh-Taylor turbulence (an intrinsically multidimensional effect). But in a recent study, Paul Duffell (University of California, Berkeley) has explored how a 1D model could be used to reproduce the multidimensional dynamics that occur in turbulence from this instability. For more information, check out the paper below!CitationPaul C. Duffell 2016 ApJ 821 76. doi:10.3847/0004-637X/821/2/76

  13. Standardization of type Ia supernovae

    CERN Document Server

    Coelho, Rodrigo C V; Reis, Ribamar R R; Siffert, Beatriz B

    2014-01-01

    Type Ia supernovae (SNe Ia) have been intensively investigated due to its great homogeneity and high luminosity, which make it possible to use them as standardizable candles for the determination of cosmological parameters. In 2011, the physics Nobel prize was awarded for the discovery of the accelerating expansion of the Universe through observations of distant supernovae. This is a pedagogical article, aimed at those starting their study of that subject, in which we dwell on some topics related to the analysis of SNe Ia and their use in luminosity distance estimators. Here we investigate their spectral properties and light curve standardization, paying careful attention to the fundamental quantities directly related to the SNe Ia observables. Finally, we describe our own step-by-step implementation of a classical light curve fi?tter, the stretch, applying it to real data from the Carnegie Supernova Project.

  14. Dynamics of Kepler's supernova remnant

    Science.gov (United States)

    Borkowski, Kazimierz J.; Blondin, John M.; Sarazin, Craig L.

    1992-01-01

    Observations of Kepler's SNR have revealed a strong interaction with the ambient medium, far in excess of that expected at a distance of about 600 pc away from the Galactic plane where Kepler's SNR is located. This has been interpreted as a result of the interaction of supernova ejecta with the dense circumstellar medium (CSM). Based on the bow-shock model of Bandiera (1985), we study the dynamics of this interaction. The CSM distribution consists of an undisturbed stellar wind of a moving supernova progenitor and a dense shell formed in its interaction with a tenuous interstellar medium. Supernova ejecta drive a blast wave through the stellar wind which splits into the transmitted and reflected shocks upon hitting this bow-shock shell. We identify the transmitted shock with the nonradiative, Balmer-dominated shocks found recently in Kepler's SNR. The transmitted shock most probably penetrated the shell in the vicinity of the stagnation point.

  15. RUSSIA AND ITS PIPELINE WEAPON

    Directory of Open Access Journals (Sweden)

    FODOR Cosmin

    2010-12-01

    Full Text Available In this paper we intend to present the new power which is given to Russia upon EU due to her great natural resources and due to her control upon pipelines. Now Moscow can exert influence upon countries in Europe not through its revolutionary zeal and its tanks and army, but through its resources. And she knows how to use them and how make the EU dependent on her will: this is a new geopolitics, a 21-th century geopolitics, which is centered upon the control of gas pipelines in Central Asian states and upon EU states great dependence on Russian pipeline system.

  16. Natural gas pipeline technology overview.

    Energy Technology Data Exchange (ETDEWEB)

    Folga, S. M.; Decision and Information Sciences

    2007-11-01

    The United States relies on natural gas for one-quarter of its energy needs. In 2001 alone, the nation consumed 21.5 trillion cubic feet of natural gas. A large portion of natural gas pipeline capacity within the United States is directed from major production areas in Texas and Louisiana, Wyoming, and other states to markets in the western, eastern, and midwestern regions of the country. In the past 10 years, increasing levels of gas from Canada have also been brought into these markets (EIA 2007). The United States has several major natural gas production basins and an extensive natural gas pipeline network, with almost 95% of U.S. natural gas imports coming from Canada. At present, the gas pipeline infrastructure is more developed between Canada and the United States than between Mexico and the United States. Gas flows from Canada to the United States through several major pipelines feeding U.S. markets in the Midwest, Northeast, Pacific Northwest, and California. Some key examples are the Alliance Pipeline, the Northern Border Pipeline, the Maritimes & Northeast Pipeline, the TransCanada Pipeline System, and Westcoast Energy pipelines. Major connections join Texas and northeastern Mexico, with additional connections to Arizona and between California and Baja California, Mexico (INGAA 2007). Of the natural gas consumed in the United States, 85% is produced domestically. Figure 1.1-1 shows the complex North American natural gas network. The pipeline transmission system--the 'interstate highway' for natural gas--consists of 180,000 miles of high-strength steel pipe varying in diameter, normally between 30 and 36 inches in diameter. The primary function of the transmission pipeline company is to move huge amounts of natural gas thousands of miles from producing regions to local natural gas utility delivery points. These delivery points, called 'city gate stations', are usually owned by distribution companies, although some are owned by

  17. Effort problem of chemical pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Okrajni, J.; Ciesla, M.; Mutwil, K. [Silesian Technical University, Katowice (Poland)

    1998-12-31

    The problem of the technical state assessment of the chemical pipelines working under mechanical and thermal loading has been shown in the paper. The pipelines effort after the long time operating period has been analysed. Material geometrical and loading conditions of the crack initiation and crack growth process in the chosen object has been discussed. Areas of the maximal effort have been determined. The material structure charges after the long time operating period have been described. Mechanisms of the crack initiation and crack growth in the pipeline elements have been analysed and mutual relations between the chemical and mechanical influences have been shown. (orig.) 16 refs.

  18. Distant Supernovae Indicate Ever-Expanding Universe

    Science.gov (United States)

    1998-12-01

    and its inhabitants are made comprise only a small fration of the gravitating mass in the Universe. There is now a new component, the "dark energy" which joins the "dark matter" in shaping the large-scale geometric and dynamical structure. Clearly, more observations are needed to further support the findings described here. They will soon be forthcoming, especially from new and large telescopes like the ESO Very Large Telescope (VLT) , that has recently delivered its first, impressive results. But already now, on the verge of the new millenium, we are having a first glimpse of extremely exciting and fundamental aspects in the continuing human quest for the deep truths of nature. Notes: [1] The ESO members of the "High-z Supernova Search" team (see URL: http://cfa-www.harvard.edu/cfa/oir/Research/supernova/HighZ.html) are Bruno Leibundgut and Patrick Woudt (ESO HQ, Garching, Germany) and Jason Spyromilio (Paranal Observatory, Chile). Chris Lidman (La Silla Observatory, Chile) and Isobel Hook (formerly ESO HQ, now Royal Observatory, Edinburgh, UK) are members of the "Supernova Cosmology Project" (see URL: http://www-supernova.lbl.gov/). The astronomers mostly used the ESO 3.6-m and 3.6-m NTT telescopes at La Silla for these research programmes. [2] In astronomy, the redshift (z) denotes the fraction by which the lines in the spectrum of an object are shifted towards longer wavelengths. The observed redshift of a distant galaxy or quasar gives a direct estimate of the universal expansion (i.e. the "recession velocity"). Since this expansion rate increases with the distance, the velocity is itself a function (the Hubble relation) of the distance to the object. For instance, a redshift of z = 0.1 corresponds to a velocity of 30,000 km/sec, and assuming a Hubble constant of 20 km/sec per million light-years, to a distance of about 1,500 million light-years. How to obtain ESO Press Information ESO Press Information is made available on the World-Wide Web (URL: http

  19. Software Based Supernova Recognition

    Science.gov (United States)

    Walters, Stephen M.

    2014-05-01

    This paper describes software for detecting Supernova (SN) in images. The software can operate in real-time to discover SN while data is being collected so the instrumentation can immediately be re-tasked to perform spectroscopy or photometry of a discovery. Because the instrumentation captures two images per minute, the realtime budget is constrained to 30 seconds per target, a challenging goal. Using a set of two to four images, the program creates a "Reference" (REF) image and a "New" (NEW) image where all images are used in both NEW and REF but any SN survives the combination process only in the NEW image. This process produces good quality images having similar noise characteristics but without artifacts that might be interpreted as SN. The images are then adjusted for seeing and brightness differences using a variant of Tomaney and Crotts method of Point Spread Function (PSF) matching after which REF is subtracted from NEW to produce a Difference (DIF) image. A Classifier is then trained on a grid of artificial SN to estimate the statistical properties of four attributes and used in a process to mask false positives that can be clearly identified as such. Further training to avoid any remaining false positives sets the range, in standard deviations for each attribute, that the Classifier will accept as a valid SN. This training enables the Classifier to discriminate between SN and most subtraction residue. Lastly, the DIF image is scanned and measured by the Classifier to find locations where all four properties fall within their acceptance ranges. If multiple locations are found, the one best conforming to the training estimates is chosen. This location is then declared as a Candidate SN, the instrumentation re-tasked and the operator notified.

  20. 75 FR 72877 - Pipeline Safety: Updates to Pipeline and Liquefied Natural Gas Reporting Requirements

    Science.gov (United States)

    2010-11-26

    ... Safety: Updates to Pipeline and Liquefied Natural Gas Reporting Requirements; Final Rule #0;#0;Federal... to Pipeline and Liquefied Natural Gas Reporting Requirements AGENCY: Pipeline and Hazardous Materials... collections from operators of natural gas pipelines, hazardous liquid pipelines, and liquefied natural......

  1. Dust around Type Ia supernovae

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Lifan

    2005-10-20

    An explanation is given of the low value of R lambda triple bond A lambda/E(B - V), the ratio of absolute to selective extinction deduced from Type Ia supernova observations. The idea involves scattering by dust clouds located in the circumstellar environment, or at the highest velocity shells of the supernova ejecta. The scattered light tends to reduce the effective R lambda in the optical, but has an opposite effect in the ultraviolet. The presence of circumstellar dust can be tested by ultraviolet to near infrared observations and by multi-epoch spectropolarimetry of SNe Ia.

  2. Logistics aspects of petroleum pipeline operations

    Directory of Open Access Journals (Sweden)

    W. J. Pienaar

    2010-11-01

    Full Text Available The paper identifies, assesses and describes the logistics aspects of the commercial operation of petroleum pipelines. The nature of petroleum-product supply chains, in which pipelines play a role, is outlined and the types of petroleum pipeline systems are described. An outline is presented of the nature of the logistics activities of petroleum pipeline operations. The reasons for the cost efficiency of petroleum pipeline operations are given. The relative modal service effectiveness of petroleum pipeline transport, based on the most pertinent service performance measures, is offered. The segments in the petroleum-products supply chain where pipelines can play an efficient and effective role are identified.

  3. Pipeline integrity handbook risk management and evaluation

    CERN Document Server

    Singh, Ramesh

    2013-01-01

    Based on over 40 years of experience in the field, Ramesh Singh goes beyond corrosion control, providing techniques for addressing present and future integrity issues. Pipeline Integrity Handbook provides pipeline engineers with the tools to evaluate and inspect pipelines, safeguard the life cycle of their pipeline asset and ensure that they are optimizing delivery and capability. Presented in easy-to-use, step-by-step order, Pipeline Integrity Handbook is a quick reference for day-to-day use in identifying key pipeline degradation mechanisms and threats to pipeline integrity. The book begins

  4. Type Ia Supernovae and the discovery of the Cosmic Acceleration

    CERN Document Server

    Clocchiatti, Alejandro

    2011-01-01

    I present a review of the research and analysis paths that converged to make Type Ia SNe the most mature cosmological distance estimator of the present time. The narrative starts with the first works in the early decades of the 20th century and finishes with the more recent results. The review was written by a member of the High Z Supernova Search Team, the international group of astronomers that discovered Cosmic Acceleration in 1998. This result, confirmed by the Supernova Cosmology Project in 1999, received an impressive string of recognition culminating with the current Nobel prize in Physics. The review is presented thinking of physicists with a strong interest in Cosmology, who might have pondered why was that, after decades of not being able to agree upon the rate of cosmic expansion, astronomers were so quick to concur on cosmic acceleration.

  5. Spectroscopy of twelve Type Ia supernovae at intermediate redshift

    CERN Document Server

    Balland, C; Pain, R; Walton, N A; Amanullah, R; Astier, Pierre; Ellis, Richard S; Fabbro, S; Goobar, A; Hardin, D; Hook, I M; Irwin, M J; McMahon, R M; Mendez, J M; Ruiz-Lapuente, P; Sainton, G; Schahmaneche, K; Stanishev, V

    2005-01-01

    We present spectra of twelve Type Ia supernovae obtained in 1999 at the William Herschel Telescope and the Nordic Optical Telescope during a search for Type Ia supernovae (SN Ia) at intermediate redshift. The spectra range from z=0.178 to z=0.493, including five high signal-to-noise ratio SN Ia spectra in the still largely unexplored range 0.15 < z < 0.3. Most of the spectra were obtained before or around restframe B-band maximum light. None of them shows the peculiar spectral features found in low-redshift over- or under-luminous SN Ia. Expansion velocities of characteristic spectral absorption features such as SiII at 6355 angs., SII at 5640 angs. and CaII at 3945 angs. are found consistent with their low-z SN Ia counterparts.

  6. Magnetar-Powered Supernovae in Two Dimensions. I. Superluminous Supernovae

    CERN Document Server

    Chen, Ke-Jung; Sukhbold, Tuguldur

    2016-01-01

    Previous studies have shown that the radiation emitted by a rapidly rotating magnetar embedded in a young supernova can greatly amplify its luminosity. These one-dimensional studies have also revealed the existence of an instability arising from the piling up of radiatively accelerated matter in a thin dense shell deep inside the supernova. Here we examine the problem in two dimensions and find that, while instabilities cause mixing and fracture this shell into filamentary structures that reduce the density contrast, the concentration of matter in a hollow shell persists. The extent of the mixing depends upon the relative energy input by the magnetar and the kinetic energy of the inner ejecta. The light curve and spectrum of the resulting supernova will be appreciably altered, as will the appearance of the supernova remnant, which will be shellular and filamentary. A similar pile up and mixing might characterize other events where energy is input over an extended period by a centrally concentrated source, e.g...

  7. Core-collapse supernovae as possible counterparts of IceCube neutrino multiplets

    Energy Technology Data Exchange (ETDEWEB)

    Strotjohann, Nora Linn; Kowalski, Marek; Franckowiak, Anna [DESY, Zeuthen (Germany); Voge, Markus [Bonn Univ. (Germany). Physikalisches Institut; Collaboration: IceCube-Collaboration

    2016-07-01

    While an astrophysical neutrino flux has been detected by the IceCube Neutrino Observatory its sources remain so far unidentified. IceCube's Optical Follow-up Program is designed to search for the counterparts of neutrino multiplets using the full energy range of the IceCube detector down to 100 GeV. Two or more muon neutrinos arriving from the same direction within few seconds can trigger follow-up observations with optical and X-ray telescopes. Since 2010 the Palomar Transient Factory has followed up about 40 such neutrino alerts and detected several supernovae. Many of the detections are however likely random coincidences. In this talk I describe our search for supernovae and the prospects of identifying a supernova as a source of high-energy neutrinos.

  8. PIPELINES AS COMMUNICATION NETWORK LINKS

    Energy Technology Data Exchange (ETDEWEB)

    Kelvin T. Erickson; Ann Miller; E. Keith Stanek; C.H. Wu; Shari Dunn-Norman

    2005-03-14

    This report presents the results of an investigation into two methods of using the natural gas pipeline as a communication medium. The work addressed the need to develop secure system monitoring and control techniques between the field and control centers and to robotic devices in the pipeline. In the first method, the pipeline was treated as a microwave waveguide. In the second method, the pipe was treated as a leaky feeder or a multi-ground neutral and the signal was directly injected onto the metal pipe. These methods were tested on existing pipeline loops at UMR and Batelle. The results reported in this report indicate the feasibility of both methods. In addition, a few suitable communication link protocols for this network were analyzed.

  9. Nondestructive characterization of pipeline materials

    Science.gov (United States)

    Engle, Brady J.; Smart, Lucinda J.; Bond, Leonard J.

    2015-03-01

    There is a growing need to quantitatively and nondestructively evaluate the strength and toughness properties of pipeline steels, particularly in aging pipeline infrastructure. These strength and toughness properties, namely yield strength, tensile strength, transition temperature, and toughness, are essential for determining the safe operating pressure of the pipelines. For some older pipelines crucial information can be unknown, which makes determining the pressure rating difficult. Current inspection techniques address some of these issues, but they are not comprehensive. This paper will briefly discuss current inspection techniques and relevant literature for relating nondestructive measurements to key strength and toughness properties. A project is in progress to provide new in-trench tools that will give strength properties without the need for sample removal and destructive testing. Preliminary experimental ultrasonic methods and measurements will be presented, including velocity, attenuation, and backscatter measurements.

  10. Are Supernovae Recorded in Indigenous Astronomical Traditions?

    CERN Document Server

    Hamacher, Duane W

    2014-01-01

    Novae and supernovae are rare astronomical events that would have had an influence on the sky-watching peoples who witnessed them. Although several bright novae/supernovae have been visible during recorded human history, there are many proposed but no confirmed accounts of supernovae in oral traditions or material culture. Criteria are established for confirming novae/supernovae in oral and material culture, and claims from around the world are discussed to determine if they meet these criteria. Australian Aboriginal traditions are explored for possible descriptions of novae/supernovae. Although representations of supernovae may exist in Indigenous traditions, and an account of a nova in Aboriginal traditions has been confirmed, there are currently no confirmed accounts of supernovae in Indigenous oral or material traditions.

  11. VLT Instruments Pipeline System Overview

    Science.gov (United States)

    Jung, Y.; Ballester, P.; Banse, K.; Hummel, W.; Izzo, C.; McKay, D. J.; Kiesgen, M.; Lundin, L. K.; Modigliani, A.; Palsa, R. M.; Sabet, C.

    2004-07-01

    Since the beginning of the VLT operations in 1998, substantial effort has been put in the development of automatic data reduction tools for the VLT instruments. A VLT instrument pipeline is a complex system that has to be able to identify and classify each produced FITS file, optionally retrieve calibration files from a database, use an image processing software to reduce the data, compute and log quality control parameters, produce FITS images or tables with the correct headers, optionally display them in the control room and send them to the archive. Each instrument has its own dedicated pipeline, based on a common infrastructure and installed with the VLT Data Flow System (DFS). With the increase in the number and the complexity of supported instruments and in the rate of produced data, these pipelines are becoming vital for both the VLT operations and the users, and request more and more resources for development and maintenance. This paper describes the different pipeline tasks with some real examples. It also explains how the development process has been improved to both decrease its cost and increase the pipelines quality using the lessons learned from the first instruments pipelines development.

  12. Real-Time Pulsars Pipeline Using Many-Cores

    Science.gov (United States)

    Sclocco, Alessio; Van Nieuwpoort, R.; Bal, H. E.

    2014-04-01

    Exascale radio astronomy presents challenges to both astronomers and computer scientists. One of these challenges is processing the enormous amount of data that will be produced by exascale instruments, like the Square Kilometer Array (SKA). Traditional approaches, based on storing data to process them off-line, are common nowadays, but are unfeasible in the exascale era due to the high bandwidths. We investigate the use of many-core accelerators as a way to achieve real-time performance without exceeding cost and power constraints. In our current research, we aim at accelerating the pulsar searching process, and produce a real-time and scalable software pipeline for the exascale era. Our pipeline consists of three main steps: dedispersion, folding and signal-to-noise ratio computation. It is open source and implemented using the Open Computing Language (OpenCL). To achieve our goals of real-time performance, scalability and portability, we applied three different techniques. First, we designed all steps of the pulsars pipeline to run on many-core accelerators, even the less computational intensive. This way, communication between host and accelerator is minimized, avoiding a common bottleneck of many-core accelerated computing. Second, we parallelized the pipeline with a fine-grained approach. Because of this parallelization strategy, it is not only possible to distribute the input beams to different computation nodes, but also to define which part of the search space is explored by any node. This completely avoids inter-node communication, and scalability of the pipeline can simply be achieved by adding more machines. Third, we use extensive auto-tuning for both the single processing kernels and the pipeline as a whole. By using auto-tuning, we do not simply find the best possible parameter configuration, thus obtaining high-performance, but also make the pipeline portable among different computing devices, and adaptable to different telescopes and observational

  13. Supernova neutrinos and explosive nucleosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Kajino, T. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan and Department of Astronomy, Graduate School of Science, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033 (Japan); Aoki, W. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Cheoun, M.-K. [Department of Physics, Soongsil University, Seoul 156-743 (Korea, Republic of); Hayakawa, T. [Japan Atomic Energy Agency, Shirakara-Shirane 2-4, Tokai-mura, Ibaraki 319-1195 (Japan); Hidaka, J.; Hirai, Y.; Shibagaki, S. [National Astronomical Observatory, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Mathews, G. J. [Center for Astrophysics, Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Nakamura, K. [Faculty of Science and Engineering, Waseda University, Ohkubo 3-4-1, Shinjuku, Tokyo 169-8555 (Japan); Suzuki, T. [Department of Physics, College of Humanities and Sciences, Nihon University, Sakurajosui 3-25-40, Setagaya-ku, Tokyo 156-8550 (Japan)

    2014-05-09

    Core-collapse supernovae eject huge amount of flux of energetic neutrinos. We studied the explosive nucleosyn-thesis in supernovae and found that several isotopes {sup 7}Li, {sup 11}B, {sup 92}Nb, {sup 138}La and {sup 180}Ta as well as r-process nuclei are affected by the neutrino interactions. The abundance of these isotopes therefore depends strongly on the neutrino flavor oscillation due to the Mikheyev-Smirnov-Wolfenstein (MSW) effect. We discuss first how to determine the neutrino temperatures in order to explain the observed solar system abundances of these isotopes, combined with Galactic chemical evolution of the light nuclei and the heavy r-process elements. We then study the effects of neutrino oscillation on their abundances, and propose a novel method to determine the still unknown neutrino oscillation parameters, mass hierarchy and θ{sub 13}, simultaneously. There is recent evidence that SiC X grains from the Murchison meteorite may contain supernova-produced light elements {sup 11}B and {sup 7}Li encapsulated in the presolar grains. Combining the recent experimental constraints on θ{sub 13}, we show that our method sug-gests at a marginal preference for an inverted neutrino mass hierarchy. Finally, we discuss supernova relic neutrinos that may indicate the softness of the equation of state (EoS) of nuclear matter as well as adiabatic conditions of the neutrino oscillation.

  14. The Supernova - A Stellar Spectacle.

    Science.gov (United States)

    Straka, W. C.

    This booklet is part of an American Astronomical Society curriculum project designed to provide teaching materials to teachers of secondary school chemistry, physics, and earth science. The following topics concerning supernovae are included: the outburst as observed and according to theory, the stellar remnant, the nebular remnant, and a summary…

  15. Strange matter, detonations and supernovae

    Energy Technology Data Exchange (ETDEWEB)

    Benvenuto, O.G.; Horvath, J.E.; Vucetich, H.

    1989-01-01

    The authors present a possible scenario driven by QCD deconfinement in a high density nuclear matter medium. Some expected consequences for type II supernovae explosions are also given, particularly, the output energy that might be enough to account for the observed events.

  16. First-Year Spectroscopy for the SDSS-II Supernova Survey

    CERN Document Server

    Zheng, Chen; Sako, Masao; Marriner, John; Bassett, Bruce; Becker, Andrew; Choi, Changsu; Cinabro, David; DeJongh, Fritz; Depoy, Darren L; Dilday, Ben; Doi, Mamoru; Frieman, Joshua A; Garnavich, Peter M; Hogan, Craig J; Holtzman, Jon; Im, Myungshin; Jha, Saurabh; Kessler, Richard; Konishi, Kohki; Lampeitl, Hubert; Marshall, Jennifer L; McGinnis, David; Miknaitis, Gajus; Nichol, Robert C; Prieto, Jose Luis; Riess, Adam G; Richmond, Michael W; Schneider, Donald P; Smith, Mathew; Takanashi, Naohiro; Tokita, Kouichi; van der Heyden, Kurt; Yasuda, Naoki; Assef, Roberto J; Barentine, John; Bender, Ralf; Blandford, Roger D; Bremer, Malcolm; Brewington, Howard; Collins, Chris A; Crotts, Arlin; Dembicky, Jack; Eastman, Jason; Edge, Alastair; Elson, Ed; Eyler, Michael E; Filippenko, Alexei V; Foley, Ryan J; Frank, Stephan; Goobar, Ariel; Harvanek, Michael; Hopp, Ulrich; Ihara, Yutaka; Kahn, Steven; Ketzeback, William; Kleinman, Scott J; Kollatschny, Wolfram; Krzesiński, Jurek; Leloudas, Giorgos; Long, Daniel C; Lucey, John; Malanushenko, Elena; Malanushenko, Viktor; McMillan, Russet J; Morgan, Christopher W; Morokuma, Tomoki; Nitta, Atsuko; Ostman, Linda; Pan, Kaike; Romer, A Kathy; Saurage, Gabrelle; Schlesinger, Katie; Snedden, Stephanie A; Sollerman, Jesper; Stritzinger, Maximilian; Watson, Linda C; Watters, Shannon; Wheeler, J Craig; York, Donald

    2008-01-01

    This paper presents spectroscopy of supernovae discovered in the first season of the Sloan Digital Sky Survey-II Supernova Survey. This program searches for and measures multi-band light curves of supernovae in the redshift range z = 0.05 - 0.4, complementing existing surveys at lower and higher redshifts. Our goal is to better characterize the supernova population, with a particular focus on SNe Ia, improving their utility as cosmological distance indicators and as probes of dark energy. Our supernova spectroscopy program features rapid-response observations using telescopes of a range of apertures, and provides confirmation of the supernova and host-galaxy types as well as precise redshifts. We describe here the target identification and prioritization, data reduction, redshift measurement, and classification of 129 SNe Ia, 16 spectroscopically probable SNe Ia, 7 SNe Ib/c, and 11 SNe II from the first season. We also describe our efforts to measure and remove the substantial host galaxy contamination existi...

  17. First-Year Spectroscopy for the SDSS-II Supernova Survey

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Chen; Romani, Roger W.; Sako, Masao; Marriner, John; Bassett, Bruce; Becker, Andrew; Choi, Changsu; Cinabro, David; DeJongh, Fritz; Depoy, Darren L.; Dilday, Ben; Doi, Mamoru; Frieman, Joshua A.; Garnavich, Peter M.; Hogan, Craig J.; Holtzman, Jon; Im, Myungshin; Jha, Saurabh; Kessler, Richard; Konishi, Kohki; Lampeitl, Hubert

    2008-03-25

    This paper presents spectroscopy of supernovae discovered in the first season of the Sloan Digital Sky Survey-II Supernova Survey. This program searches for and measures multi-band light curves of supernovae in the redshift range z = 0.05-0.4, complementing existing surveys at lower and higher redshifts. Our goal is to better characterize the supernova population, with a particular focus on SNe Ia, improving their utility as cosmological distance indicators and as probes of dark energy. Our supernova spectroscopy program features rapid-response observations using telescopes of a range of apertures, and provides confirmation of the supernova and host-galaxy types as well as precise redshifts. We describe here the target identification and prioritization, data reduction, redshift measurement, and classification of 129 SNe Ia, 16 spectroscopically probable SNe Ia, 7 SNe Ib/c, and 11 SNe II from the first season. We also describe our efforts to measure and remove the substantial host galaxy contamination existing in the majority of our SN spectra.

  18. Use of pipe saks on pipeline construction

    Energy Technology Data Exchange (ETDEWEB)

    Ghio, Alberto F.M.; Caciatori, Angelo [Galvao Engenharia S.A., Sao Paulo, SP (Brazil); Ruschi, Allan A.; Santos, Felipe A. dos; Barros, Horacio B. de; Loureiro, Regis R. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil)

    2009-07-01

    The use of new technologies applied to pipeline construction and assembling, aimed at enhancing productivity has been searched by PETROBRAS, throughout its subcontractors, assemblers, by transference in the mentioned constructions. Along the construction of Cacimbas Catu Pipeline, Spread 1 A, placed between the Cacimbas Gas Treatment Station (Linhares, ES) and the future Compression Station of Sao Mateus (ES), one, by means of surveys, noticed that the length of flooded or prone to flooding areas was way superior to the ones foreseen in the basic design. One of the broadly used methods for assuring buoyancy control is concreting the pipes. Such method deeply impacts work's logistics in for instance, the pipe stringing work; in this one, a maximum load of two pipes can be transported until the area to applied, what leads to lower productivity and higher risk due to the increase of trips by heavy load trucks. As an alternative to regular concrete, the Pipe Sak System was adopted and such method improved productivity and decreased discontinuities. (author)

  19. Classifying supernovae using only galaxy data

    Energy Technology Data Exchange (ETDEWEB)

    Foley, Ryan J. [Astronomy Department, University of Illinois at Urbana-Champaign, 1002 West Green Street, Urbana, IL 61801 (United States); Mandel, Kaisey [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

    2013-12-01

    We present a new method for probabilistically classifying supernovae (SNe) without using SN spectral or photometric data. Unlike all previous studies to classify SNe without spectra, this technique does not use any SN photometry. Instead, the method relies on host-galaxy data. We build upon the well-known correlations between SN classes and host-galaxy properties, specifically that core-collapse SNe rarely occur in red, luminous, or early-type galaxies. Using the nearly spectroscopically complete Lick Observatory Supernova Search sample of SNe, we determine SN fractions as a function of host-galaxy properties. Using these data as inputs, we construct a Bayesian method for determining the probability that an SN is of a particular class. This method improves a common classification figure of merit by a factor of >2, comparable to the best light-curve classification techniques. Of the galaxy properties examined, morphology provides the most discriminating information. We further validate this method using SN samples from the Sloan Digital Sky Survey and the Palomar Transient Factory. We demonstrate that this method has wide-ranging applications, including separating different subclasses of SNe and determining the probability that an SN is of a particular class before photometry or even spectra can. Since this method uses completely independent data from light-curve techniques, there is potential to further improve the overall purity and completeness of SN samples and to test systematic biases of the light-curve techniques. Further enhancements to the host-galaxy method, including additional host-galaxy properties, combination with light-curve methods, and hybrid methods, should further improve the quality of SN samples from past, current, and future transient surveys.

  20. X-ray upper limits on the progenitor of the Type Ia supernova 2017cbv

    Science.gov (United States)

    Kong, A. K. H.

    2017-04-01

    Following the discovery of the Type Ia supernova 2017cbv (ATel #10158), we examined a combined archival Chandra observation of the host galaxy NGC 5643 taken in 2015 May 21 and Dec 26 to search for the X-ray progenitor.

  1. Acceleration of cosmic rays and gamma-ray emission from supernova remnant/molecular cloud associations

    CERN Document Server

    Gabici, S; Morlino, G; Nava, L

    2015-01-01

    The gamma-ray observations of molecular clouds associated with supernova remnants are considered one of the most promising ways to search for a solution of the problem of cosmic ray origin. Here we briefly review the status of the field, with particular emphasis on the theoretical and phenomenological aspects of the problem.

  2. Acceleration of cosmic rays and gamma-ray emission from supernova remnant/molecular cloud associations

    Directory of Open Access Journals (Sweden)

    Gabici Stefano

    2015-01-01

    Full Text Available The gamma-ray observations of molecular clouds associated with supernova remnants are considered one of the most promising ways to search for a solution of the problem of cosmic ray origin. Here we briefly review the status of the field, with particular emphasis on the theoretical and phenomenological aspects of the problem.

  3. 75 FR 5244 - Pipeline Safety: Integrity Management Program for Gas Distribution Pipelines; Correction

    Science.gov (United States)

    2010-02-02

    ... implement integrity management programs. In addition to a minor correction in terminology, this document...: Integrity Management Program for Gas Distribution Pipelines; Correction AGENCY: Pipeline and...

  4. Local scour at submarine pipelines

    Institute of Scientific and Technical Information of China (English)

    Yee-Meng Chiew

    2010-01-01

    The rapid development of offshore oil_fields has increased the number of submarine pipelines being constructed for the transport of crude oil to onshore refineries.Interactions between the pipeline and an erodible bed under the influence of current and waves often lead to local scouring around the structure.When this occurs, the pipeline may be suspended on the seabed resulting in the formation of a span.If the free span is long enough, the pipe may experience resonant flow-induced oscillations,leading to structural failure.This study examines the complex flow-structure-sediment interaction leading to the development of local scour holes around submarine pipelines.It reviews published literature in this area,which primarily is confined to the development of 2-dimensional scour holes.Despite the abundance of such research studies,pipeline-scour in the field essentially is 3-dimensional in nature.Hence, most of these studies have overlooked the importance of the transverse dimension of the scour hole,while emphasizing on its vertical dimension.This dearly is an issue that must be re-examined in light of the potential hazard and environmental disaster that one faces in the event of a pipeline failure.Recent studies have begun to recognize this shortcoming,and attempts have been made to overcome the deficiency.The study presents the state-of-the-art knowledge on local scour at submarine pipelines,both from a 2-dimensional as well as the 3-dimensional perspective.

  5. China Oil & Gas Pipeline Survey & Design Institute, Pipeline

    Institute of Scientific and Technical Information of China (English)

    Bureau of CNPC; Zhao Surong

    1995-01-01

    @@ China Oil/Gas Pipeline Bureau(P.B) is the only professional organization in China specialized in oil/gas pipelines design and construction since 1980s. It has ever cooperated with certain number of well known companies from Japan,USA, Germany, Canada, as well as Italy in the designs of many large oil/gas pipeline projects, during the course of which, personnel from P.B accumulated much experience in international project designs. During the execution of each particular project, they strictly followed the common-use international codes and standards with computers as the auxiliary design system combined with the self-developed software. All its clients showed their trust in this organization and gave it high praise for its outstanding survey, design and technical service.

  6. X-Ray Studies of Supernova Remnants: A Different View of Supernova Explosions

    CERN Document Server

    Badenes, Carles

    2010-01-01

    The unprecedented spatial and spectral resolutions of Chandra have revolutionized our view of the X-ray emission from supernova remnants. The excellent data sets accumulated on young, ejecta dominated objects like Cas A or Tycho present a unique opportunity to study at the same time the chemical and physical structure of the explosion debris and the characteristics of the circumstellar medium sculpted by the progenitor before the explosion. Supernova remnants can thus put strong constraints on fundamental aspects of both supernova explosion physics and stellar evolution scenarios for supernova progenitors. This view of the supernova phenomenon is completely independent of, and complementary to, the study of distant extragalactic supernovae at optical wavelengths. The calibration of these two techniques has recently become possible thanks to the detection and spectroscopic follow-up of supernova light echoes. In this paper, I will review the most relevant results on supernova remnants obtained during the first...

  7. Supernova neutrino detection in LAr TPCs

    Energy Technology Data Exchange (ETDEWEB)

    Gil-Botella, Ines, E-mail: ines.gil@ciemat.es [CIEMAT, Basic Research Department, Avenida Complutense, 22, 28040 Madrid (Spain)

    2011-08-10

    The neutrino burst from a core collapse supernova can provide information about the explosion mechanism and the mechanisms of proto neutron star cooling but also about the intrinsic properties of the neutrino such as flavor oscillations. One important question is to understand to which extent can the supernova and the neutrino physics be decoupled in the observation of a single supernova. The possibility to probe the neutrino mixing angle {theta}{sub 13} and the type of mass hierarchy from the detection of supernova neutrinos with liquid argon detectors is summarized in this paper. Moreover, a quantitative study about the possibility to constrain the supernova parameters is presented. A very massive liquid argon detector ({approx} 100 kton) is needed to perform accurate measurements of these parameters. In addition, these detectors could also provide information on the {nu}{sub e} component of the diffuse supernova neutrino background.

  8. Finding Distances to Type Ia Supernovae

    Science.gov (United States)

    Kohler, Susanna

    2016-03-01

    Type Ia supernovae are known as standard candles due to their consistency, allowing us to measure distances based on their brightness. But what if these explosions arent quite as consistent as we thought? Due scientific diligence requires careful checks, so a recent study investigates whether the metallicity of a supernovas environment affects the peak luminosity of the explosion.Metallicity Dependence?Type Ia supernovae are incredibly powerful tools for determining distances in our universe. Because these supernovae are formed by white dwarfs that explode when they reach a uniform accreted mass, the supernova peak luminosity is thought to be very consistent. This consistency allows these supernovae to be used as standard candles to measure distances to their host galaxies.But what if that peak luminosity is affected by a factor that we havent taken into account? Theorists have proposed that the luminosities of Type Ia supernovae might depend on the metallicity of their environments with high-metallicity environments suppressing supernova luminosities. If this is true, then we could be systematically mis-measuring cosmological distances using these supernovae.Testing AbundancesSupernova brightnesses vs. the metallicity of their environments. Low-metallicity supernovae (blue shading) and high-metallicity supernovae (red shading) have an average magnitude difference of ~0.14. [Adapted from Moreno-Raya et al. 2016]A team led by Manuel Moreno-Raya, of the Center for Energy, Environment and Technology (CIEMAT) in Spain, has observed 28 Type Ia supernovae in an effort to test for such a metallicity dependence. These supernovae each have independent distance measurements (e.g., from Cepheids or the Tully-Fisher relation).Moreno-Raya and collaborators used spectra from the 4.2-m William Herschel Telescope to estimate oxygen abundances in the region where each of these supernovae exploded. They then used these measurements to determine if metallicity of the local region

  9. VLBI observations of young Type II supernovae

    CERN Document Server

    Pérez-Torres, M A; Marcaide, J M

    2005-01-01

    We give an overview of circumstellar interaction in young Type II supernovae, as seen through the eyes of very-long-baseline interferometry (VLBI) observations. The resolution attained by such observations (best than 1 mas) is a powerful tool to probe the interaction that takes place after a supernova goes off. The direct imaging of a supernova permits, in principle, to estimate the deceleration of its expansion, and to obtain information on the eject and circumstellar density profiles, as well as estimates of the magnetic field intensity and relativistic particle energy density in the supernova. Unfortunately, only a handful of radio supernovae are close and bright enough as to permit their study with VLBI. We present results from our high-resolution observations of the nearby Type II radio supernovae SN1986J and SN2001gd.

  10. Improvements to type Ia supernova models

    Science.gov (United States)

    Saunders, Clare M.

    Type Ia Supernovae provided the first strong evidence of dark energy and are still an important tool for measuring the accelerated expansion of the universe. However, future improvements will be limited by systematic uncertainties in our use of Type Ia supernovae as standard candles. Using Type Ia supernovae for cosmology relies on our ability to standardize their absolute magnitudes, but this relies on imperfect models of supernova spectra time series. This thesis is focused on using data from the Nearby Supernova Factory both to understand current sources of uncertainty in standardizing Type Ia supernovae and to develop techniques that can be used to limit uncertainty in future analyses. (Abstract shortened by ProQuest.).

  11. A New Search for $ \

    CERN Multimedia

    Dore, U; Kodama, K; Ushida, N; Loverre, P F

    2002-01-01

    % WA95\\\\ \\\\ The question whether neutrino flavours mix at some level - and the related question whether neutrinos have non-zero mass - is one of the remaining great challenges of experimental physics. Neutrinos from supernovae, from the sun, from the earth's atmosphere, from nuclear reactors and from radioactive decays are currently under study; in this frame, experiments using accelerators play a privileged role because the well known neutrino source properties allow high precision measurements and background control.\\\\ \\\\The main goal of the CHORUS experiment is to search for neutrino oscillations in the $\

  12. Emergency preparedness of OSBRA Pipeline

    Energy Technology Data Exchange (ETDEWEB)

    Magalhaes, Milton P.; Torres, Carlos A.R.; Almeida, Francisco J.C. [TRANSPETRO, Rio de Janeiro, RJ (Brazil)

    2009-07-01

    This paper presents the experience of PETROBRAS Transporte S. A. - TRANSPETRO in the preparation for emergencies in the OSBRA pipeline, showing specific aspects and solutions developed. The company has a standardized approach for the emergency management, based on risk analysis studies, risk management plan and contingency plans. To cover almost 1,000 km of pipeline, the Company avails of Emergency Response Centers and Environmental Defense Center, located at strategic points. In order to achieve preparation, fire fighting training and oil leakage elimination training are provided. Additionally, simulation exercises are performed, following a schedule worked out according to specific criteria and guidelines. As a conclusion, a picture is presented of the evolution of the preparation for emergencies in the OSBRA System which bears the enormous responsibility of transporting flammable products for almost 1,000 km of pipeline, crossing 40 municipalities, 3 states and the Federal District. (author)

  13. High-energy antiprotons from old supernova remnants.

    Science.gov (United States)

    Blasi, Pasquale; Serpico, Pasquale D

    2009-08-21

    A recently proposed model explains the rise in energy of the positron fraction measured by the PAMELA satellite in terms of hadronic production of positrons in aged supernova remnants, and acceleration therein. Here we present a preliminary calculation of the antiproton flux produced by the same mechanism. While the model is consistent with present data, a rise of the antiproton to proton ratio is predicted at high energy, which strikingly distinguishes this scenario from other astrophysical explanations of the positron fraction (such as pulsars). We briefly discuss important implications for dark matter searches via antimatter.

  14. High-energy antiprotons from old supernova remnants

    CERN Document Server

    Blasi, Pasquale

    2009-01-01

    A recently proposed model (arXiv:0903.2794) explains the rise in energy of the positron fraction measured by the PAMELA satellite in terms of hadronic production of positrons in aged supernova remnants, and acceleration therein. Here we present a preliminary calculation of the anti-proton flux produced by the same mechanism. While the model is consistent with present data, a rise of the antiproton to proton ratio is predicted at high energy, which strikingly distinguishes this scenario from other astrophysical explanations of the positron fraction (like pulsars). We briefly discuss important implications for Dark Matter searches via antimatter.

  15. The Scientific Potential of Supernova Neutrinos

    Energy Technology Data Exchange (ETDEWEB)

    Pagliaroli, G.; Vissani, F.

    2013-04-15

    Thanks to recent theoretical progresses and to the test bench of SN1987A, it has been possible to improve our ability to extract information from the future observations. In this paper we discuss a parameterized model of the neutrino emission. Two applications of this model are considered: 1) the investigation of the scientific potential of a future supernova for the study of the astrophysical parameters; 2) the expectations regarding the diffuse supernova neutrino background, namely, the relic supernova neutrinos.

  16. Magnetares como fuentes para potenciar supernovas superluminosas

    Science.gov (United States)

    Bersten, M. C.; Benvenuto, O. G.

    2016-08-01

    Magnetars have been proposed as one of the possible sources to power the light curve of super-luminous supernovae. We have included the energy deposited by a hypothetical magnetar in our one-dimensional hydrodynamical code, and analyzed the dynamical effect on the supernova ejecta. In particular, we present a model for SN 2011kl, the first object associated with a ultra-long-duration gamma-ray burst. Finally, we show its effect on the light curves of hydrogen rich supernovae.

  17. Magnetar Powered Ordinary Type IIP Supernovae

    OpenAIRE

    Sukhbold, Tuguldur; Thompson, Todd A.

    2017-01-01

    We investigate the properties of Type IIP supernovae that are dominantly powered by the rotational kinetic energy of the newly born neutron star. While the spin-down of a magnetar has previously been proposed as a viable energy source in the context of super-luminous supernovae, we show that a similar mechanism could produce both normal and peculiar Type IIP supernova light curves from red supergiant progenitors for a range of initial spin periods and equivalent dipole magnetic field strength...

  18. Interface dynamos in supernova progenitors

    CERN Document Server

    Blackman, E G; Thomas, J H; Blackman, Eric G.; Nordhaus, Jason T.; Thomas, John H.

    2004-01-01

    Observational evidence for anisotropy in supernovae (SN) and their phenomenological connection to jetted sources such as gamma-ray bursts^Mhave revived considerations of the role magnetohydrodynamic outflows might play therein. Understanding the types of dynamos that might operate in supernova progenitors is therefore relevant. In contrast to previous work, here we study an ``interface dynamo'' for the conditions of a rapidly rotating neutron star surrounded by a convective envelope. Such dynamos have been studied for the Sun, naked white dwarfs,and post-AGB stars, where analogous configurations of strong shear layers surrounded by convective envelopes are present. The interface dynamo provides estimates of large-scale poloidal and toroidal fields, whose product enters the Poynting flux. Because the poloidal field is much weaker than the toroidal magnetic field, the actual average Poynting flux is lower than rough estimates which invoke the only the magnitude of the total magnetic energy. The lower value is s...

  19. Cosmology from Type Ia Supernovae

    CERN Document Server

    Perlmutter, S; Deustua, S; Fabbro, S; Goldhaber, Gerson; Groom, D E; Kim, A G; Kim, M Y; Knop, R A; Nugent, P; Pennypacker, C R; Goobar, A; Pain, R; Hook, I M; Lidman, C E; Ellis, Richard S; Irwin, M J; McMahon, R G; Ruiz-Lapuente, P; Walton, N A; Schaefer, B; Boyle, B J; Filippenko, A V; Matheson, T; Fruchter, A S; Panagia, N; Newberg, H J M; Couch, W J

    1997-01-01

    This presentation reports on first evidence for a low-mass-density/positive-cosmological-constant universe that will expand forever, based on observations of a set of 40 high-redshift supernovae. The experimental strategy, data sets, and analysis techniques are described. More extensive analyses of these results with some additional methods and data are presented in the more recent LBNL report #41801 (Perlmutter et al., 1998; accepted for publication in Ap.J.), astro-ph/9812133 . This Lawrence Berkeley National Laboratory reprint is a reduction of a poster presentation from the Cosmology Display Session #85 on 9 January 1998 at the American Astronomical Society meeting in Washington D.C. It is also available on the World Wide Web at http://supernova.LBL.gov/ This work has also been referenced in the literature by the pre-meeting abstract citation: Perlmutter et al., B.A.A.S., volume 29, page 1351 (1997).

  20. Environmental impact of Supernova Remnants

    CERN Document Server

    Dubner, Gloria

    2015-01-01

    The explosion of a supernovae (SN) represents the sudden injection of about 10^51 ergs of thermal and mechanical energy in a small region of space, causing the formation of powerful shock waves that propagate through the interstellar medium at speeds of several thousands of km/s. These waves sweep, compress and heat the interstellar material that they encounter, forming the supernova remnants. Their evolution over thousands of years change forever, irreversibly, not only the physical but also the chemical properties of a vast region of space that can span hundreds of parsecs. This contribution briefly analyzes the impact of these explosions, discussing the relevance of some phenomena usually associated with SNe and their remnants in the light of recent theoretical and observational results.

  1. Connecting supernovae with their environments

    Science.gov (United States)

    Galbany, L.

    2017-03-01

    We present MUSE observations of galaxy NGC 7469 from its Science Verification to show how powerful is the combination of high-resolution wide-field integral field spectroscopy with both photometric and spectroscopic observations of supernova (SN) explosions. Using STARLIGHT and H II explorer, we selected all H II regions of the galaxy and produced 2-dimensional maps of the Hα equivalent width, average luminosity-weighted stellar age, and oxygen abundance. We measured deprojected galactocentric distances for all H II regions, and radial gradients for all above-mentioned parameters. We positioned the type Ia SN2008ec in the Branch et al. diagram, and finally discussed the characteristics of the SN parent H II region compared to all other H II regions in the galaxy. In a near future, the AMUSING survey will be able to reproduce this analysis and construct statistical samples to enable the characterization of the progenitors of different supernova types.

  2. An Update on Radio Supernovae

    Science.gov (United States)

    van Dyk, Schuyler D.; Sramek, Richard A.; Weiler, Kurt W.; Montes, Marcos J.; Panagia, Nino

    The radio emission from supernovae (SNe) is nonthermal synchrotron radiation of high brightness temperature, with a ``turn-on'' delay at longer wavelengths, power-law decline after maximum with index beta, and spectral index alpha asymptotically decreasing with time to a final, optically thin value. Radio supernovae (RSNe) are best described by the Chevalier (1982) ``mini-shell'' model, with modifications by Weiler \\etal\\ (1990). RSNe observations provide a valuable probe of the SN circumstellar environment and constraints on progenitor masses. We present a progress report on a number of recent RSNe, as well as on new behavior from RSNe 1979C and 1980K, and on RSNe as potential distance indicators. In particular, we present updated radio light curves for SN 1993J in M81.

  3. Evidence for Nearby Supernova Explosions

    CERN Document Server

    Benítez, N; Canelles, M; Benitez, Narciso; Maiz-Apellaniz, Jesus; Canelles, Matilde

    2002-01-01

    Supernova explosions are one of the most energetic--and potentially lethal--phenomena in the Universe. Scientists have speculated for decades about the possible consequences for life on Earth of a nearby supernova, but plausible candidates for such an event were lacking. Here we show that the Scorpius-Centaurus OB association, a group of young stars currently located at~130 parsecs from the Sun, has generated 20 SN explosions during the last 11 Myr, some of them probably as close as 40 pc to our planet. We find that the deposition on Earth of 60Fe atoms produced by these explosions can explain the recent measurements of an excess of this isotope in deep ocean crust samples. We propose that ~2 Myr ago, one of the SNe exploded close enough to Earth to seriously damage the ozone layer, provoking or contributing to the Pliocene-Pleistocene boundary marine extinction.

  4. Performance and Cost Analysis of the Supernova Factory on the Amazon AWS Cloud

    Directory of Open Access Journals (Sweden)

    Keith R. Jackson

    2011-01-01

    Full Text Available Today, our picture of the Universe radically differs from that of just over a decade ago. We now know that the Universe is not only expanding as Hubble discovered in 1929, but that the rate of expansion is accelerating, propelled by mysterious new physics dubbed “Dark Energy”. This revolutionary discovery was made by comparing the brightness of nearby Type Ia supernovae (which exploded in the past billion years to that of much more distant ones (from up to seven billion years ago. The reliability of this comparison hinges upon a very detailed understanding of the physics of the nearby events. To further this understanding, the Nearby Supernova Factory (SNfactory relies upon a complex pipeline of serial processes that execute various image processing algorithms in parallel on ~10 TBs of data. This pipeline traditionally runs on a local cluster. Cloud computing [Above the clouds: a Berkeley view of cloud computing, Technical Report UCB/EECS-2009-28, University of California, 2009] offers many features that make it an attractive alternative. The ability to completely control the software environment in a cloud is appealing when dealing with a community developed science pipeline with many unique library and platform requirements. In this context we study the feasibility of porting the SNfactory pipeline to the Amazon Web Services environment. Specifically we: describe the tool set we developed to manage a virtual cluster on Amazon EC2, explore the various design options available for application data placement, and offer detailed performance results and lessons learned from each of the above design options.

  5. A New Determination of the High Redshift Type Ia Supernova Rates with the Hubble Space Telescope Advanced Camera for Surveys

    CERN Document Server

    Kuznetsova, N; Connolly, B; Kim, A G; Pain, R; Roe, N A; Aldering, G; Amanullah, R; Dawson, K; Doi, M; Fadeev, V; Fruchter, A S; Gibbons, R; Goldhaber, G; Goobar, A; Gude, A; Knop, R A; Kowalski, M; Lidman, C; Morokuma, T; Meyers, J; Perlmutter, S; Rubin, D; Schlegel, D J; Spadafora, A L; Stanishev, V; Strovink, M; Suzuki, N; Wang, L; Yasuda, N

    2007-01-01

    We present a new measurement of the volumetric rate of Type Ia supernova up to a redshift of 1.7, using the Hubble Space Telescope (HST) GOODS data combined with an additional HST dataset covering the North GOODS field collected in 2004. We employ a novel technique that does not require spectroscopic data for identifying Type Ia supernovae (although spectroscopic measurements of redshifts are used for over half the sample); instead we employ a Bayesian approach using only photometric data to calculate the probability that an object is a Type Ia supernova. This Bayesian technique can easily be modified to incorporate improved priors on supernova properties, and it is well-suited for future high-statistics supernovae searches in which spectroscopic follow up of all candidates will be impractical. Here, the method is validated on both ground- and space-based supernova data having some spectroscopic follow up. We combine our volumetric rate measurements with low redshift supernova data, and fit to a number of pos...

  6. Convection in Type 2 supernovae

    Energy Technology Data Exchange (ETDEWEB)

    Miller, D.S.

    1993-10-15

    Results are presented here from several two dimensional numerical calculations of events in Type II supernovae. A new 2-D hydrodynamics and neutrino transport code has been used to compute the effect on the supernova explosion mechanism of convection between the neutrinosphere and the shock. This convection is referred to as exterior convection to distinguish it from convection beneath the neutrinosphere. The model equations and initial and boundary conditions are presented along with the simulation results. The 2-D code was used to compute an exterior convective velocity to compare with the convective model of the Mayle and Wilson 1-D code. Results are presented from several runs with varying sizes of initial perturbation, as well as a case with no initial perturbation but including the effects of rotation. The M&W code does not produce an explosion using the 2-D convective velocity. Exterior convection enhances the outward propagation of the shock, but not enough to ensure a successful explosion. Analytic estimates of the growth rate of the neutron finger instability axe presented. It is shown that this instability can occur beneath the neutrinosphere of the proto-neutron star in a supernova explosion with a growth time of {approximately} 3 microseconds. The behavior of the high entropy bubble that forms between the shock and the neutrinosphere in one dimensional calculations of supernova is investigated. It has been speculated that this bubble is a site for {gamma}-process generation of heavy elements. Two dimensional calculations are presented of the time evolution of the hot bubble and the surrounding stellar material. Unlike one dimensional calculations, the 2D code fails to achieve high entropies in the bubble. When run in a spherically symmetric mode the 2-D code reaches entropies of {approximately} 200. When convection is allowed, the bubble reaches {approximately} 60 then the bubble begins to move upward into the cooler, denser material above it.

  7. Understanding Core-Collapse Supernovae

    CERN Document Server

    Burrows, A

    2004-01-01

    I summarize, in the form of an extended abstract, the ongoing efforts at the University of Arizona (and in collaboration) to understand core-collapse supernovae theoretically. Included are short discussions of 1D (SESAME) and 2D (VULCAN/2D) codes and results, as well as discussions of the possible role of rotation. Highlighted are recent developments in multi-dimensional radiation hydrodynamics and the essential physics of the neutrino-driven mechanism.

  8. Convection in Type 2 supernovae

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Douglas Scott [Univ. of California, Davis, CA (United States)

    1993-10-15

    Results are presented here from several two dimensional numerical calculations of events in Type II supernovae. A new 2-D hydrodynamics and neutrino transport code has been used to compute the effect on the supernova explosion mechanism of convection between the neutrinosphere and the shock. This convection is referred to as exterior convection to distinguish it from convection beneath the neutrinosphere. The model equations and initial and boundary conditions are presented along with the simulation results. The 2-D code was used to compute an exterior convective velocity to compare with the convective model of the Mayle and Wilson 1-D code. Results are presented from several runs with varying sizes of initial perturbation, as well as a case with no initial perturbation but including the effects of rotation. The M&W code does not produce an explosion using the 2-D convective velocity. Exterior convection enhances the outward propagation of the shock, but not enough to ensure a successful explosion. Analytic estimates of the growth rate of the neutron finger instability axe presented. It is shown that this instability can occur beneath the neutrinosphere of the proto-neutron star in a supernova explosion with a growth time of ~ 3 microseconds. The behavior of the high entropy bubble that forms between the shock and the neutrinosphere in one dimensional calculations of supernova is investigated. It has been speculated that this bubble is a site for γ-process generation of heavy elements. Two dimensional calculations are presented of the time evolution of the hot bubble and the surrounding stellar material. Unlike one dimensional calculations, the 2D code fails to achieve high entropies in the bubble. When run in a spherically symmetric mode the 2-D code reaches entropies of ~ 200. When convection is allowed, the bubble reaches ~60 then the bubble begins to move upward into the cooler, denser material above it.

  9. Cosmic Ray Acceleration in Supernova Remnants

    CERN Document Server

    Blasi, Pasquale

    2010-01-01

    We review the main observational and theoretical facts about acceleration of Galactic cosmic rays in supernova remnants, discussing the arguments in favor and against a connection between cosmic rays and supernova remnants, the so-called supernova remnant paradigm for the origin of Galactic cosmic rays. Recent developments in the modeling of the mechanism of diffusive shock acceleration are discussed, with emphasis on the role of 1) magnetic field amplification, 2) acceleration of nuclei heavier than hydrogen, 3) presence of neutrals in the circumstellar environment. The status of the supernova-cosmic ray connection in the time of Fermi-LAT and Cherenkov telescopes is also discussed.

  10. Method and system for pipeline communication

    Science.gov (United States)

    Richardson,; John, G [Idaho Falls, ID

    2008-01-29

    A pipeline communication system and method includes a pipeline having a surface extending along at least a portion of the length of the pipeline. A conductive bus is formed to and extends along a portion of the surface of the pipeline. The conductive bus includes a first conductive trace and a second conductive trace with the first and second conductive traces being adapted to conformally couple with a pipeline at the surface extending along at least a portion of the length of the pipeline. A transmitter for sending information along the conductive bus on the pipeline is coupled thereto and a receiver for receiving the information from the conductive bus on the pipeline is also couple to the conductive bus.

  11. Pulsational-Pair Instability Supernovae

    CERN Document Server

    Woosley, S E

    2016-01-01

    The final evolution of stars in the mass range 60 - 150 solar masses is explored. Depending upon their mass loss and rotation rates, many of these stars will end their lives as pulsational pair-instability supernovae. Even a non-rotating 70 solar mass star is pulsationally unstable during oxygen shell burning and can power a sub-luminous supernova. Rotation decreases the limit further. For more massive stars, the pulsations are less frequent, span a longer time, and are more powerful. Violent pulsations eject not only any residual low density envelope, but also that fraction of the helium core mass outside about 35 - 50 solar masses. The remaining core of helium and heavy elements continues to evolve, ultimately forming an iron core of about 2.5 solar masses that probably collapses to a black hole. A variety of observational transients result with total durations ranging from days to 10,000 years, and luminosities from 10$^{41}$ to 10$^{44}$ erg s$^{-1}$. Many transients resemble ordinary Type IIp supernovae,...

  12. Dark Energy and Termonuclear Supernovae

    Science.gov (United States)

    Domíngez, I.; Bravo, E.; Piersanti, L.; Tornambé, A.; Straniero, O.; Höflich, P.

    2008-12-01

    Nowadays it is widely accepted that the current Universe is dominated by dark energy and exotic matter, the so called StandardModel of Cosmoloy or CDM model. All the available data (Thermonuclear Supernovae, Cosmic Microwave Background, Baryon Acoustic Oscillations, Large Scale Structure, etc.) are compatible with a flat Universe made by ~70% of dark energy. Up to now observations agree that dark energy may be the vacuum energy (or cosmological constant) although improvements are needed to constrain further its equation of state. In this context, the cosmic destiny of the Universe is no longer linked to its geometry but to the nature of dark energy; it may be flat and expand forever or collapse. To understand the nature of dark energy is probably the most fundamental problem in physics today; it may open new roads of knowledge and led to unify gravity with the other fundamental interactions in nature. It is expected that astronomical data will continue to provide directions to theorists and experimental physicists. Type Ia supernovae (SNe Ia) have played a fundamental role, showing the acceleration of the expansion rate of the Universe a decade ago, and up to now they are the only astronomical observations that provide a direct evidence of the acceleration. However, in order to determine the source of the dark energy term it is mandatory to improve the precision of supernovae as distance indicators on cosmological scale.

  13. 77 FR 19799 - Pipeline Safety: Pipeline Damage Prevention Programs

    Science.gov (United States)

    2012-04-02

    ..., excavation, tunneling, or construction activity to establish the location of underground facilities in the demolition, excavation, tunneling, or construction area; 2. Disregard location information or markings... construction activity; and 3. Fail to report excavation damage to a pipeline facility to the owner or operator...

  14. 75 FR 13342 - Pipeline Safety: Workshop on Distribution Pipeline Construction

    Science.gov (United States)

    2010-03-19

    ... practices in natural gas distribution pipeline construction management and quality control. This workshop... St. Louis at the Ballpark, 1 South Broadway, St. Louis, MO 63102. Hotel reservations under the ``U.S...-845-7354. A daily base rate of $110.00 is available. The meeting room will be posted at the hotel on...

  15. A spitzer space telescope study of SN 2002hh: An infrared echo from a type llP supernova

    DEFF Research Database (Denmark)

    Meikle, W. P. S.; Mattila, S.; Gerardy, C. L.;

    2006-01-01

    Stars: Supernovae: General, supernovae: individual (NGC 6946), Stars: Supernovae: Individual: Alphanumeric: SN 2002hh Udgivelsesdato: May 22......Stars: Supernovae: General, supernovae: individual (NGC 6946), Stars: Supernovae: Individual: Alphanumeric: SN 2002hh Udgivelsesdato: May 22...

  16. 78 FR 41496 - Pipeline Safety: Meetings of the Gas and Liquid Pipeline Advisory Committees

    Science.gov (United States)

    2013-07-10

    ... Pipeline and Hazardous Materials Safety Administration Pipeline Safety: Meetings of the Gas and Liquid... for natural gas pipelines and for hazardous liquid pipelines. Both committees were established under.... ACTION: Notice of advisory committee meeting. SUMMARY: This notice announces a public meeting of the...

  17. California Natural Gas Pipelines: A Brief Guide

    Energy Technology Data Exchange (ETDEWEB)

    Neuscamman, Stephanie [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Price, Don [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Pezzola, Genny [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Glascoe, Lee [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2013-01-22

    The purpose of this document is to familiarize the reader with the general configuration and operation of the natural gas pipelines in California and to discuss potential LLNL contributions that would support the Partnership for the 21st Century collaboration. First, pipeline infrastructure will be reviewed. Then, recent pipeline events will be examined. Selected current pipeline industry research will be summarized. Finally, industry acronyms are listed for reference.

  18. Research on Pipeline Holdup Measurement Technology

    Institute of Scientific and Technical Information of China (English)

    LU; Wen-guang; XU; Zheng; CHENG; Yi-mei; SUI; Hong-zhi; YIN; Hong-he

    2012-01-01

    <正>Some of the nuclear material could be deposited in the pipeline system of the nuclear facilities in the operation process. That kind of nuclear materials in the pipeline are called holdup. The measurement of pipeline holdup is not only important for the nuclear material accounting and control of facilities, but also important for the safe operation of facilities.

  19. Cygnus Loop Supernova Blast Wave

    Science.gov (United States)

    1993-01-01

    This is an image of a small portion of the Cygnus Loop supernova remnant, which marks the edge of a bubble-like, expanding blast wave from a colossal stellar explosion, occurring about 15,000 years ago. The HST image shows the structure behind the shock waves, allowing astronomers for the first time to directly compare the actual structure of the shock with theoretical model calculations. Besides supernova remnants, these shock models are important in understanding a wide range of astrophysical phenomena, from winds in newly-formed stars to cataclysmic stellar outbursts. The supernova blast is slamming into tenuous clouds of insterstellar gas. This collision heats and compresses the gas, causing it to glow. The shock thus acts as a searchlight revealing the structure of the interstellar medium. The detailed HST image shows the blast wave overrunning dense clumps of gas, which despite HST's high resolution, cannot be resolved. This means that the clumps of gas must be small enough to fit inside our solar system, making them relatively small structures by interstellar standards. A bluish ribbon of light stretching left to right across the picture might be a knot of gas ejected by the supernova; this interstellar 'bullet' traveling over three million miles per hour (5 million kilometres) is just catching up with the shock front, which has slowed down by ploughing into interstellar material. The Cygnus Loop appears as a faint ring of glowing gases about three degrees across (six times the diameter of the full Moon), located in the northern constellation, Cygnus the Swan. The supernova remnant is within the plane of our Milky Way galaxy and is 2,600 light-years away. The photo is a combination of separate images taken in three colors, oxygen atoms (blue) emit light at temperatures of 30,000 to 60,000 degrees Celsius (50,000 to 100,000 degrees Farenheit). Hydrogen atoms (green) arise throughout the region of shocked gas. Sulfur atoms (red) form when the gas cools to

  20. The MACHO data pipeline

    CERN Document Server

    Axelrod, T S; Quinn, P J; Bennett, D P; Freeman, K C; Peterson, B A; Rodgers, A W; Alcock, C B; Cook, K H; Griest, K; Marshall, S L; Pratt, M R; Stubbs, C W; Sutherland, W

    1995-01-01

    The MACHO experiment is searching for dark matter in the halo of the Galaxy by monitoring more than 20 million stars in the LMC and Galactic bulge for gravitational microlensing events. The hardware consists of a 50 inch telescope, a two-color 32 megapixel ccd camera, and a network of computers. On clear nights the system generates up to 8 GB of raw data and 1 GB of reduced data. The computer system is responsible for all realtime control tasks, for data reduction, and for storing all data associated with each observation in a data base. The subject of this paper is the software system that handles these functions. It is an integrated system controlled by Petri nets that consists of multiple processes communicating via mailboxes and a bulletin board. The system is highly automated, readily extensible, and incorporates flexible error recovery capabilities. It is implemented with C++ in a Unix environment.

  1. See Change: the Supernova Sample from the Supernova Cosmology Project High Redshift Cluster Supernova Survey

    Science.gov (United States)

    Hayden, Brian; Perlmutter, Saul; Boone, Kyle; Nordin, Jakob; Rubin, David; Lidman, Chris; Deustua, Susana E.; Fruchter, Andrew S.; Aldering, Greg Scott; Brodwin, Mark; Cunha, Carlos E.; Eisenhardt, Peter R.; Gonzalez, Anthony H.; Jee, James; Hildebrandt, Hendrik; Hoekstra, Henk; Santos, Joana; Stanford, S. Adam; Stern, Daniel; Fassbender, Rene; Richard, Johan; Rosati, Piero; Wechsler, Risa H.; Muzzin, Adam; Willis, Jon; Boehringer, Hans; Gladders, Michael; Goobar, Ariel; Amanullah, Rahman; Hook, Isobel; Huterer, Dragan; Huang, Xiaosheng; Kim, Alex G.; Kowalski, Marek; Linder, Eric; Pain, Reynald; Saunders, Clare; Suzuki, Nao; Barbary, Kyle H.; Rykoff, Eli S.; Meyers, Joshua; Spadafora, Anthony L.; Sofiatti, Caroline; Wilson, Gillian; Rozo, Eduardo; Hilton, Matt; Ruiz-Lapuente, Pilar; Luther, Kyle; Yen, Mike; Fagrelius, Parker; Dixon, Samantha; Williams, Steven

    2017-01-01

    The Supernova Cosmology Project has finished executing a large (174 orbits, cycles 22-23) Hubble Space Telescope program, which has measured ~30 type Ia Supernovae above z~1 in the highest-redshift, most massive galaxy clusters known to date. Our SN Ia sample closely matches our pre-survey predictions; this sample will improve the constraint by a factor of 3 on the Dark Energy equation of state above z~1, allowing an unprecedented probe of Dark Energy time variation. When combined with the improved cluster mass calibration from gravitational lensing provided by the deep WFC3-IR observations of the clusters, See Change will triple the Dark Energy Task Force Figure of Merit. With the primary observing campaign completed, we present the preliminary supernova sample and our path forward to the supernova cosmology results. We also compare the number of SNe Ia discovered in each cluster with our pre-survey expectations based on cluster mass and SFR estimates. Our extensive HST and ground-based campaign has already produced unique results; we have confirmed several of the highest redshift cluster members known to date, confirmed the redshift of one of the most massive galaxy clusters at z~1.2 expected across the entire sky, and characterized one of the most extreme starburst environments yet known in a z~1.7 cluster. We have also discovered a lensed SN Ia at z=2.22 magnified by a factor of ~2.7, which is the highest spectroscopic redshift SN Ia currently known.

  2. Detecting abnormalities in gas pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Smati, A. (Institut National des Hydrocarbures et de la Chimie, Bournerdes (Azerbaijan))

    1994-12-01

    The results of the measurement of the principal operating parameters can contain precious information on the condition of gas pipelines. This article explains how statistical tests may be useful in detecting anomalies that can occur on lines and in compressor stations. (author). 6 refs., 3 tabs., 1 fig.

  3. COMPTEL upper limits on gamma-ray line emission from Supernova 1991T

    Science.gov (United States)

    Lichti, G. G.; Bennett, K.; Herder, J. W. Den; Diehl, R.; Morris, D.; Ryan, J.; Schoenfelder, V.; Steinle, H.; Strong, A. W.; Winkler, C.

    1994-01-01

    The imaging Compton telescope COMPTEL on board the Compton Gamma-Ray Observatory (CGRO) measures gamma-rays in the energy range 0.75-30 MeV with an energy resolution of 9.7% full width at half maximum (FWHM) at 1 MeV. From June 15 to 28, 1991 and again from October 3 to 17, 1991 the region containing the supernova SN 1991T was observed. A search for gamma-ray line emission from the supernova yields no detection of line emission from the supernova. 2 sigma upper limits for the two predicted lines at 847 keV and at 1.238 MeV of approximately equal to 3 x 10(exp -5) photons/(sq cm)(s) were derived. These limits are compared with the predictions of some theoretical models and constraints imposed by these limits on these models are discussed.

  4. Dusty supernovae running the thermodynamics of the matter reinserted within young and massive super stellar clusters

    CERN Document Server

    Tenorio-Tagle, Guillermo; González, Sergio Martínez; Muñoz-Tuñón, Casiana; Palouš, Jan; Wünsch, Richard

    2013-01-01

    Following the observational and theoretical evidence that points at core collapse supernovae as major producers of dust, here we calculate the hydrodynamics of the matter reinserted within young and massive super stellar clusters under the assumption of gas and dust radiative cooling. The large supernova rate expected in massive clusters allows for a continuous replenishment of dust immersed in the high temperature thermalized reinserted matter and warrants a stationary presence of dust within the cluster volume during the type II supernova era. We first show that such a balance determines the range of dust to gas mass ratio and this the dust cooling law. We then search for the critical line that separates stationary cluster winds from the bimodal cases in the cluster mechanical luminosity (or cluster mass) vs cluster size parameter space. In the latter, strong radiative cooling reduces considerably the cluster wind mechanical energy output and affects particularly the cluster central regions, leading to freq...

  5. Expansion of Kes 73, a shell supernova remnant containing a magnetar

    Science.gov (United States)

    Borkowski, Kazimierz

    2014-09-01

    Formation and evolution of highly magnetized neutron stars (magnetars) remain poorly understood. We can learn about magnetars by studying their remnants. Kes 73 is a young supernova remnant containing a magnetar. But basic properties of Kes 73, including its age, remain poorly known. We propose a third-epoch observation of Kes 73 with Chandra. When combined with the 2000 and 2006 observations, this will allow for determination of the remnant's age through expansion rate measurements. We will also search for spatial variations in expansion rate that will help in understanding of the remnant's dynamics. New observations will also be used to determine abundances of heavy-element supernova ejecta, placing further constraints on the supernova that produced Kes 73.

  6. COMPTEL upper limits on gamma-ray line emission from Supernova 1991T

    Science.gov (United States)

    Lichti, G. G.; Bennett, K.; Herder, J. W. Den; Diehl, R.; Morris, D.; Ryan, J.; Schoenfelder, V.; Steinle, H.; Strong, A. W.; Winkler, C.

    1994-01-01

    The imaging Compton telescope COMPTEL on board the Compton Gamma-Ray Observatory (CGRO) measures gamma-rays in the energy range 0.75-30 MeV with an energy resolution of 9.7% full width at half maximum (FWHM) at 1 MeV. From June 15 to 28, 1991 and again from October 3 to 17, 1991 the region containing the supernova SN 1991T was observed. A search for gamma-ray line emission from the supernova yields no detection of line emission from the supernova. 2 sigma upper limits for the two predicted lines at 847 keV and at 1.238 MeV of approximately equal to 3 x 10(exp -5) photons/(sq cm)(s) were derived. These limits are compared with the predictions of some theoretical models and constraints imposed by these limits on these models are discussed.

  7. Data Validation in the Kepler Science Operations Center Pipeline

    Science.gov (United States)

    Wu, Hayley; Twicken, Joseph D.; Tenenbaum, Peter; Clarke, Bruce D.; Li, Jie; Quintana, Elisa V.; Allen, Christopher; Chandrasekaran, Hema; Jenkins, Jon M.; Caldwell, Douglas A.; Wohler, Bill; Girouard, Forrest; McCauliff, Sean; Cote, Miles T.; Klaus, Todd C.

    2010-01-01

    We present an overview of the Data Validation (DV) software component and its context within the Kepler Science Operations Center (SOC) pipeline and overall Kepler Science mission. The SOC pipeline performs a transiting planet search on the corrected light curves for over 150,000 targets across the focal plane array. We discuss the DV strategy for automated validation of Threshold Crossing Events (TCEs) generated in the transiting planet search. For each TCE, a transiting planet model is fitted to the target light curve. A multiple planet search is conducted by repeating the transiting planet search on the residual light curve after the model flux has been removed; if an additional detection occurs, a planet model is fitted to the new TCE. A suite of automated tests are performed after all planet candidates have been identified. We describe a centroid motion test to determine the significance of the motion of the target photocenter during transit and to estimate the coordinates of the transit source within the photometric aperture; a series of eclipsing binary discrimination tests on the parameters of the planet model fits to all transits and the sequences of odd and even transits; and a statistical bootstrap to assess the likelihood that the TCE would have been generated purely by chance given the target light curve with all transits removed. Keywords: photometry, data validation, Kepler, Earth-size planets

  8. Shipbuilding pipeline production quality improvement

    Directory of Open Access Journals (Sweden)

    T. Buksa

    2010-06-01

    Full Text Available Purpose: The pipeline production is one of major processes in shipbuilding industry. Quality improvement and risk assessment in this process can yield significant savings, both in terms of internal quality costs as well as in terms of customer satisfactions.Design/methodology/approach: Shipbuilding pipeline production quality improvement has been carried out by application of FMEA (Failure Mode and Effect Analysis method. For the successful implementation of FMEA method it is necessary to identify process failure modes or possibility of the appearance of non-compliance, as well as their possible causes. For qualitative analysis of key input variables of the process, in the paper is used Ishikawa diagram and p-chart.Findings: It is shown that proposed approach to risk assessment in shipbuilding pipeline production is applicable to real casa scenario. The analysis has identified the points in the process with the highest probability of occurrence of nonconformities, or the highest risk for error.Research limitations/implications: As the experimenting has been conducted in shipyard, within production process, research schedule must have been set in accordance with production pace. Also, due to character of production process the data collecting was adopted to the production plan in that particular moment.Practical implications: Dealing with causes of potential nonconformities in the process can significantly contribute to the reliability and robustness of the process. Corrective actions that have been taken based on results of analysis significantly contributed to the level of quality in the pipeline production process.Originality/value: The pepper is dealing with a well known method applied in different production environment that are mostly conservative in production approach. It was shown that successful application of proposed approach can yield benefits especially in improved quality of produced pipelines within shipbuilding industry.

  9. Optical Fiber Pipeline Security Forewarning System

    Institute of Scientific and Technical Information of China (English)

    Jiang Qishan; Ren Ruijun; Ren Peikui

    2010-01-01

    @@ With the rapid development of China's economy,such incidents occurring to oil & gas pipelines as industrial and agricultural production,natural disasters,oil stealing,etc.have been prevailing and brought negative influences to the normal operation of pipelines.On account of all such destructive activities,firstly the soil around the pipeline should be vibrated,and then the cable laid in the pipe trench could respond to the vibration.Using this technology,the Department of Science & Technology of CNPC has embarked on the research of relevant equipment to monitor pipeline activities along the pipeline since 2001.

  10. Supernova remnants: the X-ray perspective

    NARCIS (Netherlands)

    Vink, J.

    2012-01-01

    Supernova remnants are beautiful astronomical objects that are also of high scientific interest, because they provide insights into supernova explosion mechanisms, and because they are the likely sources of Galactic cosmic rays. X-ray observations are an important means to study these objects. And i

  11. Single Degenerate Progenitors of Type Ia Supernovae

    Science.gov (United States)

    Bours, Madelon; Toonen, Silvia; Nelemans, Gijs

    2013-01-01

    There is a general agreement that Type Ia supernovae correspond to the thermonuclear runaway of a white dwarf (WD) in a compact binary. The details of these progenitor systems are still unclear. Using the population synthesis code SeBa and several assumption for the WD retention efficiency, we estimate the delay times and supernova rates for the single degenerate scenario.

  12. Supernova constraints on neutrino mass and mixing

    Indian Academy of Sciences (India)

    Srubabati Goswami

    2000-01-01

    In this article I review the constraints on neutrino mass and mixing coming from type-II supernovae. The bounds obtained on these parameters from shock reheating, -process nucleosynthesis and from SN1987A are discussed. Given the current constraints on neutrino mass and mixing the effect of oscillations of neutrinos from a nearby supernova explosion in future detectors will also be discussed.

  13. Cosmic-ray acceleration in supernova remnants

    NARCIS (Netherlands)

    Helder, E.A.

    2010-01-01

    Supernovae are among the most energetic events in the Universe. During the event, they expel their material with enormous speeds into the surroundings. In addition, supernovae are thought to transfer a sizable fraction of their energy into just a few particles: cosmic rays. These cosmic rays acquire

  14. A relativistic type Ibc supernova without a detected gamma-ray burst.

    Science.gov (United States)

    Soderberg, A M; Chakraborti, S; Pignata, G; Chevalier, R A; Chandra, P; Ray, A; Wieringa, M H; Copete, A; Chaplin, V; Connaughton, V; Barthelmy, S D; Bietenholz, M F; Chugai, N; Stritzinger, M D; Hamuy, M; Fransson, C; Fox, O; Levesque, E M; Grindlay, J E; Challis, P; Foley, R J; Kirshner, R P; Milne, P A; Torres, M A P

    2010-01-28

    Long duration gamma-ray bursts (GRBs) mark the explosive death of some massive stars and are a rare sub-class of type Ibc supernovae. They are distinguished by the production of an energetic and collimated relativistic outflow powered by a central engine (an accreting black hole or neutron star). Observationally, this outflow is manifested in the pulse of gamma-rays and a long-lived radio afterglow. Until now, central-engine-driven supernovae have been discovered exclusively through their gamma-ray emission, yet it is expected that a larger population goes undetected because of limited satellite sensitivity or beaming of the collimated emission away from our line of sight. In this framework, the recovery of undetected GRBs may be possible through radio searches for type Ibc supernovae with relativistic outflows. Here we report the discovery of luminous radio emission from the seemingly ordinary type Ibc SN 2009bb, which requires a substantial relativistic outflow powered by a central engine. A comparison with our radio survey of type Ibc supernovae reveals that the fraction harbouring central engines is low, about one per cent, measured independently from, but consistent with, the inferred rate of nearby GRBs. Independently, a second mildly relativistic supernova has been reported.

  15. A mildly relativistic radio jet from the otherwise normal Type Ic Supernova 2007gr

    CERN Document Server

    Paragi, Z; Kouveliotou, C; Granot, J; Ramirez-Ruiz, E; Bietenholz, M; van der Horst, A J; Pidopryhora, Y; van Langevelde, H J; Garrett, M A; Szomoru, A; Argo, M; Bourke, S; Paczynski, B; 10.1038/nature08713

    2010-01-01

    The class of type Ic supernovae have drawn increasing attention since 1998 owing to their sparse association (only four so far) with long duration gamma-ray bursts. Although both phenomena originate from the core collapse of a massive star, supernovae emit mostly at optical wavelengths, whereas GRBs emit mostly in soft gamma-rays or hard X-rays. Though the GRB central engine generates ultra-relativistic jets, which beam the early emission into a narrow cone, no relativistic outflows have hitherto been found in type Ib/c supernovae explosions, despite theoretical expectations and searches. Here we report radio (interferometric) observations that reveal a mildly relativistic expansion in a nearby type Ic supernova, SN 2007gr. Using two observational epochs 60 days apart, we detect expansion of the source and establish a conservative lower limit for the average apparent expansion velocity of 0.6c. Independently, a second mildly relativistic supernova has been reported. Contrary to the radio data, optical observa...

  16. Oil pipeline valve automation for spill reduction

    Energy Technology Data Exchange (ETDEWEB)

    Mohitpour, Mo; Trefanenko, Bill [Enbridge Technology Inc, Calgary (Canada); Tolmasquim, Sueli Tiomno; Kossatz, Helmut [TRANSPETRO - PETROBRAS Transporte S.A., Rio de Janeiro, RJ (Brazil)

    2003-07-01

    Liquid pipeline codes generally stipulate placement of block valves along liquid transmission pipelines such as on each side of major river crossings where environmental hazards could cause or are foreseen to potentially cause serious consequences. Codes, however, do not stipulate any requirement for block valve spacing for low vapour pressure petroleum transportation, nor for remote pipeline valve operations to reduce spills. A review of pipeline codes for valve requirement and spill limitation in high consequence areas is thus presented along with a criteria for an acceptable spill volume that could be caused by pipeline leak/full rupture. A technique for deciding economically and technically effective pipeline block valve automation for remote operation to reduce oil spilled and control of hazards is also provided. In this review, industry practice is highlighted and application of the criteria for maximum permissible oil spill and the technique for deciding valve automation thus developed, as applied to ORSUB pipeline is presented. ORSUB is one of the three initially selected pipelines that have been studied. These pipelines represent about 14% of the total length of petroleum transmission lines operated by PETROBRAS Transporte S.A. (TRANSPETRO) in Brazil. Based on the implementation of valve motorization on these three pipeline, motorization of block valves for remote operation on the remaining pipelines is intended, depending on the success of these implementations, on historical records of failure and appropriate ranking. (author)

  17. Upstream pipelines : inspection, corrosion and integrity management

    Energy Technology Data Exchange (ETDEWEB)

    Paez, J.; Stephenson, M. [Talisman Energy Inc., Calgary, AB (Canada)] (comps.)

    2009-07-01

    Accurate inspection techniques are needed to ensure the integrity of pipelines. This working group discussed methods of reducing pipeline failures for a variety of pipes. A summary of recent pipeline performance statistics was presented, as well as details of third party damage and fiberglass pipe failures. A batch inhibitor joint industry project was described. The session demonstrated that integrity program need to be developed at the field-level as well as at the upper management level. Fiberglass pipeline failures are significant problem for pipeline operators. Corrosion monitoring, pigging and specific budgets are needed in order to ensure the successful management of pipeline integrity. New software developed to predict pipeline corrosion rates was discussed, and methods of determining mole fractions and flow regimes were presented. The sessions included updates from regulators and standards agencies as well as discussions of best practices, regulations, codes and standards related to pipeline integrity. The working group was divided into 4 sessions: (1) updates since 2007 with input from the Canadian Association of Petroleum Producers (CAPP) and the Upstream Pipeline Integrity Management Association (UPIMA); (2) integrity of non-metallic pipelines; (3) upstream pipeline integrity issues; and (4) hot topics. tabs., figs.

  18. The MIRI Medium Resolution Spectrometer calibration pipeline

    CERN Document Server

    Labiano, A; Bailey, J I; Beard, S; Dicken, D; García-Marín, M; Geers, V; Glasse, A; Glauser, A; Gordon, K; Justtanont, K; Klaassen, P; Lahuis, F; Law, D; Morrison, J; Müller, M; Rieke, G; Vandenbussche, B; Wright, G

    2016-01-01

    The Mid-Infrared Instrument (MIRI) Medium Resolution Spectrometer (MRS) is the only mid-IR Integral Field Spectrometer on board James Webb Space Telescope. The complexity of the MRS requires a very specialized pipeline, with some specific steps not present in other pipelines of JWST instruments, such as fringe corrections and wavelength offsets, with different algorithms for point source or extended source data. The MRS pipeline has also two different variants: the baseline pipeline, optimized for most foreseen science cases, and the optimal pipeline, where extra steps will be needed for specific science cases. This paper provides a comprehensive description of the MRS Calibration Pipeline from uncalibrated slope images to final scientific products, with brief descriptions of its algorithms, input and output data, and the accessory data and calibration data products necessary to run the pipeline.

  19. Snapping Supernovae at z>1.7

    CERN Document Server

    Aldering, G; Kowalski, M; Linder, E V; Perlmutter, S; Aldering, Greg; Kim, Alex G.; Kowalski, Marek; Linder, Eric V.; Perlmutter, Saul

    2006-01-01

    We examine the utility of very high redshift Type Ia supernovae for cosmology and systematic uncertainty control. Next generation space surveys such as the Supernova/Acceleration Probe (SNAP) will obtain thousands of supernovae at z>1.7, beyond the design redshift for which the supernovae will be exquisitely characterized. We find that any z\\gtrsim2 standard candles' use for cosmological parameter estimation is quite modest and subject to pitfalls; we examine gravitational lensing, redshift calibration, and contamination effects in some detail. The very high redshift supernovae - both thermonuclear and core collapse - will provide copious interesting information on star formation, environment, and evolution. However, the new observational systematics that must be faced, as well as the limited expansion of SN-parameter space afforded, does not point to high value for 1.7

  20. Supernova shock breakout from a red supergiant.

    Science.gov (United States)

    Schawinski, Kevin; Justham, Stephen; Wolf, Christian; Podsiadlowski, Philipp; Sullivan, Mark; Steenbrugge, Katrien C; Bell, Tony; Röser, Hermann-Josef; Walker, Emma S; Astier, Pierre; Balam, Dave; Balland, Christophe; Carlberg, Ray; Conley, Alex; Fouchez, Dominique; Guy, Julien; Hardin, Delphine; Hook, Isobel; Howell, D Andrew; Pain, Reynald; Perrett, Kathy; Pritchet, Chris; Regnault, Nicolas; Yi, Sukyoung K

    2008-07-11

    Massive stars undergo a violent death when the supply of nuclear fuel in their cores is exhausted, resulting in a catastrophic "core-collapse" supernova. Such events are usually only detected at least a few days after the star has exploded. Observations of the supernova SNLS-04D2dc with the Galaxy Evolution Explorer space telescope reveal a radiative precursor from the supernova shock before the shock reached the surface of the star and show the initial expansion of the star at the beginning of the explosion. Theoretical models of the ultraviolet light curve confirm that the progenitor was a red supergiant, as expected for this type of supernova. These observations provide a way to probe the physics of core-collapse supernovae and the internal structures of their progenitor stars.

  1. Supernovae and Cosmology with Future European Facilities

    CERN Document Server

    Hook, I M

    2012-01-01

    Prospects for future supernova surveys are discussed, focusing on the ESA Euclid mission and the European Extremely Large Telescope(E-ELT), both expected to be in operation around the turn of the decade. Euclid is a 1.2m space survey telescope that will operate at visible and near-infrared wavelengths, and has the potential to find and obtain multi-band lightcurves for thousands of distant supernovae. The E-ELT is a planned general-purpose ground-based 40m-class optical-IR telescope with adaptive optics built in, which will be capable of obtaining spectra of Type Ia supernovae to redshifts of at least four. The contribution to supernova cosmology with these facilities will be discussed in the context of other future supernova programs such as those proposed for DES, JWST, LSST and WFIRST.

  2. The Population of Supernova Remnants in M51

    Science.gov (United States)

    Long, Knox S.; Blair, William P.; Kuntz, K. D.; Winkler, P. Frank

    2017-08-01

    The nearby, actively star-forming, nearly face-on spiral galaxy, M51 (NGC 5194/5), has been the site of four supernovae since 1941. As a result it should have a rich population of young supernova remnants (SNRs). Here we describe a search for optical SNRs in M51 among the 298 X-ray sources discovered inside the D25 contour in deep Chandra observations. The search uses interference filter images obtained with the WFC3 on Hubble Space Telescope and more recent images from GMOS on Gemini North. Of 80 emission nebulae identified in the HST images as SNR candidates based on elevated [SII]: Ha ratios compared to HII regions, 40 have X-ray counterparts. The diameters of the SNRs and SNR candidates detected with HST are systematically smaller than seen in SNR populations of other galaxies at comparable distances. However, this is most likely an instrumental effect, which our ongoing analysis of the new GMOS images will correct. At that point, we will be able to make of fair multi-wavelength comparison of the SNR population in M51 with other nearby, actively star-forming spiral galaxies, such as M83 and NGC6946.

  3. Russia: the pipeline diplomacy; Russie: la diplomatie du pipeline

    Energy Technology Data Exchange (ETDEWEB)

    Bourdillon, Y

    2005-01-15

    First world producer of oil and gas, Russia wishes to use its mastery of energy distribution to recover its great power status. The oil and gas pipelines network is the basement used by Russia to build up its hegemony in Europe. The Russian oil and gas companies are also carrying out a long-term strategy of international expansion, in particular thanks to investments in the neighboring countries for the building of new infrastructures or the purchase of oil refineries. (J.S.)

  4. Rapidly Rising Transients in the Supernova - Superluminous Supernova Gap

    CERN Document Server

    Arcavi, Iair; Howell, D Andrew; Bildsten, Lars; Leloudas, Giorgos; Hardin, Delphine; Prajs, Szymon; Perley, Daniel A; Svirski, Gilad; Gal-Yam, Avishay; Katz, Boaz; McCully, Curtis; Cenko, S Bradley; Lidman, Chris; Sullivan, Mark; Valenti, Stefano; Astier, Pierre; Balland, Cristophe; Carlberg, Ray G; Conley, Alex; Fouchez, Dominique; Guy, Julien; Pain, Reynald; Palanque-Delabrouille, Nathalie; Perrett, Kathy; Pritchet, Chris J; Regnault, Nicolas; Rich, James; Ruhlmann-Kleider, Vanina

    2015-01-01

    We present observations of four rapidly rising (t_{rise}~10d) transients with peak luminosities between those of supernovae (SNe) and superluminous SNe (M_{peak}~-20) - one discovered and followed by the Palomar Transient Factory (PTF) and three by the Supernova Legacy Survey (SNLS). The light curves resemble those of SN 2011kl, recently shown to be associated with an ultra-long-duration gamma ray burst (GRB), though no GRB was seen to accompany our SNe. The rapid rise to a luminous peak places these events in a unique part of SN phase space, challenging standard SN emission mechanisms. Spectra of the PTF event formally classify it as a Type II SN due to broad Halpha emission, but an unusual absorption feature, which can be interpreted as either high velocity Halpha (though deeper than in previously known cases) or Si II (as seen in Type Ia SNe), is also observed. We find that existing models of white dwarf detonations, CSM interaction, shock breakout in a wind (or steeper CSM) and magnetar spindown can not r...

  5. Spectroscopy of Type Ia Supernovae by the Carnegie Supernova Project

    CERN Document Server

    Folatelli, Gastón; Phillips, Mark M; Hsiao, Eric; Campillay, Abdo; Contreras, Carlos; Castellón, Sergio; Hamuy, Mario; Krzeminski, Wojtek; Roth, Miguel; Stritzinger, Maximilian; Burns, Christopher R; Freedman, Wendy L; Madore, Barry F; Murphy, David; Persson, S E; Prieto, José L; Suntzeff, Nicholas B; Krisciunas, Kevin; Anderson, Joseph P; Förster, Francisco; Maza, José; Pignata, Giuliano; Rojas, P Andrea; Boldt, Luis; Salgado, Francisco; Wyatt, Pamela; E., Felipe Olivares; Gal-Yam, Avishay; Sako, Masao

    2013-01-01

    This is the first release of optical spectroscopic data of low-redshift Type Ia supernovae (SNe Ia) by the Carnegie Supernova Project including 604 previously unpublished spectra of 93 SNe Ia. The observations cover a range of phases from 12 days before to over 150 days after the time of B-band maximum light. With the addition of 228 near-maximum spectra from the literature we study the diversity among SNe Ia in a quantitative manner. For that purpose, spectroscopic parameters are employed such as expansion velocities from spectral line blueshifts, and pseudo-equivalent widths (pW). The values of those parameters at maximum light are obtained for 78 objects, thus providing a characterization of SNe Ia that may help to improve our understanding of the properties of the exploding systems and the thermonuclear flame propagation. Two objects, namely SNe 2005M and 2006is, stand out from the sample by showing peculiar Si II and S II velocities but otherwise standard velocities for the rest of the ions. We further s...

  6. Carnegie Supernova Project: Observations of Type IIn Supernovae

    CERN Document Server

    Taddia, F; Sollerman, J; Phillips, M M; Anderson, J P; Boldt, L; Campillay, A; Castellón, S; Contreras, C; Folatelli, G; Hamuy, M; Heinrich-Josties, E; Krzeminski, W; Morrell, N; Burns, C R; Freedman, W L; Madore, B F; Persson, S E; Suntzeff, N B

    2013-01-01

    The observational diversity displayed by various Type IIn supernovae (SNe IIn) is explored and quantified. In doing so a more coherent picture ascribing the variety of observed SNe IIn types to particular progenitor scenarios is sought. Carnegie Supernova Project (CSP) optical and near-infrared light curves and visual-wavelength spectroscopy of the Type IIn SNe 2005kj, 2006aa, 2006bo, 2006qq and 2008fq are presented. Combined with previously published observations of the Type IIn SNe 2005ip and 2006jd (Stritzinger et al. 2012), the full CSP sample is used to derive physical parameters which describe the nature of the interaction between the expanding SN ejecta and the circum-stellar material (CSM). For each SN of our sample we find counterparts, identifying objects similar to SNe 1994W (SN 2006bo), 1998S (SN 2008fq) and 1988Z (SN 2006qq). We present the unprecedented initial u-band plateau of SN 2006aa, and its peculiar late-time luminosity and temperature evolution. For each SN, assuming the CSM was formed b...

  7. Statistics of Galactic Supernova Remnants

    Institute of Scientific and Technical Information of China (English)

    Jian-Wen Xu; Xi-Zhen Zhang; Jin-Lin Han

    2005-01-01

    We collected the basic parameters of 231 supernova remnants (SNRs) in our Galaxy, namely, distances (d) from the Sun, linear diameters (D), Galactic heights (Z), estimated ages (t), luminosities (L), surface brightness (∑) and flux densities (Si) at 1-GHz frequency and spectral indices (α). We tried to find possible correlations between these parameters. As expected, the linear diameters were found to increase with ages for the shell-type remnants, and also to have a tendency to increase with the Galactic heights. Both the surface brightness and luminosity of SNRs at 1-GHz tend to decrease with the linear diameter and with age. No other relations between the parameters were found.

  8. Petascale Supernova Simulation with CHIMERA

    Energy Technology Data Exchange (ETDEWEB)

    Messer, Bronson [ORNL; Bruenn, S. W. [Florida Atlantic University; Blondin, J. M. [North Carolina State University; Mezzacappa, Anthony [ORNL; Hix, William Raphael [ORNL; Dirk, Charlotte [Florida Atlantic University

    2007-01-01

    CHIMERA is a multi-dimensional radiation hydrodynamics code designed to study core-collapse supernovae. The code is made up of three essentially independent parts: a hydrodynamics module, a nuclear burning module, and a neutrino transport solver combined within an operator-split approach. We describe some ma jor algorithmic facets of the code and briefly discuss some recent results. The multi-physics nature of the problem, and the specific implementation of that physics in CHIMERA, provide a rather straightforward path to effective use of multi-core platforms in the near future.

  9. Petascale supernova simulation with CHIMERA

    Energy Technology Data Exchange (ETDEWEB)

    Messer, O E B [National Center for Computational Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6008 (United States); Bruenn, S W [Department of Physics, Florida Atlantic University, 777 W Glades Road, Boca Raton, FL 33431-0991 (United States); Blondin, J M [Department of Physics, North Carolina State University, Raleigh, NC 27695-8202 (United States); Hix, W R [Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6354 (United States); Mezzacappa, A [Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6354 (United States); Dirk, C J [Department of Physics, Florida Atlantic University, 777 W Glades Road, Boca Raton, FL 33431-0991 (United States)

    2007-07-15

    CHIMERA is a multi-dimensional radiation hydrodynamics code designed to study core-collapse supernovae. The code is made up of three essentially independent parts: a hydrodynamics module, a nuclear burning module, and a neutrino transport solver combined within an operator-split approach. We describe some major algorithmic facets of the code and briefly discuss some recent results. The multi-physics nature of the problem, and the specific implementation of that physics in CHIMERA, provide a rather straightforward path to effective use of multi-core platforms in the near future.

  10. Shell-type Supernova Remnants

    OpenAIRE

    Völk, H.

    2006-01-01

    The role of Supernova Remnants (SNRs) for the production of the Galactic Cosmic Rays is reviewed from the point of view of theory and very high energy gamma-ray experiments. The point is made that theory can describe young SNRs very well, if the evidence from the synchrotron emission is used to empirically determine several parameters of the theory, and thus theory can predict the relative contributions of hadronic and leptonic gamma rays at TeV energies. This is exemplified for several objec...

  11. Progress on multi-waveband observations of supernova remnants

    OpenAIRE

    Yang, Xuejuan; Lu, Fangjun; Tian, Wenwu

    2008-01-01

    The development of observational techniques has inriched our knowledge of supernova remnants. In this paper, we review the main progresses in the last decade, including new discoveries of supernova remnants and the associated (rare type of) pulsars, nucleosynthesis, the interaction between supernova remnants and molecular clouds, dust in the supernova remnants, shock physics, and cosmic ray accelerations.

  12. Accelerated Profile HMM Searches.

    Directory of Open Access Journals (Sweden)

    Sean R Eddy

    2011-10-01

    Full Text Available Profile hidden Markov models (profile HMMs and probabilistic inference methods have made important contributions to the theory of sequence database homology search. However, practical use of profile HMM methods has been hindered by the computational expense of existing software implementations. Here I describe an acceleration heuristic for profile HMMs, the "multiple segment Viterbi" (MSV algorithm. The MSV algorithm computes an optimal sum of multiple ungapped local alignment segments using a striped vector-parallel approach previously described for fast Smith/Waterman alignment. MSV scores follow the same statistical distribution as gapped optimal local alignment scores, allowing rapid evaluation of significance of an MSV score and thus facilitating its use as a heuristic filter. I also describe a 20-fold acceleration of the standard profile HMM Forward/Backward algorithms using a method I call "sparse rescaling". These methods are assembled in a pipeline in which high-scoring MSV hits are passed on for reanalysis with the full HMM Forward/Backward algorithm. This accelerated pipeline is implemented in the freely available HMMER3 software package. Performance benchmarks show that the use of the heuristic MSV filter sacrifices negligible sensitivity compared to unaccelerated profile HMM searches. HMMER3 is substantially more sensitive and 100- to 1000-fold faster than HMMER2. HMMER3 is now about as fast as BLAST for protein searches.

  13. High-redshift supernova rates measured with the gravitational telescope A1689

    CERN Document Server

    Petrushevska, Tanja; Goobar, Ariel; Fabbro, Sebastien; Johansson, Joel; Kjellsson, Tor; Lidman, Chris; Paech, Kerstin; Richard, Johan; Dahle, Hakon; Ferretti, Raphael; Kneib, Jean-Paul; Limousin, Marceau; Nordin, Jakob; Stanishev, Vallery

    2016-01-01

    We present a ground-based near-infrared search for lensed supernovae behind the massive cluster Abell 1689 at z=0.18, one of the most powerful gravitational telescopes that nature provides. Our survey was based on multi-epoch $J$-band observations with the HAWK-I instrument on VLT, with supporting optical data from the Nordic Optical Telescope. Our search resulted in the discovery of five high-redshift, $0.671supernovae with magnifications in the range $\\Delta m$ = $-0.31$ to $-1.58$ mag, as calculated from lensing models in the literature. Thanks to the power of the lensing cluster, the survey had the sensitivity to detect supernovae up to very high-redshifts, $z$$\\sim$$3$, albeit for a limited region of space. We present a study of the core-collapse supernova rates for $0.4\\leq z< 2.9$, and find good agreement with both previous estimates, and the predictions from the star formation history. During our survey, we also discovered 2 type Ia supernov...

  14. CfAIR2: Near Infrared Light Curves of 94 Type Ia Supernovae

    CERN Document Server

    Friedman, Andrew S; Marion, G H; Challis, Peter; Mandel, Kaisey S; Bloom, Joshua S; Modjaz, Maryam; Narayan, Gautham; Hicken, Malcolm; Foley, Ryan; Klein, Christopher R; Starr, Dan L; Morgan, Adam; Rest, Armin; Blake, Cullen H; Miller, Adam A; Falco, Emilio E; Wyatt, William F; Mink, Jessica; Skrutskie, Michael F; Kirshner, Robert P

    2014-01-01

    CfAIR2 is a large homogeneously reduced set of near-infrared (NIR) light curves for Type Ia supernovae (SN Ia) obtained with the 1.3m PAIRITEL (Peters Automated InfraRed Imaging TELescope). This data set includes 4607 measurements of 94 SN Ia and 4 additional SN Iax observed from 2005-2011 at the Fred Lawrence Whipple Observatory on Mount Hopkins, Arizona. CfAIR2 includes JHKs photometric measurements for 88 normal and 6 spectroscopically peculiar SN Ia in the nearby universe, with a median redshift of z~0.021 for the normal SN Ia. CfAIR2 data span the range from -13 days to +127 days from maximum in the B-band. More than half of the light curves begin before the time of maximum and the coverage typically contains ~13-18 epochs of observation, depending on the filter. We present extensive tests that verify the fidelity of the CfAIR2 data pipeline, including comparison to the excellent data of the Carnegie Supernova Project. CfAIR2 contributes to a firm local anchor for supernova cosmology studies in the NIR. ...

  15. Analytic prognostic for petrochemical pipelines

    CERN Document Server

    Jaoude, Abdo Abou; El-Tawil, Khaled; Noura, Hassan; Ouladsine, Mustapha

    2012-01-01

    Pipelines tubes are part of vital mechanical systems largely used in petrochemical industries. They serve to transport natural gases or liquids. They are cylindrical tubes and are submitted to the risks of corrosion due to high PH concentrations of the transported liquids in addition to fatigue cracks due to the alternation of pressure-depression of gas along the time, initiating therefore in the tubes body micro-cracks that can propagate abruptly to lead to failure. The development of the prognostic process for such systems increases largely their performance and their availability, as well decreases the global cost of their missions. Therefore, this paper deals with a new prognostic approach to improve the performance of these pipelines. Only the first mode of crack, that is, the opening mode, is considered.

  16. The life of hydrotransport pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Turchaninov, S.P.

    1973-01-01

    This book summarizes information on the hydroabrasive wear of pressurized pipes transporting bulk solid materials, such as coal. An analysis is presented of the operation of pipelines, and measures are recommended for their effective use. Methods of laboratory and production studies of hydroabrasive wear of pipes are described. The regularities of hydroabrasive wear of pipes are systematized as functions of the hydraulic characteristics of transportation and other operational factors. Methods are studied for increasing the durability of pipelines, and recommendations are given for determination of their throughput capacity through their entire service life. The book is designed for engineering and technical workers, planning-design and scientific research organizations, and may also be useful to university students. (87 refs.)

  17. Runaway Stars in Supernova Remnants

    Science.gov (United States)

    Pannicke, Anna; Neuhaeuser, Ralph; Dinçel, Baha

    2016-07-01

    Half of all stars and in particular 70 % of the massive stars are a part of a multiple system. A possible development for the system after the core collapse supernova (SN) of the more massive component is as follows: The binary is disrupted by the SN. The formed neutron star is ejected by the SN kick whereas the companion star either remains within the system and is gravitationally bounded to the neutron star, or is ejected with a spatial velocity comparable to its former orbital velocity (up to 500 km/s). Such stars with a large peculiar space velocity are called runaway stars. We present our observational results of the supernova remnants (SNRs) G184.6-5.8, G74.0-8.5 and G119.5+10.2. The focus of this project lies on the detection of low mass runaway stars. We analyze the spectra of a number of candidates and discuss their possibility of being the former companions of the SN progenitor stars. The spectra were obtained with INT in Tenerife, Calar Alto Astronomical Observatory and the University Observatory Jena. Also we investigate the field stars in the neighborhood of the SNRs G74.0-8.5 and G119.5+10.2 and calculate more precise distances for these SNRs.

  18. Dark Matter Triggers of Supernovae

    CERN Document Server

    Graham, Peter W; Varela, Jaime

    2015-01-01

    The transit of primordial black holes through a white dwarf causes localized heating around the trajectory of the black hole through dynamical friction. For sufficiently massive black holes, this heat can initiate runaway thermonuclear fusion causing the white dwarf to explode as a supernova. The shape of the observed distribution of white dwarfs with masses up to $1.25 M_{\\odot}$ rules out primordial black holes with masses $\\sim 10^{19}$ gm - $10^{20}$ gm as a dominant constituent of the local dark matter density. Black holes with masses as large as $10^{24}$ gm will be excluded if recent observations by the NuStar collaboration of a population of white dwarfs near the galactic center are confirmed. Black holes in the mass range $10^{20}$ gm - $10^{22}$ gm are also constrained by the observed supernova rate, though these bounds are subject to astrophysical uncertainties. These bounds can be further strengthened through measurements of white dwarf binaries in gravitational wave observatories. The mechanism p...

  19. How supernovae launch galactic winds?

    Science.gov (United States)

    Fielding, Drummond; Quataert, Eliot; Martizzi, Davide; Faucher-Giguère, Claude-André

    2017-09-01

    We use idealized three-dimensional hydrodynamic simulations of global galactic discs to study the launching of galactic winds by supernovae (SNe). The simulations resolve the cooling radii of the majority of supernova remnants (SNRs) and thus self-consistently capture how SNe drive galactic winds. We find that SNe launch highly supersonic winds with properties that agree reasonably well with expectations from analytic models. The energy loading (η _E= \\dot{E}_wind/ \\dot{E}_SN) of the winds in our simulations are well converged with spatial resolution while the wind mass loading (η _M= \\dot{M}_wind/\\dot{M}_\\star) decreases with resolution at the resolutions we achieve. We present a simple analytic model based on the concept that SNRs with cooling radii greater than the local scaleheight break out of the disc and power the wind. This model successfully explains the dependence (or lack thereof) of ηE (and by extension ηM) on the gas surface density, star formation efficiency, disc radius and the clustering of SNe. The winds our simulations are weaker than expected in reality, likely due to the fact that we seed SNe preferentially at density peaks. Clustering SNe in time and space substantially increases the wind power.

  20. Type Ia Supernova Carbon Footprints

    CERN Document Server

    Thomas, R C; Aragon, C; Antilogus, P; Bailey, S; Baltay, C; Bongard, S; Buton, C; Canto, A; Childress, M; Chotard, N; Copin, Y; Fakhouri, H K; Gangler, E; Hsiao, E Y; Kerschhaggl, M; Kowalski, M; Loken, S; Nugent, P; Paech, K; Pain, R; Pecontal, E; Pereira, R; Perlmutter, S; Rabinowitz, D; Rigault, M; Rubin, D; Runge, K; Scalzo, R; Smadja, G; Tao, C; Weaver, B A; Wu, C; Brown, P J; Milne, P A

    2011-01-01

    We present convincing evidence of unburned carbon at photospheric velocities in new observations of 5 Type Ia supernovae (SNe Ia) obtained by the Nearby Supernova Factory. These SNe are identified by examining 346 spectra from 124 SNe obtained before +2.5 d relative to maximum. Detections are based on the presence of relatively strong C II 6580 absorption "notches" in multiple spectra of each SN, aided by automated fitting with the SYNAPPS code. Four of the 5 SNe in question are otherwise spectroscopically unremarkable, with ions and ejection velocities typical of SNe Ia, but spectra of the fifth exhibits high-velocity (v > 20,000 km/s) Si II and Ca II features. On the other hand, the light curve properties are preferentially grouped, strongly suggesting a connection between carbon-positivity and broad band light curve/color behavior: Three of the 5 have relatively narrow light curves but also blue colors, and a fourth may be a dust-reddened member of this family. Accounting for signal-to-noise and phase, we ...

  1. Discovery Prospects for a Biogenic Supernova Signature

    CERN Document Server

    Bishop, Shawn

    2010-01-01

    Within the universe, the astrophysical sites responsible for the production of radioactive 60Fe, of half life 2.62 Myr, are primarily confined to two: Type 1a supernovae and massive stars that end their lives as Type II supernovae. Approximately 2.8 Myr before the present, our planet was subjected to the debris of a supernova explosion. The terrestrial proxy for this event was the discovery of live atoms of 60Fe in a deep sea ferromanganese crust, from which the terrestrial flux of supernova 60Fe was deduced. The signature for this supernova event should also be contained in microfossils produced by magnetotactic bacteria extant at the time of the Earth-supernova interaction. Using estimates for the terrestrial supernova 60Fe flux, combined with our empirically derived microfossil concentrations of a deep sea drill core, we deduce a conservative estimate of the 60Fe fraction as 60Fe/Fe = 3.6 x 10^{-15}; this value sits comfortably within the sensitivity limit of present accelerator mass spectrometry capabilit...

  2. An Open Catalog for Supernova Data

    CERN Document Server

    Guillochon, James; Margutti, Raffaella

    2016-01-01

    We present the Open Supernova Catalog, an online collection of observations and metadata for presently 20,000+ supernovae and related candidates. The catalog is freely available on the web (https://sne.space), with its main interface having been designed to be a user-friendly, rapidly-searchable table accessible on desktop and mobile devices. In addition to the primary catalog table containing supernova metadata, an individual page is generated for each supernova which displays its available metadata, light curves, and spectra spanning X-ray to radio frequencies. The data presented in the catalog is automatically rebuilt on a daily basis and is constructed by parsing several dozen sources, including the data presented in the supernova literature and from secondary sources such as other web-based catalogs. Individual supernova data is stored in the hierarchical, human- and machine-readable JSON format, with the entirety of each supernova's data being contained within a single JSON file bearing its name. The se...

  3. 18 CFR 284.12 - Standards for pipeline business operations and communications.

    Science.gov (United States)

    2010-04-01

    ... adverse impacts of operational flow orders (OFOs) or other measures taken to respond to adverse... adverse impacts of these measures. (v) Penalties. A pipeline may include in its tariff transportation... access requirement; (B) Users must be able to search an entire document online for selected words,...

  4. Type Ia Supernova Modeling with Spectrophotometric Data from the Nearby Supernova Factory

    Science.gov (United States)

    Saunders, Clare; Nearby Supernova Factory

    2017-01-01

    Type Ia supernova cosmology is currently limited by dispersion in standardized magnitudes, driven by a combination of calibration uncertainty and so-called ‘intrinsic dispersion.' This intrinsic dispersion is caused by supernova behavior that the current lightcurve fitters do not account for, and it can involve systematic trends. Using data from the Nearby Supernova Factory, we have developed an empirical model that captures a wider range of Type Ia supernova behavior and can be used to improve standardized magnitude dispersion. To do this, Gaussian Processes and Expectation Maximization Factor Analysis are used to generate spectral time series templates that can be combined linearly. Variations of this model are optimized, alternatively for supernova standardization or for maximum accuracy in the description of supernova spectral features. We present these models along with interpretation of the model components. Methods are discussed for the most efficient application of the models in cosmological surveys.

  5. First Results from the La Silla-QUEST Supernova Survey and the Carnegie Supernova Project

    CERN Document Server

    Walker, E S; Campillay, A; Citrenbaum, C; Contreras, C; Ellman, N; Feindt, U; Gonzalez, C; Graham, M L; Hadjiyska, E; Hsiao, E Y; Krisciunas, K; McKinnon, R; Ment, K; Morrell, N; Nugent, P; Phillips, M; Rabinowitz, D; Rostami, S; Seron, J; Stritzinger, M; Sullivan, M; Tucker, B E

    2016-01-01

    The LaSilla/QUEST Variability Survey (LSQ) and the Carnegie Supernova Project (CSP II) are collaborating to discover and obtain photometric light curves for a large sample of low redshift (z < 0.1) Type Ia supernovae. The supernovae are discovered in the LSQ survey using the 1 m ESO Schmidt telescope at the La Silla Observatory with the 10 square degree QUEST camera. The follow-up photometric observations are carried out using the 1 m Swope telescope and the 2.5 m du Pont telescopes at the Las Campanas Observatory. This paper describes the survey, discusses the methods of analyzing the data and presents the light curves for the first 31 Type Ia supernovae obtained in the survey. The SALT 2.4 supernova light curve fitter was used to analyze the photometric data, and the Hubble diagram for this first sample is presented. The measurement errors for these supernovae averaged 4%, and their intrinsic spread was 14%.

  6. An Open Catalog for Supernova Data

    Science.gov (United States)

    Guillochon, James; Parrent, Jerod; Kelley, Luke Zoltan; Margutti, Raffaella

    2017-01-01

    We present the Open Supernova Catalog, an online collection of observations and metadata for presently 36,000+ supernovae and related candidates. The catalog is freely available on the web (https://sne.space), with its main interface having been designed to be a user-friendly, rapidly searchable table accessible on desktop and mobile devices. In addition to the primary catalog table containing supernova metadata, an individual page is generated for each supernova, which displays its available metadata, light curves, and spectra spanning X-ray to radio frequencies. The data presented in the catalog is automatically rebuilt on a daily basis and is constructed by parsing several dozen sources, including the data presented in the supernova literature and from secondary sources such as other web-based catalogs. Individual supernova data is stored in the hierarchical, human- and machine-readable JSON format, with the entirety of each supernova’s data being contained within a single JSON file bearing its name. The setup we present here, which is based on open-source software maintained via git repositories hosted on github, enables anyone to download the entirety of the supernova data set to their home computer in minutes, and to make contributions of their own data back to the catalog via git. As the supernova data set continues to grow, especially in the upcoming era of all-sky synoptic telescopes, which will increase the total number of events by orders of magnitude, we hope that the catalog we have designed will be a valuable tool for the community to analyze both historical and contemporary supernovae.

  7. Supernova Remnant Observations with Micro-X

    Science.gov (United States)

    Figueroa, Enectali

    explosion mechanisms of supernovae and their roles in energy and heavy-element injection into galaxies, their evolution into SNRs, their interactions with their environments, and finally their roles as particle accelerators. For the first flight, we will observe an ejecta region in the Puppis A SNR. The Puppis A bright eastern knot (BEK), is the target of second flight in 2014. The third flight, in late 2015 or early 2016, will make an observation of the Cas A SNR. We will continue to advance the technology readiness of TES microcalorimeters while enhancing the science capability of the payload by implementing a series of improvements for the third flight. For the observation of Cas A in the third flight, we will upgrade from the 128-pixel array with 1 arcminute pixels used in the first two flights to a higher-energy resolution (1 eV FWHM) 256-pixel array with 20 arcsecond pixels and a new 30 arcsecond HPD mirror to enable improved imaging spectroscopy with our payload. The Micro-X team includes leaders in the development of microcalorimeters, SQUID readout systems, and segmented and full-shell grazing incidence X-ray optics, as well as highly experienced sounding rocket instrument developers, and scientific experts on supernova remnants. These investigators are located at institutions with strong space instrumentation traditions with the infrastructure to ensure a successful flight program. With Micro-X, we have designed a versatile payload capable of providing high-resolution science and a testbed for new technology. The first flight this year will make significant scientific contributions well ahead of the Astro-H mission. The program will also aid in the understanding and development of future flight-qualified microcalorimeter systems for larger orbiting missions. Finally, it will continue to attract talented young scientists to X-ray astrophysics and thus serve as a direct pipeline of future leaders of NASA missions.

  8. STATUS AND PROSPECT OF OIL AND GAS PIPELINES IN CHINA

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ With the exploration and development of natural gas and the increase of crude oil import, the industry of China's Oil and Gas Pipelines has witnessed rapid development. Especially the gas pipeline industry is entering a peak period of development. Thanks to the completion and operation of large-scale pipeline projects including West-East Gas Transportation Pipeline project,Shanxi-Beijing Gas Pipeline Ⅱ, Ji-Ning Pipeline,Huaiyang-Wuhan Pipeline, Guangdong LNG Pipeline,Western Pipeline and Pearl River Delta Oil Product Pipeline, many trans-regional gas and oil pipeline networks with initial scale have been gradually established and improved in China. Meanwhile, the metallurgy,manufacturing and construction level of pipelines has been greatly developed, achieving world top level. The next five years is still a peak period of development for China's gas and oil pipeline industry which will enjoy a broader prospect.

  9. Postexplosion hydrodynamics of supernovae in red supergiants

    Science.gov (United States)

    Herant, Marc; Woosley, S. E.

    1994-01-01

    Shock propagation, mixing, and clumping are studied in the explosion of red supergiants as Type II supernovae using a two-dimensional smooth particle hydrodynamic (SPH) code. We show that extensive Rayleigh-Talor instabilities develop in the ejecta in the wake of the reverse shock wave. In all cases, the shell structure of the progenitor is obliterated to leave a clumpy, well-mixed supernova remnant. However, the occurrence of mass loss during the lifetime of the progenitor can significantly reduce the amount of mixing. These results are independent of the Type II supernova explosion mechanism.

  10. Chiral transport of neutrinos in supernovae

    Directory of Open Access Journals (Sweden)

    Yamamoto Naoki

    2017-01-01

    Full Text Available The conventional neutrino transport theory for core-collapse supernovae misses one key property of neutrinos: the left-handedness. The chirality of neutrinos modifies the hydrodynamic behavior at the macroscopic scale and leads to topological transport phenomena. We argue that such transport phenomena should play important roles in the evolution of core-collapse supernovae, and, in particular, lead to a tendency toward the inverse energy cascade from small to larger scales, which may be relevant to the origin of the supernova explosion.

  11. Chiral transport of neutrinos in supernovae

    CERN Document Server

    Yamamoto, Naoki

    2016-01-01

    The conventional neutrino transport theory for core-collapse supernovae misses one key property of neutrinos: the left-handedness. The chirality of neutrinos modifies the hydrodynamic behavior at the macroscopic scale and leads to topological transport phenomena. We argue that such transport phenomena should play important roles in the evolution of core-collapse supernovae, and, in particular, lead to a tendency toward the inverse energy cascade from small to larger scales, which may be relevant to the origin of the supernova explosion.

  12. A New Supernova Discovery/Classification

    Science.gov (United States)

    Howell, D. A.; Nugent, P. E.; Sullivan, M.; Gal-Yam, A.

    2010-10-01

    The Type Ia supernova science working group of the Palomar Transient Factory (ATEL#1964) reports the discovery of the Type Ia supernova PTF10ygu at RA=09:37:30.30, Dec=+23:09:33.6 (J2000) in the host galaxy NGC 2929 at z=0.025. The supernova was discovered on Oct. 12.5 UT when it was at magnitude 19.2 in R-band (calibrated wrt the USNO catalog). There was nothing at this location on Oct 8.5 UT to a limiting magnitude of 20.3, and a marginal detection (S/N=5) at R=19.6 on Oct.

  13. Supernovae and Gamma-Ray Bursts

    Science.gov (United States)

    Livio, Mario; Panagia, Nino; Sahu, Kailash

    2001-07-01

    Participants; Preface; Gamma-ray burst-supernova relation B. Paczynski; Observations of gamma-ray bursts G. Fishman; Fireballs T. Piran; Gamma-ray mechanisms M. Rees; Prompt optical emission from gamma-ray bursts R. Kehoe, C. Akerlof, R. Balsano, S. Barthelmy, J. Bloch, P. Butterworth, D. Casperson, T. Cline, S. Fletcher, F. Frontera, G. Gisler, J. Heise, J. Hills, K. Hurley, B. Lee, S. Marshall, T. McKay, A. Pawl, L. Piro, B. Priedhorsky, J. Szymanski and J. Wren; X-ray afterglows of gamma-ray bursts L. Piro; The first year of optical-IR observations of SN1998bw I. Danziger, T. Augusteijn, J. Brewer, E. Cappellaro, V. Doublier, T. Galama, J. Gonzalez, O. Hainaut, B. Leibundgut, C. Lidman, P. Mazzali, K. Nomoto, F. Patat, J. Spyromilio, M. Turatto, J. Van Paradijs, P. Vreeswijk and J. Walsh; X-ray emission of Supernova 1998bw in the error box of GRB980425 E. Pian; Direct analysis of spectra of type Ic supernovae D. Branch; The interaction of supernovae and gamma-ray bursts with their surroundings R. Chevalier; Magnetars, soft gamma-ray repeaters and gamma-ray bursts A. Harding; Super-luminous supernova remnants Y. -H. Chu, C. -H. Chen and S. -P. Lai; The properties of hypernovae: SNe Ic 1998bw, 1997ef, and SN IIn 1997cy K. Nomoto, P. Mazzali, T. Nakamura, K. Iwanmoto, K. Maeda, T. Suzuki, M. Turatto, I. Danziger and F. Patat; Collapsars, Gamma-Ray Bursts, and Supernovae S. Woosley, A. MacFadyen and A. Heger; Pre-supernova evolution of massive stars N. Panagia and G. Bono; Radio supernovae and GRB 980425 K. Weiler, N. Panagia, R. Sramek, S. Van Dyk, M. Montes and C. Lacey; Models for Ia supernovae and evolutionary effects P. Hoflich and I. Dominguez; Deflagration to detonation A. Khokhlov; Universality in SN Iae and the Phillips relation D. Arnett; Abundances from supernovae F. -K. Thielemann, F. Brachwitz, C. Freiburghaus, S. Rosswog, K. Iwamoto, T. Nakamura, K. Nomoto, H. Umeda, K. Langanke, G. Martinez-Pinedo, D. Dean, W. Hix and M. Strayer; Sne, GRBs, and the

  14. Neutrino scattering and flavor transformation in supernovae

    CERN Document Server

    Cherry, John F; Friedland, Alexander; Fuller, George M; Vlasenko, Alexey

    2012-01-01

    We argue that the small fraction of neutrinos that undergo direction-changing scattering outside of the neutrinosphere could have significant influence on neutrino flavor transformation in core-collapse supernova environments. We show that the standard treatment for collective neutrino flavor transformation is adequate at late times, but could be inadequate in the crucial shock revival/explosion epoch of core-collapse supernovae, where the potentials that govern neutrino flavor evolution are affected by the scattered neutrinos. Taking account of this effect, and the way it couples to entropy and composition, will require a new paradigm in supernova modeling.

  15. FPGA Implementation of Wave Pipelining CORDIC Algorithms

    Institute of Scientific and Technical Information of China (English)

    CUI Wei

    2008-01-01

    The implementation of the coordinate rotational digital computer (CORDIC) algorithm with wave pipelining technique on field programmable gate array (FPGA) is described. All data in FPGA-based wave pipelining pass through a number of logic gates, in the same way that all data pass through the same number of registers in a conventional pipeline. Moreover, all paths are routed using identical routing resources. The manual placement, timing driven routing and timing analyzing techniques are applied to optimize the layout for achieving good path balance. Experimental results show that a 256-LUT logic depth circuit mapped on XC4VLX15-12 runs as high as 330MHz, which is a little lower than the speed of 336MHz based on the conventional 16-stage pipelining in the same chip. The latency of the wave pipelining circuit is 30.3ns, which is 36.4% shorter than the latency of 16-stage conventional pipelining circuit.

  16. 49 CFR 195.9 - Outer continental shelf pipelines.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Outer continental shelf pipelines. 195.9 Section... HAZARDOUS LIQUIDS BY PIPELINE General § 195.9 Outer continental shelf pipelines. Operators of transportation pipelines on the Outer Continental Shelf must identify on all their respective pipelines the specific...

  17. Radio Supernovae: Circum-Stellar Investigation (C.S.I.) of Supernova Progenitor Stars

    Science.gov (United States)

    2009-02-24

    ar X iv :0 90 2. 40 59 v1 [ as tr o- ph .H E ] 2 4 Fe b 20 09 Radio Supernovae : Circum-Stellar Investigation (C.S.I.) of Supernova Progenitor...FEB 2009 2. REPORT TYPE 3. DATES COVERED 00-00-2009 to 00-00-2009 4. TITLE AND SUBTITLE Radio Supernovae : Circum-Stellar Investigation (C.S.I...of Supernova Progenitor Stars 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f

  18. Observational data on Galactic supernova remnants: II. The supernova remnants within l = 90°-270°

    Directory of Open Access Journals (Sweden)

    Guseinov O.H.

    2004-01-01

    Full Text Available We have collected all the available data on Galactic supernova remnants given in the literature. The data of Galactic supernova remnants located in the Galactic longitude interval l=90° - 270° in all spectral bands are represented in this work. We have adopted distance values for the SNRs by examining these data. The data of various types on neutron stars connected to these supernova remnants are also represented. Remarks of some authors and by ourselves regarding the data and some properties of both the supernova remnants and the point sources are given.

  19. X-ray studies of supernova remnants: a different view of supernova explosions.

    Science.gov (United States)

    Badenes, Carles

    2010-04-20

    The unprecedented spatial and spectral resolutions of Chandra have revolutionized our view of the X-ray emission from supernova remnants. The excellent datasets accumulated on young, ejecta-dominated objects like Cas A or Tycho present a unique opportunity to study at the same time the chemical and physical structure of the explosion debris and the characteristics of the circumstellar medium sculpted by the progenitor before the explosion. Supernova remnants can thus put strong constraints on fundamental aspects of both supernova explosion physics and stellar evolution scenarios for supernova progenitors. This view of the supernova phenomenon is completely independent of, and complementary to, the study of distant extragalactic supernovae at optical wavelengths. The calibration of these two techniques has recently become possible thanks to the detection and spectroscopic follow-up of supernova light echoes. In this paper, I review the most relevant results on supernova remnants obtained during the first decade of Chandra and the impact that these results have had on open issues in supernova research.

  20. Tubular lining material for pipelines having bends

    Energy Technology Data Exchange (ETDEWEB)

    Moringa, A.; Sakaguchi, Y.; Hyodo, M.; Yagi, I.

    1987-03-24

    A tubular lining material for pipelines having bends or curved portions comprises a tubular textile jacket made of warps and wefts woven in a tubular form overlaid with a coating of a flexible synthetic resin. It is applicable onto the inner surface of a pipeline having bends or curved portions in such manner that the tubular lining material with a binder onto the inner surface thereof is inserted into the pipeline and allowed to advance within the pipeline, with or without the aid of a leading rope-like elongated element, while turning the tubular lining material inside out under fluid pressure. In this manner the tubular lining material is applied onto the inner surface of the pipeline with the binder being interposed between the pipeline and the tubular lining material. The lining material is characterized in that a part of all of the warps are comprised of an elastic yarn around which, over the full length thereof, a synthetic fiber yarn or yarns have been left-and/or right-handedly coiled. This tubular lining material is particularly suitable for lining a pipeline having an inner diameter of 25-200 mm and a plurality of bends, such as gas service pipelines or house pipelines, without occurrence of wrinkles in the lining material in a bend.

  1. Transmission pipeline calculations and simulations manual

    CERN Document Server

    Menon, E Shashi

    2014-01-01

    Transmission Pipeline Calculations and Simulations Manual is a valuable time- and money-saving tool to quickly pinpoint the essential formulae, equations, and calculations needed for transmission pipeline routing and construction decisions. The manual's three-part treatment starts with gas and petroleum data tables, followed by self-contained chapters concerning applications. Case studies at the end of each chapter provide practical experience for problem solving. Topics in this book include pressure and temperature profile of natural gas pipelines, how to size pipelines for specified f

  2. A quick guide to pipeline engineering

    CERN Document Server

    Alkazraji, D

    2008-01-01

    Pipeline engineering requires an understanding of a wide range of topics. Operators must take into account numerous pipeline codes and standards, calculation approaches, and reference materials in order to make accurate and informed decisions.A Quick Guide to Pipeline Engineering provides concise, easy-to-use, and accessible information on onshore and offshore pipeline engineering. Topics covered include: design; construction; testing; operation and maintenance; and decommissioning.Basic principles are discussed and clear guidance on regulations is provided, in a way that will

  3. How to Find Gravitationally Lensed Type Ia Supernovae

    Science.gov (United States)

    Goldstein, Daniel A.; Nugent, Peter E.

    2017-01-01

    Type Ia supernovae (SNe Ia) that are multiply imaged by gravitational lensing can extend the SN Ia Hubble diagram to very high redshifts (z ≳ 2), probe potential SN Ia evolution, and deliver high-precision constraints on H0, w, and Ωm via time delays. However, only one, iPTF16geu, has been found to date, and many more are needed to achieve these goals. To increase the multiply imaged SN Ia discovery rate, we present a simple algorithm for identifying gravitationally lensed SN Ia candidates in cadenced, wide-field optical imaging surveys. The technique is to look for supernovae that appear to be hosted by elliptical galaxies, but that have absolute magnitudes implied by the apparent hosts’ photometric redshifts that are far brighter than the absolute magnitudes of normal SNe Ia (the brightest type of supernovae found in elliptical galaxies). Importantly, this purely photometric method does not require the ability to resolve the lensed images for discovery. Active galactic nuclei, the primary sources of contamination that affect the method, can be controlled using catalog cross-matches and color cuts. Highly magnified core-collapse SNe will also be discovered as a byproduct of the method. Using a Monte Carlo simulation, we forecast that the Large Synoptic Survey Telescope can discover up to 500 multiply imaged SNe Ia using this technique in a 10 year z-band search, more than an order of magnitude improvement over previous estimates. We also predict that the Zwicky Transient Facility should find up to 10 multiply imaged SNe Ia using this technique in a 3 year R-band search—despite the fact that this survey will not resolve a single system.

  4. IceCube sensitivity for low-energy neutrinos from nearby supernovae

    Science.gov (United States)

    Abbasi, R.; Abdou, Y.; Abu-Zayyad, T.; Ackermann, M.; Adams, J.; Aguilar, J. A.; Ahlers, M.; Allen, M. M.; Altmann, D.; Andeen, K.; Auffenberg, J.; Bai, X.; Baker, M.; Barwick, S. W.; Baum, V.; Bay, R.; Bazo Alba, J. L.; Beattie, K.; Beatty, J. J.; Bechet, S.; Becker, J. K.; Becker, K. H.; Benabderrahmane, M. L.; Benzvi, S.; Berdermann, J.; Berghaus, P.; Berley, D.; Bernardini, E.; Bertrand, D.; Besson, D. Z.; Bindig, D.; Bissok, M.; Blaufuss, E.; Blumenthal, J.; Boersma, D. J.; Bohm, C.; Bose, D.; Böser, S.; Botner, O.; Brown, A. M.; Buitink, S.; Caballero-Mora, K. S.; Carson, M.; Chirkin, D.; Christy, B.; Clevermann, F.; Cohen, S.; Colnard, C.; Cowen, D. F.; Cruz Silva, A. H.; D'Agostino, M. V.; Danninger, M.; Daughhetee, J.; Davis, J. C.; de Clercq, C.; Degner, T.; Demirörs, L.; Descamps, F.; Desiati, P.; de Vries-Uiterweerd, G.; Deyoung, T.; Díaz-Vélez, J. C.; Dierckxsens, M.; Dreyer, J.; Dumm, J. P.; Dunkman, M.; Eisch, J.; Ellsworth, R. W.; Engdegård, O.; Euler, S.; Evenson, P. A.; Fadiran, O.; Fazely, A. R.; Fedynitch, A.; Feintzeig, J.; Feusels, T.; Filimonov, K.; Finley, C.; Fischer-Wasels, T.; Fox, B. D.; Franckowiak, A.; Franke, R.; Gaisser, T. K.; Gallagher, J.; Gerhardt, L.; Gladstone, L.; Glüsenkamp, T.; Goldschmidt, A.; Goodman, J. A.; Góra, D.; Grant, D.; Griesel, T.; Groß, A.; Grullon, S.; Gurtner, M.; Ha, C.; Haj Ismail, A.; Hallgren, A.; Halzen, F.; Han, K.; Hanson, K.; Heinen, D.; Helbing, K.; Hellauer, R.; Hickford, S.; Hill, G. C.; Hoffman, K. D.; Hoffmann, B.; Homeier, A.; Hoshina, K.; Huelsnitz, W.; Hülß, J.-P.; Hulth, P. O.; Hultqvist, K.; Hussain, S.; Ishihara, A.; Jakobi, E.; Jacobsen, J.; Japaridze, G. S.; Johansson, H.; Kampert, K.-H.; Kappes, A.; Karg, T.; Karle, A.; Kenny, P.; Kiryluk, J.; Kislat, F.; Klein, S. R.; Köhne, H.; Kohnen, G.; Kolanoski, H.; Köpke, L.; Kopper, S.; Koskinen, D. J.; Kowalski, M.; Kowarik, T.; Krasberg, M.; Kroll, G.; Kurahashi, N.; Kuwabara, T.; Labare, M.; Laihem, K.; Landsman, H.; Larson, M. J.; Lauer, R.; Lünemann, J.; Madsen, J.; Marotta, A.; Maruyama, R.; Mase, K.; Matis, H. S.; Meagher, K.; Merck, M.; Mészáros, P.; Meures, T.; Miarecki, S.; Middell, E.; Milke, N.; Miller, J.; Montaruli, T.; Morse, R.; Movit, S. M.; Nahnhauer, R.; Nam, J. W.; Naumann, U.; Nygren, D. R.; Odrowski, S.; Olivas, A.; Olivo, M.; O'Murchadha, A.; Panknin, S.; Paul, L.; Pérez de Los Heros, C.; Petrovic, J.; Piegsa, A.; Pieloth, D.; Porrata, R.; Posselt, J.; Price, P. B.; Przybylski, G. T.; Rawlins, K.; Redl, P.; Resconi, E.; Rhode, W.; Ribordy, M.; Richard, A. S.; Richman, M.; Rodrigues, J. P.; Rothmaier, F.; Rott, C.; Ruhe, T.; Rutledge, D.; Ruzybayev, B.; Ryckbosch, D.; Sander, H.-G.; Santander, M.; Sarkar, S.; Schatto, K.; Schmidt, T.; Schönwald, A.; Schukraft, A.; Schulte, L.; Schultes, A.; Schulz, O.; Schunck, M.; Seckel, D.; Semburg, B.; Seo, S. H.; Sestayo, Y.; Seunarine, S.; Silvestri, A.; Singh, K.; Slipak, A.; Spiczak, G. M.; Spiering, C.; Stamatikos, M.; Stanev, T.; Stezelberger, T.; Stokstad, R. G.; Stößl, A.; Strahler, E. A.; Ström, R.; Stüer, M.; Sullivan, G. W.; Swillens, Q.; Taavola, H.; Taboada, I.; Tamburro, A.; Tepe, A.; Ter-Antonyan, S.; Tilav, S.; Toale, P. A.; Toscano, S.; Tosi, D.; van Eijndhoven, N.; Vandenbroucke, J.; van Overloop, A.; van Santen, J.; Vehring, M.; Voge, M.; Walck, C.; Waldenmaier, T.; Wallraff, M.; Walter, M.; Weaver, Ch.; Wendt, C.; Westerhoff, S.; Whitehorn, N.; Wiebe, K.; Wiebusch, C. H.; Williams, D. R.; Wischnewski, R.; Wissing, H.; Wolf, M.; Wood, T. R.; Woschnagg, K.; Xu, C.; Xu, D. L.; Xu, X. W.; Yanez, J. P.; Yodh, G.; Yoshida, S.; Zarzhitsky, P.; Zoll, M.; IceCube Collaboration

    2011-11-01

    This paper describes the response of the IceCube neutrino telescope located at the geographic south pole to outbursts of MeV neutrinos from the core collapse of nearby massive stars. IceCube was completed in December 2010 forming a lattice of 5160 photomultiplier tubes that monitor a volume of ~1 km3 in the deep Antarctic ice for particle induced photons. The telescope was designed to detect neutrinos with energies greater than 100 GeV. Owing to subfreezing ice temperatures, the photomultiplier dark noise rates are particularly low. Hence IceCube can also detect large numbers of MeV neutrinos by observing a collective rise in all photomultiplier rates on top of the dark noise. With 2 ms timing resolution, IceCube can detect subtle features in the temporal development of the supernova neutrino burst. For a supernova at the galactic center, its sensitivity matches that of a background-free megaton-scale supernova search experiment. The sensitivity decreases to 20 standard deviations at the galactic edge (30 kpc) and 6 standard deviations at the Large Magellanic Cloud (50 kpc). IceCube is sending triggers from potential supernovae to the Supernova Early Warning System. The sensitivity to neutrino properties such as the neutrino hierarchy is discussed, as well as the possibility to detect the neutronization burst, a short outbreak of \\barνe's released by electron capture on protons soon after collapse. Tantalizing signatures, such as the formation of a quark star or a black hole as well as the characteristics of shock waves, are investigated to illustrate IceCube's capability for supernova detection.

  5. 77 FR 16471 - Pipeline Safety: Implementation of the National Registry of Pipeline and Liquefied Natural Gas...

    Science.gov (United States)

    2012-03-21

    ...: Implementation of the National Registry of Pipeline and Liquefied Natural Gas Operators AGENCY: Pipeline and... registry of pipeline and liquefied natural gas operators. This notice provides updates to the information... and liquefied natural gas (LNG) operators. New operators use the national registry to obtain...

  6. Radio emision from supernova remnants

    Science.gov (United States)

    Dubner, G.

    2016-06-01

    The vast majority of supernova remnants (SNRs) in our Galaxy and nearby galaxies have been discovered through radio observations, and only a very small number of the SNRs catalogued in the Milky Way have not been detected in the radio band, or are poorly defined by current radio observations. The study of the radio emission from SNRs is an excellent tool to investigate morphological characteristics, marking the location of shock fronts and contact discontinuities; the presence, orientation and intensity of the magnetic field; the energy spectrum of the emitting particles; and the dynamical consequences of the interaction with the circumstellar and interstellar medium. I will review the present knowledge of different important aspects of radio remnants and their impact on the interstellar gas. Also, new radio studies of the Crab Nebula carried out with the Karl Jansky Very Large Array (JVLA) at 3 GHz and with ALMA at 100 GHz, will be presented.

  7. Supernova 1987A at 30

    Science.gov (United States)

    Spyromilio, J.; Leibundgut, B.; Fransson, C.; Larsson, J.; Migotto, K.; Girard, J.

    2017-03-01

    Thirty years on, SN 1987A continues to develop and, over the last decade in particular, has: revealed the presence of a large centrally concentrated reservoir of dust; shown the presence of molecular species within the ejecta; expanded such that the ejecta structure is angularly resolved; begun the destruction of the circumstellar ring and transitioned to being dominated by energy sources external to the ejecta. We are participating in a live experiment in the creation of a supernova remnant and here the recent progress is briefly overviewed. Exciting developments can be expected as the ejecta and the reverse shock continue their interaction, the X-rays penetrate into the cold molecular core and we observe the return of the material into the interstellar medium. We anticipate that the nature of the remnant of the leptonisation event in the centre will also be revealed.

  8. Progenitors of Supernovae Type Ia

    CERN Document Server

    Toonen, S; Bours, M; Zwart, S Portegies; Claeys, J; Mennekens, N; Ruiter, A

    2013-01-01

    Despite the significance of Type Ia supernovae (SNeIa) in many fields in astrophysics, SNeIa lack a theoretical explanation. The standard scenarios involve thermonuclear explosions of carbon/oxygen white dwarfs approaching the Chandrasekhar mass; either by accretion from a companion or by a merger of two white dwarfs. We investigate the contribution from both channels to the SNIa rate with the binary population synthesis (BPS) code SeBa in order to constrain binary processes such as the mass retention efficiency of WD accretion and common envelope evolution. We determine the theoretical rates and delay time distribution of SNIa progenitors and in particular study how assumptions affect the predicted rates.

  9. ANTIPROTONS PRODUCED IN SUPERNOVA REMNANTS

    Energy Technology Data Exchange (ETDEWEB)

    Berezhko, E. G.; Ksenofontov, L. T., E-mail: ksenofon@ikfia.sbras.ru [Yu. G. Shafer Institute of Cosmophysical Research and Aeronomy, 31 Lenin Avenue, 677891 Yakutsk (Russian Federation)

    2014-08-20

    We present the energy spectrum of an antiproton cosmic ray (CR) component calculated on the basis of the nonlinear kinetic model of CR production in supernova remnants (SNRs). The model includes the reacceleration of antiprotons already existing in the interstellar medium as well as the creation of antiprotons in nuclear collisions of accelerated protons with gas nuclei and their subsequent acceleration by SNR shocks. It is shown that the production of antiprotons in SNRs produces a considerable effect in their resultant energy spectrum, making it essentially flatter above 10 GeV so that the spectrum at TeV energies increases by a factor of 5. The calculated antiproton spectrum is consistent with the PAMELA data, which correspond to energies below 100 GeV. As a consistency check, we have also calculated within the same model the energy spectra of secondary nuclei and show that the measured boron-to-carbon ratio is consistent with the significant SNR contribution.

  10. Progenitors of type Ia supernovae

    CERN Document Server

    Maeda, Keiichi

    2016-01-01

    Natures of progenitors of type Ia Supernovae (SNe Ia) have not yet been clarified. There has been long and intensive discussion on whether the so-called single degenerate (SD) scenario or the double degenerate (DD) scenario, or anything else, could explain a major population of SNe Ia, but the conclusion has not yet been reached. With rapidly increasing observational data and new theoretical ideas, the field of studying the SN Ia progenitors has been quickly developing, and various new insights have been obtained in recent years. This article aims at providing a summary of the current situation regarding the SN Ia progenitors, both in theory and observations. It seems difficult to explain the emerging diversity seen in observations of SNe Ia by a single population, and we emphasize that it is important to clarify links between different progenitor scenarios and different sub-classes of SNe Ia.

  11. Mass extinctions and supernova explosions

    CERN Document Server

    Korschinek, Gunther

    2016-01-01

    A nearby supernova (SN) explosion could have negatively influenced life on Earth, maybe even been responsible for mass extinctions. Mass extinction poses a significant extinction of numerous species on Earth, as recorded in the paleontologic, paleoclimatic, and geological record of our planet. Depending on the distance between the Sun and the SN, different types of threats have to be considered, such as ozone depletion on Earth, causing increased exposure to the Sun's ultraviolet radiation, or the direct exposure of lethal x-rays. Another indirect effect is cloud formation, induced by cosmic rays in the atmosphere which result in a drop in the Earth's temperature, causing major glaciations of the Earth. The discovery of highly intensive gamma ray bursts (GRBs), which could be connected to SNe, initiated further discussions on possible life-threatening events in Earth's history. The probability that GRBs hit the Earth is very low. Nevertheless, a past interaction of Earth with GRBs and/or SNe cannot be exclude...

  12. Astrophysics: Echo from an ancient supernova

    Science.gov (United States)

    Pastorello, Andrea; Patat, Ferdinando

    2008-12-01

    Light reflected off a dust cloud in the vicinity of the relic of Tycho Brahe's supernova, whose light first swept past Earth more than four centuries ago, literally sheds light on the nature of this cosmic explosion.

  13. The Supernova Impostor SN 2010da

    Science.gov (United States)

    Binder, Breanna A.; Williams, Benjamin F.; Kong, Albert K. H.; Plucinsky, Paul P.; Gaetz, Terrance J.; Skillman, Evan D.; Dolphin, Andrew E.

    2016-01-01

    Supernova impostors are optical transients that, despite being assigned a supernova designation, do not signal the death of a massive star or accreting white dwarf. Instead, many impostors are thought to be major eruptions from luminous blue variables. Although the physical cause of these eruptions is still debated, tidal interactions from a binary companion has recently gained traction as a possible explanation for observations of some supernova impostors. In this talk, I will discuss the particularly interesting impostor SN 2010da, which exhibits high-luminosity, variable X-ray emission. The X-ray emission is consistent with accretion onto a neutron star, making SN 2010da a likely high mass X-ray binary in addition to a supernova impostor. SN 2010da is a unique laboratory for understanding both binary interactions as drivers of massive star eruptions and the evolutionary processes that create high mass X-ray binaries.

  14. Physical processes in collapse driven supernova

    Energy Technology Data Exchange (ETDEWEB)

    Mayle, R.W.

    1985-11-01

    A model of the supernova explosion is discussed. The method of neutrino transport is discussed, since the explosive mechanism depends on neutrino heating of the material behind the accretion shock. The core region of these exploding stars becomes unstable to convective motions during the supernova evolution. Convective mixing allows more neutrinos to escape from under the neutrinosphere, and thus increases the amount of heating by neutrinos. An approximate method of incorporating convection is described, and some results of including convection in a computer model is presented. Another phenomena is seen in computer simulations of supernova, oscillations in the neutrino luminosity and mass accretion rate onto the protoneutron star. The last topic discussed in this thesis describes the attempt to understand this oscillation by perturbation of the steady state solution to equations approximating the complex physical processes occurring in the late time supernova. 42 refs., 31 figs.

  15. Inside the supernova a powerful convective engine

    CERN Document Server

    Herant, M; Hix, W R; Fryer, C F; Colgate, S A; Marc Herant; Willy Benz; Chris F Fryer; Stirling Colgate

    1994-01-01

    We present an extensive study of the inception of supernova explosions by following the evolution of the cores of two massive stars (15 Msun and 25 Msun) in two dimensions. Our calculations begin at the onset of core collapse and stop several 100 ms after the bounce, at which time successful explosions of the appropriate magnitude have been obtained. (...) Guided by our numerical results, we have developed a paradigm for the supernova explosion mechanism. We view a supernova as an open cycle thermodynamic engine in which a reservoir of low-entropy matter (the envelope) is thermally coupled and physically connected to a hot bath (the protoneutron star) by a neutrino flux, and by hydrodynamic instabilities. (...) In essence, a Carnot cycle is established in which convection allows out-of-equilibrium heat transfer mediated by neutrinos to drive low entropy matter to higher entropy and therefore extracts mechanical energy from the heat generated by gravitational collapse. We argue that supernova explosions are ne...

  16. Detecting supernovae neutrino with Earth matter effect

    CERN Document Server

    Liao, Wei

    2016-01-01

    We study Earth matter effect in oscillation of supernovae neutrinos. We show that detecting Earth matter effect gives an independent measurement of spectra of supernovae neutrinos, i.e. the flavor difference of the spectra of supernovae neutrinos. We study the effect of energy resolution and angular resolution of final electron or positron on detecting the signal of Earth matter effect. We show that varying the widths of energy bins in analysis can change the signal strength of Earth matter effect and the statistical fluctuation. A reasonable choice of energy bins can both suppress the statistical fluctuation and make out a good signal strength relative to the statistical fluctuation. Neutrino detectors with good energy resolution and good angular resolution are therefore preferred so that there are more freedom to vary energy bins and to optimize the signal of Earth matter effect in analyzing events of supernovae neutrinos.

  17. Supernovae, dark energy and the accelerating universe

    CERN Document Server

    Perlmutter, Saul

    1999-01-01

    Based on an analysis of 42 high-redshift supernovae discovered by the supernovae cosmology project, we have found evidence for a positive cosmological constant, Lambda, and hence an accelerating universe. In particular, the data are strongly inconsistent with a Lambda=0 flat cosmology, the simplest inflationary universe model. The size of our supernova sample allows us to perform a variety of statistical tests to check for possible systematic errors and biases. We will discuss results of these and other studies and the ongoing hunt for further loopholes to evade the apparent consequences of the measurements. We will present further work that begins to constrain the alternative physics theories of "dark energy" that have been proposed to explain these results. Finally, we propose a new concept for a definitive supernova measurement of the cosmological parameters.

  18. Shock Heated Dust in Young Supernova Remnants

    Science.gov (United States)

    Braun, R.; Strom, R. G.; van der Laan, H.; Greidanus, H.

    Infrared emission in young supernova remnants is interpreted as coming from shock-heated dust. Using models and data from other wavelength regimes, many physical parameters of the remnants can accurately be derived.

  19. Cosmic ray escape from supernova remnants

    CERN Document Server

    Gabici, Stefano

    2011-01-01

    Galactic cosmic rays are believed to be accelerated at supernova remnants via diffusive shock acceleration. Though this mechanism gives fairly robust predictions for the spectrum of particles accelerated at the shock, the spectrum of the cosmic rays which are eventually injected in the interstellar medium is more uncertain and depends on the details of the process of particle escape from the shock. Knowing the spectral shape of these escaping particles is of crucial importance in order to assess the validity of the supernova remnant paradigm for cosmic ray origin. Moreover, after escaping from a supernova remnant, cosmic rays interact with the surrounding ambient gas and produce gamma rays in the vicinity of the remnant itself. The detection of this radiation can be used as an indirect proof of the fact that the supernova remnant was indeed accelerating cosmic rays in the past.

  20. An "archaeological" quest for galactic supernova neutrinos

    CERN Document Server

    Lazauskas, Rimantas; Volpe, Cristina

    2009-01-01

    We explore the possibility to observe the effects of electron neutrinos from past galactic supernovae, through a geochemical measurement of the amount of Technetium 97 produced by neutrino-induced reactions in a Molybdenum ore. The calculations we present take into account the recent advances in our knowledge of neutrino interactions, of neutrino oscillations inside a supernova, of the solar neutrino flux at Earth and of possible failed supernovae. The predicted Technetium 97 abundance is of the order of 10^7 atoms per 10 kilotons of ore, which is close to the current geochemical experimental sensitivity. Of this, 10-20% is from supernovae. Considering the comparable size of uncertainties, more precision in the modeling of neutrino fluxes as well as of neutrino cross sections is required for a meaningful measurement.

  1. A review of type Ia supernova spectra

    CERN Document Server

    Parrent, J; Parthasarathy, M

    2014-01-01

    SN 2011fe was the nearest and best-observed type Ia supernova in a generation, and brought previous incomplete datasets into sharp contrast with the detailed new data. In retrospect, documenting spectroscopic behaviors of type Ia supernovae has been more often limited by sparse and incomplete temporal sampling than by consequences of signal-to-noise ratios, telluric features, or small sample sizes. As a result, type Ia supernovae have been primarily studied insofar as parameters discretized by relative epochs and incomplete temporal snapshots near maximum light. Here we discuss a necessary next step toward consistently modeling and directly measuring spectroscopic observables of type Ia supernova spectra. In addition, we analyze current spectroscopic data in the parameter space defined by empirical metrics, which will be relevant even after progenitors are observed and detailed models are refined.

  2. SN 1054: A pulsar-powered supernova?

    Science.gov (United States)

    Li, Shao-Ze; Yu, Yun-Wei; Huang, Yan

    2015-11-01

    The famous ancient supernova SN 1054 could have been too bright to be explained in the “standard” radioactive-powered supernova scenario. As an alternative attempt, we demonstrate that the spin-down of the newly born Crab pulsar could provide a sufficient energy supply to make SN 1054 visible at daytime for 23 days and at night for 653 days, where a one-zone semi-analytical model is employed. Our results indicate that SN 1054 could be a “normal” cousin of magnetar-powered superluminous supernovae. Therefore, SN 1054-like supernovae could be a probe to uncover the properties of newly born neutron stars, which provide initial conditions for studies on neutron star evolutions.

  3. Supernova Shock Breakout from a Red Supergiant

    CERN Document Server

    Schawinski, Kevin; Wolf, Christian; Podsiadlowski, Philipp; Sullivan, Mark; Steenbrugge, Katrien C; Bell, Tony; Roeser, Hermann-Josef; Walker, Emma; Astier, Pierre; Balam, Dave; Balland, Christophe; Basa, Stephane; Carlberg, Ray; Conley, Alex; Fouchez, Dominque; Guy, Julien; Hardin, Delphine; Hook, Isobel; Howell, Andy; Pain, Reynald; Perrett, Kathy; Pritchet, Chris; Regnault, Nicolas; Yi, Sukyoung K

    2008-01-01

    Massive stars undergo a violent death when the supply of nuclear fuel in their cores is exhausted, resulting in a catastrophic `core-collapse' supernova. Such events are usually detected long after the star has exploded. Here we report the first detection of the radiative precursor from a supernova shock before it has reached the surface of a star followed by the initial expansion of the star at the beginning of the explosion. Theoretical models of the ultraviolet light curve show that the progenitor was a red supergiant, as expected for this type of supernova. These observations provide a promising and novel way to probe the physics of core-collapse supernovae and the internal structures of their progenitors.

  4. Supernova Classification Using Swift UVOT Photometry

    Science.gov (United States)

    Smith, Madison; Brown, Peter J.

    2017-01-01

    With the great influx of supernova discoveries over the past few years, the observation time needed to acquire the spectroscopic data needed to classify supernova by type has become unobtainable. Instead, using the photometry of supernovae could greatly reduce the amount of time between discovery and classification. For this project we looked at the relationship between colors and supernova types through machine learning packages in Python. Using data from the Swift Ultraviolet/Optical Telescope (UVOT), each photometric point was assigned values corresponding to colors, absolute magnitudes, and the relative times from the peak brightness in several filters. These values were fed into three classifying methods, the nearest neighbors, decision tree, and random forest methods. We will discuss the success of these classification systems, the optimal filters for photometric classification, and ways to improve the classification.

  5. MDM OSMOS Spectroscopic classification of Supernovae

    Science.gov (United States)

    Bose, Subhash; Dong, Subo; Chen, Ping; Klusmeyer, J.; Prieto, Jose Luis; Shappee, B.; Shields, J.; Brown, J.; Stanek, K. Z.; Kochanek, C.

    2016-11-01

    We report optical spectroscopic classification of supernova candidates 2016hgd (ATel #9651), 2016hli (ATel #9685), CSS161013:015319+171853 and CSS161013:020130+141534 (http://nesssi.cacr.caltech.edu/catalina/AllSN.html).

  6. TYPE Ia SUPERNOVA CARBON FOOTPRINTS

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, R. C.; Nugent, P. [Computational Cosmology Center, Computational Research Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road MS 50B-4206, Berkeley, CA 94611 (United States); Aldering, G.; Aragon, C.; Bailey, S.; Childress, M.; Fakhouri, H. K.; Hsiao, E. Y.; Loken, S. [Physics Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Antilogus, P.; Bongard, S.; Canto, A. [Laboratoire de Physique Nucleaire et des Hautes Energies, Universite Pierre et Marie Curie Paris 6, Universite Paris Diderot Paris 7, CNRS-IN2P3, 4 place Jussieu, 75252 Paris Cedex 05 (France); Baltay, C. [Department of Physics, Yale University, New Haven, CT 06250-8121 (United States); Buton, C.; Kerschhaggl, M.; Kowalski, M.; Paech, K. [Physikalisches Institut, Universitaet Bonn, Nussallee 12, 53115 Bonn (Germany); Chotard, N.; Copin, Y.; Gangler, E. [Universite de Lyon, F-69622 Lyon (France); and others

    2011-12-10

    We present convincing evidence of unburned carbon at photospheric velocities in new observations of five Type Ia supernovae (SNe Ia) obtained by the Nearby Supernova Factory. These SNe are identified by examining 346 spectra from 124 SNe obtained before +2.5 days relative to maximum. Detections are based on the presence of relatively strong C II {lambda}6580 absorption 'notches' in multiple spectra of each SN, aided by automated fitting with the SYNAPPS code. Four of the five SNe in question are otherwise spectroscopically unremarkable, with ions and ejection velocities typical of SNe Ia, but spectra of the fifth exhibit high-velocity (v > 20, 000 km s{sup -1}) Si II and Ca II features. On the other hand, the light curve properties are preferentially grouped, strongly suggesting a connection between carbon-positivity and broadband light curve/color behavior: three of the five have relatively narrow light curves but also blue colors and a fourth may be a dust-reddened member of this family. Accounting for signal to noise and phase, we estimate that 22{sup +10}{sub -6%} of SNe Ia exhibit spectroscopic C II signatures as late as -5 days with respect to maximum. We place these new objects in the context of previously recognized carbon-positive SNe Ia and consider reasonable scenarios seeking to explain a physical connection between light curve properties and the presence of photospheric carbon. We also examine the detailed evolution of the detected carbon signatures and the surrounding wavelength regions to shed light on the distribution of carbon in the ejecta. Our ability to reconstruct the C II {lambda}6580 feature in detail under the assumption of purely spherical symmetry casts doubt on a 'carbon blobs' hypothesis, but does not rule out all asymmetric models. A low volume filling factor for carbon, combined with line-of-sight effects, seems unlikely to explain the scarcity of detected carbon in SNe Ia by itself.

  7. Neutrino-nucleus reactions in supernovae

    Science.gov (United States)

    Dzhioev, Alan A.; Vdovin, A. I.

    2016-01-01

    We study thermal effects on neutrino-nucleus reactions occurring under supernova conditions. The approach we use is based on the QRPA extended to finite temperature by the thermofield dynamics formalism. For the relevant supernova conditions we calculate inelastic neutrino scattering and neutrino absorption cross sections for two sample nuclei, 56Fe and 82Ge. In addition, we apply the approach to examine the rate of neutrino-antineutrino pair emission by hot nuclei.

  8. Neutrino-nucleus reactions in supernovae

    Directory of Open Access Journals (Sweden)

    Dzhioev Alan A.

    2016-01-01

    Full Text Available We study thermal effects on neutrino-nucleus reactions occurring under supernova conditions. The approach we use is based on the QRPA extended to finite temperature by the thermofield dynamics formalism. For the relevant supernova conditions we calculate inelastic neutrino scattering and neutrino absorption cross sections for two sample nuclei, 56Fe and 82Ge. In addition, we apply the approach to examine the rate of neutrino-antineutrino pair emission by hot nuclei.

  9. Supernova neutrino oscillations: What do we understand?

    Energy Technology Data Exchange (ETDEWEB)

    Dighe, Amol, E-mail: amol@theory.tifr.res.i [Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005 (India)

    2010-01-01

    We summarize our current understanding of the neutrino flavor conversions inside a core collapse supernova, clarifying the important role played by the 'collective effects' in determining flavor conversion probabilities. The potentially observable {nu}{sub e} and {nu}-bar {sub e} spectra may help us identify the neutrino mixing scenario, distinguish between primary flux models, and learn more about the supernova explosion.

  10. Collective flavor transitions of supernova neutrinos

    CERN Document Server

    Sigl, Guenter; Esteban-Pretel, Andreu; Pastor, Sergio; Mirizzi, Alessandro; Raffelt, Georg G; Serpico, Pasquale D

    2009-01-01

    We give a very brief overview of collective effects in neutrino oscillations in core collapse supernovae where refractive effects of neutrinos on themselves can considerably modify flavor oscillations, with possible repercussions for future supernova neutrino detection. We discuss synchronized and bipolar oscillations, the role of energy and angular neutrino modes, as well as three-flavor effects. We close with a short summary and some open questions.

  11. The SuperNova Early Warning System

    OpenAIRE

    Scholberg, K.

    2008-01-01

    A core collapse in the Milky Way will produce an enormous burst of neutrinos in detectors world-wide. Such a burst has the potential to provide an early warning of a supernova's appearance. I will describe the nature of the signal, the sensitivity of current detectors, and SNEWS, the SuperNova Early Warning System, a network designed to alert astronomers as soon as possible after the detected neutrino signal.

  12. Close binary white dwarfs and supernovae IA

    Directory of Open Access Journals (Sweden)

    R. Napiwotzki

    2004-01-01

    Full Text Available Informamos sobre el estado actual de los \\surveys" de velocidades radiales para binarias de enanas blancas (degeneradas dobles - DDs incluyendo SPY (Exploraci on ESO de progenitoras de supernovas Ia que recien- temente se llevaron a cabo en el VLT. Una amplia muestra de DDs nos permitir a poner fuertes restricciones sobre las fases evolutivas de los sistemas progenitores de binarias cercanas y tambi en llevar a cabo pruebas observacionales del escenario DD para supernovas de tipo Ia.

  13. The CARMA Data Reduction Pipeline

    Science.gov (United States)

    Friedel, D. N.

    2013-10-01

    The Combined Array for Millimeter-wave Astronomy (CARMA) data reduction pipeline (CADRE) has been developed to give investigators a first look at a fully reduced set of their data. It runs automatically on all data produced by the telescope as they arrive in the data archive. CADRE is written in Python and uses Python wrappers for MIRIAD subroutines for direct access to the data. It applies passband, gain and flux calibration to the data sets and produces a set of continuum and spectral line maps in both MIRIAD and FITS format. CADRE has been in production for a year and this poster will discuss the current capabilities and planned improvements.

  14. Addressing the workforce pipeline challenge

    Energy Technology Data Exchange (ETDEWEB)

    Leonard Bond; Kevin Kostelnik; Richard Holman

    2006-11-01

    A secure and affordable energy supply is essential for achieving U.S. national security, in continuing U.S. prosperity and in laying the foundations to enable future economic growth. To meet this goal the next generation energy workforce in the U.S., in particular those needed to support instrumentation, controls and advanced operations and maintenance, is a critical element. The workforce is aging and a new workforce pipeline, to support both current generation and new build has yet to be established. The paper reviews the challenges and some actions being taken to address this need.

  15. Neutrino oscillations in core-collapse supernovae

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Meng-Ru [TU Darmstadt (Germany); University of Minnesota, MN (United States); Huther, Lutz [TU Darmstadt (Germany); Fischer, Tobias; Martinez-Pinedo, Gabriel [TU Darmstadt (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Qian, Yong-Zhong [University of Minnesota, MN (United States)

    2013-07-01

    Neutrino oscillations play an important role in determining the spectra of neutrinos emitted from core-collapse supernova and must be considered in the analysis of supernova neutrino detection to understand both the supernova dynamics and the unknown neutrino mass hierarchy. We have studied neutrino oscillations in supernovae using the emission spectra of neutrinos and the dynamically evolving supernova density profile from a state-of-the-art supernova model. We find that in this model, different regions of neutrino oscillations are well separated. Collective neutrino oscillations happen at the innermost part such that the spectra of electron neutrinos and mu/tau neutrinos are partly swapped for the first few seconds in the cooling phase. Then, the high and low MSW resonances that occur after collective oscillations are both adiabatic. Using these results, we find that in this model, neutrino oscillations have little effect on the nucleosynthesis in the neutrino-driven winds. However, the detection of such a signal could possibly allow us to differentiate the neutrino mass hierarchy and to extract the shock revival time.

  16. The Distant Type Ia Supernova Rate

    Science.gov (United States)

    Pain, R.; Fabbro, S.; Sullivan, M.; Ellis, R. S.; Aldering, G.; Astier, P.; Deustua, S. E.; Fruchter, A. S.; Goldhaber, G.; Goobar, A.; Groom, D. E.; Hardin, D.; Hook, I. M.; Howell, D. A.; Irwin, M. J.; Kim, A. G.; Kim, M. Y.; Knop, R. A.; Lee, J. C.; Perlmutter, S.; Ruiz-Lapuente, P.; Schahmaneche, K.; Schaefer, B.; Walton, N. A.

    2002-05-28

    We present a measurement of the rate of distant Type Ia supernovae derived using 4 large subsets of data from the Supernova Cosmology Project. Within this fiducial sample, which surveyed about 12 square degrees, thirty-eight supernovae were detected at redshifts 0.25--0.85. In a spatially flat cosmological model consistent with the results obtained by the Supernova Cosmology Project, we derive a rest-frame Type Ia supernova rate at a mean red shift z {approx_equal} 0.55 of 1.53 {sub -0.25}{sub -0.31}{sup 0.28}{sup 0.32} x 10{sup -4} h{sup 3} Mpc{sup -3} yr{sup -1} or 0.58{sub -0.09}{sub -0.09}{sup +0.10}{sup +0.10} h{sup 2} SNu(1 SNu = 1 supernova per century per 10{sup 10} L{sub B}sun), where the first uncertainty is statistical and the second includes systematic effects. The dependence of the rate on the assumed cosmological parameters is studied and the redshift dependence of the rate per unit comoving volume is contrasted with local estimates in the context of possible cosmic star formation histories and progenitor models.

  17. The distant Type Ia supernova rate

    CERN Document Server

    Pain, R; Sullivan, M; Ellis, Richard S; Aldering, G; Astier, Pierre; Duestua, S E; Fruchter, A S; Goldhaber, Gerson; Goobar, A; Groom, D E; Hardin, D; Hook, I M; Howell, D A; Irwin, M J; Kim, A G; Kim, M Y; Knop, R A; Lee, J C; Lidman, C E; McMahon, R G; Nugent, P; Panagia, N; Pennypacker, C R; Perlmutter, S; Ruiz-Lapuente, P; Schahmaneche, K; Schaefer, B; Walton, N A

    2001-01-01

    We present a measurement of the rate of distant Type Ia supernovae derived using 4 large subsets of data from the Supernova Cosmology Project. Within this fiducial sample, which surveyed about 12 square degrees, thirty-eight supernovae were detected at redshifts 0.25--0.85. In a spatially-flat cosmological model consistent with the results obtained by the Supernova Cosmology Project, we derive a rest-frame Type Ia supernova rate at a mean redshift $z\\simeq0.55$ of $1.53 {^{+0.28}_{-0.25}} {^{+0.32}_{-0.31}} 10^{-4} h^3 {\\rm Mpc}^{-3} {\\rm yr}^{-1}$ or $0.58 {^{+0.10}_{-0.09}} {^{+0.10}_{-0.09}} h^2 {\\rm SNu}$ (1 SNu = 1 supernova per century per $10^{10}$\\Lbsun), where the first uncertainty is statistical and the second includes systematic effects. The dependence of the rate on the assumed cosmological parameters is studied and the redshift dependence of the rate per unit comoving volume is contrasted with local estimates in the context of possible cosmic star formation histories and progenitor models.

  18. 77 FR 51848 - Pipeline Safety: Information Collection Activities

    Science.gov (United States)

    2012-08-27

    ... Pipeline and Hazardous Materials Safety Administration Pipeline Safety: Information Collection Activities...) Current expiration date; (4) Type of request; (5) Abstract of the information collection activity; (6... activity. PHMSA requests comments on the following information collections: Title: Pipeline Safety:...

  19. 75 FR 30099 - Pipeline Safety: Information Collection Activities

    Science.gov (United States)

    2010-05-28

    ... TRANSPORTATION Pipeline and Hazardous Materials Safety Administration Pipeline Safety: Information Collection Activities AGENCY: Pipeline and Hazardous Materials Safety Administration, DOT. ACTION: Notice. SUMMARY: In compliance with the Paperwork Reduction Act, PHMSA announces that the currently approved...

  20. Oil and Natural Gas Pipelines, North America, 2010, Platts

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Oil and Natural Gas Pipeline geospatial data layer contains gathering, interstate, and intrastate natural gas pipelines, crude and product oil pipelines, and...

  1. 18 CFR 284.227 - Certain transportation by intrastate pipelines.

    Science.gov (United States)

    2010-04-01

    ... Interstate Pipelines on Behalf of Others and Services by Local Distribution Companies § 284.227 Certain... interstate pipeline or local distribution company served by an interstate pipeline. (e) Pregrant...

  2. Type Ia supernova rate at a redshift of ­0.1

    DEFF Research Database (Denmark)

    Blanc ...[et al], G.; Andersen, J.

    2004-01-01

    stars: supernovae: general; galaxies: evolution; cosmology: miscellaneous; methods: observational......stars: supernovae: general; galaxies: evolution; cosmology: miscellaneous; methods: observational...

  3. Exploring the Outer Solar System with the ESSENCE Supernova Survey

    Energy Technology Data Exchange (ETDEWEB)

    Becker, A.C.; /Washington U., Seattle, Astron. Dept.; Arraki, K.; /Washington U., Seattle, Astron. Dept.; Kaib, N.A.; /Washington U., Seattle, Astron. Dept.; Wood-Vasey, W.M.; /Harvard-Smithsonian Ctr. Astrophys.; Aguilera, C.; /Cerro-Tololo InterAmerican Obs.; Blackman, J.W.; /Australian Natl. U., Canberra; Blondin, S.; /Harvard-Smithsonian Ctr. Astrophys.; Challis, P.; /Harvard-Smithsonian Ctr. Astrophys.; Clocchiatti, A.; /Rio de Janeiro, Pont. U. Catol.; Covarrubias, R.; /Kyushu Sangyo U.; Damke, G.; /Cerro-Tololo InterAmerican Obs.; Davis, T.M.; /Bohr Inst. /Queensland U.; Filippenko, A.V.; /UC, Berkeley; Foley, R.J.; /UC, Berkeley; Garg, A.; /Harvard-Smithsonian Ctr. Astrophys. /Harvard U.; Garnavich, P.M.; /Notre Dame U.; Hicken, M.; /Harvard-Smithsonian Ctr. Astrophys. /Harvard U.; Jha, S.; /Harvard U. /SLAC; Kirshner, R.P.; /Harvard-Smithsonian Ctr. Astrophys.; Krisciunas, K.; /Notre Dame U. /Texas A-M; Leibundgut, B.; /Munich, Tech. U. /UC, Berkeley /NOAO, Tucson /Washington U., Seattle, Astron. Dept. /Fermilab /Harvard-Smithsonian Ctr. Astrophys. /Harvard U. /Chile U., Santiago /Ohio State U. /Cerro-Tololo InterAmerican Obs. /Harvard U. /Baltimore, Space Telescope Sci. /Johns Hopkins U. /Australian Natl. U., Canberra /Australian Natl. U., Canberra /Cerro-Tololo InterAmerican Obs. /Munich, Tech. U. /Harvard-Smithsonian Ctr. Astrophys. /Harvard U. /Cerro-Tololo InterAmerican Obs. /Texas A-M /Cerro-Tololo InterAmerican Obs.

    2011-11-10

    We report the discovery and orbital determination of 14 trans-Neptunian objects (TNOs) from the ESSENCE Supernova Survey difference imaging data set. Two additional objects discovered in a similar search of the SDSS-II Supernova Survey database were recovered in this effort. ESSENCE repeatedly observed fields far from the solar system ecliptic (-21{sup o} < {beta} < -5{sup o}), reaching limiting magnitudes per observation of I {approx} 23.1 and R {approx} 23.7. We examine several of the newly detected objects in detail, including 2003 UC{sub 414}, which orbits entirely between Uranus and Neptune and lies very close to a dynamical region that would make it stable for the lifetime of the solar system. 2003 SS{sub 422} and 2007 TA{sub 418} have high eccentricities and large perihelia, making them candidate members of an outer class of TNOs. We also report a new member of the 'extended' or 'detached' scattered disk, 2004 VN{sub 112}, and verify the stability of its orbit using numerical simulations. This object would have been visible to ESSENCE for only {approx}2% of its orbit, suggesting a vast number of similar objects across the sky. We emphasize that off-ecliptic surveys are optimal for uncovering the diversity of such objects, which in turn will constrain the history of gravitational influences that shaped our early solar system.

  4. Tests of Environmental Effects on Type Ia Supernova Production

    Science.gov (United States)

    Sadler, Suzanna M.; Strolger, L.; Wolff, S.

    2011-01-01

    The host galaxy environments of type Ia supernovae (SNe Ia) provide our best opportunity for constraining the mechanism(s) of the SN Ia progenitor system, i.e., the stars involved, the incubation times, and the sensitivity of SNe Ia to changes in the local gas-phase metallicity. The latter can affect the luminosity of the resultant event, and possibly the success in ultimately yielding a SN Ia. We seek to solidify possible environmental trends in SN Ia rates from direct measures of host galaxy properties, using the sample collected by the Nearby Galaxies Supernova Search project. This study will uncover which has the greatest influence on SN Ia production efficiency: parent population age, rate of star-formation, or metallicity. Here, we will show some preliminary results from SSP model fitting (of age and [Fe/H]) to a selection of hosts obtained thus far from this study. The complete sample will provide a validity test of the mostly indirect trends being established for SNe Ia from the LOSS, SDSS, SNfactory and other surveys, and may ultimately steer future investigations towards more precise SN Ia cosmology.

  5. NTT and NOT spectroscopy of SDSS-II supernovae

    CERN Document Server

    Ostman, L; Goobar, A; Amanullah, R; Smith, M; Sollerman, J; Stanishev, V; Stritzinger, M D; Bassett, B A; Davis, T M; Edmondson, E; Frieman, J A; Garnavich, P M; Lampeitl, H; Leloudas, G; Marriner, J; Nichol, R C; Romer, K; Sako, M; Schneider, D P; Zheng, C

    2010-01-01

    Context. The SDSS-II Supernova Survey, conducted between 2005 and 2007, was designed to detect a large number of Type Ia supernovae (SNe Ia) around z~0.2, the redshift “gap” between low-z and high-z SN searches. The survey has provided multi-band photometric lightcurves for variable targets, and SN candidates were scheduled for spectroscopic observations, primarily to provide SN classification and accurate redshifts. We present SN spectra obtained in 2006 and 2007 using the NTT and the NOT. Aims. We provide an atlas of SN spectra in the range z =0.03-0.32 that complements the well-sampled lightcurves from SDSS-II in the forthcoming three-year SDSS SN cosmology analysis. The sample can, for example, be used for spectral studies of SNe Ia, which are critical for understanding potential systematic effects when SNe are used to determine cosmological distances. Methods. The spectra were reduced in a uniform manner, and special care was taken in estimating the uncertainties for the different processing st...

  6. Insights into thermonuclear supernovae from the incomplete silicon burning process

    CERN Document Server

    Bravo, E

    2012-01-01

    Type Ia supernova (SNIa) explosions synthesize a few tenths to several tenths of a solar mass, whose composition is the result of incomplete silicon burning that reaches peak temperatures of 4 GK to 5 GK. The elemental abundances are sensitive to the physical conditions in the explosion, making their measurement a promising clue to uncovering the properties of the progenitor star and of the explosion itself. Using a parameterized description of the thermodynamic history of matter undergoing incomplete silicon burning, we computed the final composition for a range of parameters wide enough to encompass current models of SNIa. Then, we searched for combinations of elemental abundances that trace the parameters values and are potentially measurable. For this purpose, we divide the present study into two epochs of SNIa, namely the optical epoch, from a few weeks to several months after the explosion, and the X-ray epoch, which refers to the time period in which the supernova remnant is young, starting one or two ...

  7. Photometric selection of high-redshift type Ia supernovae

    CERN Document Server

    Sullivan, M; Perrett, K; Nugent, P; Astier, Pierre; Aubourg, E; Balam, D; Basa, S; Carlberg, R; Conley, A; Fabbro, S; Fouchez, D; Guy, J; Hook, I; Lafoux, H; Neill, J D; Pain, R; Palanque-Delabrouille, Nathalie; Pritchet, C; Regnault, N; Rich, J; Taillet, R; Aldering, G; Baumont, S; Bronder, J; Filiol, M; Knop, R; Perlmutter, S; Tao, C

    2005-01-01

    We present a method for selecting high-redshift type Ia supernovae (SNe Ia) located via rolling SN searches. The technique, using both color and magnitude information of events from only 2-3 epochs of multi-band real-time photometry, is able to discriminate between SNe Ia and core collapse SNe. Furthermore, for the SNe Ia, the method accurately predicts the redshift, phase and light-curve parameterization of these events based only on pre-maximum-light data. We demonstrate the effectiveness of the technique on a simulated survey of SNe Ia and core-collapse SNe, where the selection method effectively rejects most core-collapse SNe while retaining SNe Ia. We also apply the selection code to real-time data acquired as part of the Canada-France-Hawaii Telescope Supernova Legacy Survey (SNLS). During the period May 2004 to January 2005 in the SNLS, 440 SN candidates were discovered of which 70 were confirmed spectroscopically as SNe Ia and 15 as core-collapse events. For this test dataset, the selection technique ...

  8. Supernova remnants: the X-ray perspective

    Science.gov (United States)

    Vink, Jacco

    2012-12-01

    Supernova remnants are beautiful astronomical objects that are also of high scientific interest, because they provide insights into supernova explosion mechanisms, and because they are the likely sources of Galactic cosmic rays. X-ray observations are an important means to study these objects. And in particular the advances made in X-ray imaging spectroscopy over the last two decades has greatly increased our knowledge about supernova remnants. It has made it possible to map the products of fresh nucleosynthesis, and resulted in the identification of regions near shock fronts that emit X-ray synchrotron radiation. Since X-ray synchrotron radiation requires 10-100 TeV electrons, which lose their energies rapidly, the study of X-ray synchrotron radiation has revealed those regions where active and rapid particle acceleration is taking place. In this text all the relevant aspects of X-ray emission from supernova remnants are reviewed and put into the context of supernova explosion properties and the physics and evolution of supernova remnants. The first half of this review has a more tutorial style and discusses the basics of supernova remnant physics and X-ray spectroscopy of the hot plasmas they contain. This includes hydrodynamics, shock heating, thermal conduction, radiation processes, non-equilibrium ionization, He-like ion triplet lines, and cosmic ray acceleration. The second half offers a review of the advances made in field of X-ray spectroscopy of supernova remnants during the last 15 year. This period coincides with the availability of X-ray imaging spectrometers. In addition, I discuss the results of high resolution X-ray spectroscopy with the Chandra and XMM-Newton gratings. Although these instruments are not ideal for studying extended sources, they nevertheless provided interesting results for a limited number of remnants. These results provide a glimpse of what may be achieved with future microcalorimeters that will be available on board future X

  9. Review of Oil and Gas Pipeline Construction in 2007

    Institute of Scientific and Technical Information of China (English)

    Qu Hong

    2008-01-01

    @@ China's pipeline industry has developed for 50 years till 2008. In the past 10 years, more than 50,000 kilometers of long-distance oil and gas pipelines have been constructed,of which gas pipelines reached about 30,000 kilometers,crude oil pipelines about 17,000 kilometers, and product oil pipelines about 7,000 kilometers. Oil and gas pipeline networks across regions have taken shape.

  10. Neutrinos from type-II supernovae and the neutrino-driven supernova mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Janka, H.T. [Max-Planck-Institut fuer Astrophysik, Garching (Germany)

    1996-11-01

    Supernova 1987A has confirmed fundamental aspects of our theoretical view of type-II supernovae: Type-II supernovae are a consequence of the collapse of the iron core of a massive evolved star and lead to the formation of a neutron star or black hole. This picture is most strongly supported by the detection of electron antineutrinos in the IMB and Kamiokande II experiments in connection with SN 1987A. However, the mechanism causing the supernova explosion is not yet satisfactorily understood. In this paper the properties of the neutrino emission from supernovae and protoneutron stars will be reviewed; analytical estimates will be derived and results of numerical simulations will be shown. It will be demonstrated that the spectral distributions of the emitted neutrinos show clear and systematic discrepancies compared with thermal (black body-type) emission. This must be taken into account when neutrino observations from supernovae are to be interpreted, or when implications of the neutrino emission on nucleosynthesis processes in mantle and envelope of the progenitor star are to be investigated. Furthermore, the influence of neutrinos on the supernova dynamics will be discussed, in particular their crucial role in causing the explosion by Wilson`s neutrino-driven delayed mechanism. Possible implications of convection inside the newly born neutron star and between surface and the supernova shock will be addressed and results of multi-dimensional simulations will be presented. (author) 7 figs., 1 tab., refs.

  11. NCBI prokaryotic genome annotation pipeline.

    Science.gov (United States)

    Tatusova, Tatiana; DiCuccio, Michael; Badretdin, Azat; Chetvernin, Vyacheslav; Nawrocki, Eric P; Zaslavsky, Leonid; Lomsadze, Alexandre; Pruitt, Kim D; Borodovsky, Mark; Ostell, James

    2016-08-19

    Recent technological advances have opened unprecedented opportunities for large-scale sequencing and analysis of populations of pathogenic species in disease outbreaks, as well as for large-scale diversity studies aimed at expanding our knowledge across the whole domain of prokaryotes. To meet the challenge of timely interpretation of structure, function and meaning of this vast genetic information, a comprehensive approach to automatic genome annotation is critically needed. In collaboration with Georgia Tech, NCBI has developed a new approach to genome annotation that combines alignment based methods with methods of predicting protein-coding and RNA genes and other functional elements directly from sequence. A new gene finding tool, GeneMarkS+, uses the combined evidence of protein and RNA placement by homology as an initial map of annotation to generate and modify ab initio gene predictions across the whole genome. Thus, the new NCBI's Prokaryotic Genome Annotation Pipeline (PGAP) relies more on sequence similarity when confident comparative data are available, while it relies more on statistical predictions in the absence of external evidence. The pipeline provides a framework for generation and analysis of annotation on the full breadth of prokaryotic taxonomy. For additional information on PGAP see https://www.ncbi.nlm.nih.gov/genome/annotation_prok/ and the NCBI Handbook, https://www.ncbi.nlm.nih.gov/books/NBK174280/.

  12. Software for pipeline integrity administration

    Energy Technology Data Exchange (ETDEWEB)

    Soula, Gerardo; Perona, Lucas Fernandez [Gie SA., Buenos Aires (Argentina); Martinich, Carlos [Refinaria do Norte S. A. (REFINOR), Tartagal, Provincia de Salta (Argentina)

    2009-07-01

    A Software for 'pipeline integrity management' was developed. It allows to deal with Geographical Information and a PODS database (Pipeline Open database Standard) simultaneously, in a simple and reliable way. The premises for the design were the following: didactic, geo referenced, multiple reference systems. Program skills: 1.PODS+GIS: the PODS database in which the software is based on is completely integrated with the GIS module. 2 Management of different kinds of information: it allows to manage information on facilities, repairs, interventions, physical inspections, geographical characteristics, compliance with regulations, training, offline events, operation measures, O and M information treatment and importing specific data and studies in a massive way. It also assures the integrity of the loaded information. 3 Right of way survey: it allows to verify the class location, ROW occupation, sensitive areas identification and to manage landowners. 4 Risk analysis: it is done in a qualitative way, depending on the entered data, allowing the user to identify the riskiest stretches of the system. Either results from risk analysis, data and consultations made about the database, can be exported to standard formats. (author)

  13. Pipelined Viterbi Decoder Using FPGA

    Directory of Open Access Journals (Sweden)

    Nayel Al-Zubi

    2013-02-01

    Full Text Available Convolutional encoding is used in almost all digital communication systems to get better gain in BER (Bit Error Rate, and all applications needs high throughput rate. The Viterbi algorithm is the solution in decoding process. The nonlinear and feedback nature of the Viterbi decoder makes its high speed implementation harder. One of promising approaches to get high throughput in the Viterbi decoder is to introduce a pipelining. This work applies a carry-save technique, which gets the advantage that the critical path in the ACS feedback becomes in one direction and get rid of carry ripple in the “Add” part of ACS unit. In this simulation and implementation show how this technique will improve the throughput of the Viterbi decoder. The design complexities for the bit-pipelined architecture are evaluated and demonstrated using Verilog HDL simulation. And a general algorithm in software that simulates a Viterbi Decoder was developed. Our research is concerned with implementation of the Viterbi Decoders for Field Programmable Gate Arrays (FPGA. Generally FPGA's are slower than custom integrated circuits but can be configured in the lab in few hours as compared to fabrication which takes few months. The design implemented using Verilog HDL and synthesized for Xilinx FPGA's.

  14. Electrical fingerprint of pipeline defects

    Energy Technology Data Exchange (ETDEWEB)

    Mica, Isabella [STMicroelectronics Srl, via C.Olivetti 2, 20041 Agrate Brianza (Italy)]. E-mail: isabella.mica@st.com; Polignano, Maria Luisa [STMicroelectronics Srl, via C.Olivetti 2, 20041 Agrate Brianza (Italy); Marco, Cinzia De [STMicroelectronics Srl, via C.Olivetti 2, 20041 Agrate Brianza (Italy)

    2004-12-15

    Pipeline defects are dislocations that connect the source region of the transistor with the drain region. They were widely reported to occur in CMOS, BiCMOS devices and recently in SOI technologies. They can reduce device yield either by affecting the devices functionality or by increasing the current consumption under stand-by conditions. In this work the electrical fingerprint of these dislocations is studied, its purpose is to enable us to identify these defects as the ones responsible for device failure. It is shown that the pipeline defects are responsible for a leakage current from source to drain in the transistors. This leakage has a resistive characteristic and it is lightly modulated by the body bias. It is not sensitive to temperature; vice versa the off-current of a good transistor exhibits the well-known exponential dependence on 1/T. The emission spectrum of these defects was studied and compared with the spectrum of a good transistor. The paper aims to show that the spectrum of a defective transistor is quite peculiar; it shows well defined peaks, whereas the spectrum of a good transistor under saturation conditions is characterized by a broad spectral light emission distribution. Finally the deep-level transient spectroscopy (DLTS) is tried on defective diodes.

  15. Offshore Pipeline Locations in the Gulf of Mexico, Geographic NAD27, MMS (2007) [pipelines_points_mms_2007

    Data.gov (United States)

    Louisiana Geographic Information Center — Offshore Minerals Management Pipeline Locations for the Gulf of Mexico (GOM). Contains the points of the pipeline in the GOM. All pipelines existing in the databases...

  16. Offshore Pipeline Locations in the Gulf of Mexico, Geographic NAD27, MMS (2007) [pipelines_vectors_mms_2007

    Data.gov (United States)

    Louisiana Geographic Information Center — Offshore Minerals Management Pipeline Locations for the Gulf of Mexico (GOM). Contains the lines of the pipeline in the GOM. All pipelines existing in the databases...

  17. PETROCHINA WEST EAST GAS PIPELINE & SALES COMPANY

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ PetroChina West East Gas Pipeline & Sales Company, a regional company directly under PetroChina Company Limited (PetroChina), is responsible for the construction and operation of the West-East Gas Pipeline Project, and the gas marketing and sales of the natural gas market in China.

  18. Testing the School-to-Prison Pipeline

    Science.gov (United States)

    Owens, Emily G.

    2017-01-01

    The School-to-Prison Pipeline is a social phenomenon where students become formally involved with the criminal justice system as a result of school policies that use law enforcement, rather than discipline, to address behavioral problems. A potentially important part of the School-to-Prison Pipeline is the use of sworn School Resource Officers…

  19. China Pins Hopes on Pipeline with Russia

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    @@ China still has faith in the gigantic Sino-Russia oil pipeline, despite reports which said that Russia is inclined to build a competing pipeline in favor of Japan. CNPC, the company representing China to negotiate with Russia on the project, is reported to continue its preparation work to receive Russian crude.

  20. Maurer computers for pipelined instruction processing

    NARCIS (Netherlands)

    Bergstra, J.A.; Middelburg, C.A.

    2008-01-01

    We model micro-architectures with non-pipelined instruction processing and pipelined instruction processing using Maurer machines, basic thread algebra and program algebra. We show that stored programs are executed as intended with these micro-architectures. We believe that this work provides a new

  1. Pipeline Protection Has Its Own Law

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    @@ The Law of the People's Republic of China on the Protection of Oil and Natural Gas Pipelines (hereinafter called "the Law") will be implemented officially on October 1 this year.This is the first time that oil and natural gas pipelines were protected and managed on legal basis.

  2. Efficiency improvements in pipeline transportation systems

    Energy Technology Data Exchange (ETDEWEB)

    Banks, W. F.; Horton, J. F.

    1977-09-09

    This report identifies potential energy-conservative pipeline innovations that are most energy- and cost-effective and formulates recommendations for the R, D, and D programs needed to exploit those opportunities. From a candidate field of over twenty classes of efficiency improvements, eight systems are recommended for pursuit. Most of these possess two highly important attributes: large potential energy savings and broad applicability outside the pipeline industry. The R, D, and D program for each improvement and the recommended immediate next step are described. The eight technologies recommended for R, D, and D are gas-fired combined cycle compressor station; internally cooled internal combustion engine; methanol-coal slurry pipeline; methanol-coal slurry-fired and coal-fired engines; indirect-fired coal-burning combined-cycle pump station; fuel-cell pump station; drag-reducing additives in liquid pipelines; and internal coatings in pipelines.

  3. optimization for trenchless reconstruction of pipelines

    Directory of Open Access Journals (Sweden)

    Zhmakov Gennadiy Nikolaevich

    2015-01-01

    Full Text Available Today the technologies of trenchless reconstruction of pipelines are becoming and more widely used in Russia and abroad. One of the most perspective is methods is shock-free destruction of the old pipeline being replaced with the help of hydraulic installations with working mechanism representing a cutting unit with knife disks and a conic expander. A construction of a working mechanism, which allows making trenchless reconstruction of pipelines of different diameters, is optimized and patented and its developmental prototype is manufactured. The dependence of pipeline cutting force from knifes obtusion of the working mechanisms. The cutting force of old steel pipelines with obtuse knife increases proportional to the value of its obtusion. Two stands for endurance tests of the knifes in laboratory environment are offered and patented.

  4. Cartier Pipeline : tying it all together

    Energy Technology Data Exchange (ETDEWEB)

    Brochu, S. [Enbridge Consumers Gas, Calgary, AB (Canada); Gaz Metropolitain, Montreal, PQ (Canada)

    2001-07-01

    The Cartier Pipeline is a proposed stand-alone pipeline involving equal partnership between Alberta's Enbridge Consumers Gas and Quebec's Gaz Metropolitain to bring offshore Atlantic gas to markets in eastern Canada and the New England states. The inservice date for the proposed pipeline is November 2004. The $270 million dollar project will require 262 km of pipeline in Quebec with an annual transportation capacity of 67 Bcf initially with a cost effective expandability to 125 Bcf. Contracted commitments so far include 30 Bcf/year from Gaz Metropolitain and the same from Enbridge. Cartier offers attractive, base load, long term, complementary market diversification for Atlantic production. It also provides producers with a competitive channel to Ontario storage. In addition, the pipeline will contribute to lower tolls in Canada and the overall path to Dracut (Boston). Several graphs depicting expected costs of delivered gas supplies to Montreal were also included with this power point presentation. tabs., figs.

  5. Technical progress in pipeline design and construction

    Energy Technology Data Exchange (ETDEWEB)

    Hausken, K.B.

    1995-12-31

    This paper considers the technical progress in offshore pipeline construction with limitation to some general subjects covering pipeline design, installation and start-up. In future the use of limit state pipeline design philosophy, may be implemented as an alternative to the stress based design commonly used to day giving a potential for further optimisation of the pipeline design and consequently reduction of the initial investment. Comprehensive research and development efforts in Norway in the second half of the 1970`s, made it technically feasible to cross the deep water Norwegian Trench in the 1980`s. In addition, the development of several offshore pipeline systems until to day including gas distribution systems to the European continent, have brought Norway to the forefront of technical expertise

  6. Pipeline modeling and assessment in unstable slopes

    Energy Technology Data Exchange (ETDEWEB)

    Caceres, Carlos Nieves [Oleoducto Central S.A., Bogota, Cundinamarca (Colombia); Ordonez, Mauricio Pereira [SOLSIN S.A.S, Bogota, Cundinamarca (Colombia)

    2010-07-01

    The OCENSA pipeline system is vulnerable to geotechnical problems such as faults, landslides or creeping slopes, which are well-known in the Andes Mountains and tropical countries like Colombia. This paper proposes a methodology to evaluate the pipe behaviour during the soil displacements of slow landslides. Three different cases of analysis are examined, according to site characteristics. The process starts with a simplified analytical model and develops into 3D finite element numerical simulations applied to the on-site geometry of soil and pipe. Case 1 should be used when the unstable site is subject to landslides impacting significant lengths of pipeline, pipeline is straight, and landslide is simple from the geotechnical perspective. Case 2 should be used when pipeline is straight and landslide is complex (creeping slopes and non-conventional stabilization solutions). Case 3 should be used if the pipeline presents vertical or horizontal bends.

  7. HET LRS2 Observations of Halpha in Old Hydrogen-deficient Supernovae

    Science.gov (United States)

    Wheeler, J. Craig Craig; Pooley, David A.; Vinko, Jozsef; Szalai, Tamas; Marion, Howie H.; Sand, David J.; McQueen, Phillip; Silverman, Jeffrey M.

    2017-06-01

    For 3 years, we have been using narrow-band filters with the DIAFI imager on the HJS 2.7 m telescope to search for evidence that hydrogen-deficient supernovae undergo delayed collision with previously ejected circumstellar material and associated excitation of Halpha (see abstract by Pooley et al.). A powerful method to determine whether detected Halpha flux is from an HII region or a supernova is to obtain spectra; broad lines (> 1000 km/s) will be a certain indicator of a supernova. We have observed about 20 events that ranged in age from about 1000 days to nearly 80 years for which we have detected Halpha in the vicinity of the supernova. So far, only SN 2014C showed the broad H that is concrete evidence of ongoing circumstellar interaction. One interesting aspect revealed by the spectra is that we often pick up the two [N II] lines that typically accompany H in H II regions. Our spectra of SN 2008ha did not show these [N II] lines. The absence of the [N II] lines might be a clue to circumstellar interaction in conditions where the shock had slowed to a point where the H is not detectably broadened.

  8. Extending the supernova Hubble diagram to z~1.5 with the Euclid space mission

    CERN Document Server

    Astier, P; Brescia, M; Cappellaro, E; Carlberg, R G; Cavuoti, S; Della Valle, M; Gangler, E; Goobar, A; Guy, J; Hardin, D; Hook, I M; Kessler, R; Kim, A; Linder, E; Longo, G; Maguire, K; Mannucci, F; Mattila, S; Nichol, R; Pain, R; Regnault, N; Spiro, S; Sullivan, M; Tao, C; Turatto, M; Wang, X F; Wood-Vasey, W M

    2014-01-01

    We forecast dark energy constraints that could be obtained from a new large sample of Type Ia supernovae where those at high redshift are acquired with the Euclid space mission. We simulate a three-prong SN survey: a z<0.35 nearby sample (8000 SNe), a 0.2Supernova Infra-Red Experiment" (DESIRE), is designed to fit within 6 months of Euclid observing time, with a dedicated observing program. We simulate the SN events as they would be observed in rolling-search mode by the various instruments, and derive the quality of expected cosmological constraints. We account for known systematic uncertainties, in particular calibration uncertainties including their contribution through the training of the supernova model used to fit the supernovae li...

  9. The Carnegie Supernova Project: Intrinsic Colors of Type Ia Supernovae

    CERN Document Server

    Burns, Christopher R; Phillips, M M; Hsiao, E Y; Contreras, Carlos; Persson, S E; Folatelli, Gaston; Boldt, Luis; Campillay, Abdo; Catellón, Sergio; Freedman, Wendy L; Madore, Barry F; Morrell, Nidia; Salgado, Francisco; Suntzeff, Nicholas B

    2014-01-01

    We present an updated analysis of the intrinsic colors of SNe Ia using the latest data release of the Carnegie Supernova Project. We introduce a new light-curve parameter very similar to stretch that is better suited for fast-declining events, and find that these peculiar types can be seen as extensions to the population of "normal" SNe Ia. With a larger number of objects, an updated fit to the Lira relation is presented along with evidence for a dependence on the late-time slope of the B-V color-curves with stretch and color. Using the full wavelength range from u to H band, we place constraints on the reddening law for the sample as a whole and also for individual events/hosts based solely on the observed colors. The photometric data continue to favor low values of Rv, though with large variations from event to event, indicating an intrinsic distribution. We confirm the findings of other groups that there appears to be a correlation between the derived reddening law, Rv, and the color excess, E(B-V), such t...

  10. Type Ia Supernova Progenitors, Environmental Effects and Cosmic Supernova Rates

    CERN Document Server

    Nomoto, K; Hachisu, I; Kato, M; Kobayashi, C; Tsujimoto, T; Nomoto, Ken'ichi; Umeda, Hideyuki; Hachisu, Izumi; Kato, Mariko; Kobayashi, Chiaki; Tsujimoto, Takuji

    1999-01-01

    Relatively uniform light curves and spectral evolution of Type Ia supernovae (SNe Ia) have led to the use of SNe Ia as a ``standard candle'' to determine cosmological parameters, such as the Hubble constant, the density parameter, and the cosmological constant. Whether a statistically significant value of the cosmological constant can be obtained depends on whether the peak luminosities of SNe Ia are sufficiently free from the effects of cosmic and galactic evolutions. Here we first review the single degenerate scenario for the Chandrasekhar mass white dwarf (WD) models of SNe Ia. We identify the progenitor's evolution and population with two channels: (1) the WD+RG (red-giant) and (2) the WD+MS (near main-sequence He-rich star) channels. In these channels, the strong wind from accreting white dwarfs plays a key role, which yields important age and metallicity effects on the evolution. We then address the questions whether the nature of SNe Ia depends systematically on environmental properties such as metalli...

  11. Supernovae under microscope: how supernovae overlap to form superbubbles

    CERN Document Server

    Yadav, Naveen; Sharma, Prateek; Nath, Biman B

    2016-01-01

    We explore the formation of superbubbles through energy deposition by multiple supernovae (SNe) in a uniform medium. We use total energy conserving, 3-D hydrodynamic simulations to study how SNe correlated in space and time create superbubbles. While isolated SNe fizzle out completely by $\\sim 1$ Myr due to radiative losses, for a realistic cluster size it is likely that subsequent SNe go off within the hot/dilute bubble and sustain the shock till the cluster lifetime. We scan the parameter space of ISM density ($n_{g0}$), number of SNe ($N_{\\rm OB}$), and star cluster radius ($r_{\\rm cl}$) to study the conditions for the formation of an overpressured (super)bubble. For realistic cluster sizes, we find that the bubble remains overpressured only if, for a given $n_{g0}$, $N_{\\rm OB}$ is sufficiently large. While most of the input energy is still lost radiatively, superbubbles can retain up to $\\sim 5-10\\%$ of the input energy in form of kinetic+thermal energy till 10 Myr for ISM density $n_{g0} \\approx 1$ cm$^...

  12. Pulsar Search Results from the Arecibo Remote Command Center

    Science.gov (United States)

    Garcia, Alejandro; Stovall, K.; Banaszak, S. A.; Becker, A.; Biwer, C. M.; Boehler, K.; Caballero, K.; Christy, B.; Cohen, S.; Crawford, F.; Cuellar, A.; Danford, A.; Dartez, L. P.; Day, D.; Flanigan, J. D.; Gonzalez, A.; Gustavson, K.; Handzo, E.; Hinojosa, J.; Jenet, F.; Kaplan, D. L.; Kayal, K.; Lommen, A. N.; Longoria, C.; Lopez, J.; Lunsford, G.; Mahany, N.; Martinez, J.; Mata, A.; Miller, A.; Murray, J.; Pankow, C.; Ramirez, I.; Reser, J.; Rojas, P.; Rohr, M.; Rolph, K.; Rose, C.; Rudnik, P.; Siemens, X.; Tellez, A.; Tillman, N.; Walker, A.; Wells, B. L.; Zermeno, A.; Consortium, GBNCC; Consortium, PALFA; Consortium, GBTDrift; Consortium, AO327

    2014-01-01

    The Arecibo Remote Command Center (ARCC) at the University of Texas at Brownsville, in collaboration with various Universities, is currently engaged in searching through ongoing radio telescope surveys for radio pulsars. ARCC is an integrated research/education program that allows students at the high school and undergraduate level to be directly involved with the research at the Arecibo and Green Bank radio telescopes. We discuss the progress of our search effort with PRESTO pulsar search pipelines. Web based tools have been developed so that high school, undergraduate, and graduate students could rank the pulsar candidates created by PRESTO pipelines. We describe these tools and present our current discoveries.

  13. Pipeline integrity: ILI baseline data for QRA

    Energy Technology Data Exchange (ETDEWEB)

    Porter, Todd R. [Tuboscope Pipeline Services, Houston, TX (United States)]. E-mail: tporter@varco.com; Silva, Jose Augusto Pereira da [Pipeway Engenharia, Rio de Janeiro, RJ (Brazil)]. E-mail: guto@pipeway.com; Marr, James [MARR and Associates, Calgary, AB (Canada)]. E-mail: jmarr@marr-associates.com

    2003-07-01

    The initial phase of a pipeline integrity management program (IMP) is conducting a baseline assessment of the pipeline system and segments as part of Quantitative Risk Assessment (QRA). This gives the operator's integrity team the opportunity to identify critical areas and deficiencies in the protection, maintenance, and mitigation strategies. As a part of data gathering and integration of a wide variety of sources, in-line inspection (ILI) data is a key element. In order to move forward in the integrity program development and execution, the baseline geometry of the pipeline must be determined with accuracy and confidence. From this, all subsequent analysis and conclusions will be derived. Tuboscope Pipeline Services (TPS), in conjunction with Pipeway Engenharia of Brazil, operate ILI inertial navigation system (INS) and Caliper geometry tools, to address this integrity requirement. This INS and Caliper ILI tool data provides pipeline trajectory at centimeter level resolution and sub-metre 3D position accuracy along with internal geometry - ovality, dents, misalignment, and wrinkle/buckle characterization. Global strain can be derived from precise INS curvature measurements and departure from the initial pipeline state. Accurate pipeline elevation profile data is essential in the identification of sag/over bend sections for fluid dynamic and hydrostatic calculations. This data, along with pipeline construction, operations, direct assessment and maintenance data is integrated in LinaViewPRO{sup TM}, a pipeline data management system for decision support functions, and subsequent QRA operations. This technology provides the baseline for an informed, accurate and confident integrity management program. This paper/presentation will detail these aspects of an effective IMP, and experience will be presented, showing the benefits for liquid and gas pipeline systems. (author)

  14. The physics of core collapse supernovae

    Science.gov (United States)

    Swesty, Frank Douglas

    1993-01-01

    I have developed an equation of state (EOS) for hot, dense matter that is intended specifically for use in radiation hydrodynamic simulations of supernovae, proto-neutron star cooling, and neutron stars. This EOS makes use of an adjustable nucleon-nucleon interaction that allows for the input of various nuclear force parameters that are not well determined by laboratory measurements. Properties of the EOS as a function of these input parameters were studied and comparisons were made to another EOS that is currently used in stellar collapse simulations. Using this EOS I have conducted simulations of core collapse supernovae with several ideas in mind. First, I have attempted to delineate role of the incompressibility of dense matter in supernovae. I have conducted a parameter study in which the compression modulous of bulk nuclear matter was varied and have found some new and surprising results. When the EOS is constrained by the observed mass of 1.44M(solar mass) for one of the components of the binary pulsar system PSR1913+16, the 'stiffness' of the EOS no longer plays a role in the shock dynamics of the supernova. Secondly, I varied the symmetry energy coefficients in the EOS to determine the role of these coefficients in supernovae. I have found that the symmetry energy behavior of the EOS has potentially observable effects and may play an important role in determining the efficacy of the late-time heating mechanism for the explosion and the stability of the post-bounce core against convection. Finally, I have developed an implicit, general relativistic, radiation hydrodynamics algorithm for the numerical simulation of supernovae. By allowing simulation timesteps to exceed the Courant timescale, this algorithm makes practical high resolution simulations of supernovae to late times. I discuss this algorithm and the associated computer code along with code verification tests and an example of a late-time calculation.

  15. Supernova Dust at Sub-micrometer Scales

    Science.gov (United States)

    Nittler, Larry; Stroud, R. M.

    2006-06-01

    Meteorites contain nanometer to micrometer stardust grains, which formed in pre-solar generations of stars and exhibit large isotopic anomalies that reflect the nuclear processes that occurred in their individual parent stars [1]. Supernovae of Type II have been identified as the sources of much of the stardust, including grains of SiC, Si3N4, graphite and Mg2SiO4. Although, the isotopic compositions of many elements in these grains point unambiguously to supernova nucleosynthesis processes [2], the data require extensive and heterogeneous mixing of disparate nuclear burning zones. A recent study found that individual 200 nm TiC sub-grains within a 12 micron supernova graphite grain have uniform Ti isotopic composition but a range of O isotopic ratios [3]. New microanalysis techniques allow us to correlate the physical microstructures of supernova grains with isotopic composition, e.g., SiC and Si3N4, providing a sub-micron view of condensation processes in supernova ejecta. Results on two SiC grains indicate that micron-sized SiC grains from supernovae consist of assemblages of smaller crystallites with some evidence of radiation and/or shock processing. This is in strong contrast to SiC grains from AGB stars, which are typically single euhedral crystals [4]. The Si, C and N isotopic compositions of the grains are highly uniform, in contrast to the model of [5], which predicts strong isotopic gradients in supernova-derived SiC grains.This work is supported by NASA.[1] Clayton D. D. and Nittler L. R. (2004) ARAA, 42, 39-78.[2] Nittler L. R., et al. (1996) ApJ, 462, L31-34.[3] Stadermann F. J., et al. (2005) GCA, 69, 177-188.[4] Daulton T. L., et al. (2002) Science, 296, 1852-1855.[5] Deneault E. A.-N., et al. (2003) ApJ, 594, 312-325.

  16. 77 FR 17119 - Pipeline Safety: Cast Iron Pipe (Supplementary Advisory Bulletin)

    Science.gov (United States)

    2012-03-23

    ... Pipeline and Hazardous Materials Safety Administration Pipeline Safety: Cast Iron Pipe (Supplementary... operators of natural gas cast iron distribution pipelines and state pipeline safety representatives. Recent deadly explosions in Philadelphia and Allentown, Pennsylvania involving cast iron pipelines installed...

  17. High-redshift supernova rates measured with the gravitational telescope A 1689

    Science.gov (United States)

    Petrushevska, T.; Amanullah, R.; Goobar, A.; Fabbro, S.; Johansson, J.; Kjellsson, T.; Lidman, C.; Paech, K.; Richard, J.; Dahle, H.; Ferretti, R.; Kneib, J. P.; Limousin, M.; Nordin, J.; Stanishev, V.

    2016-10-01

    Aims: We present a ground-based, near-infrared search for lensed supernovae behind the massive cluster Abell 1689 at z = 0.18, which is one of the most powerful gravitational telescopes that nature provides. Methods: Our survey was based on multi-epoch J-band observations with the HAWK-I instrument on VLT, with supporting optical data from the Nordic Optical Telescope. Results: Our search resulted in the discovery of five photometrically classified, core-collapse supernovae with high redshifts of 0.671 formula>math id="mml_eq2" type="inline">10-12 SNe L⊙,B-1 yr-1math>formula->), where the error bars indicate 1σ confidence intervals, statistical and systematic, respectively. The cluster rate normalized by the stellar mass is 0.10+0.13-0.096±0.02 in SNuM h2 (SNuM ≡10-12SNe M-1⊙ yr-1). Furthermore, we explore the optimal future survey for improving the core-collapse supernova rate measurements at z ≳ 2 using gravitational telescopes, and for detections with multiply lensed images, and we find that the planned WFIRST space mission has excellent prospects. Conclusions: Massive clusters can be used as gravitational telescopes to significantly expand the survey range of supernova searches, with important implications for the study of the high-z transient Universe. Based on observations made with European Southern Observatory (ESO) telescopes at the Paranal Observatory under programme ID 082.A-0431; 0.83.A-0398, 091.A-0108 and ID 093.A-0278, PI: A. Goobar.The deep average image (FITS file) is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/594/A54

  18. Professional Microsoft search fast search, Sharepoint search, and search server

    CERN Document Server

    Bennett, Mark; Kehoe, Miles; Voskresenskaya, Natalya

    2010-01-01

    Use Microsoft's latest search-based technology-FAST search-to plan, customize, and deploy your search solutionFAST is Microsoft's latest intelligent search-based technology that boasts robustness and an ability to integrate business intelligence with Search. This in-depth guide provides you with advanced coverage on FAST search and shows you how to use it to plan, customize, and deploy your search solution, with an emphasis on SharePoint 2010 and Internet-based search solutions.With a particular appeal for anyone responsible for implementing and managing enterprise search, this book presents t

  19. The Supernovae Analysis Application (SNAP)

    Science.gov (United States)

    Bayless, Amanda J.; Fryer, Chris L.; Wollaeger, Ryan; Wiggins, Brandon; Even, Wesley; de la Rosa, Janie; Roming, Peter W. A.; Frey, Lucy; Young, Patrick A.; Thorpe, Rob; Powell, Luke; Landers, Rachel; Persson, Heather D.; Hay, Rebecca

    2017-09-01

    The SuperNovae Analysis aPplication (SNAP) is a new tool for the analysis of SN observations and validation of SN models. SNAP consists of a publicly available relational database with observational light curve, theoretical light curve, and correlation table sets with statistical comparison software, and a web interface available to the community. The theoretical models are intended to span a gridded range of parameter space. The goal is to have users upload new SN models or new SN observations and run the comparison software to determine correlations via the website. There are problems looming on the horizon that SNAP is beginning to solve. For example, large surveys will discover thousands of SNe annually. Frequently, the parameter space of a new SN event is unbounded. SNAP will be a resource to constrain parameters and determine if an event needs follow-up without spending resources to create new light curve models from scratch. Second, there is no rapidly available, systematic way to determine degeneracies between parameters, or even what physics is needed to model a realistic SN. The correlations made within the SNAP system are beginning to solve these problems.

  20. The Supernovae Analysis Application (SNAP)

    CERN Document Server

    Bayless, Amanda J; Wiggins, Brandon; Even, Wesley; Wollaeger, Ryan; de la Rosa, Janie; Roming, Peter W A; Frey, Lucy; Young, Patrick A; Thorpe, Rob; Powell, Luke; Landers, Rachel; Persson, Heather D; Hay, Rebecca

    2016-01-01

    The SuperNovae Analysis aPplication (SNAP) is a new tool for the analysis of SN observations and validation of SN models. SNAP consists of an open source relational database with (a) observational light curve, (b) theoretical light curve, and (c) correlation table sets, statistical comparison software, and a web interface available to the community. The theoretical models are intended to span a gridded range of parameter space. The goal is to have users to upload new SN models or new SN observations and run the comparison software to determine correlations via the web site. There are looming problems on the horizon that SNAP begins to solve. Namely, large surveys will discover thousands of SNe annually. Frequently, the parameter space of a new SN event is unbounded. SNAP will be a resource to constrain parameters and determine if an event needs follow-up without spending resources to create new light curve models from scratch. Secondly, there is not a rapidly available, systematic way to determine degeneracie...