Download or read book Spectral Properties of Gamma ray Bursts Observed by the Burst and Transient Source Experiment written by Lyle A. Ford and published by . This book was released on 1996 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Study of the Temporal and Spectral Characteristics of Gamma Ray Bursts written by Jay Preston Norris and published by . This book was released on 1983 with total page 570 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book X ray Spectral Properties of gamma ray Bursts written by and published by . This book was released on 1997 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors summarize the spectral characteristics of a sample of 22 bright gamma-ray bursts detected with the gamma-ray burst sensors aboard the satellite Ginga. This instrument employed a proportional and scintillation counter to provide sensitivity to photons in the 2--400 keV range, providing a unique opportunity to characterize the largely unexplored X-ray properties of gamma-ray bursts. The photon spectra of the Ginga bursts are well described by a low energy slope, a bend energy, and a high energy slope. In the energy range where they can be compared, this result is consistent with burst spectral analyses obtained from the BATSE experiment aboard the Compton Observatory. However, below 20 keV they find evidence for a positive spectral number index in approximately 40% of their burst sample, with some evidence for a strong rolloff at lower energies in a few events. They find that the distribution of spectral bend energies extends below 10 keV. The observed ratio of energy emitted in the X-rays relative to the gamma-rays can be much larger than a few percent and, in fact, is sometimes larger than unity. The average for their sample is 24%.
Download or read book Gamma ray Bursts written by Cheng Ho and published by Cambridge University Press. This book was released on 1992-03-12 with total page 532 pages. Available in PDF, EPUB and Kindle. Book excerpt: Summarizes the current understanding of Astronomical gamma-ray bursts, short-lived flashes of high-energy radiation, which have eluded even a basic explanation for over twenty years, and describes directions for future research.
Download or read book Gamma Ray Bursts written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-03 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gamma ray bursts display a wide range of temporal and spectral characteristics, but typically last several seconds and emit most of their energy in a low energy, gamma ray region. The burst sources appear to be isotropically distributed on the sky. Several lines of evidence suggest magnetic neutron stars as sources for bursts. A variety of energy sources and emission mechanisms are proposed. Meegan, Charles A. Marshall Space Flight Center ...
Download or read book Statistical Analysis of the Observable Data of Gamma Ray Bursts written by Jakub Ripa and published by LAP Lambert Academic Publishing. This book was released on 2011-07 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gamma-ray bursts are still not fully understood events. However, their exploration could provide a useful tool for a better understanding of the early Universe because they belong to the most distant and violent objects that astronomers know. This book tries to bring more information about a so-called group of intermediate-duration bursts claimed by different authors employing different data samples. Firstly, duration and spectral hardness properties of bursts from the Reuven Ramaty High-Energy Solar Spectroscopic Imager are statistically analysed. The obtained results bring a suspicion that these intermediate bursts gather into a separate group. Secondly, these bursts are investigated in more detail with respect to their spectral lags, peak count rates, redshifts, supernova observations, and so forth. Thirdly, long-duration bursts with known redshifts and with derived pseudo-redshifts detected by The Burst and Transient Source Experiment, Swift and Fermi bursts with known redshifts, are used to study the cosmological effects on the observed flux and fluence distributions.
Download or read book Gamma Ray Bursts written by Gilbert Vedrenne and published by Springer Science & Business Media. This book was released on 2009-03-20 with total page 613 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since their discovery was first announced in 1973, gamma-ray bursts (GRBs) have been among the most fascination objects in the universe. While the initial mystery has gone, the fascination continues, sustained by the close connection linking GRBs with some of the most fundamental topics in modern astrophysics and cosmology. Both authors have been active in GRB observations for over two decades and have produced an outstanding account on both the history and the perspectives of GRB research.
Download or read book A Study of the Temporal and Spectral Characteristics of Gamma Ray Bursts written by Jay Preston Norris and published by . This book was released on 1983 with total page 514 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Toward an Understanding of the Progenitors of Gamma Ray Bursts written by Joshua S. Bloom and published by Universal-Publishers. This book was released on 2002 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: The various possibilities for the origin ("progenitors") of gamma-ray bursts (GRBs) manifest in differing observable properties. Through deep spectroscopic and high-resolution imaging observations of some GRB hosts, I demonstrate that well-localized long-duration GRBs are connected with otherwise normal star-forming galaxies at moderate redshifts of order unity. Using high-mass binary stellar population synthesis models, I quantify the expected spatial extent around galaxies of coalescing neutron stars, one of the leading contenders for GRB progenitors. I then test this scenario by examining the offset distribution of GRBs about their apparent hosts making extensive use of ground-based optical data from Keck and Palomar and space-based imaging from the Hubble Space Telescope. The offset distribution appears to be inconsistent with the coalescing neutron star binary hypothesis (and, similarly, black-hole--neutron star coalescences); instead, the distribution is statistically consistent with a population of progenitors that closely traces the ultra-violet light of galaxies. This is naturally explained by bursts which originate from the collapse of massive stars ``collapsars''). This claim is further supported by the unambiguous detections of intermediate-time (approximately three weeks after the bursts) emission ``bumps'' which appear substantially more red than the afterglows themselves. I claim that these bumps could originate from supernovae that occur at approximately the same time as the associated GRB; if true, GRB 980326 and GRB 011121 provide strong observational evidence connecting cosmological GRBs to high-redshift supernovae and implicate massive stars as the progenitors of at least some long-duration GRBs.
Download or read book An Analysis of Gamma Ray Burst Time Profiles from the Burst and Transient Source Experiment written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-08-16 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: This proposal requested funding to measure the durations of gamma-ray bursts (GRB) in the 4B catalog as well as to study the structure of GRB time profiles returned by the Burst And Transient Source Experiment (BATSE) on board the Compton Gamma-Ray Observatory. The duration (T90) was to be measured using the same techniques and algorithms developed by the principal investigator for the 3B data. The profile structure studies fall into the two categories of variability and fractal analyses. Lestrade, John Patrick Marshall Space Flight Center NASA/CR-97-205827, NAS 1.26:205827 NCC8-82...
Download or read book On the Spectral Properties and High Energy Emission from Gamma Ray Bursts written by Paz Beniamini and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Gamma ray Bursts written by Juri Poutanen and published by . This book was released on 1999 with total page 468 pages. Available in PDF, EPUB and Kindle. Book excerpt: Annotation Papers from a February 1999 workshop discuss unresolved issues regarding prompt emission of gamma-ray bursts (GRBs). Themes are temporal properties, spectral properties, central engine and radiative mechanisms, spatial distribution, luminosity function, cosmological effects, and future missions. Specific topics include radiation from relativistic strongly magnetized outflows, quasi-thermal comptonization and GRBs, and cosmological signatures in temporal and spectral characteristics of GRBs. The volume lacks a subject index. The editors are affiliated with the Stockholm Observatory. Annotation c. Book News, Inc., Portland, OR (booknews.com)
Download or read book Catalog of Cosmic Gamma Ray Bursts from the KONUS Experiment Data written by E.P. Mazets and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt: continues to be extremely rewarding. Experiments on future missions, such as the two 1981 Veneras, Gamma Ray Observatory, and the International Solar Polar Mission, will undoubtedly provide new and unexpected discoveries, but the work of the Leningrad group is likely to remain an important contribution to the field for some time to come. c.E.S.R. KEVIN HURLEY Toulouse, France June 9, 1981 CATALOG OF COSMIC GAMMA-RAY BURSTS FROM THE KONUS EXPERIMENT DATA Parts I and II E. P. MAZETS, S. V. GOLENETSKII, V. N. IL'INSKII, V. N. PANOV, R. L. APTEKAR, YU. A. GUR'YAN, M. P. PROSKURA, 1. A. SOKOLOV, Z. Y A. SOKOLOV A, and T. V. KHARITONOV A A. F. Ioffe Physical-Technical Institute, U.S.S.R. Academy of Sciences, Leningrad, U.S.S.R. and A. V. DYATCHKOV and N. G. KHAVENSON Institute of Cosmic Research, U.S.S.R. Academy of Sciences, Moscow, U.S.S.R. (Received 2 July, 1980) Abstract. Data are presented on the temporal structure, fluxes, energy spectra and coordinates of the sources of gamma-ray bursts detected in the KONUS experiment on Venera 1 I and Venera 12 space probes in the period September 1978 to May 1979. The statistical distributions of gamma bursts in duration, intensity, and peak power, as well as the distribution of the burst sources over the celestial sphere presented are based on the updated KONUS information obtained until February 1980.
Download or read book On The Origin Of High Energy Correlations in Gamma ray Bursts written by and published by . This book was released on 2012 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: I investigate the origin of the observed correlation between a gamma-ray burst's?F{sub {nu}} spectral peak E{sub pk} and its isotropic equivalent energy E{sub iso} through the use of a population synthesis code to model the prompt gamma-ray emission from GRBs. By using prescriptions for the distribution of prompt spectral parameters as well as the population's luminosity function and co-moving rate density, I generate a simulated population of GRBs and examine how bursts of varying spectral properties and redshift would appear to a gamma-ray detector here on Earth. I find that a strong observed correlation can be produced between the source frame Epk and Eiso for the detected population despite the existence of only a weak and broad correlation in the original simulated population. The energy dependance of a gamma-ray detector's flux-limited detection threshold acts to produce a correlation between the source frame E{sub pk} and E{sub iso} for low luminosity GRBs, producing the left boundary of the observed correlation. Conversely, very luminous GRBs are found at higher redshifts than their low luminosity counterparts due to the standard Malquest bias, causing bursts in the low E{sub pk}, high E{sub iso} regime to go undetected because their E{sub pk} values would be redshifted to energies at which most gamma-ray detectors become less sensitive. I argue that it is this previously unexamined effect which produces the right boundary of the observed correlation. Therefore, the origin of the observed correlation is a complex combination of the instrument's detection threshold, the intrinsic cutoff in the GRB luminosity function, and the broad range of redshifts over which GRBs are detected. Although the GRB model presented here is a very simplified representation of the complex nature of GRBs, these simulations serve to demonstrate how selection effects caused by a combination of instrumental sensitivity and the cosmological nature of an astrophysical population can act to produce an artificially strong correlation between observed properties.
Download or read book Science With The Cherenkov Telescope Array written by The Cta Consortium and published by World Scientific. This book was released on 2018-12-31 with total page 365 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book summarizes the science to be carried out by the upcoming Cherenkov Telescope Array, a major ground-based gamma-ray observatory that will be constructed over the next six to eight years. The major scientific themes, as well as core program of key science projects, have been developed by the CTA Consortium, a collaboration of scientists from many institutions worldwide.CTA will be the major facility in high-energy and very high-energy photon astronomy over the next decade and beyond. CTA will have capabilities well beyond past and present observatories. Thus, CTA's science program is expected to be rich and broad and will complement other major multiwavelength and multimessenger facilities. This book is intended to be the primary resource for the science case for CTA and it thus will be of great interest to the broader physics and astronomy communities. The electronic version (e-book) is available in open access.
Download or read book Gamma ray Bursts written by Gerald J. Fishman and published by American Institute of Physics. This book was released on 2000-04-14 with total page 776 pages. Available in PDF, EPUB and Kindle. Book excerpt: Annotation Proceedings of the Second Huntsville Gamma-Ray Burst Workshop, held in Huntsville, Alabama, October 1993. Papers are grouped in thematic sections, some with subsections: general observations and global studies (general burst observations/intensity distributions and isotropy measures/studies of and searches for burst repetition and clustering); temporal studies; spectral studies; burst localizations and searches for counterparts (burst localization/counterpartsgeneral/optical counterparts/x-ray counterparts/very high energy counterpart searches/soft gamma-ray repeaters--counterparts); burst origins and emission processes--theory (cosmological models/galactic models/soft gamma-ray repeaters--theory); instrumentation and new analysis techniques; and miscellaneous. No index. Annotation c. by Book News, Inc., Portland, Or.
Download or read book Continuum Spectra for Gamma ray Bursts written by and published by . This book was released on 1989 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Gamma-ray bursts are observed to have very steep spectra below photon energy /approximately/100 keV; some have photon number spectra as steep as F /proportional to/ E/sup 0/. This property has been difficult to explain in terms of most radiation processes. The BATSE experiment on the Gamma Ray Observatory should be able to test how common this spectral property is and whether there are bursts with even steeper low-energy spectra. To explain this spectral steepness, we study a model in which the /gamma/ radiation is produced by inverse-Compton and cyclotron scattering of blackbody radiation from the surface of a neutron star by relativistic electrons. If the neutron star has negligible magnetic field, Compton scattering dominates in producing the observed gamma-ray burst spectra. If the field exceeds 10/sup 10/ G, cyclotron scattering is more important. In the low-magnetic-field case, steep spectra may be produced via the suppression of the low energy part of the ''cooling spectrum'' (the spectrum integrated over the radiation lifetime of an electron), as a result of the smaller and more collimated photon flux an electron sees as it moves away from the neutron star. In the high-magnetic-field case, low-energy suppression occurs because electrons with higher energies scatter the blackbody photons more efficiently due to the cyclotron resonance, preferentially producing high energy photons. 27 refs., 5 figs.
