Author: Chryssa Kouveliotou Publisher: Cambridge University Press ISBN: 1139576488 Category : Science Languages : en Pages : 361
Book Description
Cosmic gamma ray bursts (GRBs) have fascinated scientists and the public alike since their discovery in the late 1960s. Their story is told here by some of the scientists who participated in their discovery and, after many decades of false starts, solved the problem of their origin. Fourteen chapters by active researchers in the field present a detailed history of the discovery, a comprehensive theoretical description of GRB central engine and emission models, a discussion of GRB host galaxies and a guide to how GRBs can be used as cosmological tools. Observations are grouped into three sets from the satellites CGRO, BeppoSAX and Swift, and followed by a discussion of multi-wavelength observations. This is the first edited volume on GRB astrophysics that presents a fully comprehensive review of the subject. Utilizing the latest research, Gamma-ray Bursts is an essential desktop companion for graduate students and researchers in astrophysics.
Author: Razieh Behkam Publisher: ISBN: Category : Gamma ray bursts Languages : en Pages : 89
Book Description
Gamma-ray burst observations provide a great opportunity for cosmography in high redshift. Some tight correlations between different physical properties of GRBs are discovered and used for cosmography. However, data selection, assumptions, systematic uncertainty and some other issues affect most of them. Most importantly, until the physical origin of a relation is understood, one should be cautious to employ the relation to utilize Gamma ray bursts for cosmography. In the first part of this dissertation, I use Liang-Zhang correlation to constrain ± Cold Dark Matter standard cosmology and a particular class of brane cosmology (brane-induced gravity model). With the most probable model being _m=0.23 and _±=0.77 for flat ±CDM cosmology and _m=0.18 and _(r_c)=0.17 for flat brane-induced gravity cosmology, my result for the energy components of these two models is comparable with the result from SNIa observation. With average uncertainty of distance modulus being 0.2771, the two discussed cosmologies are indistinguishable using my current sample of GRB with redshift ranging between 0.1685 and 3.2. I argue that by expanding my sample and adding more low and high redshift GRBs and also with improvement in using GRB for cosmography, we might be able to distinguish between different cosmological models and tighten the most probable model. Looking into correlation and evolution of GRB prompt emission and afterglow has many advantages. It helps to open windows to comprehend the physics of GRBs and examine different GRB models. It is also possible to use GRB correlation as an accurate redshift estimator and more importantly to constrain the cosmological parameters. XRT flares of GRB afterglow are thought to be the result of central engine activity. Studying this component leads us to understand GRB flare and central engine nature. In the next part of this dissertation, I study the correlation and evolution of different prompt emission and afterglow GRB properties and some GRB flare-based quantities. Considering instrument bias and selection effect, I conclude some well-correlated correlations and establish some property evolution. The correlation between average luminosity and isotropic Ã-ray energy, energy of plateau and isotropic Ã-ray energy and luminosity at break time and break time and evolution of plateau energy are well established. It is also realized that the apparent evolution of isotropic Ã-ray energy and average luminosity is due to the instrumental flux threshold. With expanding the sample of GRB and accommodating more GRBs with XRT flares to my sample, I can reevaluate my result more firmly and confirm or rule out some hard to assert results due to limited number of data. In search for physically motivated GRB relation, analyzing the thermal component of GRB prompt emission, I derive two well-correlated relations. They are between calculated and estimated flux of the GRB thermal component for the co-moving bolometric and co-moving detector band-pass range of spectrum. In this study, three samples of Swift, pre-Swift and combined samples are used. The quality of this correlation is comparable with the Ghirlanda relation in terms of Spearman rank correlation parameters (correlation coefficient and correlation significance) and reduced Ö^2of best fit. These results for the Swift GRB sample for co-moving bolometric range of spectrum are 0.81, 4.07¡Á¡10¡^( -7) and 0.66 respectively. The derived correlations also imply a E_(Ã, iso)-E_peak^4 relation that provides physical insight to E_Ã-E_peak Ghirlanda correlation. Three scaling coefficients are employed to study these correlations. Monte Carlo statistics indicates that the existing correlations are independent of these constants. For Swift and combined sample 73% - 84.8% successes are recorded. Therefore, it is expected by determining these constants, the tightness of these correlations will further improve.
Author: Gilbert Vedrenne Publisher: Springer Science & Business Media ISBN: 354039088X Category : Science Languages : en Pages : 613
Book Description
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.
Author: Andrew Levan Publisher: ISBN: 9780750315005 Category : Science Languages : en Pages : 250
Book Description
As the most powerful explosion that occurs in the universe, gamma-ray bursts (GRBs) are one of the most exciting topics being studied in astrophysics. Creating more energy than the Sun does in its entire lifetime, GRBs create a blaze of light that will outshine every other object visible in the sky, enabling us to measure galaxies that are several million years old.GRBs cover various areas of astronomy and interest in them reaches a wide range of fields. Andrew Levan explores the fascinating history of these astronomical occurrences and details our current understanding of GRBs. The science behind them is rapidly moving and this book examines the knowledge that we now have as well as the questions that are continually being raised. Predominantly aimed at PhD students and researchers in the area, Gamma-Ray Bursts addresses this captivating topic and outlines the principles and initial applications of a fascinating astronomical phenomena.
Author: Joshua S. Bloom Publisher: Princeton University Press ISBN: 1400837006 Category : Science Languages : en Pages : 271
Book Description
A brief, cutting-edge introduction to the brightest cosmic phenomena known to science Gamma-ray bursts are the brightest—and, until recently, among the least understood—cosmic events in the universe. Discovered by chance during the cold war, these evanescent high-energy explosions confounded astronomers for decades. But a rapid series of startling breakthroughs beginning in 1997 revealed that the majority of gamma-ray bursts are caused by the explosions of young and massive stars in the vast star-forming cauldrons of distant galaxies. New findings also point to very different origins for some events, serving to complicate but enrich our understanding of the exotic and violent universe. What Are Gamma-Ray Bursts? is a succinct introduction to this fast-growing subject, written by an astrophysicist who is at the forefront of today's research into these incredible cosmic phenomena. Joshua Bloom gives readers a concise and accessible overview of gamma-ray bursts and the theoretical framework that physicists have developed to make sense of complex observations across the electromagnetic spectrum. He traces the history of remarkable discoveries that led to our current understanding of gamma-ray bursts, and reveals the decisive role these phenomena could play in the grand pursuits of twenty-first century astrophysics, from studying gravity waves and unveiling the growth of stars and galaxies after the big bang to surmising the ultimate fate of the universe itself. What Are Gamma-Ray Bursts? is an essential primer to this exciting frontier of scientific inquiry, and a must-read for anyone seeking to keep pace with cutting-edge developments in physics today.
Author: Diego Götz Publisher: Springer ISBN: 9789402416404 Category : Science Languages : en Pages : 0
Book Description
This topical volume reviews a comprehensive set of problems raised by the use of Gamma Ray Bursts (GRBs) as cosmological probes, as they were addressed and debated during the ISSI-Beijing workshop “Gamma Ray Bursts: A Tool to Explore the Young Universe," which took place from April 13 to 17, 2015, in Beijing. The invited authors represent both the GRB community stricto sensu and the community studying high-redshift galaxies and star formation history. The chapters of the book elucidate the connection between GRBs and the deep universe, stimulating thoughts on how to develop worldwide synergies between high-redshift GRB studies and surveys of the deep universe. Originally published in Space Science Reviews, Volume 202, Issue 1-4, December 2016
Author: Juri Poutanen Publisher: ISBN: Category : Nature Languages : en Pages : 468
Book Description
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)
Author: Maria Dainotti Publisher: Iph001 ISBN: 9780750315739 Category : Science Languages : en Pages : 200
Book Description
Impressively, gamma-ray bursts (GRBs) release the same amount of energy in a mere matter of seconds as the sun does in its lifetime. Gamma-ray Burst Correlations presents an overview of the observational correlations; their physical interpretations; their use as redshift estimators; and their potential use as cosmological tools. The author describes the existing correlations as well as breaching the possible meaning and controversy behind the results, and the applicability of several GRB correlations as model discriminators and cosmological indicators. A description of selection bias and the attempts made so far in order to use them as standard candles can help scientists to find the key to solve this puzzling problem. Covering an ever-expanding topic, this book will reach a wide audience, including students and researchers within the astronomical community.
Author: Joshua S. Bloom Publisher: Universal-Publishers ISBN: 1581121695 Category : Science Languages : en Pages : 198
Book Description
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.
Author: Chryssa Kouveliotou
Author: Razieh Behkam
Author: Gilbert Vedrenne
Author: Andrew Levan
Author: Bing Zhang
Author: Joshua S. Bloom
Author: Diego Götz
Author: Juri Poutanen
Author: Maria Dainotti
Author: Joshua S. Bloom