scholarly journals A Stretched Exponential Law for the Average Time History of Gamma-Ray Bursts and Their Time Dilations

1996 ◽  
Vol 464 (2) ◽  
pp. L111-L114 ◽  
Author(s):  
Boris E. Stern
Keyword(s):  
Gamma Ray ◽  
Time History ◽  
Gamma Ray Bursts ◽  
Stretched Exponential ◽  
Exponential Law ◽  
History Of

Gamma-Ray Bursts as Probes of the Universe

2011 ◽  
Author(s):  
Joshua S. Bloom
Keyword(s):  
Star Formation ◽  
Cosmic Rays ◽  
Gravitational Waves ◽  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Ongoing Study ◽  
Observable Universe ◽  
History Of ◽  
Expansion Of The Universe ◽  
The Universe

This chapter focuses on how gamma-ray bursts (GRBs) are emerging as unique tools in the study of broad areas of astronomy and physics by virtue of their special properties. The unassailable fact about GRBs that makes them such great probes is that they are fantastically bright and so can be seen to the farthest reaches of the observable Universe. In parallel with the ongoing study of GRB events and progenitors, new lines of inquiry have burgeoned: using GRBs as unique probes of the Universe in ways that are almost completely divorced from the nature of GRBs themselves. Topics discussed include studies of gas, dust, and galaxies; the history of star formation; measuring reionization and the first objects in the universe; neutrinos, gravitational waves, and cosmic rays; quantum gravity and the expansion of the universe; and the future of GRBs.

A brief history of the discovery of cosmic gamma-ray bursts

1996 ◽  
Author(s):  
J. T. Bonnell ◽  
R. W. Klebesadel
Keyword(s):  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
History Of

Unusual Time History of Hard X-Ray and Gamma-Ray Emissions from the 1981 April 4 Flare

1986 ◽  
Vol 55 (10) ◽  
pp. 3683-3688 ◽  
Author(s):  
Masato Yoshimori ◽  
Kiyoaki Okudaira ◽  
Tomoki Yanagimachi
Keyword(s):  
Gamma Ray ◽  
Time History ◽  
X Ray ◽  
History Of

scholarly journals Gamma-Ray Burst Theory: Back to the Drawing Board

1994 ◽  
Vol 142 ◽  
pp. 863-868
Author(s):  
Alice K. Harding
Keyword(s):  
Particle Acceleration ◽  
Neutron Stars ◽  
Gamma Rays ◽  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Acceleration Of Particles ◽  
Gamma Ray Burst ◽  
History Of ◽  
Drawing Board ◽  
The Impact

AbstractGamma-ray bursts have always been intriguing sources to study in terms of particle acceleration, but not since their discovery two decades ago has the theory of these objects been in such turmoil. Prior to the launch of Compton Gamma-Ray Observatory and observations by BATSE, there was strong evidence pointing to magnetized Galactic neutron stars as the sources of gamma-ray bursts. However, since BATSE the observational picture has changed dramatically, requiring much more distant and possibly cosmological sources. I review the history of gamma-ray burst theory from the era of growing consensus for nearby neutron stars to the recent explosion of halo and cosmological models and the impact of the present confusion on the particle acceleration problem.Subject headings: acceleration of particles — gamma rays: bursts

scholarly journals Comparing the birth rate of stellar black holes in binary black hole mergers and long gamma-ray bursts

2018 ◽  
Vol 610 ◽  
pp. A58
Author(s):  
J.-L. Atteia ◽  
J.-P. Dezalay ◽  
O. Godet ◽  
A. Klotz ◽  
D. Turpin ◽  
...  
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Birth Rate ◽  
Gamma Ray ◽  
Reference Model ◽  
Stellar Mass ◽  
Gamma Ray Bursts ◽  
Birth Rates ◽  
Binary Black Hole ◽  
History Of

Context. Gravitational wave interferometers have proven the existence of a new class of binary black hole (BBH) weighing tens of solar masses, and have provided the first reliable measurement of the rate of coalescing black holes (BHs) in the local Universe. Furthermore, long gamma-ray bursts (GRBs) detected with gamma-ray satellites are believed to be associated with the birth of stellar-mass BHs, providing a measure of the rate of these events across the history of the Universe, thanks to the measure of their cosmological redshift. These two types of sources, which are subject to different detection biases and involve BHs born in different environments with potentially different characteristics, provide complementary information on the birth rate of stellar BHs. Aims. We compare the birth rates of BHs found in BBH mergers and in long GRBs. Methods. We construct a simple model that makes reasonable assumptions on the history of GRB formation, and takes into account some major uncertainties, like the beaming angle of GRBs or the delay between the formation of BBHs and their coalescence. We use this model to evaluate the ratio of the number of stellar mass BHs formed in BBH mergers to those formed in GRBs. Results. We find that in our reference model the birth rate of stellar BHs in BBH mergers represents a significant fraction of the rate of long GRBs and that comparable birth rates are favored by models with moderate beaming angles. These numbers, however, do not consider subluminous GRBs, which may represent another population of sources associated with the birth of stellar mass BHs. We briefly discuss this result in view of our understanding of the progenitors of GRBs and BBH mergers, and we emphasize that this ratio, which will be better constrained in the coming years, can be directly compared with the prediction of stellar evolution models if a single model is used to produce GRBs and BBH mergers with the same assumptions.

scholarly journals Comptel Observations of X-Ray Binaries

1996 ◽  
Vol 158 ◽  
pp. 277-278
Author(s):  
A. F. Iyudin
Keyword(s):  
Energy Range ◽  
Gamma Ray ◽  
Plasma Temperature ◽  
Time History ◽  
Spectral Model ◽  
Broad Line ◽  
X Ray ◽  
History Of ◽  
X Ray Binaries ◽  
Best Fit

The COMPTEL experiment on the Compton Gamma-Ray Observatory measures γ–radiation in the energy range from 0.75 to 30 MeV [10]. X-ray binaries form one category of potential γ-ray sources. Up to now only two X-ray binaries, Cyg X-l and Nova Per, have been seen by COMPTEL.Cyg X-l. Preliminary results were reported by [6] and indicate that (i) there was no evidence for any hardening of the spectrum near lMeV, (ii) the plasma temperature suggested by a Wien spectral model was much higher than that implied by hard X-ray observations. This latter conclusion seems to require a revision in the standard spectral model for Cyg X-l.The α–ray flux from Cyg X-l is constant up to several MeV. The time history of the flux in the 0.75… 2.0 MeV energy range shows that there are no significant variations near 1 MeV. The average photon spectrum derived from all observations up to 1994 July shows evidence for significant emission extending well above 2 MeV, with a data point in the 2…5 MeV range at 4.3 σ significance. However, the observed flux near 1 MeV is significantly below that reported by HEAO-3 and several other balloon observations [6]. The COMPTEL spectral data show a broad line-like feature around ~ 4 MeV with the best fit of a single power law plus Gaussian. If we assume that the Gaussian represents a single broadened nuclear line of 12C*, then the width of 1.38 MeV demands a temperature of ~ 2 1012 K [7].

scholarly journals Observations of GRBs at high redshift

2007 ◽  
Vol 365 (1854) ◽  
pp. 1377-1384 ◽  
Author(s):  
Nial R Tanvir ◽  
Páll Jakobsson
Keyword(s):  
Gamma Ray ◽  
High Redshift ◽  
Cosmological Parameters ◽  
Gamma Ray Bursts ◽  
Star Formation History ◽  
Redshift Distribution ◽  
Formation History ◽  
History Of ◽  
The Universe

The extreme luminosity of gamma-ray bursts and their afterglows means they are detectable, in principle, to very high redshifts. Although the redshift distribution of gamma-ray bursts (GRBs) is difficult to determine, due to incompleteness of present samples, we argue that for Swift-detected bursts, the median redshift is between 2.5 and 3, with a few per cent probably at z >6. Thus, GRBs are potentially powerful probes of the era of reionization and the sources responsible for it. Moreover, it seems probable that they can provide constraints on the star-formation history of the Universe and may also help in the determination of the cosmological parameters.

scholarly journals MEASURING COSMOLOGICAL PARAMETERS WITH GAMMA RAY BURSTS

2013 ◽  
Vol 22 (14) ◽  
pp. 1330028 ◽  
Author(s):  
LORENZO AMATI ◽  
MASSIMO DELLA VALLE
Keyword(s):  
Gamma Ray ◽  
Cosmological Parameters ◽  
Gamma Ray Bursts ◽  
Density Parameter ◽  
Data Set ◽  
Independent Evidence ◽  
Radiated Energy ◽  
Type Ia ◽  
History Of ◽  
Ia Supernovae

In a few dozen seconds, gamma ray bursts (GRBs) emit up to ~1054 erg in terms of an equivalent isotropically radiated energy E iso , so they can be observed up to z ~ 10. Thus, these phenomena appear to be very promising tools to describe the expansion rate history of the universe. Here, we review the use of the Ep,i–E iso correlation of GRBs to measure the cosmological density parameter ΩM. We show that the present data set of GRBs, coupled with the assumption that we live in a flat universe, can provide independent evidence, from other probes, that ΩM ~ 0.3. We show that current (e.g. Swift, Fermi/GBM, Konus-WIND) and forthcoming gamma ray burst (GRB) experiments (e.g. CALET/GBM, SVOM, Lomonosov/UFFO, LOFT/WFM) will allow us to constrain ΩM with an accuracy comparable to that currently exhibited by Type Ia supernovae (SNe–Ia) and to study the properties of dark energy and their evolution with time.

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