Related papers: Gamma-Ray Burst Lines
Gamma-ray bursts are known to be sources of high-energy gamma rays, and are likely to be sources of high-energy cosmic rays and neutrinos. Following a short review of observations of GRBs at multi-MeV energies and above, the physics of…
One of the principal results obtained by the Compton Gamma Ray Observatory relating to the study of gamma-ray bursts was the detection by the EGRET instrument of energetic ($>$100 MeV) photons from a handful of bright bursts. The most…
Recently, tentative evidence for an excess of gamma rays at energies around 130 GeV has been reported from analyses of data from the Fermi Large Area Telescope (LAT). The excess is potentially of great interest, as it could be associated…
A review on the spectral and temporal properties of gamma-ray bursts is given. Special attention is paid to the spectral evolution of their continuum emission and its connection to the time evolution of the intensity. Efforts on…
We evaluate the significance of the line candidates identified by a visual search of burst spectra from BATSE's Spectroscopy Detectors. None of the candidates satisfy our detection criteria: an F-test probability less than 10^-4 for a…
All gamma-ray bursts are observed to have approximately the same characteristic gamma-ray energy. We show in this article that for bursts in the BATSE data set, this property as measured by the E-peak value is not an instrumental effect,…
We present the spectral analysis of duration-integrated broadband spectra (in $\sim30 $keV$-200 $MeV) of 15 bright BATSE gamma-ray bursts (GRBs). Some GRB spectra are very hard, with their spectral peak energies being above the BATSE LAD…
A computer-based technique has been developed to search bright BATSE gamma-ray bursts for spectral lines in a comprehensive manner. The first results of the search are discussed and an example line candidate shown.
Recently, the detection of discrete features in the X-ray afterglow spectra of GRB970508 and GRB970828 was reported. The most natural interpretation of these features is that they are redshifted Fe K emission complexes. The identification…
We have developed an automatic search procedure to identify low-energy spectral features in GRBs. We have searched 133,000 spectra from 117 bright bursts and have identified 12 candidate features with significances ranging from our…
The low energy spectra of some gamma-ray bursts' show excess components beside the power-law dependence. The consequences of such a feature allows to estimate the gamma photometric redshift of the long gamma-ray bursts in the BATSE Catalog.…
Since their discovery in 1973, Gamma-Ray Bursts (GRBs) have remained for many years one of the most elusive mysteries in High Energy-Astrophysics. The main problem regarding the nature of GRBs has usually been the lack of knowledge of their…
We present a systematic spectral analysis of 350 bright Gamma-Ray Bursts (GRBs) observed with the Burst and Transient Source Experiment (BATSE; $\sim$ 30 keV -- 2 MeV) with high temporal and spectral resolution. Our sample was selected from…
The proportional counter and scintillator on Ginga provided unprecented spectral coverage of GRBs, from 2 - 400 keV. Below 20 keV we find evidence for a positive spectral number index in approximately 40% of our burst sample, with some…
We study the prospects for studying line features in gamma-ray spectra with upcoming gamma-ray experiments, such as HESS-II, the Cherenkov Telescope Array (CTA), and the GAMMA-400 satellite. As an example we use the narrow feature at 130…
The little we do know of the physical conditions in gamma-ray bursters makes them conducive to the acceleration of high-energy cosmic rays, especially if they are at cosmological distances. We find that, with the observed statistics and…
We calculate the spectrum of blast wave models of gamma-ray burst sources, for various assumptions about the magnetic field density and the relativistic particle acceleration efficiency. For a range of physically plausible models we find…
The modelling of gamma-ray burst (GRB) spectra has considerable potential for increasing the understanding of these enigmatic sources. A diversity of ideas and analyses has been generated over the last two decades to explain line features…
We give an upper estimate for the number of gamma ray bursts from ordinary (non-superconducting) cosmic strings expected to be observed at terrestrial detectors. Assuming that cusp annihilation is the mechanism responsible for the bursts we…
Gamma-ray bursts (GRBs) are short and intense emission of soft gamma-rays, which have fascinated astronomers and astrophysicists since their unexpected discovery in 1960s. The X-ray/optical/radio afterglow observations confirm the…