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Related papers: Are gamma-ray bursts cosmological?

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We discuss detailed fits of the BATSE and PVO gamma-ray burst peak-flux distributions with Friedman models taking into account possible density evolution and standard candle or power law luminosity functions. A chi-square analysis is used…

Astrophysics · Physics 2009-10-28 I. Horvath , P. Meszaros , A. Meszaros

The cosmological expansion cannot produce the reported correlations of the gamma-ray burst timescale and spectral energy with peak flux if the burst model reproduces the BATSE 3B peak-flux distribution for a non-evolving burst source…

Astrophysics · Physics 2009-10-30 J. J. Brainerd

We present analytical solutions for the integral distribution of arbitrary bursting or steady source counts as a function of peak photon count rate within Friedmann cosmological models. We discuss both the standard candle and truncated…

Astrophysics · Physics 2009-10-28 P. Meszaros , A. Meszaros

The positions of over 1000 gamma-ray bursts detected with the BATSE experiment on board of the Compton Gamma Ray Observatory are uniformly and randomly distributed in the sky, with no significant concentration to the galactic plane or to…

Astrophysics · Physics 2016-08-30 Bohdan Paczynski

We use Bayesian methods to analyze the distribution of gamma ray burst intensities reported in the Third BATSE Catalog (3B catalog) of gamma ray bursts, presuming the distribution of burst sources (``bursters'') is isotropic. We study both…

Astrophysics · Physics 2009-10-30 Thomas J. Loredo , Ira M. Wasserman

The cosmological origin of cosmic gamma-ray bursts is tested using the method of peak alignment for the averaging of time profiles. The test is applied to the basic cosmological model with standard sources, which postulates that difference…

Astrophysics · Physics 2009-10-30 I. G. Mitrofanov , M. L. Litvak , D. A. Ushakov

If gamma-ray bursts have a cosmological origin, the sources are expected to trace the large-scale structure of luminous matter in the universe. I use a new likelihood method that compares the counts-in-cells distribution of gamma-ray bursts…

Astrophysics · Physics 2007-05-23 Jean M. Quashnock

We compare the burst distribution of the new (2B) BATSE catalogue to a cosmological distribution. We find that the distribution is insensitive to cosmological parameters such as Omega and Lambda and to the width of the bursts luminosity…

Astrophysics · Physics 2009-09-25 Ehud Cohen , Tsafrir Kolatt , Tsvi Piran

The observation by the BATSE instrument on the Compton Gamma Ray Observatory that gamma-ray bursts (GRBs) are distributed isotropically around the Earth but nonuniformly in distance has led to the widespread conclusion that GRBs are most…

Astrophysics · Physics 2016-08-30 S. E. Thorsett

We use a new method of analysis to determine parameters of cosmological gamma-ray bursts (GRBs), assuming that their distribution follows the star-formation history of the universe. Spectral evolution is calculated from an external shock…

Astrophysics · Physics 2015-06-24 M. Boettcher , C. D. Dermer

We compare the burst distribution of the new (2B) BATSE catalogue to a cosmological distribution. The observed distribution agrees well with a cosmological one, however, it is insensitive to cosmological parameters such as $\O$ and…

Astrophysics · Physics 2009-10-28 Ehud Cohen , Tsvi Piran

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…

Astrophysics · Physics 2008-11-26 Mordehai Milgrom , Vladimir Usov

The unrivalled, extreme luminosities of gamma-ray bursts (GRBs) make them the favored beacons for sampling the high redshift Universe. To employ GRBs to study the cosmic terrain -- e.g., star and galaxy formation history -- GRB luminosities…

Astrophysics · Physics 2007-05-23 J. P. Norris

If gamma-ray bursters are at cosmological distances - as suggested by their isotropic distribution on the sky and by their number-intensity relation - then the burst profiles will be stretched in time, by an amount proportional to the…

We use Bayesian methods to study anisotropic models for the distribution of gamma ray burst intensities and directions reported in the Third BATSE Catalog (3B catalog) of gamma ray bursts. We analyze data obtained using both the 64 ms and…

Astrophysics · Physics 2009-10-30 Thomas J. Loredo , Ira M. Wasserman

The observed spatial distribution of $\gamma-$ray bursts indicates that they probably originate at cosmological distances. At this distance scale their variability timescale and flux above MeV imply an initial optical-depth to pair…

Astrophysics · Physics 2010-01-06 Abraham Loeb

In the use and interpretation of $\log{N}$--$\log{S}$ distributions for gamma-ray bursts, burst peak flux has typically been used for $S$. We consider here the use of the fluence as a measure of $S$, which may be a more appropriate quantity…

Astrophysics · Physics 2009-10-28 Vahe Petrosian , Theodore T. Lee

It is known that some observed gamma-ray bursts (GRBs) are produced at cosmological distances and that the GRB production rate may follow the star formation rate. We model the BATSE-detected intensity distribution of long GRBs in order to…

Astrophysics · Physics 2007-05-23 J. R. Lin , S. N. Zhang , T. P. Li

Apparently, Gamma-Ray Bursts (GRBs) are all but standard candles. Their emission is collimated into a cone and the received flux depends on the cone aperture angle. Fortunately we can derive the aperture angle through an achromatic…

Astrophysics · Physics 2010-11-11 G. Ghisellini , G. Ghirlanda , C. Firmani , D. Lazzati , V. Avila-Reese , .

In recent years there has been considerable activity in using gamma-ray bursts as cosmological probes for determining global cosmological parameters complementing results from type Ia supernovae and other methods. This requires a…

High Energy Astrophysical Phenomena · Physics 2009-09-29 Vahe Petrosian , Aurelien Bouvier , Felix Ryde
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