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The brightest events in a time series of cosmological transients obey an observation time dependence which is often overlooked. This dependence can be exploited to probe the global properties of electromagnetic and gravitational wave…

High Energy Astrophysical Phenomena · Physics 2015-05-19 E. Howell , D. Coward , R. Burman , D. Blair

We argue that recent observations of afterglows and some theoretical considerations indicate that the gamma-ray fluence may be a better measure of strength of a burst than its peak flux. We discuss how the distribution of the fluence, or…

Astrophysics · Physics 2018-11-06 Vahe' Petrosian , Nicole M. Lloyd-Ronning

We present analytic formulae for the integral number count distribution of cosmological bursting or steady sources valid over the entire range of fluxes, including density evolution and either standard candle or a power law luminosity…

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

In the new precision era for cosmic ray astrophysics, theoretical predictions cannot content themselves with average trends, but need to correctly take into account intrinsic uncertainties. The space-time discreteness of the cosmic ray…

High Energy Astrophysical Phenomena · Physics 2017-04-05 Yoann Genolini , Pierre Salati , Pasquale Serpico , Richard Taillet

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

Suppose an astronomer is equipped with a device capable of detecting emissions -- whether they be electromagnetic, gravitational, or neutrino -- from transient sources distributed throughout the cosmos. Because of source rate density…

Astrophysics · Physics 2009-11-11 D. M. Coward , R. R. Burman

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 show how the redshift and peak-flux distributions of gamma-ray bursts (GRBs) have an observation time dependence that can be used to discriminate between different burst populations. We demonstrate how observation time relations can be…

High Energy Astrophysical Phenomena · Physics 2013-02-20 E. J. Howell , D. M. Coward

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

Cosmological time dilation is a fundamental phenomenon in an expanding universe, which stresses that both the duration and wavelength of the emitted light from a distant object at the redshift $z$ will be dilated by a factor of $1+z$ at the…

High Energy Astrophysical Phenomena · Physics 2013-11-08 Fu-Wen Zhang , Yi-Zhong Fan , Lang Shao , Da-Ming Wei

The unique capabilities of Swift that make it ideal for discovery and follow-up of Gamma-Ray bursts also makes it the idea mission for discovery and monitoring of X-ray Transients in the Milky Way and the Large and Small Magellanic Clouds.…

High Energy Astrophysical Phenomena · Physics 2015-03-27 Jamie A. Kennea

We present an overview of our Supergiant Fast X-ray Transients (SFXT) project, that started in 2007, by highlighting the unique observational contribution Swift is giving to this exciting new field. By means of outburst detection with…

High Energy Astrophysical Phenomena · Physics 2011-04-01 P. Romano , S. Vercellone , V. La Parola , G. Cusumano , V. Mangano , P. Esposito , J. A. Kennea , D. N. Burrows , H. A. Krimm , C. Pagani , N. Gehrels

We introduce a method for detecting astrophysical transients evolving on timescales of milliseconds to minutes using cosmic microwave background (CMB) survey telescopes. While previous transient searches in CMB data operate in map space,…

We present maximum-likelihood search methods for time-dependent fluxes from point sources, such as flares or periodic emissions. We describe a method for the case when the time dependence of the flux can be assumed a priori from other…

Instrumentation and Methods for Astrophysics · Physics 2011-02-01 Jim Braun , Mike Baker , Jon Dumm , Chad Finley , Albrecht Karle , Teresa Montaruli

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

Many of the important conclusions about Gamma-Ray Bursts follow from the distributions of various quantities such as peak flux or duration. We show that for astrophysical transients such as bursts, multiple selection thresholds can lead to…

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

The duration of more than one thousand gamma-ray bursts (GRBs) has been measured by Swift satellite. Besides the redshift distribution of GRBs, the burst duration could be another significant property of GRBs that can be analyzed. In this…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-28 Zeinab Kalantari , Sohrab Rahvar

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

We remark on the utility of an observational relation between the absorption column density in excess of the Galactic absorption column density, $\Delta N_{\rm H} = N_{\rm H, fit} - N_{\rm H, gal}$, and redshift, z, determined from all 55…

The spatial distribution of sources of gamma-ray bursts (GRB) with known red shifts is analyzed by the conditional density and pairwise distance methods. The sample of GRB is based on data from the Swift mission and contains fluxes,…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-06 S. I. Shirokov , A. A. Raikov , Yu. V. Baryshev
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