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Related papers: Likelihood Analysis of GRB Evolution with Redshift

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The majority of Swift gamma-ray bursts (GRBs) observed at z > 6 have prompt durations of T90 < 30s, which, at first sight, is surprising given that cosmological time-dilation means this corresponds to < 5s in their rest frames. We have…

High Energy Astrophysical Phenomena · Physics 2015-06-17 O. M. Littlejohns , N. R. Tanvir , R. Willingale , P. A. Evans , P. T. O'Brien , A. J. Levan

We present the first Swift Burst Alert Telescope (BAT) catalog of gamma-ray bursts (GRBs), which contains bursts detected by the BAT between 2004 December 19 and 2007 June 16. This catalog (hereafter BAT1 catalog) contains burst trigger…

The ranking of experiments by expected information gain (EIG) in Bayesian experimental design is sensitive to changes in the model's prior distribution, and the approximation of EIG yielded by sampling will have errors similar to the use of…

Machine Learning · Statistics 2022-05-23 Jinwoo Go , Tobin Isaac

We propose an improved version of the redshift indicator developed by Atteia (2003), which gets rid of the dependence on the burst duration and provides better estimates for high-redshift GRBs. We present the derivation and the definition…

Aims. We analyze and characterize the angular distribution of selected samples of gamma ray bursts (GRBs) from Batse and Swift data to confirm that the division in two classes of short- and long-duration GRBs correspond also to the…

Cosmology and Nongalactic Astrophysics · Physics 2010-01-15 Fabrizio Tamburini

We present zephyr, a novel method that integrates cutting-edge normalizing flow techniques into a mixture density estimation framework, enabling the effective use of heterogeneous training data for photometric redshift inference. Compared…

Instrumentation and Methods for Astrophysics · Physics 2023-11-01 Zechang Sun , Joshua S. Speagle , Song Huang , Yuan-Sen Ting , Zheng Cai

The very high energy (VHE) gamma-ray spectral indices of blazars show strong correlation with the source redshift. Absence of any such correlation in low energy gamma rays and X-rays indicate the presence of Extragalactic Background Light…

High Energy Astrophysical Phenomena · Physics 2022-02-23 Malik Zahoor , Sunder Sahayanathan , Shah Zahir , Naseer Iqbal , Aaqib Manzoor , Nilay Bhatt

Correlations among pulse properties in the prompt emission of long GRBs can potentially be used as cosmological distance indicators to estimate redshifts of GRBs to which these pulses belong. We demonstrate application of this technique to…

High Energy Astrophysical Phenomena · Physics 2009-06-25 Jon Hakkila , P. Chris Fragile , Timothy W. Giblin

Accurate knowledge of gamma-ray burst (GRB) redshifts is essential for studying their intrinsic properties and exploring their potential application in cosmology. Currently, only a small fraction of GRBs have independent redshift…

High Energy Astrophysical Phenomena · Physics 2025-02-20 Emre S. Yorgancioglu , Yun-Fei Du , Shu-Xu Yi , Rahim Moradi , Hua Feng , Shuang-Nan Zhang

We constrain the deceleration-acceleration epoch, namely the transition redshift $z_{tr}$, adopting model-independent techniques that utilize a calibrated $E_{\rm p}$-$E_{\rm iso}$ correlation for gamma-ray bursts (GRBs). To do so, in…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-30 Marco Muccino , Orlando Luongo , Deepak Jain

Several correlations among Gamma Ray Burst (GRB) observables with available redshifts have been recently identified. Proper evaluation and calibration of these correlations may facilitate the use of GRBs as standard candles constraining the…

Astrophysics · Physics 2010-03-19 S. Basilakos , L. Perivolaropoulos

Stochastic dynamical systems arise as models for fluid particle motion in geophysical flows with random velocity fields. Escape probability (from a fluid domain) and mean residence time (in a fluid domain) quantify fluid transport between…

Dynamical Systems · Mathematics 2025-10-20 Jinqiao Duan , James R. Brannan , Vincent J. Ervin

Recent optical afterglow observations of gamma-ray bursts indicate a setting and distance scale that many relate to star-formation regions. In this paper, we use $<V/V_{max}>$ and a set of artificial trigger thresholds to probe several…

Astrophysics · Physics 2009-10-31 H. Che , Y. Yang , R. J. Nemiroff

We characterize the error distribution of BATSE GRB locations by modeling the distribution of separations between BATSE locations and IPN annuli. We determine error model parameters by maximizing likelihood and rank the models by their…

Gravitational wave data are often contaminated by non-Gaussian noise transients, glitches, which can bias the inference of astrophysical signal parameters. Traditional approaches either subtract glitches in a pre-processing step, or a…

General Relativity and Quantum Cosmology · Physics 2025-08-01 Ann-Kristin Malz , John Veitch

The idea that GRBs originate from uniform jets has been used to explain numerous observations of breaks in the GRB afterglow lightcurves. We explore the possibility that GRBs instead originate from a structured jet that may be…

Astrophysics · Physics 2009-11-10 Nicole Lloyd-Ronning , Xinyu Dai , Bing Zhang

We present the redshift results from a Very Large Telescope program aimed at optimizing the legacy value of the Swift mission: to characterize a homogeneous, X-ray selected, sample of 69 GRB host galaxies. 19 new redshifts have been…

Cosmology and Nongalactic Astrophysics · Physics 2013-09-20 P. Jakobsson , R. Chapman , J. Hjorth , D. Malesani , J. P. U. Fynbo , B. Milvang-Jensen , T. Kruhler , N. R. Tanvir

We perform a detailed analysis on broad pulses in bright Gamma-ray bursts (GRBs) to understand the evolution of GRB broad pulses. Using the temporal and spectral properties, we test the high latitude emission (HLE) scenario in the decaying…

High Energy Astrophysical Phenomena · Physics 2023-06-14 Donggeun Tak , Z. Lucas Uhm , Judith Racusin , Bing Zhang , Sylvain Guiriec , Daniel Kocevski , Bin-Bin Zhang , Julie McEnery

Gamma-ray bursts (GRBs) are among the most energetic explosive phenomena in the Universe, and their peak energy ($E_{\rm p}$) is a key physical quantity for understanding the prompt emission mechanism. However, due to the limited energy…

High Energy Astrophysical Phenomena · Physics 2026-04-08 Wan-Peng Sun , Si-Yuan Zhu , Da-Ling Ma , Fu-Wen Zhang

A general formalism is developed for calculating the luminosity function and the expected number $N$ of observed GRBs above a peak photon flux $S$ for any GRB jet structure. This new formalism directly provides the true GRB rate without the…

Astrophysics · Physics 2009-11-10 Dafne Guetta , Jonathan Granot , Mitchell C. Begelman
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