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Related papers: Two Dimensional Classification of the Swift/BAT GR…

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The extreme luminosity of gamma-ray bursts (GRBs) and their afterglows means they are detectable, in principle, to very high redshifts. Although the redshift distribution of GRBs is difficult to determine, due to incompleteness of present…

Astrophysics · Physics 2009-11-13 N. R. Tanvir , P. Jakobsson

We present a homogeneous X-ray analysis of all 318 Gamma Ray Bursts detected by the X-ray Telescope on the Swift satellite up to 2008 July 23; this represents the largest sample of X-ray GRB data published to date. In Sections 2--3 we…

We study the evolution with redshift of three measures of gamma-ray burst (GRB) duration ($T_{\rm 90}$, $T_{\rm 50}$ and $T_{\rm R45}$) in a fixed rest frame energy band for a sample of 232 Swift/BAT detected GRBs. Binning the data in…

High Energy Astrophysical Phenomena · Physics 2015-06-22 O. M. Littlejohns , N. R. Butler

We propose to use high-redshift long $\gamma$-ray bursts (GRBs) as cosmological tools to constrain the amount of primordial non-Gaussianity in the density field. By using numerical, N-body, hydrodynamic, chemistry simulations of different…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Umberto Maio , Ruben Salvaterra , Lauro Moscardini , Benedetta Ciardi

Theory suggests that about 10% of Swift-detected gamma-ray bursts (GRBs) will originate at redshifts greater than 5 yet a number of high redshift candidates may be left unconfirmed due to the lack of measured redshifts. Here we introduce…

A sample of almost 400 Gamma-ray bursts (GRBs) detected by the RHESSI satellite is studied statistically. We focus on GRB duration and hardness ratio and use the statistical chi^2 test and the F-test to compare the number of GRB subgroups…

High Energy Astrophysical Phenomena · Physics 2015-05-14 J. Ripa , D. Huja , R. Hudec , W. Hajdas , C. Wigger

Presently only 30% of short gamma ray bursts (SGRBs) have accurate redshifts, and this sample is highly biased by the limited sensitivity of {\it Swift} to detect SGRBs. We account for the dominant biases to calculate a realistic SGRB rate…

High Energy Astrophysical Phenomena · Physics 2012-06-25 David Coward , Eric Howell , Tsvi Piran , Giulia Stratta , Marica Branchesi , Omer Bromberg , Bruce Gendre , Ronald Burman , Dafne Guetta

We calculate durations and spectral paramaters for 218 Swift bursts detected by the BAT instrument between and including GRBs 041220 and 070509, including 77 events with measured redshifts. Incorporating prior knowledge into the spectral…

Astrophysics · Physics 2009-11-13 Nathaniel R. Butler , Daniel Kocevski , Joshua S. Bloom , Jason L. Curtis

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…

Generalized Chinese Remainder Theorem (CRT) has been shown to be a powerful approach to solve the ambiguity resolution problem. However, with its close relationship to number theory, study in this area is mainly from a coding theory…

Machine Learning · Statistics 2018-11-29 Nan Du , Zhikang Wang , Hanshen Xiao

Preliminary results of our analysis on the extended emission of short/medium duration GRBs observed with Swift/BAT are presented. The Bayesian blocks algorithm is used to analyze the burst durations and the temporal structure of the…

Astrophysics · Physics 2009-11-13 Lin Lin , En-Wei Liang , Bin-Bin Zhang , Shuang Nan Zhang

In this work we present spectra of all $\gamma$-ray burst (GRB) afterglows that have been promptly observed with the X-shooter spectrograph until 31-03-2017. In total, we obtained spectroscopic observations of 103 individual GRBs observed…

The gamma-ray burst (GRB) rate is essential for revealing the connection between GRBs, supernovae and stellar evolution. Additionally, the GRB rate at high redshift provides a strong probe of star formation history in the early universe.…

High Energy Astrophysical Phenomena · Physics 2016-03-25 Amy Lien , Takanori Sakamoto , Neil Gehrels , David M. Palmer , Scott D. Barthelmy , Carlo Graziani , John K. Cannizzo

(Abridged). We present a sample of 77 optical afterglows (OAs) of Swift detected GRBs for which spectroscopic follow-up observations have been secured. We provide linelists and equivalent widths for all detected lines redward of Ly-alpha.…

We use the possible Cepheid-like luminosity estimator for the long-duration gamma-ray bursts (GRBs) developed by Reichart et al. (2000) to estimate the intrinsic luminosity, and thus the redshift, of 907 long-duration GRBs from the BATSE 4B…

Astrophysics · Physics 2009-11-07 Timothy Donaghy , Donald Q. Lamb , Daniel E. Reichart , Carlo Graziani

We present a catalog of the redshift estimates and probability distributions for 1366 individual Long-duration Gamma-Ray Bursts (LGRBs) detected by the Burst And Transient Source Experiment (BATSE). This result is based on a careful…

High Energy Astrophysical Phenomena · Physics 2019-03-19 Amir Shahmoradi , Robert J. Nemiroff

Ten years of operations of the Swift satellite have allow us to collect a small sample of long Gamma-Ray Bursts (GRBs) at redshift larger than six. I will review here the present status of this research field and discuss the possible use of…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-12 R. Salvaterra

Although linear regression models are fundamental tools in statistical science, the estimation results can be sensitive to outliers. While several robust methods have been proposed in frequentist frameworks, statistical inference is not…

Methodology · Statistics 2020-07-15 Shintaro Hashimoto , Shonosuke Sugasawa

The long gamma-ray burst (GRB) rate is essential for revealing the connection between GRBs, supernovae and stellar evolution. Additionally, the GRB rate at high redshift provides a strong probe of star formation history in the early…

Cosmology and Nongalactic Astrophysics · Physics 2013-08-20 Amy Lien , Takanori Sakamoto , Neil Gehrels , David M. Palmer , Scott D. Barthelmy , Carlo Graziani , John K. Cannizzo

Computer vision models excel at making predictions when the test distribution closely resembles the training distribution. Such models have yet to match the ability of biological vision to learn from multiple sources and generalize to new…

Computer Vision and Pattern Recognition · Computer Science 2022-05-04 Tanmay Gupta , Ryan Marten , Aniruddha Kembhavi , Derek Hoiem