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Related papers: Anomalies in the GRB spatial distribution

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We compute the probability to detect long Gamma Ray Bursts (GRBs) at z>5 with Swift, assuming that GRBs form preferentially in low-metallicity environments. The model fits well both the observed BATSE and Swift GRB differential peak flux…

Astrophysics · Physics 2009-11-13 R. Salvaterra , S. Campana , G. Chincarini , G. Tagliaferri , S. Covino

Short gamma-ray bursts (SGRBs) observed by {\it Swift} are potentially revealing the first insight into cataclysmic compact object mergers. To ultimately acquire a fundamental understanding of these events requires pan-spectral observations…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 David Coward , Eric Howell , Tsvi Piran , Giulia Stratta , Marica Branchesi , Omer Bromberg , Bruce Gendre , Ronald Burman , Dafne Guetta

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 investigate the angular distribution of gamma-ray bursts using the largest catalog of well-localized events that is currently available---combined BATSE/Ulysses burst locations. We present the preliminary spatial analysis of 415…

Astrophysics · Physics 2007-05-23 R. M. Kippen , K. Hurley , G. N. Pendleton

In an effort to understand the puzzle of classifying gamma-ray bursts (GRBs), we perform a systematic study of {\it Swift} GRBs and investigate several short GRB issues. Though short GRBs have a short ($\lesssim2$ s) prompt duration as…

High Energy Astrophysical Phenomena · Physics 2011-08-24 Lang Shao , Zi-Gao Dai , Yi-Zhong Fan , Fu-Wen Zhang , Zhi-Ping Jin , Da-Ming Wei

Gamma-ray bursts (GRBs) are intense, short-lived bursts of gamma-ray radiation observed up to a high redshift ($z \sim 10$) due to their luminosities. Thus, they can serve as cosmological tools to probe the early Universe. However, we need…

If Gamma-Ray-Bursts (GRBs) occur at high redshifts, then their bright afterglow emission can be used to probe the ionization and metal enrichment histories of the intervening intergalactic medium during the epoch of reionization. In…

Astrophysics · Physics 2009-10-31 Benedetta Ciardi , Abraham Loeb

Gamma-ray bursts (GRBs) are cosmologically distributed, very energetic and very transient sources detected in the gamma-ray domain. The identification of their x-ray and optical afterglows allowed so far the redshift measurement of 150…

Astrophysics · Physics 2009-11-13 Sandra Savaglio

In Budai et al. (2020) we argued that angular non-stationarities of gamma-ray burst (GRB) jets can result in a statistical connection between the angle values deduced from jet break times and the variabilities of prompt light curves. The…

High Energy Astrophysical Phenomena · Physics 2021-12-28 Andor Budai , Peter Raffai , Balint Borgulya , Brian Albert Dawes , Gabor Szeifert

The measured redshifts of gamma-ray bursts (GRBs), which were first detected by the Swift satellite, seem to be bigger on average than the redshifts of GRBs detected by other satellites. We analyzed the redshift distribution of GRBs…

High Energy Astrophysical Phenomena · Physics 2009-01-21 Z. Bagoly , L. G. Balazs , I. Horvath , J. Kelemen , A. Meszaros , P. Veres , G. Tusnady

This is a brief review on the first Gamma-Ray Bursts (GRB) optical identifications - GRB host galaxies and Star Forming Rate (SFR) at relatively small redshifts (z), on the metallicities of GRB hosts, the similarities and differences…

High Energy Astrophysical Phenomena · Physics 2017-08-23 V. V. Sokolov

With its rapid-response capability and multiwavelength complement of instruments, the Swift satellite has transformed our physical understanding of gamma-ray bursts (GRBs). Providing high-quality observations of hundreds of bursts, and…

High Energy Astrophysical Phenomena · Physics 2014-11-20 N. Gehrels , E. Ramirez-Ruiz , D. B. Fox

We use the BD2 sample of gamma-ray bursts (GRBs) based on 5.9 years of BATSE DISCLA data with a variety of models of the luminosity function to derive characteristic GRB luminosities, space densities and redshift distributions. Previously…

Astrophysics · Physics 2009-10-31 Maarten Schmidt

Context: Before the launch of the Swift satellite, the majority of the gamma-ray burst (GRB) afterglows for which Ly-alpha was redshifted into the observable spectrum showed evidence for a damped Ly-alpha absorber. This small sample…

Measurements of the two-point angular correlation function w(\theta) for 407 short gamma-ray bursts collected in the Current BATSE Catalogue reveal a ~2 \sigma deviation from isotropy on angular scales \theta ~ 2-4 degrees. Such an…

Astrophysics · Physics 2009-11-07 M. Magliocchetti , G. Ghirlanda , A. Celotti

Many gamma ray bursts (GRBs) have been observed with the Burst-Alert and X-Ray telescopes of the Swift satellite. The successive `pulses' of these GRBs end with a fast decline and a fast spectral softening, until they are overtaken by…

Astrophysics · Physics 2009-11-13 Shlomo Dado , Arnon Dar , A. De Rujula

There is increasingly strong evidence that gamma-ray bursts (GRBs) are associated with star-forming galaxies, and occur near or in the star-forming regions of these galaxies. These associations provide indirect evidence that at least the…

Astrophysics · Physics 2009-10-31 Donald Q. Lamb , Daniel E. Reichart

Detecting high-z GRBs is important for constraining the GRB formation rate, and tracing the history of re-ionization and metallicity of the universe. Based on the current sample of GRBs detected by Swift with known redshifts, we…

Astrophysics · Physics 2009-06-23 T. N. Ukwatta , T. Sakamoto , M. Stamatikos , N. Gehrels , K. S. Dhuga

Due to their extreme luminosities, gamma-ray bursts (GRBs) can be detected in hostile regions of galaxies, nearby and at very high redshift, making them important cosmological probes. The investigation of galaxies hosting long-duration GRBs…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 S. Savaglio

Several papers were written about the gamma-ray burst (GRBs) groups. Our statistical study is based on the durations and hardness ratios of the Swift and RHESSI data.

High Energy Astrophysical Phenomena · Physics 2010-09-10 J. Ripa , D. Huja , A. Meszaros , C. Wigger