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Related papers: Classification of Fermi Gamma-RAY Bursts

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Context. The dissipation process responsible for the long gamma-ray burst (GRB) prompt emission and the kind of dynamics that drives the release of energy as a function of time are still key open issues. We recently found that the…

High Energy Astrophysical Phenomena · Physics 2024-07-09 R. Maccary , M. Maistrello , C. Guidorzi , M. Sartori , L. Amati , L. Bazzanini , M. Bulla , A. E. Camisasca , L. Ferro , F. Frontera , A. Tsvetkova

GRB170817A, associated with the LIGO-Virgo GW170817 neutron-star merger event, lacks the short duration and hard spectrum of a Short gamma-ray burst (GRB) expected from long-standing classification models. Correctly identifying the class to…

Cosmology and Nongalactic Astrophysics · Physics 2018-03-14 I. Horvath , B. G. Toth , J. Hakkila , L. V. Toth , L. G. Balazs , I. I. Racz , S. Pinter , Z. Bagoly

Two classes of gamma-ray bursts have been identified in the BATSE catalogs characterized by durations shorter and longer than about 2 seconds. There are, however, some indications for the existence of a third type of burst. Swift satellite…

High Energy Astrophysical Phenomena · Physics 2009-07-20 I. Horvath , L. G. Balazs , Z. Bagoly , J. Kelemen , P. Veres , G. Tusnady

Aims. An attempt to classify gamma-ray bursts (GRBs) with a low level of supervision using the state-of-the-start approaches stemming from graph theory was undertaken. Methods. Graph-based classification methods, relying on different…

High Energy Astrophysical Phenomena · Physics 2021-09-28 Mariusz Tarnopolski

The separation of the gamma-ray bursts (GRBs) into short/hard and long/soft subclasses, respectively, is well supported both theoretically and observationally. The long ones are coupled to supernovae type Ib/Ic - the short ones are…

High Energy Astrophysical Phenomena · Physics 2020-01-06 Attila Mészáros , Jakub Řípa

The clusters of gamma-ray bursts are considered which are assumed to be images of the repeated gamma-ray burst (GRB) sources. It is shown, that localization of the cosmic gamma-ray burst sources (GBS) is determined by the clusters of GRBs.…

Astrophysics · Physics 2007-05-23 A. V. Kuznetsov

One of the most important task of the Gamma-Ray Burst field is the classification of the bursts. Many researches have proven the existence of the third kind (intermediate duration) of GRBs in the BATSE data. Recent works have analyzed…

High Energy Astrophysical Phenomena · Physics 2015-04-30 I. Horvath , Z. Bagoly , A. de Ugarte Postigo , L. G. Balazs , P. Veres

Two classes of gamma-ray bursts have been identified in the BATSE catalogs characterized by durations shorter and longer than about 2 seconds. There are, however, some indications for the existence of a third class. Swift satellite…

Astrophysics · Physics 2008-10-01 I. Horvath , L. G. Balazs , Z. Bagoly , P. Veres

Two classes of Gamma-ray bursts (GRBs), corresponding to the short/hard and the long/soft events, with a putative intermediate class, are typically considered in the observer frame. However, when considering GRB characteristics in the…

A thermal component is suggested to be the physical composition of the ejecta of several bright gamma-ray bursts (GRBs). Such a thermal component is discovered in the time-integrated spectra of several short GRBs as well as long GRBs. In…

High Energy Astrophysical Phenomena · Physics 2022-10-04 Ying-Yong Hu , Yao-Lin Huang , Jia-Wei Huang , Zan Zhu , Qing-Wen Tang

Data from the 3B Catalogue suggest that short and long GRB are the results of different classes of events, rather than different parameter values within a single class: Short bursts have harder spectra in the BATSE bands, but chiefly long…

Astrophysics · Physics 2007-05-23 J. I. Katz , L. M. Canel

Gamma-ray bursts (GRBs) are a mixed class of sources consisting of, at least, the long duration and short-hard subclasses, the X-ray flashes, and the low-luminosity GRBs. In all cases, the release of enormous amounts of energy on a short…

Astrophysics · Physics 2008-09-24 Charles D. Dermer , Chris L. Fryer

In three years of observations since the beginning of nominal science operations in August 2008, the Large Area Telescope (LAT) on board the Fermi Gamma Ray Space Telescope has observed high-energy (>20 MeV) \gamma-ray emission from 35…

High Energy Astrophysical Phenomena · Physics 2015-06-15 LAT Collaboration

We present the fourth in a series of catalogs of gamma-ray bursts (GRBs) observed with Fermi's Gamma-Ray Burst Monitor (Fermi-GBM). It extends the six year catalog by four more years, now covering the ten year time period from trigger…

Different forms of long gamma-ray bursts (GRBs) Luminosity Functions are considered on the basis of an explicit physical model. The inferred flux distributions are compared with the observed ones from two samples of GRBs, Swift and Fermi…

High Energy Astrophysical Phenomena · Physics 2021-11-17 Shreya Banerjee , David Eichler , Dafne Guetta

The prompt emission mechanism of gamma-ray bursts (GRBs) is still unclear, and the time-resolved spectral analysis of GRBs is a powerful tool for studying their underlying physical processes. We performed a detailed time-resolved spectral…

High Energy Astrophysical Phenomena · Physics 2024-01-29 Wan-Kai Wang , Wei Xie , Zhi-Fu Gao , Shuo Xiao , Ai-Jun Dong , Bin Zhang , Qi-Jun Zhi

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

The empirical classification of gamma-ray bursts (GRBs) into long and short GRBs based on their durations is already firmly established. This empirical classification is generally linked to the physical classification of GRBs originating…

High Energy Astrophysical Phenomena · Physics 2023-10-17 Jia-Wei Luo , Fei-Fei Wang , Jia-Ming Zhu-Ge , Ye Li , Yuan-Chuan Zou , Bing Zhang

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

A sample of 427 gamma-ray bursts (GRBs), measured by the RHESSI satellite, is studied statistically to determine the number of GRB groups. Previous studies based on the BATSE Catalog and recently on the Swift data claim the existence of an…

High Energy Astrophysical Phenomena · Physics 2010-04-21 J. Ripa , C. Wigger , D. Huja , R. Hudec