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Related papers: Graph-based clustering of gamma-ray bursts

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The degree to which gamma ray bursts are collimated is now the dominant uncertainty in their energy requirements and event rates. In this review I begin with the reasons for studying GRB collimation, then discuss existing tests for…

Astrophysics · Physics 2017-08-23 James E. Rhoads

We discuss how gamma-ray burst (GRB) optical afterglows and multiwavelength observations of their host galaxies can be used to obtain information about the relative amounts of star formation happening in optical and submillimetre galaxies.…

Astrophysics · Physics 2009-11-07 Neil Trentham , Enrico Ramirez-Ruiz , A. W. Blain

Gamma-ray bursts (GRBs) are spectacularly energetic events, with the potential to inform on the early universe and its evolution, once their redshifts are known. Unfortunately, determining redshifts is a painstaking procedure requiring…

Using four mixed bivariate distributions (Normal distribution, Skew-Normal distribution, Student distribution, Skew-Student distribution) and bootstrap re-sampling analysis, we analyze the samples of CGRO/BATSE, Swift/BAT and Fermi/GBM…

High Energy Astrophysical Phenomena · Physics 2022-11-09 Liang Zhang , Juan-Juan Luo , Yong-Feng Huang , Yu-Jun Gong , Sheng Wu

We study the properties of short gamma-ray bursts (GRBs), based on the assumption that they are all connected to the binary neutron star mergers, whose formation mechanism contains a large amount of uncertainty. In particular, the merger…

Astrophysics · Physics 2010-11-15 Shin'ichiro Ando

Determining the kinds of gamma-ray bursts (GRBs) has been of interest to astronomers for many years. We analyzed 1599 GRBs from the Burst and Transient Source Experiment (BATSE) 4Br catalogue using $t$-mixtures-model-based clustering on all…

High Energy Astrophysical Phenomena · Physics 2018-09-28 Souradeep Chattopadhyay , Ranjan Maitra

Machine learning algorithms have been used to determine probabilistic classifications of unassociated sources. Often classification into two large classes, such as Galactic and extra-galactic, is considered. However, there are many more…

High Energy Astrophysical Phenomena · Physics 2023-03-29 Dmitry Malyshev , Aakash Bhat

After presenting a short history of gamma-ray burst (GRB) studies, we discuss the current constraints on GRB models which follows from astronomical observations. We concentrate on the energetics of the GRBs with known redshifts and the…

Astrophysics · Physics 2007-05-23 K. A. Postnov

We present a comprehensive study of the morphological properties of 42 gamma-ray burst (GRB) host galaxies imaged with the Hubble Space Telescope in the optical band. The purpose of this study is to understand the relation of GRBs to their…

Astrophysics · Physics 2009-09-29 C. Wainwright , E. Berger , B. E. Penprase

Bayesian nonparametric mixtures and random partition models are powerful tools for probabilistic clustering. However, standard independent mixture models can be restrictive in some applications such as inference on cell lineage due to the…

Methodology · Statistics 2025-07-15 Giovanni Rebaudo , Peter Mueller

If gamma-ray bursts (GRBs) are cosmological they need not necessarily be spatially coincident with a host galaxy--in many cosmological models the progenitors are ejected to large distances from their parent galaxies. While the optical…

Astrophysics · Physics 2007-05-23 Joshua S. Bloom , Nial R. Tanvir , Ralph A. M. J. Wijers

Gamma-ray bursts (GRBs) are short and most intense bursts of gamma-rays that come from random direction in space. Their origin are still unknown and they originate likely from cosmological distances, probably after birth of a new black hole…

Instrumentation and Methods for Astrophysics · Physics 2013-03-19 S. Akkoyun

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

The Diffusion Entropy algorithm is a method that allows the study of correlated non stationary time series and allows the discrimination between signal and uncorrelated noise. DE provides a quantitative measure of the complexity by means of…

Astrophysics · Physics 2009-11-10 N. Omodei , J. Bellazzini , S. Montangero

Phenomenologically, two classes of GRBs (long/soft vs. short/hard) are identified based on their gamma-ray properties. The boundary between the two classes is vague. Multi-wavelength observations lead to identification of two types of GRB…

High Energy Astrophysical Phenomena · Physics 2015-06-04 Bing Zhang

Gamma-ray bursts (GRBs) are typically classified into long and short GRBs based on their durations. However, there is a significant overlapping in the duration distributions of these two categories. In this paper, we apply the unsupervised…

High Energy Astrophysical Phenomena · Physics 2024-07-10 Si-Yuan Zhu , Wan-Peng Sun , Da-Ling Ma , Fu-Wen Zhang

The paper applies a new, nonparametric, interpoint distance-based measure to confirm the inherent groups prevailing in the brightest source of light in the universe: gamma-ray bursts. Our effective metric, in association with clustering…

High Energy Astrophysical Phenomena · Physics 2026-05-07 Soumita Modak

We study correlations between various hardness ratios of gamma-ray bursts (GRBs) and investigate if there are any differences between the two classes of the objects in the distributions of the ratios. The results suggest that,…

Astrophysics · Physics 2009-10-31 Yi-Ping Qin , Guang-Zhong Xie , Xue-Tang Zheng , En-Wei Liang

Gamma-ray bursts are the most luminous events in the Universe. Going beyond the short-long classification scheme we work in the context of three burst populations with the third group of intermediate duration and softest spectrum. We are…

High Energy Astrophysical Phenomena · Physics 2015-05-20 P. Veres , Z. Bagoly , I. Horváth , A. Mészáros , L. G. Balázs

Although it is generally assumed that there are two dominant classes of gamma-ray bursts (GRB) with different typical durations, it has been difficult to unambiguously classify GRBs as short or long from summary properties such as duration,…

High Energy Astrophysical Phenomena · Physics 2023-03-15 Charles L. Steinhardt , William J. Mann , Vadim Rusakov , Christian K. Jespersen