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

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As soon as their extragalactic origins were established, the hope to make Gamma - Ray Bursts (GRBs) standardizeable candles to probe the very high - z universe has opened the search for scaling relations between redshift independent…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Vincenzo F. Cardone , Didier Fraix - Burnet

This paper studies the problem of class-imbalanced graph classification, which aims at effectively classifying the graph categories in scenarios with imbalanced class distributions. While graph neural networks (GNNs) have achieved…

Machine Learning · Computer Science 2024-12-31 Wei Ju , Zhengyang Mao , Siyu Yi , Yifang Qin , Yiyang Gu , Zhiping Xiao , Jianhao Shen , Ziyue Qiao , Ming Zhang

Network-valued data are encountered in a wide range of applications and pose challenges in learning due to their complex structure and absence of vertex correspondence. Typical examples of such problems include classification or grouping of…

Machine Learning · Computer Science 2021-11-09 Mahalakshmi Sabanayagam , Leena Chennuru Vankadara , Debarghya Ghoshdastidar

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

The mechanism responsible for the prompt emission of gamma-ray bursts (GRBs) is still a debated issue. The prompt phase-related GRB correlations can allow to discriminate among the most plausible theoretical models explaining this emission.…

High Energy Astrophysical Phenomena · Physics 2018-02-01 Maria Dainotti , Roberta Del Vecchio , Mariusz Tarnopolski

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 classified as Type I GRBs originated from compact binary mergers and Type II GRBs originated from massive collapsars. While Type I GRBs are typically shorter than 2 seconds, recent observations suggest that some…

High Energy Astrophysical Phenomena · Physics 2025-06-11 Si-Yuan Zhu , Hui-Ying Deng , Fu-Wen Zhang , Qian-Zi Mo , Pak-Hin Thomas Tam

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

We applied cosmological and absorption corrections to the X-ray and optical afterglow fluxes of a sample of Gamma-Ray Burst sources of known distance. We find a good correlation in X-rays and that the GRBs in our sample form two well…

Astrophysics · Physics 2007-05-23 Michel Boer , Bruce Gendre

Gamma ray bursts have been divided into two classes, long-soft gamma ray burst and short-hard gamma ray burst according to the bimodal distribution in duration time. Due to the harder spectrum and the lack of afterglows of short-hard bursts…

Astrophysics · Physics 2007-10-09 Soomin Jeong , Chang-Hwan Lee

It is known that some observed gamma-ray bursts (GRBs) are produced at cosmological distances and that the GRB production rate may follow the star formation rate. We model the BATSE-detected intensity distribution of long GRBs in order to…

Astrophysics · Physics 2007-05-23 J. R. Lin , S. N. Zhang , T. P. Li

The data on the location of gamma-ray bursts (GRBs) relative to their host galaxies are used to derive the distribution of surface density of GRBs along the galaxy radius. It is shown that the gradient of GRB surface density changes…

Astrophysics · Physics 2007-05-23 D. Yu. Tsvetkov , S. I. Blinnikov , N. N. Pavlyuk

If the threshold for $e^{-}e^{+}$ pair production depends on an angle between photon momenta, and if the $\gamma$-rays are collimated right in gamma-ray burst (GRB) source then another solution of the compactness problem is possible. The…

Astrophysics · Physics 2008-05-22 V. V. Sokolov

The variety of long duration gamma-ray burst (LGRB) light curves (LCs) encode a wealth of information on how LGRB engines release energy following the collapse of the progenitor star. Attempts to characterise GRB LCs focused on a number of…

High Energy Astrophysical Phenomena · Physics 2024-05-01 C. Guidorzi , M. Sartori , R. Maccary , A. Tsvetkova , L. Amati , L. Bazzanini , M. Bulla , A. E. Camisasca , L. Ferro , F. Frontera , C. K. Li , S. L. Xiong , S. N. Zhang

The article introduces a new method for applying Quantum Clustering to graph structures. Quantum Clustering (QC) is a novel density-based unsupervised learning method that determines cluster centers by constructing a potential function. In…

Machine Learning · Computer Science 2025-01-17 Zhe Wang , ZhiJie He , Ding Liu

The present paper is devoted to clustering geometric graphs. While the standard spectral clustering is often not effective for geometric graphs, we present an effective generalization, which we call higher-order spectral clustering. It…

Machine Learning · Computer Science 2021-03-16 Konstantin Avrachenkov , Andrei Bobu , Maximilien Dreveton

Gamma-ray Bursts (GRBs) are the most powerful explosions known, capable of outshining the rest of gamma-ray sky during their short-lived prompt emission. Their cosmological nature makes them the best tool to explore the final stages in the…

High Energy Astrophysical Phenomena · Physics 2016-07-20 A. Cucchiara , T. Totani , N. R. Tanvir

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

In this paper, we continue to build support for the proposal to use gamma-ray bursts (GRBs) as standard candles in constructing the Hubble Diagram at redshifts beyond the current reach of Type Ia supernova observations. We confirm that…

High Energy Astrophysical Phenomena · Physics 2015-06-12 Jun-Jie Wei , Xue-Feng Wu , Fulvio Melia

Gamma-ray bursts (GRBs) can be divided into three subclasses: X-ray flash (XRF), X-ray rich (XRR), and classical GRB (C-GRB). An X-ray flare is the rebrightening emission shown in the early X-ray afterglow of some GRBs. In this paper, we…

High Energy Astrophysical Phenomena · Physics 2019-10-16 Chuanxi Liu , Jirong Mao
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