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Related papers: Generalized Linear Models of T$_{90}$-T$_{50}$ rel…

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Gamma-ray bursts (GRBs) are generally categorized into long and short bursts based on their duration ($T_{90}$). Recently, it has been proposed that GRBs can also be classified into type I (merger) and type II (collapsar) bursts based on…

High Energy Astrophysical Phenomena · Physics 2025-05-26 Yan-Kun Qu , Zhong-Xiao Man , Yu-Peng Yang , Shuang-Xi Yi , Fa-Yin Wang

Gamma-Ray Bursts (GRBs) have been conventionally bifurcated into two distinct categories dubbed "short" and "long", depending on whether their durations are less than or greater than two seconds respectively. However, many authors have…

High Energy Astrophysical Phenomena · Physics 2017-03-01 Soham Kulkarni , Shantanu Desai

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

Two classes of GRBs have been confidently identified thus far and are prescribed to different physical scenarios -- NS-NS or NS-BH mergers, and collapse of massive stars, for short and long GRBs, respectively. A third, intermediate in…

High Energy Astrophysical Phenomena · Physics 2016-03-09 Mariusz Tarnopolski

Traditionally, gamma-ray bursts (GRBs) are classified as long and short GRBs, with $T_{90} = 2$ s being the threshold duration. Generally, long-duration GRBs (LGRBs, $T_{90}>2$ s) are associated with the collapse of massive stars, and…

High Energy Astrophysical Phenomena · Physics 2024-10-03 Si-Yuan Zhu , Pak-Hin Thomas Tam

Gamma ray bursts (GRBs) are classified into long and short categories based on their durations. Broad band studies suggest that these two categories of objects roughly correspond to two different classes of progenitor systems, i.e. compact…

High Energy Astrophysical Phenomena · Physics 2016-11-15 Ye Li , Bing Zhang , Hou-Jun Lü

Many different physical processes have been suggested to explain the prompt gamma-ray emission in gamma-ray bursts (GRBs). Although there are examples of both bursts with photospheric and synchrotron emission origins, these distinct…

High Energy Astrophysical Phenomena · Physics 2018-02-07 Zeynep Acuner , Felix Ryde

A possible unified model of short and long gamma-ray bursts (GRBs), X-ray rich GRBs, and X-ray flashes is proposed. It is assumed that the jet of a GRB consists of many emitting sub-shells (i.e., an inhomogeneous jet model). The…

Astrophysics · Physics 2007-05-23 Ryo Yamazaki , Kunihito Ioka , Takashi Nakamura , Kenji Toma

We present systematic spectral analyses of GRBs detected by the Fermi Gamma-Ray Burst Monitor (GBM) during its first two years of operation. This catalog contains two types of spectra extracted from 487 GRBs, and by fitting four different…

Gamma-ray bursts (GRBs) are luminous enough to be detectable up to redshift $z\sim 10$. They are often proposed as complementary tools to type-Ia supernovae (SNe Ia) in tracing the Hubble diagram of the Universe. The distance calibrations…

General Relativity and Quantum Cosmology · Physics 2015-11-30 Hai-Nan Lin , Xin Li , Zhe Chang

To investigate GRBs in depth, it is crucial to develop an effective method for identifying GRBs accurately. Current criteria, e.g., onboard blind search, ground blind search, and target search, are limited by manually set thresholds and…

High Energy Astrophysical Phenomena · Physics 2024-12-20 Peng Zhang , Bing Li , RenZhou Gui , Shaolin Xiong , Ze-Cheng Zou , Xianggao Wang , Xiaobo Li , Ce Cai , Yi Zhao , Yanqiu Zhang , Wangchen Xue , Chao Zheng , Hongyu Zhao

Gamma-ray bursts (GRBs) are believed to belong to two classes and they are conventionally divided according to their durations. This classification scheme is not satisfied due to the fact that duration distributions of the two classes are…

High Energy Astrophysical Phenomena · Physics 2015-06-17 Yi-Ping Qin , Zhi-Fu Chen

We perform a statistical analysis of the temporal and spectral properties of the latest Fermi gamma-ray bursts (GRBs) to revisit the classification of GRBs. We find that the bimodalities of duration and the energy ratio…

High Energy Astrophysical Phenomena · Physics 2012-04-20 Fu-Wen Zhang , Lang Shao , Jing-Zhi Yan , Da-Ming Wei

Gamma-ray bursts (GRBs) are generally believed to originate from two distinct progenitors, compact binary mergers and massive collapsars. Traditional and some recent machine learning-based classification schemes predominantly rely on…

High Energy Astrophysical Phenomena · Physics 2025-10-22 Si-Yuan Zhu , Lang Shao , Pak-Hin Thomas Tam , Fu-Wen Zhang

Traditionally gamma-ray bursts (GRBs) are classified in the $T_{90}$-hardness ratio two-dimensional plane into long/soft and short/hard GRBs. In this paper, we suggest to add the "amplitude" of GRB prompt emission as the third dimension as…

High Energy Astrophysical Phenomena · Physics 2015-06-12 Hou-Jun Lü , Bing Zhang , En-Wei Liang , Bin-Bin Zhang , Takanori Sakamoto

Clustering is an important tool to describe gamma-ray bursts (GRBs). We analyzed the Final BATSE Catalog using Gaussian-mixture-models-based clustering methods for six variables (durations, peak flux, total fluence and spectral hardness…

High Energy Astrophysical Phenomena · Physics 2019-06-05 B. G. Tóth , I. I. Rácz , I. Horváth

One of the scientific objectives of NASA's Fermi Gamma-ray Space Telescope is the study of Gamma-Ray Bursts (GRBs). The Fermi Gamma-Ray Burst Monitor (GBM) was designed to detect and localize bursts for the Fermi mission. By means of an…

We propose a possible unified model of short and long gamma-ray bursts (GRBs), X-ray rich GRBs, and X-ray flashes. The jet of a GRB is assumed to consist of multiple sub-jets or sub-shells (i.e., an inhomogeneous jet model). The…

Astrophysics · Physics 2010-11-11 Ryo Yamazaki , Kunihito Ioka , Takashi Nakamura , Kenji Toma

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

Using an established classification technique, we leverage standard observations and analyses to predict the progenitors of gamma-ray bursts (GRBs). This technique, utilizing support vector machine (SVM) statistics, provides a more nuanced…

High Energy Astrophysical Phenomena · Physics 2024-07-15 P. Nuessle , J. L. Racusin , N. E. White