English
Related papers

Related papers: Statistical properties of Fermi GBM GRBs' spectra

200 papers

The jet photosphere has been proposed as the origin for the gamma-ray burst (GRB) prompt emission. In many such models, characteristic features in the spectra appear below the energy range of the $\textit{Fermi}$ GBM detectors, so joint…

High Energy Astrophysical Phenomena · Physics 2019-07-31 Björn Ahlgren , Josefin Larsson , Vlasta Valan , Daniel Mortlock , Felix Ryde , Asaf Pe'er

There is no consensus yet on whether the precursor and the main burst of gamma-ray bursts (GRBs) have the same origin, and their jet composition is still unclear. In order to further investigate this issue, we systematically search 21 Fermi…

High Energy Astrophysical Phenomena · Physics 2024-05-27 Hui-Ying Deng , Zhao-Yang Peng , Jia-Ming Chen , Yue Yin , Ting Li

We present time resolved spectral analysis of prompt emission from GRB 160625B, one of the brightest bursts ever detected by Fermi in its nine years of operations. Standard empirical functions fail to provide an acceptable fit to the GBM…

High Energy Astrophysical Phenomena · Physics 2018-05-30 M. E. Ravasio , G. Oganesyan , G. Ghirlanda , L. Nava , G. Ghisellini , A. Pescalli , A. Celotti

The jet compositions of gamma-ray bursts (GRBs) are very important to understand the energy dissipation and radiation mechanisms, but it remains an open question in GRB physics. In this paper, we present a systematic analysis to search for…

High Energy Astrophysical Phenomena · Physics 2026-01-09 Xue-Zhao Chang , HouJun Lü , Zhao-Wei Du , Xing Yang , En-Wei Liang

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

Modeling of gamma-ray burst (GRB) prompt emission spectra sometimes requires a (quasi-) thermal spectral component in addition to the Band function. In photospheric emission models, a prominent thermal component broadened by…

High Energy Astrophysical Phenomena · Physics 2020-09-30 Ramandeep Gill , Jonathan Granot , Paz Beniamini

The origin of the gamma-ray burst (GRB) prompt emission still defies explanation, in spite of recent progress made, for example, on the occasional presence of a thermal component in the spectrum along with the ubiquitous non-thermal…

High Energy Astrophysical Phenomena · Physics 2016-03-23 S. Dichiara , C. Guidorzi , L. Amati , F. Frontera , R. Margutti

The emission processes active in the highly relativistic jets of gamma-ray bursts (GRBs) remain unknown. In this paper we propose a new measure to describe spectra: the width of the $EF_E$ spectrum, a quantity dependent only on finding a…

High Energy Astrophysical Phenomena · Physics 2015-01-20 Magnus Axelsson , Luis Borgonovo

Detection of prompt emission by Swift-XRT provides a unique tool to study how the prompt spectrum of gamma-ray bursts (GRBs) extends down to the soft X-ray band. This energy band is particularly important for prompt emission studies, since…

High Energy Astrophysical Phenomena · Physics 2018-09-05 Gor Oganesyan , Lara Nava , Giancarlo Ghirlanda , Annalisa Celotti

We study the spectral evolution on second and sub--second timescales in 11 long and 12 short Gamma Ray Bursts (GRBs) with peak flux >8.5e-6 erg/cm2 s (8 keV-35 MeV) detected by the Fermi satellite. The peak flux correlates with the…

High Energy Astrophysical Phenomena · Physics 2015-05-30 G. Ghirlanda , G. Ghisellini , L. Nava

The study of the high-energy (MeV-GeV) part of GRBs spectrum can play a crucial role in investigating the physics of the prompt emission, but it is often hampered by low statistic and the paucity of GeV observations. In this work, we…

High Energy Astrophysical Phenomena · Physics 2024-05-29 M. E. Ravasio , G. Ghirlanda , G. Ghisellini

The prompt emission spectrum of Gamma-ray bursts (GRB) is characterized by a smoothly joint broken power-law spectrum known as the Band function. The typical low-energy photon index is $\sim -1$, which poses challenge to the standard…

High Energy Astrophysical Phenomena · Physics 2018-02-07 Siyao Xu , Yuan-Pei Yang , Bing Zhang

We explain the results of Yu et al. (2015b) of the novel sharpness angle measurement to a large number of spectra obtained from the Fermi gamma-ray burst monitor. The sharpness angle is compared to the values obtained from various…

Gamma Ray Bursts (GRBs) show evidence of different light curves, duration, afterglows, host galaxies and they explode within a wide redshift range. However, their spectral energy distributions (SEDs) appear to be very similar showing a…

High Energy Astrophysical Phenomena · Physics 2015-05-18 F. Massaro , J. E. Grindlay , A. Paggi

We have revisited the spectral width in the EF E spectrum of gamma-ray bursts with the BEST peak flux P and time-integrated F spectral data provided by the Fermi GBM Burst Catalog. We first compute the BEST spectral widths to compare with…

High Energy Astrophysical Phenomena · Physics 2019-08-14 Peng Zhaoyang , Zhao Xiaohong , Yin Yue , Wang Daozhou

Solar flares are known to release a large amount of energy into accelerating electrons. Studying small timescale ($\leq$ 2s) fluctuations in nonthermal X-ray flux offers the opportunity to probe the nature of those acceleration mechanisms.…

Solar and Stellar Astrophysics · Physics 2020-11-11 Trevor Knuth , Lindsay Glesener

The Gamma-Ray burst detector on Ginga consisted of a proportional counter to observe the x-rays and a scintillation counter to observe the gamma-rays. It was ideally suited to study the x-rays associated with gamma-ray bursts (GRBs). Ginga…

Astrophysics · Physics 2009-10-30 E. E. Fenimore

Results of a phenomenological model to estimate the GRB detection rate by the Fermi Gamma ray Space Telescope are reported. This estimate is based on the BATSE 4B GRB fluence distribution, the mean ratio of fluences measured at 100 MeV - 5…

Astrophysics · Physics 2015-05-13 Truong Le , Charles D. Dermer

With the confirmed detection of short gamma-ray burst (GRB) in association with a gravitational wave signal, we present the first fully Bayesian {\it Fermi}-GBM short GRB spectral catalog. Both peak flux and time-resolved spectral results…

High Energy Astrophysical Phenomena · Physics 2017-10-24 J. Michael Burgess , Jochen Greiner , Damien Bégué , Francesco Berlato

The proportional counter and scintillator on Ginga provided unprecented spectral coverage of GRBs, from 2 - 400 keV. Below 20 keV we find evidence for a positive spectral number index in approximately 40% of our burst sample, with some…

Astrophysics · Physics 2009-10-30 T. E. Strohmayer , E. E. Fenimore , T. Murakami , Y. Yoshida