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Related papers: Explaining the Gamma-Ray Burst E_peak Distribution

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The prompt emission of the gamma-ray bursts is found to be very energetic, releasing ~10^51 ergs in a flash. However, their emission mechanism remains unclear and understanding their spectra is a key to determining the emission mechanism.…

Astrophysics · Physics 2015-06-24 Y. Kaneko , R. D. Preece , M. M. Gonzalez , B. L. Dingus , M. S. Briggs

We report evidence that the asymptotic low-energy power law slope alpha (below the spectral break) of BATSE gamma-ray burst photon spectra evolves with time rather than remaining constant. We find a high degree of positive correlation…

Two models of the gamma ray burst population, one with a standard candle luminosity and one with a power law luminosity distribution, are chi^2-fitted to the union of two data sets: the differential number versus peak flux distribution of…

Astrophysics · Physics 2009-10-30 Daniel E. Reichart , P. Meszaros

Gamma Ray Bursts (GRBs) are among the most powerful sources in the Universe: they emit up to 10^54 erg in the hard X-ray band in few tens of seconds. The cosmological origin of GRBs has been confirmed by several spectroscopic measurements…

Astrophysics · Physics 2011-07-19 G. Ghirlanda , G. Ghisellini , C. Firmani

Gamma ray bursts (GRBs) are known to have short-time variability and power-law behavior with the index -1.67 in the power spectrum density. Reanalyzing the expanded data, we have found a) the power-law comes from the global profile of the…

Astrophysics · Physics 2009-11-06 Motoko Suzuki , Masahiro Morikawa , Izumi Joichi

The effect of Quantum Gravity (QG) may bring a tiny light speed variation as $v(E)=c(1-E/E_{\rm LV})$, where $E$ is the photon energy and $E_{\rm LV}$ is a Lorentz violation scale. A remarkable regularity was suggested in previous studies…

General Relativity and Quantum Cosmology · Physics 2018-02-07 Haowei Xu , Bo-Qiang Ma

Despite the great variation in the light curves of Gamma Ray Burst (GRB) prompt emission, their spectral energy distribution is generally curved and broadly peaked. In particular, their spectral evolution is well described by the…

High Energy Astrophysical Phenomena · Physics 2015-05-27 F. Massaro , J. E. Grindlay

We present a spectral analysis for a sample of redshift known GRBs observed with {\em Fermi}/GBM. Together with the results derived from our systematical spectral energy distribution modeling with the leptonic models for a {\em Fermi}/LAT…

High Energy Astrophysical Phenomena · Physics 2015-06-22 Fen Lyu , En-Wei Liang , Yun-Feng Liang , Xue-Feng Wu , Jin Zhang , Xiao-Na Sun , Rui-Jing Lu , Bing Zhang

Eleven bright gamma-ray bursts (GRBs) detected by BATSE have also been seen at much higher energies by EGRET, six at energies above 10 MeV. Such observations imply that these bursts are optically thin to photon-photon pair production at all…

Astrophysics · Physics 2009-10-30 Matthew G. Baring , Alice K. Harding

Spectral lag of the low-energy photons with respect to the high-energy ones is a common astrophysical phenomenon (such as Gamma-ray bursts and the Crab pulsar) and may serve as a key probe to the underlying radiation mechanism. However,…

Gamma-ray bursts are believed to be some catastrophic event in which material is ejected at a relativistic velocity, and internal collisions within this ejecta produce the observed $\gamma$-ray flash. The angular size of a causally…

Astrophysics · Physics 2009-10-31 Pawan Kumar , Tsvi Piran

Gamma Ray Bursts (GRBs) are notorious for their diversity. Yet, they have a series of common features. The typical energy of their $\gamma$ rays is a fraction of an MeV. The energy distributions are well described by a ``Band spectrum'',…

Astrophysics · Physics 2009-11-10 Arnon Dar , A. De Rujula

The cosmological origin of cosmic gamma-ray bursts is tested using the method of peak alignment for the averaging of time profiles. The test is applied to the basic cosmological model with standard sources, which postulates that difference…

Astrophysics · Physics 2009-10-30 I. G. Mitrofanov , M. L. Litvak , D. A. Ushakov

We have performed a systematic study of Gamma-Ray Bursts (GRBs), which have various values in the peak energy of the ${\nu}F_{\nu}$ spectrum of the prompt emission, $E_{{\rm peak}}$, observed by \textsl{Swift}/BAT and \textsl{Fermi}/GBM,…

High Energy Astrophysical Phenomena · Physics 2020-02-12 Daisuke Katsukura , Takanori Sakamoto , Makoto S. Tashiro , Yukikatsu Terada

Temporal analyses of the prompt gamma-ray and X-ray light curves of gamma-ray bursts reveal a tendency for the burst pulse time scales to increase with decreasing energy. For an ensemble of BATSE bursts, Fenimore et al. (1995) show that the…

Astrophysics · Physics 2009-10-30 James Chiang

We have analyzed the evolution of the spectral hardness parameter Epk as a function of fluence in gamma-ray bursts. We fit 41 pulses within 26 bursts with the trend reported by Liang & Kargatis (1996) which found that Epk decays…

It is generally believed that the variability of photospheric emission in gamma-ray bursts (GRBs) traces that of the jet power. This work further investigates the variability of photospheric emission in a variable jet. By setting a constant…

High Energy Astrophysical Phenomena · Physics 2020-08-26 Kai Wang , Da-Bin Lin , Yun Wang , Lu-yao Jiang , Shen-Shi Du , Xiao-Yan Li , Jia Ren , Xiang-gao Wang , En-Wei Liang

We discuss the prompt emission of Gamma-Ray Bursts in different spectral energy bands. First, we suggest that a three-part synchrotron emission model is a good description of the ~20 keV - 1 MeV gamma-ray emission of GRBs. We show that this…

Astrophysics · Physics 2009-11-07 Nicole M. Lloyd-Ronning

The evolution of the comoving cosmic merger-rate density of neutron star binaries n_c(z) is calculated using a distribution of their merging times provided by population-synthesis computations of binary stars. We adopt an exponential law…

Astrophysics · Physics 2007-05-23 Philippe Bagot , Simon F. Portegies Zwart , Lev R. Yungelson

The variety of gamma-ray burst phenomenology could be largely attributable to differences in the opening angle of an isotropic outflow or to a standard type of event viewed from different orientations. Motivated by this currently popular…

Astrophysics · Physics 2009-11-07 Enrico Ramirez-Ruiz , Nicole M. Lloyd-Ronning