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Related papers: Low-Energy Spectral Features in GRBs

200 papers

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

In recent years, our understanding of gamma-ray bursts (GRB) prompt emission has been revolutionized, due to a combination of new instruments, new analysis methods and novel ideas. In this review, I describe the most recent observational…

High Energy Astrophysical Phenomena · Physics 2015-09-23 Asaf Pe'er

The recent association of several short gamma-ray bursts (GRBs) with early type galaxies with low star formation rate demonstrates that short bursts arise from a different progenitor mechanism than long bursts. However, since the duration…

Astrophysics · Physics 2011-09-30 Jay P. Norris , Jerry T. Bonnell

We test the models of synchrotron emission presented in Part I of this series (Lloyd & Petrosian, these proceedings) against the distributions and evolution of GRB spectral parameters (particularly the low energy index, $\alpha$). With…

Astrophysics · Physics 2018-11-06 Nicole M. Lloyd-Ronning , Vahe' Petrosian , Robert D. Preece

We provide a comprehensive review of major developments in our understanding of gamma-ray bursts, with particular focus on the discoveries made within the last fifteen years when their true nature was uncovered. We describe the…

High Energy Astrophysical Phenomena · Physics 2015-06-03 Pawan Kumar , Bing Zhang

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

Many gamma ray bursts (GRBs) have been observed with the Burst-Alert and X-Ray telescopes of the Swift satellite. The successive `pulses' of these GRBs end with a fast decline and a fast spectral softening, until they are overtaken by…

Astrophysics · Physics 2009-11-13 Shlomo Dado , Arnon Dar , A. De Rujula

Recently proposed correlations between the energetics of Gamma-Ray Bursts (GRB) and their spectral properties, namely the peak energy of their prompt emission, are found to account for the observed fluence distribution of all `bright' BATSE…

Astrophysics · Physics 2007-05-23 Z. Bosnjak , A. Celotti , F. Longo , G. Barbiellini

Particles with energies below the mean energy $E_0$ in relativistic shocked plasmas should assume an equilibrium energy distribution. This leads to a synchrotron spectrum $F_\nu \propto \nu^{1/3}$ up to approximately the critical frequency…

Astrophysics · Physics 2011-03-17 J. I. Katz

Gamma ray bursts (GRB's) often feature subpulses that have a distinctively asymmetric profile -- they rise quickly and decay much more slowly, while their spectrum softens slightly with observer time. It is suggested that these subpulses…

Astrophysics · Physics 2009-11-13 David Eichler , Hadar Manis

We consider the evidence for very hard low energy spectra during the prompt phase of Gamma-Ray Bursts (GRB). In particular we examine the spectral evolution of GRB 980306 together with the detailed analysis of some other bursts already…

Astrophysics · Physics 2009-11-07 Giancarlo Ghirlanda , Annalisa Celotti , Gabriele Ghisellini

The spectral shape of the prompt emissions of gamma-ray bursts (GRBs) is typically expressed by the Band function: smooth joining of two power-law functions for high-energy and low-energy regions. To reveal the origin of the Band function,…

High Energy Astrophysical Phenomena · Physics 2015-10-21 Katsuaki Asano , Toshio Terasawa

Gamma-ray bursts are known to be sources of high-energy gamma rays, and are likely to be sources of high-energy cosmic rays and neutrinos. Following a short review of observations of GRBs at multi-MeV energies and above, the physics of…

Astrophysics · Physics 2007-05-23 Charles D. Dermer

The successful launch and operation of NASA's Swift Gamma-Ray Burst Explorer open a new era for the multi-wavelength study of the very early afterglow phase of gamma-ray bursts (GRBs). GRB early afterglow information is essential to explore…

Astrophysics · Physics 2009-11-13 Bing Zhang

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

Context. The complexity and variety exhibited by the light curves of long gamma-ray bursts (GRBs) enclose a wealth of information that still awaits being fully deciphered. Despite the tremendous advance in the knowledge of the energetics,…

I calculate spectral evolution series for pulses of GRBs, in the BATSE spectral range, for continuous particle injection and cooling by synchrotron, inverse Compton, and adiabatic expansion. The hydrodynamic properties of the relativistic…

Astrophysics · Physics 2009-10-31 H. Papathanassiou

From Galactic binary sources, to extragalactic magnetized neutron stars, to long-duration GRBs without associated supernovae, the types of sources we now believe capable of producing bursts of gamma-rays continues to grow apace. With this…

Astrophysics · Physics 2009-06-23 Joshua S. Bloom , Nathaniel R. Butler , Daniel A. Perley

We investigate spectral evolution in 37 bright, long gamma-ray bursts observed with the BATSE Spectroscopy Detectors. High resolution spectra are characterized by the energy of the peak of \nfn~and the evolution of this quantity is examined…

Absorption and Reprocessing of Gamma-ray burst radiation in the environment of cosmological GRBs can be used as a powerful probe of the elusive nature of their progenitors. In particular, transient X-ray emission line and absorption…

Astrophysics · Physics 2007-05-23 M. Boettcher