The high energy behavior of Gamma-ray Burst spectra as observed by Fermi GBM and LAT

Péter Veres; Péter Mészáros

The high energy behavior of Gamma-ray Burst spectra as observed by Fermi GBM and LAT

Péter Veres
, Péter Mészáros

Research output: Contribution to journal › Conference article › peer-review

Abstract

Most Fermi GRB spectra appear as either a broken power law extending to GeV energies or as a broken power with a separate GeV power law component. Here we show that such spectra can be understood in terms of magnetically dominated relativistic jets where a dissipative photosphere produces the prompt MeV emission, which is extended into the GeV range by inverse Compton scattering in the external shock, with possible contributions from a reverse shock as well. The bulk Lorentz factors required in these models are in the range of 300-600, and the MeV-GeV time delays arise naturally. In some cases an optical flash and a sub-dominant thermal component are also present.

Original language	English (US)
Journal	Proceedings of Science
Volume	2012-May
State	Published - 2012
Event	2012 Gamma-Ray Bursts Conference, GRB 2012 - Munich, Germany Duration: May 7 2012 → May 11 2012

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Cite this

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title = "The high energy behavior of Gamma-ray Burst spectra as observed by Fermi GBM and LAT",

abstract = "Most Fermi GRB spectra appear as either a broken power law extending to GeV energies or as a broken power with a separate GeV power law component. Here we show that such spectra can be understood in terms of magnetically dominated relativistic jets where a dissipative photosphere produces the prompt MeV emission, which is extended into the GeV range by inverse Compton scattering in the external shock, with possible contributions from a reverse shock as well. The bulk Lorentz factors required in these models are in the range of 300-600, and the MeV-GeV time delays arise naturally. In some cases an optical flash and a sub-dominant thermal component are also present.",

author = "P{\'e}ter Veres and P{\'e}ter M{\'e}sz{\'a}ros",

note = "Funding Information: ∗Speaker. †We acknowledge NASA NNX09AL40G, NSF PHY-0757155 and OTKA grant K077795 for partial support, and thank Bin-Bin Zhang, Shan Gao and Kenji Toma for useful comments. Publisher Copyright: {\textcopyright} Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence.; 2012 Gamma-Ray Bursts Conference, GRB 2012 ; Conference date: 07-05-2012 Through 11-05-2012",

year = "2012",

language = "English (US)",

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journal = "Proceedings of Science",

issn = "1824-8039",

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T1 - The high energy behavior of Gamma-ray Burst spectra as observed by Fermi GBM and LAT

AU - Veres, Péter

AU - Mészáros, Péter

N1 - Funding Information: ∗Speaker. †We acknowledge NASA NNX09AL40G, NSF PHY-0757155 and OTKA grant K077795 for partial support, and thank Bin-Bin Zhang, Shan Gao and Kenji Toma for useful comments. Publisher Copyright: © Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence.

PY - 2012

Y1 - 2012

N2 - Most Fermi GRB spectra appear as either a broken power law extending to GeV energies or as a broken power with a separate GeV power law component. Here we show that such spectra can be understood in terms of magnetically dominated relativistic jets where a dissipative photosphere produces the prompt MeV emission, which is extended into the GeV range by inverse Compton scattering in the external shock, with possible contributions from a reverse shock as well. The bulk Lorentz factors required in these models are in the range of 300-600, and the MeV-GeV time delays arise naturally. In some cases an optical flash and a sub-dominant thermal component are also present.

AB - Most Fermi GRB spectra appear as either a broken power law extending to GeV energies or as a broken power with a separate GeV power law component. Here we show that such spectra can be understood in terms of magnetically dominated relativistic jets where a dissipative photosphere produces the prompt MeV emission, which is extended into the GeV range by inverse Compton scattering in the external shock, with possible contributions from a reverse shock as well. The bulk Lorentz factors required in these models are in the range of 300-600, and the MeV-GeV time delays arise naturally. In some cases an optical flash and a sub-dominant thermal component are also present.

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UR - https://www.scopus.com/pages/publications/85052369577#tab=citedBy

M3 - Conference article

AN - SCOPUS:85052369577

SN - 1824-8039

VL - 2012-May

JO - Proceedings of Science

JF - Proceedings of Science

T2 - 2012 Gamma-Ray Bursts Conference, GRB 2012

Y2 - 7 May 2012 through 11 May 2012

ER -

The high energy behavior of Gamma-ray Burst spectra as observed by Fermi GBM and LAT

Abstract

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