Prompt high-energy emission from proton-dominated gamma-ray bursts

Katsuaki Asano, Susumu Inoue, Peter Istvan Meszaros

Research output: Contribution to journalArticle

53 Citations (Scopus)

Abstract

The prompt emission of gamma-ray bursts (GRBs) is widely thought to be radiation from accelerated electrons, but an appreciably larger amount of energy could be carried by accelerated protons, particularly if GRBs are the sources of ultra-high-energy cosmic rays (UHECRs). We model the expected photon spectra for such "proton-dominated" GRBs in the internal shock scenario through Monte Carlo simulations, accounting for various processes related to high-energy electrons and protons. Besides proton and muon synchrotron components, emission from photomeson-induced secondary pair cascades becomes crucial, generally enhancing the GeV-TeV and/or eV-keV photons and offering a signature of UHE protons. In some cases, it can overwhelm the primary electron component and result in GRBs peaking in the 10 MeV-1 GeV range, which may be relevant to some bursts discussed in a recent re-analysis of EGRET TASC data. The dependence of the spectra on key quantities such as the bulk Lorentz factor, magnetic field, and proton-to-electron ratio is nontrivial due to the nonlinear nature of cascading and the interplay of electron- and proton-induced components. Observations by Fermi, ground-based telescopes, and other facilities should test these expectations and provide critical constraints on the proton acceleration efficiency.

Original languageEnglish (US)
Pages (from-to)953-957
Number of pages5
JournalAstrophysical Journal
Volume699
Issue number2
DOIs
StatePublished - Jan 1 2009

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gamma ray bursts
electron
protons
energy
electrons
cosmic ray
magnetic field
photons
test facilities
high energy electrons
muons
cosmic rays
bursts
cascades
synchrotrons
shock
signatures
simulation
telescopes
radiation

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Asano, Katsuaki ; Inoue, Susumu ; Meszaros, Peter Istvan. / Prompt high-energy emission from proton-dominated gamma-ray bursts. In: Astrophysical Journal. 2009 ; Vol. 699, No. 2. pp. 953-957.
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Prompt high-energy emission from proton-dominated gamma-ray bursts. / Asano, Katsuaki; Inoue, Susumu; Meszaros, Peter Istvan.

In: Astrophysical Journal, Vol. 699, No. 2, 01.01.2009, p. 953-957.

Research output: Contribution to journalArticle

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