Closure relations for e± pair signatures in gamma-ray bursts

Kohta Murase, Kunihito Ioka

Research output: Contribution to journalArticlepeer-review

27 Scopus citations


We present recipes to diagnose the fireball of gamma-ray bursts (GRBs) by combining observations of e± pair signatures (the pair annihilation line and the cutoff energy due to the pair creation process). Our recipes are largely model-independent and extract information even from the nondetection of either pair signature. We evaluate physical quantities such as the Lorentz factor, optical depth, and pair-to-baryon ratio only from the observable quantities. In particular, we can test whether the prompt emission of GRBs comes from the pair/baryonic photosphere or not. The future Gamma-Ray Large Area Space Telescope (GLAST) satellite will provide us with good chances to use our recipes via either detection or nondetection of pair signatures.

Original languageEnglish (US)
Pages (from-to)1123-1129
Number of pages7
JournalAstrophysical Journal
Issue number2
StatePublished - Apr 1 2008

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science


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