University of Hertfordshire

From the same journal

Images, light curves and spectra of GRB afterglow

Research output: Contribution to journalArticlepeer-review


  • J. Granot
  • T. Piran
  • R. Sari
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Original languageEnglish
Pages (from-to)541-542
JournalAstronomy and Astrophysics: Supplement Series
Publication statusPublished - 1999


We calculate the light curve and spectra near the peak and the self absorption break, for an adiabatic blast wave described by the Blandford-McKee solution, considering the emission from the whole region behind the shock front. The expected light curve and spectra are flat near the peak. This rules out the interpretation of the sharp peak observed in the optical afterglow of GRB 970508 as the expected peak of the light curve. The observed image of an afterglow is calculated for a broad range of frequencies. We show that for frequencies below the self absorption frequency the image is rather homogeneous, as opposed to the bright ring at the outer edge and dim center, which appear at higher frequencies. We t the observed spectra of GRB 970508 to the detailed theory and obtain estimates of its physical parameters.


Original article can be found at: Copyright The European Southern Observatory (ESO) DOI : 10.1051/aas:1999344

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