TY - JOUR
T1 - Single- and two-component gamma-ray burst spectra in the Fermi GBM-LAT energy range
AU - Veres, P.
AU - Mészáros, P.
PY - 2012/8/10
Y1 - 2012/8/10
N2 - Most Fermi gamma-ray burst 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 gamma-ray burst 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.
UR - http://www.scopus.com/inward/record.url?scp=84864479596&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84864479596&partnerID=8YFLogxK
U2 - 10.1088/0004-637X/755/1/12
DO - 10.1088/0004-637X/755/1/12
M3 - Article
AN - SCOPUS:84864479596
SN - 0004-637X
VL - 755
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1
M1 - 12
ER -