TY - JOUR
T1 - An observed correlation between thermal and non-thermal emission in gamma-ray bursts
AU - Michael Burgess, J.
AU - Preece, Robert D.
AU - Ryde, Felix
AU - Veres, Peter
AU - Mészáros, Peter
AU - Connaughton, Valerie
AU - Briggs, Michael
AU - Pe'Er, Asaf
AU - Iyyani, Shabnam
AU - Goldstein, Adam
AU - Axelsson, Magnus
AU - Baring, Matthew G.
AU - Bhat, P. N.
AU - Byrne, David
AU - Fitzpatrick, Gerard
AU - Foley, Suzanne
AU - Kocevski, Daniel
AU - Omodei, Nicola
AU - Paciesas, William S.
AU - Pelassa, Veronique
AU - Kouveliotou, Chryssa
AU - Xiong, Shaolin
AU - Yu, Hoi Fung
AU - Zhang, Binbin
AU - Zhu, Sylvia
PY - 2014/4/1
Y1 - 2014/4/1
N2 - Recent observations by the Fermi Gamma-ray Space Telescope have confirmed the existence of thermal and non-thermal components in the prompt photon spectra of some gamma-ray bursts (GRBs). Through an analysis of six bright Fermi GRBs, we have discovered a correlation between the observed photospheric and non-thermal γ-ray emission components of several GRBs using a physical model that has previously been shown to be a good fit to the Fermi data. From the spectral parameters of these fits we find that the characteristic energies, Ep and kT, of these two components are correlated via the relation Ep∝T α which varies from GRB to GRB. We present an interpretation in which the value of the index α indicates whether the jet is dominated by kinetic or magnetic energy. To date, this jet composition parameter has been assumed in the modeling of GRB outflows rather than derived from the data.
AB - Recent observations by the Fermi Gamma-ray Space Telescope have confirmed the existence of thermal and non-thermal components in the prompt photon spectra of some gamma-ray bursts (GRBs). Through an analysis of six bright Fermi GRBs, we have discovered a correlation between the observed photospheric and non-thermal γ-ray emission components of several GRBs using a physical model that has previously been shown to be a good fit to the Fermi data. From the spectral parameters of these fits we find that the characteristic energies, Ep and kT, of these two components are correlated via the relation Ep∝T α which varies from GRB to GRB. We present an interpretation in which the value of the index α indicates whether the jet is dominated by kinetic or magnetic energy. To date, this jet composition parameter has been assumed in the modeling of GRB outflows rather than derived from the data.
KW - gamma-ray burst: general
KW - radiation mechanisms: non-thermal
KW - radiation mechanisms: thermal
UR - http://www.scopus.com/inward/record.url?scp=84897013356&partnerID=8YFLogxK
U2 - 10.1088/2041-8205/784/2/L43
DO - 10.1088/2041-8205/784/2/L43
M3 - مقالة
SN - 2041-8205
VL - 784
JO - Astrophysical Journal Letters
JF - Astrophysical Journal Letters
IS - 2
M1 - L43
ER -