Quasi-thermal comptonization and gamma-ray bursts

被引:128
作者
Ghisellini, G
Celotti, A
机构
[1] Osservatorio Astron Brera, I-23807 Merate, Italy
[2] Scuola Int Super Studi Avanzati, I-34014 Trieste, Italy
关键词
gamma rays : bursts; radiation mechanisms : nonthermal; radiation mechanisms : thermal X-rays : general;
D O I
10.1086/311845
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
Quasi-thermal Comptonization in internal shocks formed between relativistic shells can account for the high-energy emission of gamma-ray bursts. This is in fact the dominant cooling mechanism if the typical energy bf the emitting particles is achieved either through the balance between heating and cooling or as a result of electron-positron pair production. Both processes yield subrelativistic or mildly relativistic energies. In this case, the synchrotron spectrum is self-absorbed, providing the soft-seed photons for the Comptonization process, whose spectrum is flat [F(nu) similar to const], ending in either an exponential cutoff or a Wien peak, depending on the scattering optical depth of the emitting particles. The self-consistent particle energy and optical depth are estimated and found in agreement with the observed spectra.
引用
收藏
页码:L93 / L96
页数:4
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