Steep slopes and preferred breaks in gamma-ray burst spectra:: The role of photospheres and comptonization

被引:414
作者
Mészáros, P
Rees, MJ
机构
[1] Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA
[2] Univ Calif Santa Barbara, Inst Theoret Phys, Santa Barbara, CA 93106 USA
[3] Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England
关键词
cosmology : miscellaneous; gamma rays : bursts; radiation mechanisms : thermal;
D O I
10.1086/308371
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
The role of a photospheric component and of pair breakdown is examined in the internal shock model of gamma-ray bursts. We discuss some of the mechanisms by which they would produce anomalously steep low-energy slopes, X-ray excesses and preferred energy breaks. Subrelativistic Comptonization should dominate in high comoving luminosity bursts with high baryon load, while synchrotron radiation dominates the power-law component in bursts which have lower comoving luminosity or have moderate to low baryon loads. A photosphere leading to steep low-energy spectral slopes should be prominent in the lowest baryon load cases.
引用
收藏
页码:292 / 298
页数:7
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