具平缓电子能谱的伽玛射线暴的解析光变曲线  

Analytical Afterglow Lightcurves of Gamma-ray Bursts:the Case of a Flat Electron Spectrum

作　　者：王瑜[1,2,3] 范一中[1,2] 韦大明[1,2,4] COVINO Stefano 

机构地区：[1]中国科学院紫金山天文台,南京210008 [2]中国科学院暗物质与空间天文重点实验室,南京210008 [3]中国科学院研究生院,北京100049 [4]紫金山天文台-南京大学粒子、核物理和宇宙学联合研究中心,南京210008 [5]National Institute for Astrophysics/Brera Astronomical Observatory, Merate 23807, Italy

出　　处：《天文学报》2011年第6期460-466,共7页Acta Astronomica Sinica

基　　金：国家自然科学基金项目(10621303,11073057);国家重点基础研究发展规划(2007CB815404,2009CB824800)资助;紫金山天文台特别资助

摘　　要：在标准的伽玛暴余辉模型中,电子通过费米一级加速后形成单幂律能谱分布dn/dγe∝γe^(-p)(p≈2.3),但在某些伽玛暴事件中观测到了平缓的电子能谱分布(即p<2).在单幂律谱和分段幂律谱两种情况下,分别给出了具有平缓电子能谱的伽玛暴余辉的解析光变曲线,并以GRB 060908为例进行了讨论.同时提出了伽玛暴低能谱危机的可能的解决方案.In the standard afterglow model, the swept electrons have been accelerated to a single power-law energy distribution dn/dγeαγe^-p （p ≈ 2.3）, as expected in the first-order Fermi acceleration process. However, in some events people find evidences for a fiat electron spectrum （i.e., p 〈2）. In this work the analytical afterglow lightcurves are presented in the case of a fiat electron spectrum. The possibilities that the injected electrons take a single power-law or a broken power-law function are discussed. The results have been applied to the specific burst GRB 060908. We also speculated a possible solution of the so-called low-energy spectrum crisis of gamma-ray bursts.

关 键 词：伽玛射线暴 普通 星际介质 喷流和外流 辐射机制 非热 

分 类 号：P145[天文地球—天体物理]