Revisiting gamma-ray burst afterglows with time-dependent parameters  

作　　者：Chao Yang Yuan-Chuan Zou Wei Chen Bin Liao Wei-Hua Lei Yu Liu 

机构地区：[1]School of Physics, Huazhong University of Science and Technology

出　　处：《Research in Astronomy and Astrophysics》2018年第2期53-72,共20页天文和天体物理学研究（英文版）

基　　金：supported by the National Basic Research Program of China(973 Program,Grant 2014CB845800);the National Natural Science Foundation of China(Grant Nos.11773010,U1431124 and U1738132)

摘　　要：The relativistic external shock model of gamma-ray burst （GRB） afterglows has been estab- lished with five free parameters, i.e., the total kinetic energy E, the equipartition parameters for electrons ee and for the magnetic field eB, the number density of the environment n and the index of the power- law distribution of shocked electrons p. A lot of modified models have been constructed to consider the variety of GRB afterglows, such as： the wind medium environment by letting n change with radius, the energy injection model by letting kinetic energy change with time and so on. In this paper, by as- suming all four parameters （except p） change with time, we obtain a set of formulas for the dynamics and radiation, which can be used as a reference for modeling GRB afterglows. Some interesting results are obtained. For example, in some spectral segments, the radiated flux density does not depend on the number density or the profile of the environment. As an application, through modeling the afterglow of GRB 060607A, we find that it can be interpreted in the framework of the time dependent parameter model within a reasonable range.The relativistic external shock model of gamma-ray burst （GRB） afterglows has been estab- lished with five free parameters, i.e., the total kinetic energy E, the equipartition parameters for electrons ee and for the magnetic field eB, the number density of the environment n and the index of the power- law distribution of shocked electrons p. A lot of modified models have been constructed to consider the variety of GRB afterglows, such as： the wind medium environment by letting n change with radius, the energy injection model by letting kinetic energy change with time and so on. In this paper, by as- suming all four parameters （except p） change with time, we obtain a set of formulas for the dynamics and radiation, which can be used as a reference for modeling GRB afterglows. Some interesting results are obtained. For example, in some spectral segments, the radiated flux density does not depend on the number density or the profile of the environment. As an application, through modeling the afterglow of GRB 060607A, we find that it can be interpreted in the framework of the time dependent parameter model within a reasonable range.

关 键 词：（stars：） gamma.ray burst： general -- methods： analytical 

分 类 号：P172.3[天文地球—天文学]