Polarization of gamma-ray burst afterglows in the synchrotron self-Compton process from a highly relativistic jet

doi:10.1088/1674-1137/41/4/045101

	Polarization of gamma-ray burst afterglows in the synchrotron self-Compton process from a highly relativistic jet
	Chang Z(常哲); Lin, HN; Chang, Z; Li, X
刊名	CHINESE PHYSICS C中国物理. C
	2017
卷号	41 期号:4 页码:45101
关键词	gamma-ray burst polarization synchrotron radiation Compton scattering
ISSN号	1674-1137
DOI	10.1088/1674-1137/41/4/045101
文献子类	Article
英文摘要	Linear polarization has been observed in both the prompt phase and afterglow of some bright gamma-ray bursts (GRBs). Polarization in the prompt phase spans a wide range, and may be as high as greater than or similar to 50%. In the afterglow phase, however, it is usually below 10%. According to the standard fireball model, GRBs are produced by synchrotron radiation and Compton scattering process in a highly relativistic jet ejected from the central engine. It is widely accepted that prompt emissions occur in the internal shock when shells with different velocities collide with each other, and the magnetic field advected by the jet from the central engine can be ordered on a large scale. On the other hand, afterglows are often assumed to occur in the external shock when the jet collides with interstellar medium, and the magnetic field produced by the shock through, for example, Weibel instability, is possibly random. In this paper, we calculate the polarization properties of the synchrotron self-Compton process from a highly relativistic jet, in which the magnetic field is randomly distributed in the shock plane. We also consider the generalized situation where a uniform magnetic component perpendicular to the shock plane is superposed on the random magnetic component. We show that it is difficult for the polarization to be larger than 10% if the seed electrons are isotropic in the jet frame. This may account for the observed upper limit of polarization in the afterglow phase of GRBs. In addition, if the random and uniform magnetic components decay with time at different speeds, then the polarization angle may change 90 during the temporal evolution.
WOS关键词	LINEAR-POLARIZATION ; MAGNETIC-FIELDS ; GRB 041219A ; CIRCULAR-POLARIZATION ; OPTICAL AFTERGLOW ; PROMPT EMISSION ; LIGHT CURVES ; MODEL ; FLUX ; ACCELERATION
WOS研究方向	Physics
语种	英语
CSCD记录号	CSCD:5954036
WOS记录号	WOS:000400124800015
内容类型	期刊论文
源URL	[http://ir.ihep.ac.cn/handle/311005/284745]
专题	高能物理研究所_理论物理室中国科学院高能物理研究所_中国散裂中子源
作者单位	中国科学院高能物理研究所
推荐引用方式 GB/T 7714	Chang Z,Lin, HN,Chang, Z,et al. Polarization of gamma-ray burst afterglows in the synchrotron self-Compton process from a highly relativistic jet[J]. CHINESE PHYSICS C中国物理. C,2017,41(4):45101.
APA	常哲,Lin, HN,Chang, Z,&Li, X.(2017).Polarization of gamma-ray burst afterglows in the synchrotron self-Compton process from a highly relativistic jet.CHINESE PHYSICS C中国物理. C,41(4),45101.
MLA	常哲,et al."Polarization of gamma-ray burst afterglows in the synchrotron self-Compton process from a highly relativistic jet".CHINESE PHYSICS C中国物理. C 41.4(2017):45101.