Compton scattering of self-absorbed synchrotron emission

	Compton scattering of self-absorbed synchrotron emission
	Gao, He 1; Lei, Wei-Hua 1,2; Wu, Xue-Feng3,4 ; Zhang, Bing 1,5,6
刊名	MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
	2013-11-01
卷号	435 期号:3 页码:2520-2531
关键词	radiation mechanisms: non-thermal gamma-ray burst: general
ISSN号	0035-8711
通讯作者	Gao, H (通讯作者) Univ Nevada, Dept Phys & Astron, Las Vegas, NV 89154 USA.
英文摘要	Synchrotron self-Compton (SSC) scattering is an important emission mechanism in many astronomical sources, such as gamma-ray bursts (GRBs) and active galactic nuclei. We give a complete presentation of the analytical approximations for the Compton scattering of synchrotron emission with both weak and strong synchrotron self-absorption. All possible orders of the characteristic synchrotron spectral breaks (nu(a), nu(m) and nu(c)) are studied. In the weak self-absorption regime, i.e. nu(a) < nu(c), the electron energy distribution is not modified by the self-absorption process. The shape of the SSC component broadly resembles that of synchrotron, but with the following features: The SSC flux increases linearly with frequency up to the SSC break frequency corresponding to the self-absorption frequency nu(a); and the presence of a logarithmic term in the high-frequency range of the SSC spectra makes it harder than the power-law approximation. In the strong absorption regime, i.e. nu(a) > nu(c), heating of low-energy electrons due to synchrotron absorption leads to pile-up of electrons, and form a thermal component besides the broken power-law component. This leads to two-component (thermal + non-thermal) spectra for both the synchrotron and SSC spectral components. For nu(c) < nu(a) < nu(m), the spectrum is thermal (non-thermal) dominated if nu(a) > root nu(m)nu(c) (nu(a) < root nu(m)nu(c)). Similar to the weak-absorption regime, the SSC spectral component is broader than the simple broken power-law approximation. We derive the critical condition for strong absorption (electron pile-up), and discuss a case of GRB reverse shock emission in a wind medium, which invokes nu(a) > max(nu(m), nu(c)).
学科主题	Astronomy & Astrophysics
WOS标题词	Science & Technology ; Physical Sciences
类目[WOS]	Astronomy & Astrophysics
研究领域[WOS]	Astronomy & Astrophysics
关键词[WOS]	RAY BURST AFTERGLOWS ; LIGHT CURVES ; ABSORPTION ; RADIATION ; DISTRIBUTIONS ; MODELS ; SHOCKS ; GRBS
收录类别	SCI
语种	英语
WOS记录号	WOS:000325773000053
公开日期	2014-01-08
内容类型	期刊论文
源URL	[http://libir.pmo.ac.cn/handle/332002/9922]
专题	紫金山天文台_南极天文中心
作者单位	1.Univ Nevada, Dept Phys & Astron, Las Vegas, NV 89154 USA 2.Huazhong Univ Sci & Technol, Sch Phys, Wuhan 430074, Peoples R China 3.Chinese Acad Sci, Purple Mt Observ, Nanjing 210008, Peoples R China 4.Chinese Ctr Antarctic Astron, Nanjing 210008, Peoples R China 5.Peking Univ, Kavli Inst Astron & Astrophys, Beijing 100871, Peoples R China 6.Peking Univ, Dept Astron, Beijing 100871, Peoples R China
推荐引用方式 GB/T 7714	Gao, He,Lei, Wei-Hua,Wu, Xue-Feng,et al. Compton scattering of self-absorbed synchrotron emission[J]. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,2013,435(3):2520-2531.
APA	Gao, He,Lei, Wei-Hua,Wu, Xue-Feng,&Zhang, Bing.(2013).Compton scattering of self-absorbed synchrotron emission.MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,435(3),2520-2531.
MLA	Gao, He,et al."Compton scattering of self-absorbed synchrotron emission".MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 435.3(2013):2520-2531.