Analytical light curves in the realistic model for gamma-ray burst afterglows

	Analytical light curves in the realistic model for gamma-ray burst afterglows
	Wu, XF; Dai, ZG ; Huang, YF ; Lu, T
刊名	ASTROPHYSICAL JOURNAL
	2005-02-01
卷号	619 期号:2 页码:968-982
关键词	gamma rays : bursts hydrodynamics ISM : jets and outflows radiation mechanisms : nonthermal relativity stars : mass loss
英文摘要	Afterglow light curves are constructed analytically for realistic gamma-ray burst remnants decelerating in either a homogeneous interstellar medium or a stellar wind environment, taking into account the radiative loss of the blast wave, which affects the temporal behaviors significantly. Inverse Compton scattering, which plays an important role when the energy equipartition factor epsilon(e) of electrons is much larger than that of the magnetic field (epsilon(B)), is considered. The inverse Compton effect prolongs the fast cooling phase markedly, during which the relativistic shock is semiradiative and the radiation efficiency is approximately constant, epsilon = epsilon(e). It is further shown that the shock is still semiradiative for quite a long time after it transits into the slow cooling phase because of a slow decreasing rate of the radiation efficiency of electrons. The temporal decaying index of the X-ray afterglow light curve in this semiradiative phase is (3p + 2 + 2epsilon)/(4 - epsilon) in the interstellar medium case and [3p - 2 - (p - 2)epsilon]/2(2 - epsilon) in the stellar wind case, where p is the distribution index of the shock-accelerated electrons. Taking p = 2.2-2.3 as implied from the common shock acceleration mechanism and assuming epsilon(e) similar to 1/3, the temporal index is more consistent with the observed (alpha(X)) similar to 1.3 than the commonly used adiabatic one. The observability of the inverse Compton component in soft X-ray afterglows is also investigated. To manifest as a bump or even dominant in the X-ray afterglows during the relativistic stage, the density must be larger than similar to1-10 cm(-3) in the interstellar medium case, or the wind parameter A(*) must be larger than similar to1 in the stellar wind case.
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]	RELATIVISTIC BLAST WAVES ; 25 APRIL 1998 ; RADIATIVE EFFICIENCY ; UNUSUAL SUPERNOVA ; COMPTON EMISSION ; FLUID-DYNAMICS ; FIREBALL MODEL ; KINETIC-ENERGY ; SHOCKS ; ENVIRONMENTS
收录类别	SCI
语种	英语
WOS记录号	WOS:000226589100026
公开日期	2015-04-14
内容类型	期刊论文
源URL	[http://libir.pmo.ac.cn/handle/332002/11107]
专题	紫金山天文台_院士文集_陆埮
作者单位	1.Nanjing Univ, Dept Astron, Nanjing 210093, Jiangsu, Peoples R China 2.Chinese Acad Sci, Purple Mt Observ, Nanjing 210008, Jiangsu, Peoples R China
推荐引用方式 GB/T 7714	Wu, XF,Dai, ZG,Huang, YF,et al. Analytical light curves in the realistic model for gamma-ray burst afterglows[J]. ASTROPHYSICAL JOURNAL,2005,619(2):968-982.
APA	Wu, XF,Dai, ZG,Huang, YF,&Lu, T.(2005).Analytical light curves in the realistic model for gamma-ray burst afterglows.ASTROPHYSICAL JOURNAL,619(2),968-982.
MLA	Wu, XF,et al."Analytical light curves in the realistic model for gamma-ray burst afterglows".ASTROPHYSICAL JOURNAL 619.2(2005):968-982.