PHOTOSPHERE EMISSION IN THE X-RAY FLARES OF SWIFT GAMMA-RAY BURSTS AND IMPLICATIONS FOR THE FIREBALL PROPERTIES

	PHOTOSPHERE EMISSION IN THE X-RAY FLARES OF SWIFT GAMMA-RAY BURSTS AND IMPLICATIONS FOR THE FIREBALL PROPERTIES
	Peng, Fang-Kun 1,2,3; Liang, En-Wei 1,3,4; Wang, Xiang-Yu 2; Hou, Shu-Jin 5,6; Xi, Shao-Qiang 1; Lu, Rui-Jing 1; Zhang, Jin4 ; Zhang, Bing 1,7
刊名	ASTROPHYSICAL JOURNAL
	2014-11-10
卷号	795 期号:2
关键词	gamma-ray burst: general methods: statistical radiation mechanisms: non-thermal radiation mechanisms: thermal
英文摘要	X-ray flares of gamma-ray bursts (GRBs) are usually observed in the soft X-ray range and the spectral coverage is limited. In this paper, we present an analysis of 32 GRB X-ray flares that are simultaneously observed by both Burst Alert Telescope and X-Ray Telescope on board the Swift mission, so that a joint spectral analysis with a wider spectral coverage is possible. Our results show that the joint spectra of 19 flares are fitted with the absorbed single power law or the Band function models. More interestingly, the joint spectra of the other 13 X-ray flares are fitted with the absorbed single power-law model plus a blackbody component. Phenomenally, the observed spectra of these 13 flares are analogous to several GRBs with a thermal component, but only with a much lower temperature of kT = 1 similar to 3 keV. Assuming that the thermal emission is the photosphere emission of the GRB fireball, we derive the fireball properties of the 13 flares that have redshift measurements, such as the bulk Lorentz factor Gamma(ph) of the outflow. The derived Gamma(ph) range from 50 to 150 and a relation of Gamma(ph) to the thermal emission luminosity is found. It is consistent with the Gamma(0) - L-iso relations that are derived for the prompt gamma-ray emission. We discuss the physical implications of these results within the content of jet composition and the radiation mechanism of GRBs and X-ray flares.
收录类别	SCI
语种	英语
WOS记录号	WOS:000343857900054
内容类型	期刊论文
源URL	[http://ir.bao.ac.cn/handle/114a11/6596]
专题	国家天文台_空间科学研究部
作者单位	1.Guangxi Univ, Dept Phys, Guangxi Key Lab Relativist Astrophys, Nanning 530004, Peoples R China 2.Nanjing Univ, Sch Astron & Space Sci, Nanjing 210093, Jiangsu, Peoples R China 3.Chinese Acad Sci, Key Lab Struct & Evolut Celestial Objects, Kuming 650011, Peoples R China 4.Chinese Acad Sci, Natl Astron Observ, Beijing 100012, Peoples R China 5.Nanyang Normal Coll, Inst Phys & Elect Engn, Nanyang 473061, Peoples R China 6.Chinese Acad Sci, Purple Mt Observ, Nanjing 210008, Jiangsu, Peoples R China 7.Univ Nevada, Dept Phys & Astron, Las Vegas, NV 89154 USA
推荐引用方式 GB/T 7714	Peng, Fang-Kun,Liang, En-Wei,Wang, Xiang-Yu,et al. PHOTOSPHERE EMISSION IN THE X-RAY FLARES OF SWIFT GAMMA-RAY BURSTS AND IMPLICATIONS FOR THE FIREBALL PROPERTIES[J]. ASTROPHYSICAL JOURNAL,2014,795(2).
APA	Peng, Fang-Kun.,Liang, En-Wei.,Wang, Xiang-Yu.,Hou, Shu-Jin.,Xi, Shao-Qiang.,...&Zhang, Bing.(2014).PHOTOSPHERE EMISSION IN THE X-RAY FLARES OF SWIFT GAMMA-RAY BURSTS AND IMPLICATIONS FOR THE FIREBALL PROPERTIES.ASTROPHYSICAL JOURNAL,795(2).
MLA	Peng, Fang-Kun,et al."PHOTOSPHERE EMISSION IN THE X-RAY FLARES OF SWIFT GAMMA-RAY BURSTS AND IMPLICATIONS FOR THE FIREBALL PROPERTIES".ASTROPHYSICAL JOURNAL 795.2(2014).