Comparison between the time-integrated spectrum and the peak time spectrum of gamma-ray bursts and possible implications

作     者：LYU Fen WANG YuanZhu LIANG YunFeng LIN TingTing HU YouDong LIANG EnWei 

作者机构：Department of Physics and GXU-NAOC Center for Astrophysics and Space Sciences Guangxi University Purple Mountain Observatory Chinese Academy of Sciences Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences 

出 版 物：《Science China(Physics,Mechanics & Astronomy)》 (中国科学：物理学、力学、天文学（英文版）)

年 卷 期：2015年第58卷第3期

页      面：82-89页

核心收录：

学科分类：08[工学] 0827[工学-核科学与技术] 082701[工学-核能科学与工程] 

基　　金：supported by the National Basic Research Program of China(Grant No.2014CB845800) the National Natural Science Foundation of China(Grant No.11025313) Guangxi Science Foundation(Grant No.2013GXNSFFA019001) Key Laboratory for the Structure and Evolution of Celestial Objects of Chinese Academy of Sciences,and the Strategic Priority Research Program"The Emergence of Cosmological Structures"of the Chinese Academy of Sciences(Grant No.XDB09000000) 

主　　题：γ-ray sources γ-ray bursts gamma-rays: astronomical observations 

摘      要：The mono-frequency peak luminosity and the corresponding photon energy of the time-integrated （L~, Eg） and peak time （L~, ffp） vfv spectra were derived for a sample of 38 redshift-known Fermi GRBs by fitting the spectra with the Band function. It was found that Ept is generally consistent with Ep, and Lp is averagely three times larger than Lp. The slope of the Lp1 -Etp relation was consistent with that of the Lps - Eps relation. The photon indices in the peak time spectrum, particularly, the index of the low energy end was, were statistically larger than that in the time-integrated spectrum. These results indicate that Lp and Ep are dominated by Lp1 and Ept, respectively. The difference of the spectral indices between the time-integrated and peak time spectra may be because of the overlap effect of a series of time-resolved spectra within a GRB. Our simulations, which were based on the observed spectral evolution and correlation between the energy flux and the peak energy within individual GRBs support our speculations. The Lt - Et, relation may be less contaminated by the overla!a effect, and it would may be an intrinsic feature of radiation ohvsics.