Origins of short gamma-ray bursts deduced from offsets in their host galaxies revisited  

作　　者：Xiao-Hong Cui Shigehiro Nagataki Junichi Aoi Ren-Xin Xu 

机构地区：[1]National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, China xhcui@ bao.ac, cn [2]Yukawa Institute for Theoretical Physics, Oiwake-cho, Kitashirakawa, Sakyo-ku, Kyoto606-8502, Japan [3]School of Physics and State Key Laboratory of Nuclear Physics and Technology, PekingUniversity, Beijing 100871, China

出　　处：《Research in Astronomy and Astrophysics》2012年第9期1255-1268,共14页天文和天体物理学研究（英文版）

基　　金：the China Postdoctoral Science Foundation funded project (No. 20110490590);the National Natural Science Foundation of China under No.11103026;the National Basic Research Program of China (973 Program, 2009CB824800);Grant-in-Aid for Scientific Research on Priority Areas No. 19047004 by the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan;Grant-in-Aid for Scientific Research (S) No. 19104006 by the Japan Society for the Promotion of Science (JSPS);the Grant-in-Aid for Young Scientists (B) No.19740139 by JSPS;the Grant-in-Aid for Scientific Research on Innovative Areas No. 21105509 by MEXT;Grant-in-Aid for JSPS Fellows from MEXT;the Grant-in-Aid for the Global COE Program "The Next Generation of Physics,Spun from Universality and Emergence" from MEXT

摘　　要：The spatial distribution of short Gamma-ray bursts (GRBs) in their host galaxies provides us with an opportunity to investigate their origins. Based on the currently observed distribution of short GRBs relative to their host galaxies, we obtain the fraction of the component that traces the mergers of binary compact objects and the one that traces star formation rate (such as massive stars) in earlyand late-type host galaxies. From the analysis of projected offset distribution and only based on population synthesis and massive star models, we find that the fraction of massive stars is 0.37+-00..4327 with an error at the 1σ level for a sample with 22 short GRBs in the literature. From these results, it is hard to accept that the origin of short GRBs with observed statistics is well described by current models using only the offset distribution. The uncertainties in observational localizations of short GRBs also strongly affect the resulting fraction.The spatial distribution of short Gamma-ray bursts (GRBs) in their host galaxies provides us with an opportunity to investigate their origins. Based on the currently observed distribution of short GRBs relative to their host galaxies, we obtain the fraction of the component that traces the mergers of binary compact objects and the one that traces star formation rate (such as massive stars) in earlyand late-type host galaxies. From the analysis of projected offset distribution and only based on population synthesis and massive star models, we find that the fraction of massive stars is 0.37+-00..4327 with an error at the 1σ level for a sample with 22 short GRBs in the literature. From these results, it is hard to accept that the origin of short GRBs with observed statistics is well described by current models using only the offset distribution. The uncertainties in observational localizations of short GRBs also strongly affect the resulting fraction.

关 键 词：gamma-rays: bursts — cosmology: galaxy — methods: statistical 

分 类 号：P1[天文地球—天文学]