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 the...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.展开更多
基金the China Postdoctoral Science Foundation funded project (No. 20110490590)the National Natural Science Foundation of China under No.11103026+6 种基金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 JapanGrant-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 JSPSthe Grant-in-Aid for Scientific Research on Innovative Areas No. 21105509 by MEXTGrant-in-Aid for JSPS Fellows from MEXTthe Grant-in-Aid for the Global COE Program "The Next Generation of Physics,Spun from Universality and Emergence" from MEXT
文摘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.
