Incidence Rate of GRB-host-DLAs

摘要：

We discuss our recent work 1 on the incidence rate of damped Lyα systems associated with the host galaxies ofgamma-ray bursts (GRB-host-DLAs)using cosmological SPH simulations．Assuming that the GRB occurrence is correlatedwith the local star formation rate (SFR),we find that the median NHI of GRB-host-DLAs progressively shifts to lower NHIvalues with increasing redshift, and the incidence rate of GRB-host-DLAs with logNHI>21.0 decreases rapidly at z>6≥．Thisincreases the likelihood of observing the signature of IGM attenuation in GRB afterglows towards higher redshift,becauseit will not be blocked by the red damping wing of GRB-host-DLAs．This enhances the prospects of using high-z GRBs toprobe the reionization of the Universe．The overall incidence rate of GRB-host-DLAs decreases monotonically with increasingredshift,whereas that of QSO-DLAs increases up to z=6.A measurement of the difference between the two incidence rateswould enable an estimation of the value of ηGRB,which is the mass fraction of stars that become GRBs for a given amount ofstar formation．Our predictions can be tested by upcoming high-z GRB missions,including JANUS and SVOM．

关键词： quasar absorption system damped Lyα system gamma ray burst

作者: Kentaro Nagamine Bing Zhang Lars Hernquist

作者单位: Department of Physics and Astronomy,University of Nevada,Las Vegas,4505 S.Maryland Pkwy,Box 454002,L Department of Physics and Astronomy,University of Nevada,Las Vegas,4505 S.Maryland Pkwy,Box 454002,L Astronomy Department,Harvard University,60 Garden St.,Cambridge,MA 02138,U.S.A.

会议类型: 国际会议

会议名称: 2008 NanJing Gamma-Ray Burst Conference(2008年伽马暴国际研讨会)

会议地点: 南京

会议语种:英文

页码: 355-360

在线出版日期: 2008-06-23（万方平台首次上网日期，不代表论文的发表时间）