Kistler 2007 伽玛暴的诞生率和恒星形成率的表现不一致

主要内容:
对有红移的伽玛暴的分析发现红移分布与恒星形成历史不一致，说明可能有一些伽玛暴来源不是大质量恒星坍缩。

精彩摘抄:
上图是恒星形成率，下图是伽玛暴诞生率，后者演化更大一些。

文章信息:

arXiv:0709.0381 [ps, pdf, other]

Title: An Unexpectedly Swift Rise in the Gamma-ray Burst Rate

Authors: Matthew D. Kistler, Hasan Yuksel, John F. Beacom, Krzysztof Z. Stanek (Ohio State University)

Comments: 4 pages, 4 figures

Subjects: Astrophysics (astro-ph)

The association of long gamma-ray bursts with the deaths of massive stars naturally suggests that the cosmic GRB rate should trace the star formation history. Finding otherwise would provide important clues for the further development of our views concerning these rare, curious phenomena. Making use of a sample of 44 luminous Swift GRBs with redshifts in the range z=0-4, we find evidence of enhanced evolution in the GRB rate, with ~4 times as many GRBs being observed at z~4 than expected from star formation measurements. We discuss the origins of this observed trend, including several progenitor populations that the GRBs may actually be tracing.