Tominaga 2007 伽玛暴和极端贫金属大质量恒星的成协

主要内容:
以期解释无超新星成协的长暴如GRB060614等。

精彩摘抄:


文章信息:

astro-ph/0702471 [abs, ps, pdf, other] :

Title: The Connection between Gamma-Ray Bursts and Extremely Metal-Poor Stars: Black Hole-forming Supernovae with Relativistic Jets
Authors: Nozomu Tominaga, Keiichi Maeda, Hideyuki Umeda, Ken'ichi Nomoto, Masaomi Tanaka, Nobuyuki Iwamoto, Tomoharu Suzuki, Paolo A. Mazzali
Comments: 7 pages, 3 figures. Accepted for publication in the Astrophysical Journal Letters (10 March 2007, v657n2 issue)

Long-duration gamma-ray bursts (GRBs) are thought to be connected to luminous and energetic supernovae (SNe), called hypernovae (HNe), resulting from the black-hole (BH) forming collapse of massive stars. For recent nearby GRBs~060505 and 060614, however, the expected SNe have not been detected. The upper limits to the SN brightness are about 100 times fainter than GRB-associated HNe (GRB-HNe), corresponding to the upper limits to the ejected $^{56}$Ni masses of $M({\rm ^{56}Ni})\sim 10^{-3}M_\odot$. SNe with a small amount of $^{56}$Ni ejection are observed as faint Type II SNe. HNe and faint SNe are thought to be responsible for the formation of extremely metal-poor (EMP) stars. In this Letter, a relativistic jet-induced BH forming explosion of the 40 $M_\odot$ star is investigated and hydrodynamic and nucleosynthetic models are presented. These models can explain both GRB-HNe and GRBs without bright SNe in a unified manner. Their connection to EMP stars is also discussed. We suggest that GRBs without bright SNe are likely to synthesize $\Mni\sim 10^{-4}$ to $10^{-3}M_\odot$ or $\sim 10^{-6}M_\odot$.