伽玛暴(Gamma-Ray Burst)笔记。记录有关伽玛暴的新文章,另外也包括看的老文章、自己的想法、以及跟天文相关的一些东西。 Feel free to leave me a message by comments or by email.

星期一, 七月 16, 2007

Nomoto 2007 伽玛暴与超新星的关联

主要内容:
GRB980425/SN 1998bw, GRB030329/SN 2003dh and GRB031203/SN 2003lw 和SN 2006aj/GRB060218 四个个案。也只有这四个是大家比较公认有关联的。文章将前三个和最后一个分开为两类,前者是比较高能量的,后者较低(但可能更普遍)。作者认为前者中心会形成黑洞,而后者中心是中子星(我不这么认为)。

精彩摘抄:


文章信息:

arXiv:0707.2219 [ps, pdf, other]
Title: Hypernovae and their Gamma-Ray Bursts Connection
Comments: 23 pages, 12 figures. To appear in New Astronomy Reviews, Proceedings of the Conference ``A LIFE WITH STARS''
Subjects: Astrophysics (astro-ph)

The connection between long Gamma Ray Bursts (GRBs) and Supernovae (SNe), have been established through the well observed cases of GRB980425/SN 1998bw, GRB030329/SN 2003dh and GRB031203/SN 2003lw. These events can be explained as the prompt collapse to a black hole (BH) of the core of a massive star (M ~ 40 Msun) that had lost its outer hydrogen and helium envelopes. All these SNe exhibited strong oxygen lines, and their energies were much larger than those of typical SNe, thus these SNe are called Hypernovae (HNe). The case of SN 2006aj/GRB060218 appears different: the GRB was weak and soft (an X-Ray Flash, XRF); the SN is dimmer and has very weak oxygen lines. The explosion energy of SN 2006aj was smaller, as was the ejected mass. In our model, the progenitor star had a smaller mass than other GRB/SNe (M ~ 20 Msun), suggesting that a neutron star (NS) rather than a black hole was formed. If the nascent neutron star was strongly magnetized (a so-called magnetar) and rapidly spinning, it may launch a weak GRB or an XRF. The final fate of 20-30 Msun stars show interesting variety, as seen in the very peculiar Type Ib/c SN 2005bf. This mass range corresponds to the NS to BH transition. We also compare the nucleosynthesis feature of HNe with the metal-poor stars and suggest the Hypernova-First Star connection.

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