奇异星周围的中微子主导吸积流

Neutrino Dominated Accretion Flow Around Strange Star

为统一解释伽玛射线暴(简称伽玛暴)与暴后再活动,提出了一个新的伽玛暴中心引擎模型—"奇异星-NDAF"模型(NDAF:Neutrino Dominated Accretion Flow,中微子主导吸积流).并计算了奇异星周围NDAF的结构.与其他中心致密天体不同的是,奇异星会向吸积流反馈以中微子为载体的奇异化相变能量.不考虑NDAF与奇异星的摩擦,结果表明:奇异星周围NDAF的结构对吸积率非常敏感;当吸积率大于0.18 M_⊙·s^(-1)时,"奇异星-NDAF"模型能统一解释伽玛暴与暴后再活动,这个范围大于无摩擦的"中子星-NDAF"模型能统一解释的范围;在统一解释的情形下,"奇异星-NDAF"模型湮灭总能量的分布非常宽阔,当吸积率大于0.3 M_⊙·s^(-1)时,湮灭总能量大于10^(51) erg;最后,当吸积率大于0.3 M_⊙·s^(-1)时,"奇异星-NDAF"模型的湮灭光度超过同等吸积率下"黑洞-NDAF"模型一个多量级,有利于解释某些光度极大的伽玛暴.

The ＂strange star - NDAF＂ model （NDAF： Neutrino Dominated Accretion Flow） is proposed as an alternative central engine of gamma-ray bursts for unifying the prompt emission and post prompt activity of gamma-ray bursts. The structure of NDAF around the strange star is calculated. Different from other central compact stars, the strange star will feed back phase transition energy of strangization to the accretion flow, with neutrinos as its carriers. The friction between NDAF and the strange star is ignored in this paper. The results are indicated as follows： Firstly, the structure of NDAF around strange star is sensitive to accretion rate; Secondly, if accretion rate is larger than 0.18 Mo.s-1, the ＂strange star - NDAF＂ model can unify the prompt emission and post prompt activity of gamma-ray bursts. The range is wider than that in no-friction ＂neutron star - NDAF＂ models; Thirdly, the range of annihilation energy of ＂strange star - NDAF＂ model is very wide. When the accretion rate is larger than 0.3 Mo.s-1, the annihilation energy is larger than 1051 erg; Finally, if the accretion rate is larger than 0.3 M-s-1, the annihilation energy of ＂strange star - NDAF＂ model is larger than that of ＂black hole - NDAF＂ model with the same accretion rate by more than one order of magnitude. It is favorable to explain some gamma-ray bursts with large luminosities.