论文标题
在伽马射线爆发中识别黑洞中央发动机
Identifying Black Hole Central Engines in Gamma-Ray Bursts
论文作者
论文摘要
伽马射线爆发（GRB）中央发动机的性质仍然是一个谜。被人们普遍认为能够为极端喷气机提供动力的实体是磁铁和黑洞。在毫秒磁铁中可用的最大旋转能以形成喷气机〜10^52 ERG。我们确定了8个长GRB，其喷射角校正了迅速发射发作的能量学> 10^52 ERG，置信度很高，因此，他们的中央发动机有望为黑洞。这些GRB中的大多数在亚GEV能量范围内呈现出明显的发射。这些爆发的X射线光曲线曲线没有显示出任何浅衰减行为，例如高原，但是，有几种情况表现出耀斑和多个断裂，而不是单个幂律衰减。对于最小的黑洞（〜2 msun），我们发现从旋转能量到2％-270％的旋转能量产生射流的效率。需要高效率的高能喷射器意味着这些黑洞的质量要么大得多，要么还有其他能源的能源来源。通过考虑Blandford-Znajek射流形成的机制，我们估计这些黑洞的质量范围为〜2-60 msun。在这些灾难性事件中形成的一些较轻的黑洞可能是候选人位于质量间隙区域（2-5 msun）。
The nature of the gamma-ray burst (GRB) central engine still remains an enigma. Entities widely believed to be capable of powering the extreme jets are magnetars and black holes. The maximum rotational energy that is available in a millisecond magnetar to form a jet is ~10^52 erg. We identify 8 long GRBs whose jet opening angle corrected energetics of the prompt emission episode are >10^52 erg with high confidence level and therefore, their central engines are expected to be black holes. Majority of these GRBs present significant emission in sub-GeV energy range. The X-ray afterglow light curves of these bursts do not show any shallow decay behaviour such as a plateau, however, a few cases exhibit flares and multiple breaks instead of a single power-law decay. For a minimum mass of the black hole (~2 Msun), we find the efficiency of producing a jet from its rotational energy to range between 2%-270%. Highly energetic jets requiring high efficiencies implies that either the mass of these black holes are much larger or there are, in addition, other sources of energy which power the jet. By considering the Blandford-Znajek mechanism of jet formation, we estimate the masses of these black holes to range between ~2-60 Msun. Some of the lighter black holes formed in these catastrophic events are likely candidates to lie in the mass gap region (2-5 Msun).
