The Central Engine of Gamma-Ray Bursters
The Central Engine of Gamma-Ray Bursters
复制标题
DOI：
10.1086/311622
复制
发表时间：
1997-12
期刊：
影响因子：
--
通讯作者：
W. Kluźniak;M. Ruderman
中科院分区：
文献类型：
--
作者：
W. Kluźniak;M. Ruderman
宇宙伽马射线暴（GRB）被认为是由“中心引擎”提供动力的相对论冲击波从爆炸能量释放的地方发射出10到10，000 Au之间的伽马射线时产生的。为了解释观测到的伽玛暴的持续时间和变化性，中心引擎必须在几秒到很多秒之间保持活跃，并且通常必须在更短的时间尺度上在其输出中强烈波动。我们展示了最初以毫秒周期差分旋转的中子星是如何成为这样的发动机的，在观测到的时间尺度上，只要差分运动保持足够的活力，就会发出正确种类和功率的高能脉冲。储存在差动旋转中的能量将主要在次爆发中释放，因为环形磁场反复缠绕到~1017 G，然后才被浮力推到并穿过表面。同样的机制也可以在核密度环中起作用。差异旋转的中子星或环面可以通过几种方式形成，并且形成的速度足够高，可以解释观测到的伽马射线暴发生的频率。
Cosmic gamma-ray bursts (GRBs) are thought to be created when relativistic blast waves that are powered by "central engines" emit gamma rays between 10 and 10,000 AU from where the explosive energy has been released. To account for the observed duration and variability of GRBs, the central engines must remain active from several to very many seconds and must usually fluctuate strongly in their output on much shorter timescales. We show how neutron stars that are initially rotating differentially at millisecond periods could be such engines, emitting, on the observed timescales, energetic pulses of the right variety and power for as long as the differential motion remains sufficiently vigorous. The energy stored in the differential rotation would be released mainly in sub-bursts, as toroidal magnetic fields are repeatedly wound up to ~1017 G and, only then, pushed to and through the surface by buoyant forces. The same mechanism could also operate in nuclear density tori. The differentially rotating neutron stars or tori could be formed in several ways and at rates sufficiently high to explain the observed frequency of occurrence of GRBs.