GRB060614伽马射线暴的潮汐瓦解吸积模型

A Tidal Disruption Model for the Gamma-Ray Burst of GRB 060614

GRB060614是一个非常特殊的γ-射线暴,它具有长的持续时间但并没有与之相伴的超新星爆发,这有别于目前确定的两类γ-射线暴(一类是长而软的γ-射线暴,对应于大质量恒星的塌缩爆发;另一类是短而硬的γ-射线暴,对应于两个致密星体的并合)。这个暴的出现使人们重新思考关于γ-射线暴的分类和中心引擎问题。我们提出这个异常的γ-射线暴产生于一个中等质量黑洞对恒星的吞噬过程。该模型能成功地解释此次γ-射线暴的能量、子暴和周期性子结构等主要观测特征。同时,模型可对中等质量黑洞的性质给出一些重要限制。因此,本研究提供了理解这一新类型γ-射线暴和稀有的中等质量黑洞的新途径。

The combination of a long duration and the absence of any accompanying supernova clearly shows that GRB 060614 cannot be grouped into the two conventional classes of gamma-ray bursts; i. e. , the long/soft bursts deemed to be collapsars and the short/hard bursts deemed to be merging binary compact stars. A new progenitor model is required for this anomalous gamma-ray burst. We proposed that GRB 060614 might be produced through the tidal disruption of a star by an intermediate-mass black hole. In this scenario, the long duration and the lack of any associated supernova are naturally expected. The theoretical energy output is also consistent with observations. The observed 9 s periodicity in the gamma-ray light curve of GRB 060614 can also be satisfactorily explained.