Title: Can internal shocks produce the variability in GRBs? Show Chinese title

Title: 内部冲击能否产生伽马射线暴的变率？

Abstract: We discuss the possibility that gamma-ray bursts result from internal shocks in an ultra-relativistic matter. Using a simple model we calculate the temporal structure and we estimate the efficiency of this process. In this model the ultra-relativistic matter flow is represented by a succession of shells with random values of the Lorentz factor. We calculate the shocks that take place between those shells and we estimate the resulting emission. Internal shocks can produce the highly variable temporal structure observed in most of the bursts provided that the source emitting the relativistic flow is highly variable. The observed peaks are in almost one to one correlation to the activity of the emitting source. A large fraction of the kinetic energy is converted to radiation. The most efficient case is when an inner engine produces shells with comparable energy but very different Lorentz factors. It also gives the most preferable temporal structure. Show Chinese abstract

Abstract: 我们讨论了伽马射线暴可能由超相对论物质的内部冲击产生。 利用一个简单模型，我们计算了这种过程的时间结构，并估算了它的效率。 在这个模型中，超相对论物质流由一系列洛伦兹因子具有随机值的壳层组成。 我们计算了这些壳层之间的冲击，并估算了由此产生的辐射。 只要发射相对论流的源高度变化，内部冲击就能产生大多数爆发中观察到的高度可变的时间结构。 观测到的峰值几乎是一一对应于发射源的活动。 大量的动能被转化为辐射。 最有效的情况是当内引擎产生能量相当但洛伦兹因子非常不同的壳层时。 它也给出了最偏好的时间结构。