Short gamma-ray bursts (sGRBs) are generally thought to result from the merger of two neutron stars or the merger of a neutron star with a black hole. It is becoming standard practice to model these mergers with hydrodynamical simulations that employ equations of state that are derived, for example, for determining the behavior of matter in core-collapse supernovae, and which therefore make use of the assumption that the matter is hot and in nuclear statistical equilibrium (NSE). In this Letter we draw attention to the fact that the hydrodynamical timescale (roughly the gravitational timescale of the neutron star) may be several orders of magnitude shorter than the timescale on which such equilibrium can be reestablished in the tidal debris ejected during an sGRB, and that on the initial decompression timescales the unshocked tidal ejecta may remain sufficiently cool that the employed equations of state are not appropriate for modeling the dynamics of this part of the flow. On t...

中文翻译：

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短伽玛射线暴和潮汐流中中子星物质的减压

一般认为，短伽马射线爆发（sGRB）是由两个中子星合并或带有黑洞的中子星合并产生的。通过流体动力学模拟对合并进行建模已成为标准做法，该流体动力学模拟采用状态方程，例如用于确定核塌缩超新星中物质的行为的状态方程，因此利用物质是热的和热的​​假设。在核统计平衡（NSE）中。在这封信中，我们提请注意以下事实：流体动力时标（大致是中子星的重力时标）可能比在sGRB期间喷出的潮汐碎片中可以重新建立这种平衡的时标短几个数量级，并且在初始减压时间尺度上，未震荡的潮汐射流可能保持足够凉爽，以至于所采用的状态方程不适用于对这部分流动的动力学进行建模。在...