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arXiv 2501.00239astro-ph.HE
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论伽马射线暴的持续时间

On the Duration of Gamma-Ray Bursts

Bing Zhang

AI总结:

本文提出伽马射线暴持续时间由前身星、中心引擎、辐射体和几何四因素共同定义,并以近期观测到的持续时间与前身星不匹配事件为例,论证磁星引擎和辐射体等因素在部分伽马射线暴中起关键作用。

摘要:

最近,探测到一例与超新星成协的短持续时间伽马射线暴(GRB 200826A)以及两例与千新星成协的长持续时间伽马射线暴(GRB 211211A 和 GRB 230307A),这打破了关于伽马射线暴持续时间与其前身星系统之间存在整齐对应关系的希望。本文总结了能够塑造伽马射线暴持续时间的各种物理因素,并提出伽马射线暴的持续时间可以由四个因素定义:前身星、中心引擎、辐射体和几何结构。由前身星定义的持续时间仅在中心引擎由吸积供能且其他因素的修正不重要时才具有相关性。持续时间与前身星不匹配的混乱局面表明,至少在某些伽马射线暴中,其他因素可能在定义持续时间方面发挥重要作用。特别是,至少对于某些伽马射线暴而言,其能量来源可能不是吸积,而是毫秒磁星。GRB 211211A 的复杂光变曲线同时暗示了由前身星和引擎定义的持续时间,这可能需要一种涉及白矮星-中子星并合且并合产物为磁星的新型前身星系统。GRB 230307A 的单一宽脉冲光变曲线及其良好的能量依赖行为暗示了由辐射体定义的长持续时间。其中心引擎时标可能足够短,可以纳入标准双中子星并合的框架之内。其具有快速光变特征的尖峰状光变曲线以及延展的 X 射线辐射表明,在整体耗散区中存在由底层磁星供能的微喷流。

英文摘要:

Recently, a short-duration GRB with supernova association (GRB 200826A) and two long-duration GRBs with kilonova associations (GRB 211211A and GRB 230307A) have been detected, which demolished the hope for a tidy connection between GRB duration and their progenitor systems. Here I summarize various physical factors that can shape the duration of a GRB and propose that the duration of a GRB can be defined by four factors: progentor, central engine, emitter, and geometry. The progenitor-defined duration is only relevant when the central engine is powered by accretion and when the modifications by other factors are not important. The untidy situation of duration - progenitor mismatches suggests that other factors likely play important roles in defining GRB duration at least in some GRBs. In particular, a GRB may not be powered by accretion but rather by a millisecond magnetar at least for some GRBs. The complicated lightcurve of GRB 211211A suggests both progenitor- and engine-defined durations, which may require a new type of progenitor system involving a white dwarf - neutron star merger with a magnetar merger product. The single broad pulse lightcurve with well-behaved energy-dependent behavior of GRB 230307A suggests an emitter-defined long duration. The central engine timescale may be short enough to be accommodated within the framework of a standard binary neutron star merger. Its spiky lightcurve with fast variability as well as extended X-ray emission suggest the existence of mini-jets in the global dissipation region, powered by an underlying magnetar.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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