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arXiv 2602.23299astro-ph.HE
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一个由中间质量黑洞引发的白矮星潮汐破坏作为超长伽马射线暴250702B的前身

A White Dwarf Tidal Disruption by an Intermediate-Mass Black Hole as the Progenitor of Ultra-long GRB 250702B

Université Libre de Bruxelles(布鲁塞尔自由大学);University of Science and Technology of China(中国科学技术大学)

Chengchao Yuan, Ning Jiang, Zi-Gao Dai

AI总结:

研究发现中间质量黑洞对白矮星的潮汐破坏可解释超长伽马射线暴250702B的多波段特征。

摘要:

最近检测到的GRB 250702B,其持续时间约为2.5×10⁴秒,是迄今为止观测到的持续时间最长的伽马射线暴,挑战了传统的 collapsar 模型。其显著特征包括在探测后约1.3天出现异常的X射线爆发,X射线后光流在后期从陡峭衰减转为缓慢衰减,以及硬光谱从keV延伸到MeV能量范围。这里我们表明,这些多波段特征可以一致地解释为由中间质量黑洞(IMBH)对白矮星(WD)的连续部分潮汐破坏所驱动的相对论喷流。通过建模由重复部分破坏引起的时变吸积率和由此产生的喷流演化,我们表明外部前向和反向冲击波负责长期的X射线、近红外和无线电后光流,而明亮的X射线爆发起源于由快速和慢速相对论喷射物碰撞引起的内部能量耗散。我们的发现确立了IMBH-WD潮汐破坏事件作为超长伽马射线暴的可行引擎。

英文摘要:

The recent detection of GRB 250702B, the longest gamma-ray burst observed to date with prompt emission lasting $\sim 2.5\times 10^4$ seconds, challenges the conventional collapsar model. Its remarkable features--including an extraordinary X-ray flare at $\sim 1.3$ days post-detection, a late-time transition from steep to shallow decay in the X-ray afterglow, and hard spectra extending from keV to MeV energies--point to a novel progenitor. Here we show that these multiwavelength signatures can be consistently explained by a relativistic jet powered by successive partial tidal disruptions of a white dwarf (WD) by an intermediate-mass black hole (IMBH). By modeling the time-dependent accretion rate from repeated partial disruptions and the resulting jet evolution, we show that the external forward and reverse shocks account for the long-term X-ray, near-infrared, and radio afterglow, whereas the luminous X-ray flare originates from internal energy dissipation caused by collisions between fast and slow relativistic ejecta associated with the final complete disruption. Our findings establish IMBH-WD tidal disruption events as a viable engine for ultra-long GRBs.

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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