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arXiv 1602.04293astro-ph.GAastro-ph.HE
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由直接坍缩黑洞引起的恒星潮汐扰动事件

Stellar Tidal Disruption Events by Direct Collapse Black Holes

Kazumi Kashiyama, Kohei Inayoshi

摘要:

本文用$\sim 10^{5} \ \rm M_\odot$分析了由超大质量恒星在$z \gtrsim 10$的原子冷却晕中坍缩形成的直接坍缩黑洞的早期生长阶段。新生DCBH周围的核吸积盘在引力作用下是不稳定的,在离中心$\sim 0.01-0.1 \ \rm pc$处碎裂成带有少量$10 \ \rm M_\odot$的团块。这样的团块通过连续的气体吸积演化成具有少量$10-100 \ \rm M_\odot$的大质量III族恒星,并形成核星团。来自内部细长盘和星团的辐射和机械反馈将显著降低$\sim 10^6 \ \rm yr$内DCBH上的气体吸积速率。一些核恒星也可以分散到$\lesssim 10^6 \ \rm yr$内的损失锥轨道上,并被中央DCBH潮汐地破坏。由这样的潮汐破坏事件提供动力的喷流光度可以是$L_{\rm j} \gtrsim 10^{50} \ \rm erg \ s^{-1}$。将在X射线带中观察到即时发射,峰值持续时间为$δt_{\rm obs} \sim 10^{5-6} \ (1+z) \ \rm s$,随后是尾部$\propto t_{\rm obs}^{-5/3}$,即使从$z \sim 20$也可以通过Swift BAT和eROSITA检测到。无线电余辉的后续观测,例如,eVLA和JWST的宿主晕可以探测来自DCBH的最早AGN反馈。

英文摘要:

We analyze the early growth stage of direct-collapse black holes (DCBHs) with $\sim 10^{5} \ \rm M_\odot$, which are formed by collapse of supermassive stars in atomic-cooling halos at $z \gtrsim 10$. A nuclear accretion disk around a newborn DCBH is gravitationally unstable and fragments into clumps with a few $10 \ \rm M_\odot$ at $\sim 0.01-0.1 \ \rm pc$ from the center. Such clumps evolve into massive population III stars with a few $10-100 \ \rm M_\odot$ via successive gas accretion and a nuclear star cluster is formed. Radiative and mechanical feedback from an inner slim disk and the star cluster will significantly reduce the gas accretion rate onto the DCBH within $\sim 10^6 \ \rm yr$. Some of the nuclear stars can be scattered onto the loss cone orbits also within $\lesssim 10^6 \ \rm yr$ and tidally disrupted by the central DCBH. The jet luminosity powered by such tidal disruption events can be $L_{\rm j} \gtrsim 10^{50} \ \rm erg \ s^{-1}$. The prompt emission will be observed in X-ray bands with a peak duration of $δt_{\rm obs} \sim 10^{5-6} \ (1+z) \ \rm s$ followed by a tail $\propto t_{\rm obs}^{-5/3}$, which can be detectable by Swift BAT and eROSITA even from $z \sim 20$. Follow-up observations of the radio afterglows with, e.g., eVLA and the host halos with JWST could probe the earliest AGN feedback from DCBHs.

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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