AI 中文总结
本研究针对潮汐瓦解事件中相对论性喷流的磁通量与等离子体起源问题，提出磁通量平流与光子-光子对产生的机制，解释了BZ喷流的启动与瞬时辐射的来源。
AI 中文摘要
潮汐瓦解事件（TDE）发生于恒星接近黑洞（BH）时，被黑洞的潮汐力瓦解。尽管迄今已确认数百个TDE，但仅少数伴随相对论性喷流。这些喷流被认为是由Blandford-Znajek（BZ）机制驱动的坡印廷通量主导外流。然而，驱动BZ喷流所需的磁通量与等离子体的起源仍不明确。在本研究中，我们提出一种场景：磁通量最初存储在黑洞周围已存在的低爱丁顿吸积盘中，随后在恒星瓦解后形成的超爱丁顿吸积流作用下平流至黑洞。我们发现，红巨星等低密度恒星可提供足够磁通量以驱动BZ喷流。当黑洞附近积累足够磁通量后，会形成赤道电流片，其中的磁重联产生高能伽马射线。我们发现，这些伽马射线的光子-光子对产生过程为黑洞磁层提供了足够等离子体，以启动并维持BZ喷流。我们进一步表明，该机制同时提供了足够的辐射粒子，可解释观测到的瞬时辐射。
英文摘要
A tidal disruption event (TDE) occurs when a star approaches a black hole (BH) and is disrupted by its tidal forces. Although several hundred TDEs have been identified to date, only a small fraction are accompanied by relativistic jets. These jets are thought to be Poynting-flux-dominated outflows powered by the Blandford--Znajek (BZ) mechanism. However, the origin of the magnetic flux and plasma needed to power BZ jets remain unclear. In this Letter, we propose a scenario in which magnetic flux is initially stored in a pre-existing low-Eddington accretion disk around BH, and is subsequently advected toward the BH by the super-Eddington accretion flow formed after the stellar disruption. We show that stars with low densities, such as red giants, can supply sufficient magnetic flux to power a BZ jet. Once sufficient magnetic flux accumulates near the BH, an equatorial current sheet forms where magnetic reconnection produces high-energy gamma rays. We find that photon--photon pair production by these gamma rays supplies the BH magnetosphere with sufficient plasma to launch and sustain a BZ jet. We further show that this mechanism simultaneously provides enough radiating particles to account for the observed prompt emission.
Comments9 pages, 2 figure
