发表机构
Xiamen University; SHAO-XMU Joint Center for Astrophysics, Xiamen University; Shanghai Astronomical Observatory, Chinese Academy of Sciences（厦门大学; 厦大-上海天文台天体物理联合中心; 中国科学院上海天文台）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文提出双通道模型，认为磁化银核吸积盘内的卫星黑洞反复凌星产生准周期爆发，可解释Ansky源的X射线与延迟UV特征及其他QPE源的UV对应体缺失问题。
AI 中文摘要
准周期爆发（QPEs）是来自银核的反复软X射线耀斑，但其起源仍不确定。在Ansky源中探测到的延迟紫外（UV）对应体为可行模型提供了新约束。本文提出一个双通道模型：卫星黑洞（sBH）反复穿过由大尺度磁场贯穿的核吸积盘，引力聚焦与动力学拖拽产生热的、光学厚的抛射物，其膨胀与光子扩散为软X射线QPE提供能量。在基准邦迪尺度参数下，该模型给出特征X射线持续时间约为10³秒，光度约为10⁴² erg·s⁻¹；在较低轨道倾角下，持续时间可延长至Ansky源中观测到的日尺度。同时，sBH运动压缩并弯曲背景磁场，触发盘内重联，耗散的能量经光子扩散后以更宽、延迟的UV响应形式出现，产生的热功率与Ansky源的可变UV光度相当。不利的磁场条件或长于QPE复发周期的扩散时间会削弱或模糊UV信号，这可能解释了其他QPE源缺乏清晰UV对应体的原因。
英文摘要
Quasi-periodic eruptions (QPEs) are recurrent soft X-ray flares from galactic nuclei, but their origin remains uncertain. The delayed ultraviolet (UV) counterpart detected in ZTF19acnskyy provides a new constraint on viable models. We present a two-channel model in which a satellite black hole (sBH) repeatedly crosses a nuclear accretion disk threaded by a large-scale magnetic field. Gravitational focusing and dynamical drag generate hot, optically thick ejecta whose expansion and photon diffusion power the soft X-ray QPE. For fiducial Bondi-scale parameters, the model yields a characteristic X-ray duration of $\sim10^3\ \mathrm{s}$ and luminosity of $\sim10^{42}\ \mathrm{erg\,s^{-1}}$. For ZTF19acnskyy, the model reproduces the observed day-scale X-ray duration and energetics. Simultaneously, the sBH motion compresses and bends the background magnetic field, triggering in-disk reconnection. The reconnection channel provides the energy budget and photon-diffusion delay required for the variable UV component. Unfavorable magnetic fields or diffusion times longer than the QPE recurrence period can weaken or smear out the UV signal, potentially explaining the lack of clear UV counterparts in other QPE sources.
Comments10 pages, 1 figure, accepted for publication in ApJL
