标题： 潮汐瓦解事件几年后的准周期性X射线喷发 显示英文标题

标题： Quasi-periodic X-ray eruptions years after a nearby tidal disruption event

摘要： 准周期性爆发（QPEs）是从星系核发出的软X射线明亮爆发，重复周期从数小时到数周不等。 这些罕见系统的机制尚不确定，但大多数理论涉及围绕超大质量黑洞（SMBH）的吸积盘，该吸积盘可能经历不稳定性或与近轨道上的恒星天体相互作用。 有人提出，当SMBH摧毁经过的恒星时，这种吸积盘可能会形成，这意味着许多QPEs应该在可观察到的潮汐瓦解事件（TDEs）之前发生。 两个已知的QPE源显示出与TDE一致的宁静态光度长期衰减，而两个观测到的TDEs也表现出与单次爆发一致的X射线闪焰。 TDEs和QPEs还倾向于在相似的星系中发生。 然而，没有一个确认的重复QPE与光谱确认的TDE或峰值亮度下观测到的光学TDE相关联。 在这里，我们报告了从附近的、广泛研究过的光学选择TDE AT2019qiz检测到的九个X射线QPE，其平均复发时间为约48小时。 我们检测并建模了吸积盘的X射线、紫外和光学辐射，并表明一个环绕物体与该盘碰撞可以为QPEs提供一种合理的解释。 显示英文摘要

摘要： Quasi-periodic Eruptions (QPEs) are luminous bursts of soft X-rays from the nuclei of galaxies, repeating on timescales of hours to weeks. The mechanism behind these rare systems is uncertain, but most theories involve accretion disks around supermassive black holes (SMBHs), undergoing instabilities or interacting with a stellar object in a close orbit. It has been suggested that this disk could be created when the SMBH disrupts a passing star, implying that many QPEs should be preceded by observable tidal disruption events (TDEs). Two known QPE sources show long-term decays in quiescent luminosity consistent with TDEs, and two observed TDEs have exhibited X-ray flares consistent with individual eruptions. TDEs and QPEs also occur preferentially in similar galaxies. However, no confirmed repeating QPEs have been associated with a spectroscopically confirmed TDE or an optical TDE observed at peak brightness. Here we report the detection of nine X-ray QPEs with a mean recurrence time of approximately 48 hours from AT2019qiz, a nearby and extensively studied optically-selected TDE. We detect and model the X-ray, ultraviolet and optical emission from the accretion disk, and show that an orbiting body colliding with this disk provides a plausible explanation for the QPEs.