标题： 由TDE AT2019qiz的红外回声揭示的环状残骸：对缺失能量和QPE形成的意义 显示英文标题

标题： A Torus Remnant Revealed by the Infrared Echo of TDE AT2019qiz: Implications for the Missing Energy and QPE Formation

摘要： AT2019qiz是第一个在光学波段检测到X射线准周期性爆发（QPEs）的标准潮汐撕裂事件（TDE），为TDE-QPE关联提供了有力证据。 此外，它属于通过广域红外巡天探测器（WISE）多历元测光数据揭示出明显红外（IR）回声的罕见光学TDE子集。 红外光变曲线显示早期有一个小峰，随后持续上升直到倒数第二个历元，之后似乎进入平台阶段。 尘埃温度在第四历元前持续下降，并在随后五个历元保持大致恒定。 我们使用凸形尘埃环模型拟合了最后五个历元，得到内半径为$>1.2$光年。 如此大的半径大大超过了对于$10^6\,M_{\odot}$黑洞的活动星系核（AGN）环状结构的内半径，因此可能是环状结构的残余物，其中内部部分已经消失，进一步支持了近期熄灭的AGN、TDE和QPE的统一场景。 因此，自然预期QPE与红外明亮的TDE之间存在联系。 此外，该回声需要至少峰值光度为$(6.6, 9.5, 1.0)\times 44 \,\text{erg}\,\text{s}^{-1}$，分别假设为硅酸盐、碳化硅和石墨尘埃颗粒，所有这些都显著高于峰值光学黑体光度。 这增加了TDE缺失能量可能存在于不可观测的极端紫外线中的累积证据。 这项工作突显了红外回声在研究TDE和QPE中的独特价值，并且在近地天体（NEO）探测器时代——即WISE的继任者中具有良好的前景。 显示英文摘要

摘要： AT2019qiz is the first standard optical tidal disruption event (TDE) with detection of X-ray quasi-periodic eruptions (QPEs), providing strong evidence for TDE-QPE association. Moreover, it belongs to the rare subset of optical TDEs with prominent infrared (IR) echoes revealed by the multi-epoch photometry from the Wide-field Infrared Survey Explorer (WISE). The IR light curve shows an early bump, followed by a steady rise until the second-to-last epoch, after which it appears to enter a plateau phase. The dust temperature decreased until the fourth epoch and remains approximately constant for the subsequent five epochs. We have fitted the last five epochs using a convex dust ring model, resulting in an inner radius $>1.2$ pc. Such a large radius greatly exceeds the inner radius of the active galactic nuclei (AGN) torus for a $10^6\,M_{\odot}$ black hole and thus could be a torus remnant with the inner part having vanished, further supporting the unified scenario of recently faded AGNs, TDEs, and QPEs. Consequently, a connection between QPEs and IR-bright TDEs is naturally expected. Moreover, the echo requires at least a peak bolometric luminosity of $(6.6, 9.5, 1.0)\times 44 \,\text{erg}\,\text{s}^{-1}$ assuming silicate, silicon carbide, and graphite dust grains, respectively, all of which are significantly higher than the peak optical blackbody luminosity. It adds to the accumulating evidence that the missing energy of TDEs may lie in the unobservable extreme UV. This work highlights the unique value of IR echoes in the study of TDEs and QPEs, and a promising prospect in the era of the Near-Earth Object (NEO) Surveyor, the successor to WISE.