发表机构
College of Physics and Electronic Engineering, Northwest Normal University; School of Physical Science and Technology, Guangxi University（西北师范大学物理与电子工程学院; 广西大学物理科学与技术学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文通过时间依赖遮蔽TDE模型，成功再现AT2019aalc的光变曲线，揭示其首次耀发前的变暗与耀发后光度降低源于AGN辐射被遮蔽，并确认其为AGN中第二例遮蔽TDE候选体。
AI 中文摘要
AT2019aalc被认为是一个发生在活动星系核（AGN）中的重复潮汐瓦解事件（TDE）候选体。在本文中，我们强调了先前未被注意但引人注目的特征，包括在主耀发上升之前出现短暂的光学变暗，以及耀发后光度显著低于耀发前水平。通过将时间依赖的遮蔽TDE模型应用于AT2019aalc，我们成功地再现了其光变曲线，该事件是由一个$1.122_{-0.176}^{+0.246}\rm M_\odot$的主序星被一个$1.862_{-0.259}^{+0.255} \times 10^7{\rm M_\odot}$的超大质量黑洞（SMBH）潮汐瓦解所致。耀发前的变暗和耀发后光度降低均归因于对内在AGN辐射的遮蔽。根据我们的拟合得出的该事件总能量为$1.24\times10^{51}$尔格，约有0.2 ${\rm M_\odot}$的碎片质量被SMBH吸积。此外，AT2019aalc中净耀发的$g-r$颜色在首次耀发期间呈现持续变红的趋势，这与遮蔽TDE模型预测的$E(B-V)$逐渐增加相一致。这些结果表明，AT2019aalc可以被视为最近提出的AGN中遮蔽TDE候选体类的第二个成员。关键词：星系：活动-星系：核-类星体：超大质量黑洞-类星体：个别（AT2019aalc）-瞬变：潮汐瓦解事件。
英文摘要
AT2019aalc is considered a repeating tidal disruption event (TDE) candidate occurring in an active galactic nucleus (AGN). In this paper, we highlight previously unnoticed but intriguing features that include a brief optical dimming prior to the rise of the main flare and a significantly lower post-flare luminosity compared to the pre-flare level. By applying a time-dependent obscured TDE model to AT2019aalc, we successfully reproduce its light curves with the tidal disruption of a $1.122_{-0.176}^{+0.246}\rm M_\odot$ main-sequence star by a $1.862_{-0.259}^{+0.255} \times 10^7{\rm M_\odot}$ supermassive black hole (SMBH). Both the pre-flare dimming and the reduced post-flare luminosity are attributed to obscuration of the intrinsic AGN emission. The total energy of the event derived from our fit is $1.24\times10^{51}$ ergs and about 0.2 ${\rm M_\odot}$ of debris mass is accreted by the SMBH. In addition, the $g-r$ color of the net flare in AT2019aalc exhibits a continuous reddening trend during the first flare, consistent with a gradual increase in $E(B-V)$ predicted by the obscured TDE model. These results suggest that AT2019aalc can be considered a second member of the recently proposed class of obscured TDE candidates hosted in AGNs. } \keywords{galaxies: active-galaxies: nuclei-quasars: supermassive black holes-quasars: individual (AT2019aalc)-transients: tidal disruption events.
CommentsAccepted for publication in Astronomy & Astrophysics. 6 pages, 4 figures
