AT2019aalc: An obscured tidal disruption event candidate in an active galactic nucleus revealed by its first flare?
- 1College of Physics and Electronic Engineering, Northwest Normal University
- 2Guangxi Key Laboratory for Relativistic Astrophysics, School of Physical Science and Technology, Guangxi University
Abstract
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 main-sequence star by a 1.862−0.259+0.255 × 107 M⊙ 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 × 1051 erg and about 0.2 M⊙ 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.
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BibTeX
@article{ying2026at2019aalc,
title = {{AT2019aalc: An obscured tidal disruption event candidate in an active galactic nucleus revealed by its first flare?}},
author = {Gu Ying and Li Xiao and Zhang Xue-Guang and Liang En-Wei},
journal = {Astronomy \& Astrophysics},
year = {2026},
month = nov,
doi = {10.1051/0004-6361/202659629},
url = {https://doi.org/10.1051/0004-6361/202659629},
note = {CC BY},
}
RIS
TY - JOUR
TI - AT2019aalc: An obscured tidal disruption event candidate in an active galactic nucleus revealed by its first flare?
AU - Gu Ying
AU - Li Xiao
AU - Zhang Xue-Guang
AU - Liang En-Wei
PY - 2026
DA - 2026/11/04
JO - Astronomy & Astrophysics
DO - 10.1051/0004-6361/202659629
UR - https://doi.org/10.1051/0004-6361/202659629
AB - 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 main-sequence star by a 1.862−0.259+0.255 × 107 M⊙ 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 × 1051 erg and about 0.2 M⊙ 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.
SN - 0004-6361
SN - 1432-0746
ER -