Tsukuba Uchu Forum

149th Uchu Forum

Bridging Nuclear Transients with AGNs - Insights from The Case of AT2023clx

Kohki Uno

Kyoto University


Abstract
Supermassive black holes in galaxy cores trigger dynamical outbursts called nuclear transients. The number of such transients has been increasing, leading to discoveries of serendipitous phenomena renewing our understanding. We present spectropolarimetric observations of AT2023clx, among the most nearby nuclear transients classified as a tidal disruption event (TDE). We detected two polarization components; one originated from an aspherical outflow associated with the transient, while the other from a persisting dust torus in an active galactic nucleus (AGN) via light echoes. We found that the outflow was aligned perpendicular to the torus plane. This implies that the pre-existing AGN disk influenced the orbit of the disrupted star, or even AT2023clx might have been triggered by a sudden AGN accretion event rather than a TDE. Irrespective of whether AT2023clx was a TDE or AGN activity, we conclude that pre-existing AGNs play a crucial role in producing some transients with TDE-like features. Image