Simulations of Tidal Disruption of Supernova in Galaxy Nuclear Region: A Novel Model for Ambiguous Nuclear Transients

Abstract: An increasing number of ambiguous nuclear transients, including some extreme nuclear transients, have been reported, which cannot be simply explained by the tidal disruption event (TDE) due to their high energy and/or overmassive black holes. Stars that form in or are captured by AGN disks will grow and migrate inward, potentially exploding as supernovae once the inner cold accretion disk disappears during the phase of AGN decay. We propose that tidal disruption of a supernova (TDS) by a supermassive black hole (SMBH) can produce nuclear transients that are even more luminous than typical TDEs and are not limited by the SMBH mass. In this scenario, the SMBH can capture the supernova ejecta, which subsequently self-intersects and circularizes into an accretion disk. Based on hydrodynamical simulations, we find that the accretion rate of the TDS disk exhibits a slow decline that can last for months to decades. The peak accretion rate of a typical core-collapse SN scenario can exceed the Eddington limit for SMBHs with $M_{\rm BH} \lesssim 10<sup>{7.5}\,M_\odot$, while it remains sub-Eddington for more massive SMBHs. This model provides a mechanism for triggering an energetic TDE-like flare with luminosity (\gtrsim10^{45}\,\mathrm{erg\,s^{-1}}) in galaxies with $M_{\rm BH}\gtrsim10<sup>{8}\,M_\odot$ or triggering turn-on changing-look AGNs.