SDSS J0159 as an outlier in the Mbh-sigma space: further clues to support a central tidal disruption event?

TL;DR

This paper investigates SDSS J0159, a changing-look AGN with a tidal disruption event, revealing that overestimated virial black hole masses can be explained by stellar debris contributions, supporting the presence of a central TDE.

Contribution

It demonstrates that overestimated virial BH masses in the extit{M}– extsigma elation can be explained by stellar debris from TDEs, providing new clues to identify TDEs in AGNs.

Findings

SDSS J0159 is an outlier in the extit{M}– extsigma elation due to overestimated BH mass.

Stellar debris from TDEs can inflate broad line-based BH mass estimates.

Overestimated virial BH masses may serve as indicators of central TDEs.

Abstract

In this Letter, properties of black hole (BH) mass are well checked for the interesting object SDSS J0159, a changing-look AGN and also a host galaxy of a tidal disruption event (TDE). Through spectral absorption features, the stellar velocity dispersion of SDSS J0159 can be well measured as $\sigma\sim81~{\rm km/s}$, leading to SDSS J0159 being an apparent outlier in the \msig space, because of the BH mass estimated through the \msig relation about two magnitudes lower than the reported virial BH mass of about $10^8~{\rm M_\odot}$. After considerations of contributions of stellar debris from the central TDE to broad line emission clouds, the over-estimated virial BH mass could be well explained in SDSS J0159. Therefore, over-estimated virial BH masses through broad line properties in the \msig space could be treated as interesting clues to support central TDEs.