2021MNRAS.500L..57Z

In this Letter, we report further evidence to support a tidal disruption event (TDE) in the known changing-look AGN SDSS J0159, through the unique variabilities of asymmetric broad Hα: broader but redder in 2010 than in 2000. If we accept that broad Hα emission regions are tightly related to accreting debris in a central TDE, the well-known relativistic accretion disc origination can be applied to explain the asymmetric broad Hα variabilities in SDSS J0159 well. Moreover, the model-determined broad Hα emission regions have sizes that do not follow the empirical R-L relation valid in normal broad-line active galactic nuclei (AGNs), but have locations basically similar to the regions of accreting debris from a central TDE in SDSS J0159, indicating tight connections between the broad Hα emission material and central TDE debris. Therefore, the explanation of asymmetric broad Hα variabilities through a relativistic accretion disc origination provides further clues to support a central TDE in SDSS J0159.