Central BH Mass of Tidal Disruption Event Candidate SDSS J0159 through Long-term Optical Variabilities

Abstract

In this manuscript, central BH mass is determined in the tidal disruption event (TDE) candidate SDSS J0159, through the 9 yr long variabilities, in order to check whether the virial BH mass is consistent with the mass estimated by other independent methods. First, the host galaxy spectroscopic features are described by 350 simple stellar templates, to confirm the total stellar mass of about 7 × 10 ^10 M _⊙ in SDSS J0159, indicating the virial BH mass is about two magnitudes larger than the BH mass estimated by the total stellar mass. Second, based on an efficient method and fitting procedure, through the theoretical TDE model applied to describe the Sloan Digital Sky Survey ugriz -band light curves of SDSS J0159, the central BH mass can be determined as ${M}_{\mathrm{BH}}\sim {4.5}_{-1.1}^{+1.3}\times {10}^{6}\,{M}_{\odot }$ , well consistent with the M _σ relation expected BH mass and the total stellar mass expected BH mass. Third, the theoretical TDE model with the parameter of central BH mass limited to be higher than 10 ^8 M _⊙ cannot lead to reasonable descriptions of the light curves of SDSS J0159, indicating central BH mass higher than 10 ^8 M _⊙ is not preferred in SDSS J0159. Therefore, the TDE model determined central BH mass of SDSS J0159 is about two magnitudes lower than the virial BH mass, to support central broad-line regions, including accreting debris contributions from central TDE, and provide interesting clues to reconfirm that outliers in the space of virial BH mass versus stellar velocity dispersion should be better candidates of TDE.

Keywords

• Active galactic nuclei
• Emission line galaxies
• Supermassive black holes
• Tidal disruption
• Transient sources