A normal broad line AGN SDSS J1617+0638 as the host galaxy of a central tidal disruption event

TL;DR

This study provides evidence that the normal broad line AGN SDSS J1617+0638 hosts a central tidal disruption event, supported by optical flare analysis, spectral modeling, and consistency with TDE predictions.

Contribution

It demonstrates the application of TDE models to a broad line AGN with pre-existing activity, combining photometric and spectroscopic data for evidence of a central TDE.

Findings

Optical flare supports TDE presence in SDSS J1617+0638

Spectral analysis requires additional power law component

TDE model mass estimate aligns with virial BH mass

Abstract

In this manuscript, strong clues are reported to support the normal broad line AGN SDSS J1617+0638 as the host galaxy harboring a central tidal disruption event (TDE). Through the optical flare in the CSS 8.5years-long light curve and the none-variability in the up-to-date ASAS-SN light curves, the theoretical TDE model described by the MOSFIT code can be applied in SDSS J1617+0638. Meanwhile, considering the assumed central TDE expected continuum emissions not strong enough to describe the continuum emissions in the SDSS spectrum of SDSS J1617+0638, an additional power law component from pre-existing AGN activity should be necessary in SDSS J1617+0638. Furthermore, considering the short time duration to the observed date for the SDSS spectrum from the starting time of the assumed central TDE in SDSS J1617+0638, TDE model expected accreting mass only about 0.03$M_\odot$ can lead to few effects of TDEs debris on the observed broad emission lines in the SDSS spectrum of SDSS J1617+0638, indicating the TDE model determined BH mass simply consistent with the virial BH mass by broad emission lines, as determined results in SDSS J1617+0638. Therefore, through both the photometric variability and the spectroscopic results, a central TDE can be preferred in the normal broad line AGN SDSS J1617+0638 with pre-existing central AGN activity and pre-existing broad emission line regions.