Modeling the UV/Optical light curve of re-brightening tidal disruption events

Abstract

In recent years, a new subclass of tidal disruption events (TDEs) was reported from the literature. The light curve of these TDEs show a re-brightening feature in the decline phase after the first peak, which then leads to a second flare. The re-brightening TDEs challenges the existing light curve fitting tools, which are designed to handle single flare. In this work, we present a model, aimed at reproducing of the light curve of the re-brightening TDEs, based on the scenario that the consecutive flares are produced by the same star who experienced two partial disruptions (PTDEs). We also develop a fitting code from this model, and apply it to two re-brightening TDEs: AT 2022dbl and AT 2023adr. The light curve of both TDEs are well fitted. Finally, we forecast the time and peak brightness of the next flare for these two TDEs, so that the observers could get prepared in advance and make an examination on our model.