In this study, we extract a 7-day binned γ-ray light curve from 2008 August to 2019 March in the energy range 0.1–300 GeV and identify four outburst periods with peak flux of >8.0×10−7 ph cm−2 s−1. Four active states in the optical are also marked during this period. The fastest variability timescale suggests the emission region radius is R∼ 2.4×1016 cm, and the observed emission region lies within RBLR∼ 1.0×1017 cm) suggest that the γ-ray flaring event maybe caused by a magnetic reconnection mechanism, but we cannot completely rule out the shock-in-jet model.
Liu et al. (Fri,) studied this question.