Electromagnetic flares associated with gravitational waves from binary black hole mergers in AGN accretion disks

The gravitational wave (GW) event GW190521, likely originating from a binary black hole (BBH) merger within an active galactic nucleus (AGN) disk, is associated with the optical flare ZTF19abanrhr. The remnant black holes (BHs) from BBH mergers can launch the jet and outflow and then interact with the disk medium, which can be responsible for the associated electromagnetic radiations. In this work, we examine the shock breakout and subsequent cooling emissions from four potential components: the outflow, jet head, jet cocoon, and disk cocoon, all driven by the remnant BH within the AGN disk. Using dynamic models and observational constraints, for GW190521, we identify the parameter space for each component and conclude that either the outflow or the disk cocoon may produce the observed electromagnetic signals, whereas the outflow model requires an extremely high outflow velocity and the disk cocoon model requires a high jet power. We present best-fit light curves and spectral energy distributions for both components, showing peak emissions in the UV band for the outflow and spanning optical to UV for the disk cocoon.