A Systematic Search for Active Galactic Nucleus Flares in ZTF Data Release 23

Abstract Active galactic nuclei (AGNs) are known to exhibit stochastic variability across a wide range of timescales and wavelengths. AGN flares are extreme outbursts that deviate from this typical behavior and may trace a range of energetic physical processes. Using 6 yr of data from Zwicky Transient Facility Data Release 23, we conduct a systematic search for AGN flares among a sample of well-sampled AGNs and AGN candidates. We construct two catalogs: the AGN Flare Coarse Catalog, containing 28,504 flares identified via Bayesian blocks and Gaussian processes, and the AGN Flare Refined Catalog, comprising 1984 high-confidence flares selected using stricter criteria. We analyze their spatial distribution, temporal characteristics, host-AGN type, and potential origins. Some flares can be associated with known supernovae, tidal disruption events, or blazars, and a few may be linked to binary black hole mergers or microlensing events. These catalogs provide a valuable resource for studying transient phenomena in AGNs and are publicly available in the online machine-readable table and on GitHub.