A High Incidence of Mid-infrared Variability in Local Ultraluminous Infrared Galaxies
Researchers analyzed 11 years of mid-infrared data from WISE to find variability in local ultraluminous infrared galaxies (ULIRGs). They found 30 variable ULIRGs, with 25 showing large luminosity swings. These variations suggest compact, intensely active nuclear regions driven by tidal disruption events or changes in their central black holes (AGN).