Variability-selected Active Galactic Nuclei in the VST-SUDARE/VOICE Survey of the COSMOS Field

Understand

Optical variability has proven to be an effective way of detecting AGNs in imaging surveys, lasting from weeks to years.

• In the present work we test its use as a tool to identify AGNs in the VST multi-epoch survey of the COSMOS field, originally tailored to detect supernova events.
• We make use of the multi-wavelength data provided by other COSMOS surveys to discuss the reliability of the method and the nature of our AGN candidates.
• Our selection returns a sample of 83 AGN candidates; based on a number of diagnostics, we conclude that 67 of them are confirmed AGNs (81% purity), 12 are classified as supernovae, while the nature of the remaining 4 is unknown.