AGN’s Deadness Over Cosmic Time: UVJ Diagrams of X-Ray AGN

Abstract

Abstract Over cosmic time, galaxies tend to separate into a bimodal distribution of “red and dead” or blue and star-forming. We examine whether active galaxies evolve in a similar way, and whether this reveals anything about the complexities of the relationship between an AGN and the host galaxy. We use the Stripe82X survey to identify 3940 X-ray AGN spanning z = 0–2.5, and we measure the rest-frame UVJ colors of each galaxy. We classify AGN as star-forming or quiescent based on their location in a UVJ color diagram. We find that there is not a clear bimodal distribution between AGN in star-forming and quiescent galaxies. Furthermore, the most luminous X-ray sources tend to lie in the star-forming region, which may indicate a correlation between central engine activity and increased rates of star formation.