Star formation properties of X-ray detected galaxies in COSMOS field: Connection between AGN activity and recent star formation

Abstract

One of the key outstanding problems in studies of galaxy evolution is understanding the connection between AGN and star formation (SF). Nevertheless, finding the existence of an SF-AGN connection is still not clear which process dominates the energetic output in both local and high redshift Universe. We present 360 X-ray selected obscured (type 2) AGNs at redshift z < 1.5. We acquired star formation properties for those X-ray detected AGN which available in the Cosmological Evolution Survey (COSMOS) project. We compared the star formation properties for our X-ray detected AGNs and non-X-ray galaxies using starburstiness. The step further is analyzing the X-ray properties and starburstiness of X-ray detected AGN for proving the existence of a connection. The starburstiness distribution of X-ray detected AGNs shows some excess in low star forming activity compared with the non-AGN objects. This excess might be an interesting topic to analyze the AGN type. For X-ray detected AGNs, We found that X-ray activities arise both in high and lower star forming activity. From those properties relation, we conclude that the AGNs could be triggered by starburst either directly or delayed.