Date Published:

June 1, 2015

Abstract:

We study the evidence for a connection between active galactic nuclei(AGNs) fueling and star formation by investigating the relationshipbetween the X-ray luminosities of AGNs and the star formation rates(SFRs) of their host galaxies. We identify a sample of 309 AGNs with{10}⁴¹\lt {L}_X\lt {10}⁴⁴ ergs^-1 at 0.2\lt z\lt 1.2 in the PRIMUS redshift survey.We find AGNs in galaxies with a wide range of SFR at a givenL_X. We do not find a significant correlation between SFR andthe observed instantaneous L_X for star-forming AGN hostgalaxies. However, there is a weak but significant correlation betweenthe mean L_X and SFR of detected AGNs in star-forminggalaxies, which likely reflects that L_X varies on shortertimescales than SFR. We find no correlation between stellar mass andL_X within the AGN population. Within both populations ofstar-forming and quiescent galaxies, we find a similar power-lawdistribution in the probability of hosting an AGN as a function ofspecific accretion rate. Furthermore, at a given stellar mass, we find astar-forming galaxy ˜2-3 more likely than a quiescent galaxyto host an AGN of a given specific accretion rate. The probability of agalaxy hosting an AGN is constant across the main sequence of starformation. These results indicate that there is an underlying connectionbetween star formation and the presence of AGNs, but AGNs are oftenhosted by quiescent galaxies.

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