PRIMUS: The relationship between Star formation and AGN accretion
Publication information:
Azadi M, Aird J, Coil A, Moustakas J, Mendez A, Blanton M, Cool R, Eisenstein D, Wong K, Zhu G. PRIMUS: The relationship between Star formation and AGN accretion. ArXiv e-prints. 2014;1407:1975.
Abstract
We study the evidence for a symbiotic connection between active galacticnuclei (AGN) fueling and star formation by investigating therelationship between the X-ray luminosities of AGN and the starformation rates (SFRs) of their host galaxies. We identify a sample of309 AGN with X-ray luminosities $10^{41} z 1.2$ in the PRIMUS spectroscopicredshift survey. There is a wide range of SFR at a given $L_X$, and wedo not find a significant correlation between SFR and the observedinstantaneous $L_X$ for star forming galaxies. However, there is a weakbut significant correlation between the mean $L_\mathrm{X}$ of detectedAGN and SFR, which likely reflects that $L_\mathrm{X}$ varies on shortertimescales than SFR. We also find no correlation between stellar massand AGN luminosity. AGN are found in star forming and quiescentgalaxies, and both galaxy populations have a similar power-lawdistribution in the probability of hosting an AGN as a function ofspecific accretion rate. However, a higher fraction of AGN hosts areclassified as star forming with increasing $L_\mathrm{X}$, and a starforming galaxy is $\sim2-3$ times more likely to host an AGN of a givenspecific accretion rate than a quiescent galaxy of the same stellarmass. The probability of a galaxy hosting an AGN remains constant acrossthe main sequence of star formation. These results indicate that thereis an underlying connection between star formation and the presence ofAGN, but AGN are also widespread in quiescent galaxies.