ChandraCOSMOS Legacy Survey: Clustering dependence of Type 2 active galactic nuclei on host galaxy properties

Abstract

Aims.We perform clustering measurements of 800 X-ray selectedChandraCOSMOS Legacy (CCL) Type 2 active galactic nuclei (AGN) with known spectroscopic redshift to probe the halo mass dependence on AGN host galaxy properties, such as galaxy stellar massMstar, star formation rate (SFR), and specific black hole accretion rate (BHAR;λBHAR) in the redshift rangez = [0−3].Methods.We split the sample of AGN with known spectroscopic redshits according toMstar, SFR andλBHAR, while matching the distributions in terms of the other parameters, including redshift. We measured the projected two-point correlation functionwp(rp) and modeled the clustering signal, for the different subsamples, with the two-halo term to derive the large-scale biasband corresponding typical mass of the hosting halo.Results.We find no significant dependence of the large-scale bias and typical halo mass on galaxy stellar mass and specific BHAR for CCL Type 2 AGN at meanz ∼ 1, while a negative dependence on SFR is observed, i.e. lower SFR AGN reside in richer environment. Mock catalogs of AGN, matched to have the same X-ray luminosity, stellar mass,λBHAR, and SFR of CCL Type 2 AGN, almost reproduce the observedMstar − Mh,λBHAR − Mhand SFR–Mhrelations, when assuming a fraction of satellite AGNfAGNsat∼ 0.15. This corresponds to a ratio of the probabilities of satellite to central AGN of being activeQ ∼ 2. Mock matched normal galaxies follow a slightly steeperMstar − Mhrelation, in which low mass mock galaxies reside in less massive halos than mock AGN of similar mass. Moreover, matched mock normal galaxies are less biased than mock AGN with similar specific BHAR and SFR, at least forQ > 1.