The Chandra COSMOS Legacy Survey: Clustering of X-Ray-selected AGNs at 2.9 ≤ z ≤ 5.5 Using Photometric Redshift Probability Distribution Functions

We present the measurement of the projected and redshift-space two-point correlation function (2pcf) of the new catalog of Chandra COSMOS-Legacy active galactic nucleus (AGN) at 2.9 ≤ z ≤ 5.5 (< {L}_{bol}> ∼ 10⁴⁶ erg s^-1) using the generalized clustering estimator based on phot-z probability distribution functions in addition to any available spec-z. We model the projected 2pcf, estimated using π _max = 200 h^-1 Mpc with the two-halo term and we derive a bias at z ∼ 3.4 equal to b = {6.6}_-0.55^+0.60, which corresponds to a typical mass of the hosting halos of log M _h = {12.83}_-0.11^+0.12 h^-1 M _⊙. A similar bias is derived using the redshift-space 2pcf, modeled including the typical phot-z error σ _z = 0.052 of our sample at z ≥ 2.9. Once we integrate the projected 2pcf up to π _max = 200 h^-1 Mpc, the bias of XMM and Chandra COSMOS at z = 2.8 used in Allevato et al. is consistent with our results at higher redshifts. The results suggest only a slight increase of the bias factor of COSMOS AGNs at z ≳ 3 with the typical hosting halo mass of moderate-luminosity AGNs almost constant with redshift and equal to log M _h = {12.92}_-0.18^+0.13 at z = 2.8 and log M _h = {12.83}_-0.11^+0.12 at z ∼ 3.4, respectively. The observed redshift evolution of the bias of COSMOS AGNs implies that moderate-luminosity AGNs still inhabit group-sized halos at z ≳ 3, but slightly less massive than observed in different independent studies using X-ray AGNs at z ≤ 2.