The Chandra COSMOS Legacy Survey: Clustering of X-ray selected AGN at
  2.9<z<5.5 using photometric redshift Probability Distribution Functions
  We present the measurement of the projected and redshift space 2-point
correlation function (2pcf) of the new catalog of Chandra COSMOS-Legacy AGN at
2.9$\leq$z$\leq$5.5 ($\langle L_{bol} \rangle \sim$10$^{46}$ erg/s) using the
generalized clustering estimator based on phot-z probability distribution
functions (Pdfs) in addition to any available spec-z. We model the projected
2pcf estimated using $\pi_{max}$ = 200 h$^{-1}$ Mpc with the 2-halo term and we
derive a bias at z$\sim$3.4 equal to b = 6.6$^{+0.60}_{-0.55}$, which
corresponds to a typical mass of the hosting halos of log M$_h$ =
12.83$^{+0.12}_{-0.11}$ h$^{-1}$ M$_{\odot}$. A similar bias is derived using
the redshift-space 2pcf, modelled including the typical phot-z error $\sigma_z$
= 0.052 of our sample at z$\geq$2.9. Once we integrate the projected 2pcf up to
$\pi_{max}$ = 200 h$^{-1}$ Mpc, the bias of XMM and \textit{Chandra} COSMOS at
z=2.8 used in Allevato et al. (2014) is consistent with our results at higher
redshift. The results suggest only a slight increase of the bias factor of
COSMOS AGN at z$\gtrsim$3 with the typical hosting halo mass of moderate
luminosity AGN almost constant with redshift and equal to logM$_h$ =
12.92$^{+0.13}_{-0.18}$ at z=2.8 and log M$_h$ = 12.83$^{+0.12}_{-0.11}$ at
z$\sim$3.4, respectively. The observed redshift evolution of the bias of COSMOS
AGN implies that moderate luminosity AGN still inhabit group-sized halos at
z$\gtrsim$3, but slightly less massive than observed in different independent
studies using X-ray AGN at z$\leq2$.
