The clustering of X-ray selected AGN at z=0.1
  The clustering properties of moderate luminosity ($L_X = \rm 10^{41} -
10^{44} \, erg \,s^{-1}$) X-ray selected AGN at $z\approx0.1$ are explored.
X-ray sources in the redshift interval $0.03<z<0.2$ are selected from a
serendipitous XMM survey of the SDSS footprint (XMM/SDSS) and are
cross-correlated with the SDSS Main galaxy sample. The inferred X-ray AGN
auto-correlation function is described by a power law with amplitude
$r_0\approx5\,$h$^{-1}$Mpc and slope $\gamma\approx2.0$. The corresponding mass
of the dark matter haloes that host X-ray AGN at $z\approx0.1$ is $\approx
10^{13} \,h ^{-1} \, M_{\sun}$. Comparison with studies at higher redshift
shows that this mass scale is characteristic of moderate luminosity X-ray AGN
out to $z\approx 1$. Splitting the AGN sample by rest-frame color shows that
X-ray sources in red hosts are more clustered than those associated with blue
galaxies, in agreement with results at $z\approx1$. We also find that the host
galaxies of X-ray AGN have lower stellar masses compared to the typical central
galaxy of a $\approx 10^{13} \,h ^{-1} \, M_{\sun}$ dark matter halo. AGN hosts
either have experienced less stellar mass growth compared to the average
central galaxy of a $\approx 10^{13} \,h ^{-1} \, M_{\sun}$ halo or a fraction
of them are associated with satellite galaxies.
