Weighing obscured and unobscured quasar hosts with the CMB
  We cross-correlate a cosmic microwave background (CMB) lensing map with the
projected space densities of quasars to measure the bias and halo masses of a
quasar sample split into obscured and unobscured populations, the first
application of this method to distinct quasar subclasses. Several recent
studies of the angular clustering of obscured quasars have shown that these
objects likely reside in higher-mass halos compared to their unobscured
counterparts. This has important implications for models of the structure and
geometry of quasars, their role in growing supermassive black holes, and mutual
quasar/host galaxy evolution. However, the magnitude and significance of this
difference has varied from study to study. Using data from \planck, \wise, and
SDSS, we follow up on these results using the independent method of CMB lensing
cross-correlations. The region and sample are identical to that used for recent
angular clustering measurements, allowing for a direct comparison of the
CMB-lensing and angular clustering methods. At $z \sim 1$, we find that the
bias of obscured quasars is $b_q = 2.57 \pm 0.24$, while that of unobscured
quasars is $b_q = 1.89 \pm 0.19$. This corresponds to halo masses of $\log (M_h
/ M_{\odot} h^{-1}) = 13.24_{-0.15}^{+0.14}$ (obscured) and $\log (M_h /
M_{\odot} h^{-1}) = 12.71_{-0.13}^{+0.15}$ (unobscured). These results agree
well with with those from angular clustering (well within $1\sigma$), and
confirm that obscured quasars reside in host halos $\sim$3 times as massive as
halos hosting unobscured quasars. This implies that quasars spend a significant
portion of their lifetime in an obscured state, possibly more than one half of
the entire active phase.
