The Halo Mass of Optically Luminous Quasars at z ≈ 1–2 Measured via Gravitational Deflection of the Cosmic Microwave Background.

We measure the average deflection of cosmic microwave background photons by quasars at . Our sample is selected from the Sloan Digital Sky Survey to cover the redshift range 0.9 ≤ z ≤ 2.2 with absolute i-band magnitudes of Mi ≤ −24 (K-corrected to z = 2). A stack of nearly 200,000 targets reveals an 8σ detection of Planck's estimate of the lensing convergence toward the quasars. We fit the signal with a model comprising a Navarro–Frenk–White density profile and a two-halo term accounting for correlated large-scale structure, which dominates the observed signal. The best-fitting model is described by an average halo mass and linear bias b = 2.7 ± 0.3 at , in excellent agreement with clustering studies. We also report a hint, at a 90% confidence level, of a correlation between the convergence amplitude and luminosity, indicating that quasars brighter than Mi ≲ −26 reside in halos of typical mass , scaling roughly as at mag, in good agreement with physically motivated quasar demography models. Although we acknowledge that this luminosity dependence is a marginal result, the observed Mh–Lopt relationship could be interpreted as a reflection of the cutoff in the distribution of black hole accretion rates toward high Eddington ratios: the weak trend of Mh with Lopt observed at low luminosity becomes stronger for the most powerful quasars, which tend to be accreting close to the Eddington limit. [ABSTRACT FROM AUTHOR]