The Halo Mass of Optically Luminous Quasars at z ,F≈ ,F1-2 Measured via Gravitational Deflection of the Cosmic Microwave Background

J. E. Geach, J. A. Peacock, A. D. Myers, R. C. Hickox, M. C. Burchard, M. L. Jones

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We measure the average deflection of cosmic microwave background photons by quasars at 〈Z〉= 1.7. 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 M i ≤-24 (K-corrected to z = 2). A stack of nearly 200,000 targets reveals an 8δ 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 log 10 (M h h -1 M)12.6 ±0.2 = and linear bias b=2.7±0.3 at 〈Z 〉= 1.7, 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 M h ≈ 10 13 h -1 M, scaling roughly as M h ∞ L opt 3/4 at M i ≲-24 mag, in good agreement with physically motivated quasar demography models. Although we acknowledge that this luminosity dependence is a marginal result, the observed Mh-L opt 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.

Original languageEnglish
Article number85
Pages (from-to)1-6
Number of pages6
JournalThe Astrophysical Journal
Issue number1
Publication statusPublished - 27 Mar 2019


  • galaxies: evolution
  • galaxies: halos
  • galaxies: high-redshift
  • large-scale structure of universe
  • quasars: general


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