The halo mass of optically-luminous quasars at z=1-2 measured via gravitational deflection of the cosmic microwave background. (arXiv:1902.06955v1 [astro-ph.GA])
<a href="http://arxiv.org/find/astro-ph/1/au:+Geach_J/0/1/0/all/0/1">J. E. Geach</a> (Hertfordshire), <a href="http://arxiv.org/find/astro-ph/1/au:+Peacock_J/0/1/0/all/0/1">J. A. Peacock</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Myers_A/0/1/0/all/0/1">A. D. Myers</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hickox_R/0/1/0/all/0/1">R. C. Hickox</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Burchard_M/0/1/0/all/0/1">M. C. Burchard</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Jones_M/0/1/0/all/0/1">M. L. Jones</a>
We measure the average deflection of cosmic microwave background photons by
quasars at $langle z rangle =1.7$. Our sample is selected from the Sloan
Digital Sky Survey to cover the redshift range $0.9leq zleq2.2$ with absolute
i-band magnitudes of $M_ileq-24$ (K-corrected to z=2). A stack of nearly
200,000 targets reveals an 8$sigma$ detection of Planck’s estimate of the
lensing convergence towards the quasars. We fit the signal with a model
comprising a Navarro-Frenk-White density profile and a 2-halo term accounting
for correlated large scale structure, which dominates the observed signal. The
best-fitting model is described by an average halo mass $log_{10}(M_{rm
h}/h^{-1}M_odot)=12.6pm0.2$ and linear bias $b=2.7pm0.3$ at $z=1.7$, in
excellent agreement with clustering studies. We also report of a hint, at a 90%
confidence level, of a correlation between the convergence amplitude and
luminosity, indicating that quasars brighter than $M_ilesssim -26$ reside in
halos of typical mass ${M_{rm h}approx 10^{13},h^{-1}M_odot}$, scaling
roughly as ${M_{rm h}propto L_{rm opt}^{3/4}}$ at ${M_ilesssim-24}$, in
good agreement with physically-motivated quasar demography models. Although we
acknowledge this luminosity dependence is a marginal result, the observed
$M_{rm h}$-$L_{rm opt}$ relationship could be interpreted as a reflection of
the cutoff in the distribution of black hole accretion rates towards high
Eddington ratios: the weak trend of $M_{rm h}$ with $L_{rm opt}$ observed at
low luminosity becomes stronger for the most powerful quasars, which tend to be
accreting close to the Eddington limit.
We measure the average deflection of cosmic microwave background photons by
quasars at $langle z rangle =1.7$. Our sample is selected from the Sloan
Digital Sky Survey to cover the redshift range $0.9leq zleq2.2$ with absolute
i-band magnitudes of $M_ileq-24$ (K-corrected to z=2). A stack of nearly
200,000 targets reveals an 8$sigma$ detection of Planck’s estimate of the
lensing convergence towards the quasars. We fit the signal with a model
comprising a Navarro-Frenk-White density profile and a 2-halo term accounting
for correlated large scale structure, which dominates the observed signal. The
best-fitting model is described by an average halo mass $log_{10}(M_{rm
h}/h^{-1}M_odot)=12.6pm0.2$ and linear bias $b=2.7pm0.3$ at $z=1.7$, in
excellent agreement with clustering studies. We also report of a hint, at a 90%
confidence level, of a correlation between the convergence amplitude and
luminosity, indicating that quasars brighter than $M_ilesssim -26$ reside in
halos of typical mass ${M_{rm h}approx 10^{13},h^{-1}M_odot}$, scaling
roughly as ${M_{rm h}propto L_{rm opt}^{3/4}}$ at ${M_ilesssim-24}$, in
good agreement with physically-motivated quasar demography models. Although we
acknowledge this luminosity dependence is a marginal result, the observed
$M_{rm h}$-$L_{rm opt}$ relationship could be interpreted as a reflection of
the cutoff in the distribution of black hole accretion rates towards high
Eddington ratios: the weak trend of $M_{rm h}$ with $L_{rm opt}$ observed at
low luminosity becomes stronger for the most powerful quasars, which tend to be
accreting close to the Eddington limit.
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