2017MNRAS.464.2378R

We use a Bayesian software package to analyse CARMA-8 data towards 19 unconfirmed Planck Sunyaev-Zel'dovich-cluster candidates from Rodriguez-Gonzalvez et al. that are associated with significant overdensities in WISE. We use two cluster parameterizations, one based on a (fixed shape) generalized-NFW (gNFW) pressure profile and another on a β gas density profile (with varying shape parameters) to obtain parameter estimates from the CARMA-8 data for the nine CARMA-8-detected clusters.
Result. from the β model show that our cluster candidates exhibit a heterogeneous set of brightness-temperature profiles. Comparison of Planck and CARMA-8 measurements show good agreement in Y₅₀₀ and an absence of obvious biases. Applying a Planck prior in Y₅₀₀ to the CARMA-8 gNFW results reduces uncertainties in Y₅₀₀ and Θ₅₀₀ dramatically (by a factor >4), relative to the independent Planck or CARMA-8 measurements. From this combined analysis, we find that our sample is comprised of massive (Y₅₀₀ ranging from 3.3^+0.2_–0.2 to 10^+1.1_–1.5 x 10^–4 arcmin², sd = 2.2 x 10^–4), relatively compact (θ₅₀₀ ranging from 2.1^+0.1_–0.3 to 5.5^+0.2_–0.8 arcmin, sd = 1.0) systems. Spectroscopic Keck/MOSFIRE data confirmed a galaxy member of one of our cluster candidates at z = 0.565. At the preferred photometric redshift of 0.5, we estimate the cluster mass M₅₀₀ ≃ 0.8 ± 0.2 x 10¹⁵ M_☉. We here demonstrate a powerful technique to find massive clusters at intermediate (z >= 0.5) redshifts using a cross-correlation between Planck and WISE data, with high-resolution CARMA-8 follow-up. We also use the combined capabilities of Planck and CARMA-8 to obtain a dramatic reduction, by a factor of several, in parameter uncertainties.