Cosmological constraints from Planck galaxy clusters with CMB lensing mass bias calibration

Abstract

We present a new cosmological analysis of the galaxy clusters in the Planck MMF3 cosmology sample with a cosmic microwave background (CMB) lensing calibration of the cluster masses. As demonstrated by Planck, galaxy clusters detected via the Sunyaev-Zel'dovich (SZ) effect offer a powerful way to constrain cosmological parameters such as Ω m and σ 8 . Determining the absolute cluster mass scale is, however, difficult, and some recent calibrations have yielded cosmological constraints in apparent tension with constraints in the ΛCDM model derived from the power spectra of the primary CMB anisotropies. In order to calibrate the absolute mass scale of the full Planck cluster sample, we remeasure the masses of all 433 clusters through their weak lensing signature in the CMB temperature anisotropies as measured by Planck. We perform a joint Bayesian analysis of the cluster counts and masses taking as input the estimated cluster masses, SZ signal-to-noise ratios, and redshifts. Our analysis properly accounts for selection effects in the construction of the cluster sample. We find σ 8 (Ω m /0.33) 0.25 = 0.765 ± 0.035 and 1 − b SZ = 0.71 ± 0.10, where the mass bias factor 1 − b SZ relates cluster mass to the SZ mass that appears in the X-ray-calibrated cluster scaling relations. We find no evidence for tension with the Planck primary CMB constraints on ΛCDM model parameters.

Planck2018 results

“…( 34) is at the lower end of the weak-lensing mass estimates, but is about 2σ lower that the Planck CMB-lensing mass calibration reported in Planck Collaboration XX (2016). Zubeldia & Challinor (2019) have revisited the Planck CMB-lensing mass calibration, incorporating the CMB-lensing mass estimates within a likelihood describing the Planck cluster counts, together with a Planck prior on θ MC . This study corrects for significant biases in the analysis reported in Planck Collaboration XX (2016).…”

A space mission to map the entire observable universe using the CMB as a backlight

“…The detection levels shown in Table 1 can therefore be translated into constraints on f σ 8 . Note that the pairwise kSZ measurement based on galaxy surveys is affected by redshift-space distortions, which lead to small suppression of the signal at 20-100 Mpc and a sign inversion at 20 Mpc [21,47,48]. In Fig.…”

“…The hundreds of thousands of clusters expected to be detected by BACKLIGHT as described in Section 3.1.1 will be crucial to constrain the cosmological parameters that influence the geometry and growth of structures in the Universe. The cluster abundance measurements when combined with independent geometrical CMB and baryonic acoustic oscillation (BAO) measurements can also greatly enhance the constraining power of the overall cosmological parameter results [13,[18][19][20][21]. An important step in achieving this, however, involves an accurate measurement of the cluster masses.…”

The Cluster HEritage project with XMM-Newton: Mass Assembly and Thermodynamics at the Endpoint of structure formation

“…However, a consensus has not been reached, with, for example, WtG finding (1 − b) = 0.69 ± 0.07, marginally reconciling CMB and cluster constraints (Planck Collaboration XIII 2016) and implying a large HE bias, but LoCuSS measuring (1 − b) = 0.95 ± 0.04, indicating a low HE bias. An alternative mass measurement from lensing of the CMB itself by clusters initially suggested no significant bias (e.g., Melin & Bartlett 2015); however, recent re-analysis by Zubeldia & Challinor (2019), including the mass bias factor directly in the cosmological analysis, finds (1 − b) = 0.71 ± 0.10.…”