WMAP Observations of Planck ESZ Clusters

TL;DR

This paper analyzes the Sunyaev--Zeldovich effect in WMAP data by cross-correlating with Planck clusters, confirming detection and consistency of SZ signals with high significance and minimal bias.

Contribution

It provides the first detailed comparison of SZ measurements between WMAP and Planck data, demonstrating agreement within 25% and confirming WMAP's capability to detect SZ signals.

Findings

WMAP detects Planck clusters with S/N of 16.3

SZ amplitude measurements agree within 25%

Regression yields a=1.23 ± 0.18 for SZ amplitudes

Abstract

We examine the Sunyaev--Zeldovich (SZ) effect in the 7-yr Wilkinson Microwave Anisotropy Probe (WMAP) data by cross-correlating it with the Planck Early-release Sunyaev--Zeldovich catalog. Our analysis proceeds in two parts. We first perform a stacking analysis in which the filtered WMAP data are averaged at the locations of the 175 Planck clusters. We then perform a regression analysis to compare the mean amplitude of the SZ signal, Y_{500}, in the WMAP data to the corresponding amplitude in the Planck data. The aggregate Planck clusters are detected in the 7-yr WMAP data with a signal-to-noise ratio of 16.3. In the regression analysis we find that the SZ amplitude measurements agree to better than 25%: $a=1.23 \pm 0.18$ for the fit Y^{wmap}_{500} = aY^{planck}_{500}$.