Planck Early Results. X. Statistical analysis of Sunyaev-Zeldovich scaling relations for X-ray galaxy clusters

TL;DR

This study combines Planck and X-ray data to analyze the Sunyaev-Zeldovich effect in galaxy clusters, confirming the scaling relations and their evolution with high significance and no evidence of deviation from standard models.

Contribution

It provides the first measurement of the intrinsic scatter in SZ-X-ray luminosity scaling relations and confirms the consistency of SZ and X-ray observations across a wide luminosity range.

Findings

High-significance detection of SZ signal across luminosity range

Excellent agreement between Planck measurements and X-ray predictions

No evidence of deviation from standard scaling relation evolution

Abstract

All-sky data from the Planck survey and the Meta-Catalogue of X-ray detected Clusters of galaxies (MCXC) are combined to investigate the relationship between the thermal Sunyaev-Zeldovich (SZ) signal and X-ray luminosity. The sample comprises ~ 1600 X-ray clusters with redshifts up to ~ 1 and spans a wide range in X-ray luminosity. The SZ signal is extracted for each object individually, and the statistical significance of the measurement is maximised by averaging the SZ signal in bins of X-ray luminosity, total mass, or redshift. The SZ signal is detected at very high significance over more than two decades in X-ray luminosity (10^43 erg/s < L_500 E(z)^-7/3 < 2 X 10^45 erg/s). The relation between intrinsic SZ signal and X-ray luminosity is investigated and the measured SZ signal is compared to values predicted from X-ray data. Planck measurements and X-ray based predictions are found to be in excellent agreement over the whole explored luminosity range. No significant deviation from standard evolution of the scaling relations is detected. For the first time the intrinsic scatter in the scaling relation between SZ signal and X-ray luminosity is measured and found to be consistent with the one in the luminosity -- mass relation from X-ray studies. There is no evidence of any deficit in SZ signal strength in Planck data relative to expectations from the X-ray properties of clusters, underlining the robustness and consistency of our overall view of intra-cluster medium properties.