Scaling Relations and X-ray Properties of Moderate-Luminosity Galaxy Clusters from 0.3 < z < 0.6 with XMM-Newton

TL;DR

This study refines X-ray scaling relations for moderate-luminosity galaxy clusters at intermediate redshifts using XMM-Newton data, improving mass and luminosity estimates and reducing scatter in key relations relevant for cosmology.

Contribution

It provides improved X-ray luminosity and temperature measurements for low-mass clusters and extends scaling relations to lower masses and redshifts, with reduced scatter.

Findings

M ∝ L^0.44 ± 0.05 within r2500

T ∝ L^0.23 ± 0.02 within r2500

Intrinsic scatter in M-L relation reduced to 0.10

Abstract

We present new X-ray temperatures and improved X-ray luminosity estimates for 15 new and archival XMM-Newton observations of galaxy clusters at intermediate redshift with mass and luminosities near the galaxy group/cluster division (M2500 < $2.4\times 10^{14} h_{70}^{-1} M_\odot$, L < $2\times 10^{44}$ erg $s^{-1}$, 0.3< z < 0.6). These clusters have weak-lensing mass measurements based on Hubble Space Telescope observations of clusters representative of an X-ray selected sample (the ROSAT 160SD survey). The angular resolution of XMM-Newton allows us to disentangle the emission of these galaxy clusters from nearby point sources, which significantly contaminated previous X-ray luminosity estimates for six of the fifteen clusters. We extend cluster scaling relations between X-ray luminosity, temperature, and weak-lensing mass for low-mass, X-ray-selected clusters out to redshift $\approx$0.45. These relations are important for cosmology and the astrophysics of feedback in galaxy groups and clusters. Our joint analysis with a sample of 50 clusters in a similar redshift range but with larger masses (M500 < $21.9 \times 10^{14} M_\odot$, $0.15 \leq z \leq 0.55$) from the Canadian Cluster Comparison Project finds that within r2500, $M \propto L^{0.44 +/- 0.05}$, $T \propto L^{0.23 +/- 0.02}$, and $M \propto T^{1.9 +/- 0.2}$. The estimated intrinsic scatter in the M-L relation for the combined sample is reduced to ${\sigma}_{log(M|L)}=0.10$, from ${\sigma}_{log(M|L)}=0.26$ with the original ROSAT measurements. We also find an intrinsic scatter for the T-L relation, ${\sigma}_{log(T|L)}=0.07 +/- 0.01$.