The X-ray virial relations for relaxed lensing clusters observed with Chandra

TL;DR

This study investigates the relationships between mass, temperature, and luminosity in relaxed galaxy clusters observed with Chandra, confirming theoretical scaling laws and identifying a systematic offset in mass-temperature normalization.

Contribution

It provides empirical validation of the mass-temperature and luminosity-temperature relations in galaxy clusters and compares observed data with theoretical predictions across different cosmologies.

Findings

Observed temperature profiles are approximately universal within r_2500.

Best-fit relations align with simple scaling predictions for mass and luminosity.

Systematic offset of ~40% found between observed and predicted mass-temperature normalizations.

Abstract

We examine the relations linking mass, X-ray temperature and bolometric luminosity for a sample of luminous, relatively relaxed clusters of galaxies observed with the Chandra Observatory, for which independent confirmation of the mass results is available from gravitational lensing studies. Within radii corresponding to a fixed overdensity Delta = 2500 with respect to the critical density at the redshifts of the clusters, the observed temperature profiles, scaled in units of T_2500 and r_2500, exhibit an approximately universal form which rises within r~0.3 r_2500 and then remains approximately constant out to r_2500. We obtain best-fit slopes for the mass-temperature and temperature-luminosity relations consistent with the predictions from simple scaling arguments i.e. M_2500 \propto T_2500^{3/2} and L_2500 \propto T_2500^{2}, respectively. We confirm the presence of a systematic offset of ~40 per cent between the normalizations of the observed and predicted mass-temperature relations for both SCDM and LambdaCDM cosmologies.