X-CLASS low z groups and galaxy clusters

Observational constraints on the degree and scales of such nongravitational processes require well-selected samples of objects and deep observations of their gas content. We aim to study the scaling relation between two global properties of the hot gas, namely its soft-band X-ray luminosity (L_X_) and its temperature (T), by studying a sample of low-mass systems associated with precise redshifts, simultaneously accounting for sample selection biases and associated measurement uncertainties.

This work takes as input a large catalog of X-ray-selected galaxy clusters (X-CLASS). We performed a thorough revision of the redshifts of sources using deep photometric data from the Legacy Surveys and our own tailored spectroscopic follow-up of 52 low-redshift systems. We devised a spectroscopically complete sample of 155 low-redshift (0.07<z<0.2) systems, and we measured properties of their X-ray emitting gas, with median ^-^T=1.7keV and median ^-^L_X_=10^43^erg/s.