Physical Properties of Four SZE-Selected Galaxy Clusters in the Southern Cosmology Survey

TL;DR

This study analyzes the optical and X-ray properties of four galaxy clusters discovered via the Sunyaev-Zel'dovich effect, providing insights into their physical characteristics and confirming their massive nature.

Contribution

First detailed multi-wavelength analysis of four SZE-selected galaxy clusters in the southern sky, including mass and redshift estimates.

Findings

Clusters are very likely massive with M>~5x10^14 M_sun

Optical and X-ray properties consistent with known cluster studies

Mass estimates above detection thresholds of SPT and ACT

Abstract

We present the optical and X-ray properties of four clusters recently discovered by the South Pole Telescope (SPT) using the Sunyaev-Zel'dovich effect (SZE). The four clusters are located in one of the common survey areas of the southern sky that is also being targeted by the Atacama Cosmology Telescope (ACT) and imaged by the CTIO Blanco 4-m telescope. Based on publicly available griz optical images and XMM-Newton and ROSAT X-ray observations we analyse the physical properties of these clusters and obtain photometric redshifts, luminosities, richness and mass estimates. Each cluster contains a central elliptical whose luminosity is consistent with SDSS cluster studies. Our mass estimates are well above the nominal detection limit of SPT and ACT; the new SZE clusters are very likely massive systems with M>~5x10^14 M_sun.