XMM-Newton detection of two clusters of galaxies with strong SPT Sunyaev-Zel'dovich effect signatures

TL;DR

This paper reports the discovery of two galaxy clusters detected via X-ray, Sunyaev-Zel'dovich effect, and optical surveys, demonstrating the effectiveness of a novel XMM-Newton mosaic mode and confirming multi-wavelength detection consistency.

Contribution

First multi-wavelength detection of galaxy clusters using X-ray, SZ, and optical data with a novel XMM-Newton mosaic observation mode.

Findings

X-ray spectroscopic temperature of cluster at z=0.32 is 9.3 keV.

X-ray derived mass for the z=0.32 cluster is approximately 8.8 x 10^{14} solar masses.

X-ray and SZ mass estimates are in good agreement.

Abstract

We report on the discovery of two galaxy clusters, SPT-CL J2332-5358 and SPT-CL J2342-5411, in X-rays. These clusters were also independently detected through their Sunyaev-Zel'dovich effect by the South Pole Telescope, and confirmed in the optical band by the Blanco Cosmology Survey. They are thus the first clusters detected under survey conditions by all major cluster search approaches. The X-ray detection is made within the frame of the XMM-BCS cluster survey utilizing a novel XMM-Newton mosaic mode of observations. The present study makes the first scientific use of this operation mode. We estimate the X-ray spectroscopic temperature of SPT-CL J2332-5358 (at redshift z=0.32) to T = 9.3 (+3.3/-1.9) keV, implying a high mass, M_{500} = 8.8 +/- 3.8 \times 10^{14} M_{sun}. For SPT-CL J2342-5411, at z=1.08, the available X-ray data doesn't allow us to directly estimate the temperature with good confidence. However, using our measured luminosity and scaling relations we estimate that T = 4.5 +/- 1.3 keV and M_{500} = 1.9 +/- 0.8 \times 10^{14} M_{sun}. We find a good agreement between the X-ray masses and those estimated from the Sunyaev-Zel'dovich effect.