Deep XMM–Newton observations of the most distant SPT-SZ galaxy cluster

• Published in: Monthly Notices of the Royal Astronomical Society
• Main Authors: Mantz, Adam B, Allen, Steven W, Morris, R Glenn, Canning, Rebecca E A, Bayliss, Matthew, Bleem, Lindsey E, Floyd, Benjamin T, McDonald, Michael
• Other Authors: National Aeronautics and Space Administration, U.S. Department of Energy, National Science Foundation
• Format: Article in Journal/Newspaper
• Language: English
• Published: Oxford University Press (OUP) 2020
• Subjects: South pole
• Online Access: http://dx.doi.org/10.1093/mnras/staa1581; http://academic.oup.com/mnras/advance-article-pdf/doi/10.1093/mnras/staa1581/33347516/staa1581.pdf; http://academic.oup.com/mnras/article-pdf/496/2/1554/33483471/staa1581.pdf

ABSTRACT We present results from a 577 ks XMM–Newton observation of SPT-CL J0459–4947, the most distant cluster detected in the South Pole Telescope 2500 square degree (SPT-SZ) survey, and currently the most distant cluster discovered through its Sunyaev–Zel’dovich effect. The data confirm the cluster’s high redshift, z = 1.71 ± 0.02, in agreement with earlier, less precise optical/IR photometric estimates. From the gas density profile, we estimate a characteristic mass of $M_{500}=(1.8\pm 0.2)\times 10^{14}\, {\rm M}_{\odot }$; cluster emission is detected above the background to a radius of $\sim \!2.2\, r_{500}$, or approximately the virial radius. The intracluster gas is characterized by an emission-weighted average temperature of 7.2 ± 0.3 keV and metallicity with respect to Solar of $Z/\, Z_{\odot }=0.37\pm 0.08$. For the first time at such high redshift, this deep data set provides a measurement of metallicity outside the cluster centre; at radii $r\gt 0.3\, r_{500}$, we find $Z/\, Z_{\odot }=0.33\pm 0.17$ in good agreement with precise measurements at similar radii in the most nearby clusters, supporting an early enrichment scenario in which the bulk of the cluster gas is enriched to a universal metallicity prior to cluster formation, with little to no evolution thereafter. The leverage provided by the high redshift of this cluster tightens by a factor of 2 constraints on evolving metallicity models, when combined with previous measurements at lower redshifts.