The Xxl Survey: v. Detection of the Sunyaev-zel’dovich Effect of the Redshift 1.9 Galaxy Cluster Xlssu J021744.1−034536 with Carma

We report the detection of the Sunyaev-Zel’dovich (SZ) effect of galaxy cluster XLSSU J021744.1−034536, using 30 GHz CARMA data. This cluster was discovered via its extended X-ray emission in the XMM-Newton Large Scale Structure survey, the precursor to the XXL survey. It has a photometrically determined redshift z = 1.91 −0.21, making it among the most distant clusters known, and nominally the most distant for which the SZ effect has been measured. The spherically integrated Comptonization is Y500 = (3.0±0.4)×10−12, a measurement which is relatively insensitive to assumptions regarding the size and redshift of the cluster, as well as the background cosmology. Using a variety of locally calibrated cluster scaling relations extrapolated to z ∼ 2, we estimate a mass M500 ∼ (1–2)×10M from the X-ray flux and SZ signal. The measured properties of this cluster are in good agreement with the extrapolation of an X-ray luminosity–SZ effect scaling relation calibrated from clusters discovered by the South Pole Telescope at higher masses and lower redshifts. The full XXL-CARMA sample will provide a more complete, multi-wavelength census of distant clusters in order to robustly extend the calibration of cluster scaling relations to these high redshifts. Subject headings: galaxies: clusters: individual (XLSSU J021744.1−034536) – galaxies: clusters: intracluster medium – X-rays: galaxies: clusters