The XMM Cluster Survey: A Massive Galaxy Cluster at z=1.45
Abstract
We report the discovery of XMMXCS J2215.9-1738, a massive galaxy cluster at z =1.45, which was found in the XMM Cluster Survey. The cluster candidate was initially identified as an extended X-ray source in archival XMM data. Optical spectroscopy shows that 6 galaxies within a 60 arcsec diameter region lie at z = 1.45 +/- 0.01. Model fits to the X-ray spectra of the extended emission yield kT = 7.4 (+2.7,-1.8) keV (90 % confidence); if there is an undetected central X-ray point source then kT = 6.5 (+2.6,-1.8) keV. The bolometric X-ray luminosity is Lx = 4.4 (+0.8,-0.6) x 10^44 ergs/s over a 2 Mpc radial region. The measured Tx, which is the highest known for a cluster at z > 1, suggests that this cluster is relatively massive for such a high redshift. The redshift of XMMXCS J2215.9-1738 is the highest currently known for a spectroscopically-confirmed cluster of galaxies.
Cite
@article{arxiv.astro-ph/0606075,
title = {The XMM Cluster Survey: A Massive Galaxy Cluster at z=1.45},
author = {S. A. Stanford and A. K. Romer and K. Sabirli and M. Davidson and M. Hilton and P. T. P. Viana and C. A. Collins and S. T. Kay and A. R. Liddle and R. G. Mann and C. J. Miller and R. C. Nichol and M. J. West and C. J. Conselice and H. Spinrad and D. Stern and K. Bundy},
journal= {arXiv preprint arXiv:astro-ph/0606075},
year = {2009}
}
Comments
Accepted for publication in the The Astrophysical Journal Letters. 5 pages, 5 figures