The XMM cluster survey: The dynamical state of XMMXCS J2215.9-1738 at z=1.457

• Type: Article in International Scientific Journal
• Date: 2007

Authors

hilton, m (Author) Other; collins, ca (Author) Other; stanford, sa (Author) Other; lidman, c (Author) Other; dawson, ks (Author) Other; davidson, m (Author) Other; kay, st (Author) Other; liddle, ar (Author) Other; mann, rg (Author) Other; miller, cj (Author) Other; nichol, rc (Author) Other; romer, ak (Author) Other; sabirli, k (Author) Other; viana, ptp (Author) FCUP; west, mj (Author) Other

Journal

Title: Astrophysical Journal

Vol. 670

Pages: 1000-1009

ISSN: 0004-637X

Publisher: American Astronomical Society

Indexing

ISI Web of Knowledge - 45 Citations

Scopus - 45 Citations

Scientific classification

FOS: Natural sciences > Physical sciences

Other information

Authenticus ID: P-004-5VA

DOI: 10.1086/522827

Abstract (EN): We present new spectroscopic observations of the most distant X-ray-selected galaxy cluster currently known, XMMXCS J2215.9-1738 at z = 1.457, obtained with the DEIMOS instrument at the W. M. Keck Observatory and the FORS2 instrument on the ESO Very Large Telescope. Within the cluster virial radius, as estimated from the cluster X-ray properties, we increase the number of known spectroscopic cluster members to 17 objects, and calculate the line-of-sight velocity dispersion of the cluster to be 580 +/- 140 km s(-1). We find mild evidence that the velocity distribution of galaxies within the virial radius deviates from a single Gaussian. We show that the properties of J2215.9-1738 are inconsistent with self-similar evolution of local X-ray scaling relations, finding that the cluster is underluminous given its X-ray temperature, and that the intracluster medium contains similar to 2-3 times the kinetic energy per unit mass of the cluster galaxies. These results can perhaps be explained if the cluster is observed in the aftermath of an off-axis merger. Alternatively, heating of the intracluster medium through supernovae and/or active galactic nucleus activity, as is required to explain the observed slope of the local X-ray luminosity-temperature relation, may be responsible.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 10