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Title: HIGH-REDSHIFT X-RAY COOLING-CORE CLUSTER ASSOCIATED WITH THE LUMINOUS RADIO-LOUD QUASAR 3C 186

Journal Article · · Astrophysical Journal
; ;  [1];  [2];  [3];  [4];  [5]
  1. Harvard Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)
  2. H.H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL (United Kingdom)
  3. Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, 382 Via Pueblo Mall, Stanford, CA 94305-4060 (United States)
  4. Steward Observatory, University of Arizona, Tucson, AZ (United States)
  5. Naval Research Laboratory, Code 7200, 4555 Overlook Avenue SW, Washington, DC 20375 (United States)

We present the first results from a new, deep (200 ks) Chandra observation of the X-ray luminous galaxy cluster surrounding the powerful (L {approx} 10{sup 47} erg s{sup -1}), high-redshift (z = 1.067), compact-steep-spectrum radio-loud quasar 3C 186. The diffuse X-ray emission from the cluster has a roughly ellipsoidal shape and extends out to radii of at least {approx}60 arcsec ({approx}500 kpc). The centroid of the diffuse X-ray emission is offset by 0.68 {+-} 0.''11 ({approx}5.5 {+-} 0.9 kpc) from the position of the quasar. We measure a cluster mass within the radius at which the mean enclosed density is 2500 times the critical density, r{sub 2500} = 283{sup +18}{sub -13} kpc, of 1.02{sup +0.21}{sub -0.14} x 10{sup 14} M{sub sun}. The gas-mass fraction within this radius is f{sub gas} = 0.129{sup +0.015}{sub -0.016}. This value is consistent with measurements at lower redshifts and implies minimal evolution in the f{sub gas}(z) relation for hot, massive clusters at 0 < z < 1.1. The measured metal abundance of 0.42{sup +0.08}{sub -0.07} Solar is consistent with the abundance observed in other massive, high-redshift clusters. The spatially resolved temperature profile for the cluster shows a drop in temperature, from kT {approx} 8 keV to kT {approx} 3 keV, in its central regions that is characteristic of cooling-core clusters. This is the first spectroscopic identification of a cooling-core cluster at z>1. We measure cooling times for the X-ray emitting gas at radii of 50 kpc and 25 kpc of 1.7 {+-} 0.2 x 10{sup 9} years and 7.5 {+-} 2.6 x 10{sup 8} years, as well as a nominal cooling rate (in the absence of heating) of 400 {+-} 190 M{sub sun} year{sup -1} within the central 100 kpc. In principle, the cooling gas can supply enough fuel to support the growth of the supermassive black hole and to power the luminous quasar. The radiative power of the quasar exceeds by a factor of 10 the kinematic power of the central radio source, suggesting that radiative heating may be important at intermittent intervals in cluster cores.

OSTI ID:
21464718
Journal Information:
Astrophysical Journal, Vol. 722, Issue 1; Other Information: DOI: 10.1088/0004-637X/722/1/102; ISSN 0004-637X
Country of Publication:
United States
Language:
English