Chandra X-ray observations of the 3C 295 cluster core |
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Authors: | S.W. Allen G.B. Taylor P.E.J. Nulsen R.M. Johnstone L.P. David S. Ettori A.C. Fabian W. Forman C. Jones B. McNamara |
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Affiliation: | ;1Institute of Astronomy, Madingley Road, Cambridge CB3 0HA;2Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA;3National Radio Astronomy Observatory, Socorro, NM 87801, USA;4Department of Engineering Physics, University of Wollongong, Wollongong, NSW 2522, Australia |
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Abstract: | We examine the properties of the X-ray gas in the central regions of the distant ( z =0.46) , X-ray luminous cluster of galaxies surrounding the powerful radio source 3C 295, using observations made with the Chandra Observatory . Between radii of 50 and 500 kpc, the cluster gas is approximately isothermal with an emission-weighted temperature, kT ∼5 keV . Within the central 50-kpc radius this value drops to kT ∼3.7 keV . The spectral and imaging Chandra data indicate the presence of a cooling flow within the central 50-kpc radius of the cluster, with a mass deposition rate of approximately 280 M⊙ yr−1. We estimate an age for the cooling flow of 1–2 Gyr , which is approximately 1000 times older than the central radio source. We find no evidence in the X-ray spectra or images for significant heating of the X-ray gas by the radio source. We report the detection of an edge-like absorption feature in the spectrum for the central 50-kpc region, which may be caused by oxygen-enriched dust grains. The implied mass in metals seen in absorption could have been accumulated by the cooling flow over its lifetime. Combining the results on the X-ray gas density profile with radio measurements of the Faraday rotation measure in 3C 295, we estimate the magnetic field strength in the region of the cluster core to be B ∼12 μG . |
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Keywords: | galaxies: active galaxies: clusters: individual: 3C 295 cooling flows intergalactic medium radio continuum: galaxies X-rays: galaxies: clusters |
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