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We present an XMM-Newton observation of the radio galaxy 4C 23.56 at z=2.48 which reveals extended X-ray emission coincident with the radio lobes spanning ~0.5 Mpc. These are the largest X-ray-bright lobes known at z>2. Under the assumption that these features result from inverse-Compton scattering of cosmic microwave background photons by relativistic electrons in the radio source lobes, the measured luminosity of L_0.5-8 keV=7.5x10^44 erg s^-1 implies a minimum energy stored within the lobes of ~10^59 erg. We discuss the potential of the large-scale radio/X-ray lobes to influence evolution of the host galaxy and proto-cluster environment at high redshift.
We present sensitive, high-resolution, X-ray imaging from Chandra of the high-redshift radio galaxy 4C 41.17 (z=3.8). Our 150-ks Chandra exposure detects strong X-ray emission from a point source coincident with the nucleus of the radio galaxy. In ad
We report on deep Chandra X-ray Telescope imaging observations of 4C 63.20, one of the few known radio galaxies at z>3.5. The X-ray counterpart is resolved into a core plus two off-nuclear sources that (combined) account for close to 30% of the total
Active galaxies are the most powerful engines in the Universe for converting gravitational energy into radiation, and their study at all epochs of evolution is therefore important. Powerful radio-loud quasars and radio galaxies have the added advanta
We present the results of deep spectropolarimetry of two powerful radio galaxies at $zsim2.5$ (4C 00.54 and 4C 23.56) obtained with the W.M. Keck II 10m telescope, aimed at studying the relative contribution of the stellar and non-stellar components
We have explored the nature of the extended emission-line region around the z=0.37 quasar 4C 37.43, using extensive ground-based and HST imaging and spectroscopy. The velocity field of the ionized gas shows gradual gradients within components but lar