A Chandra DETECTION OF DIFFUSE HARD X-RAY EMISSION ASSOCIATED WITH THE LOBES OF THE RADIO GALAXY

An 80 ksec Chandra ACIS observation of the radio galaxy 3C 452 is reported. A diffuse X-ray emission associated with the lobes has been detected with high statistical significance, together with the X-ray nucleus of the host galaxy. The 0.5–5 keV ACIS spectrum of the diffuse emission is described by a twocomponent model, consisting of a soft thermal plasma emission from the host galaxy halo and a hard non-thermal power-law component. The hard component is ascribed to the inverse Comptonization of cosmic microwave background photons by the synchrotron emitting electrons in the lobes, because its spectral energy index, 0.68 ± 0.28, is consistent with the radio synchrotron index, 0.78. These results reveal a significant electron dominance in the lobes. The electrons are inferred to have a relatively uniform distribution, while the magnetic field is compressed toward the lobe periphery. Subject headings: radiation mechanisms: non-thermal — magnetic fields — X-rays: galaxies — radio continuum: galaxies — galaxies: individual (3C 452)