Extended X-ray emission in radio galaxies: the peculiar case of 3C 305

F. Massaro, M. Chiaberge, P. Grandi, G. Giovannini, C. P. O'Dea, F. D. Macchetto, S. A. Baum, R. Gilli, A. Capetti, A. Bonafede, E. Liuzzo

Published 2009-01-09, updated 2009-01-14Version 2

Extended X-ray structures are common in Active Galactic Nuclei (AGNs). Here we present the first case of a Compact Steep Spectrum (CSS) radio galaxy, 3C 305, in which the X-ray radiation appears to be associated with the optical emission line region, dominated by the [O III]5007. On the basis of a morphological study, performed using the comparison between the X-rays, the optical and the radio band, we argue that the high energy emission has a thermal nature and it is not directly linked to the radio jet and hotspots of this source. Finally, we discuss the origin of the extended X-ray structure connected with the optical emission line region following two different interpretations: as due to the interaction between matter outflows and shock-heated environment gas, or as due to gas photoionized by nuclear emission.