First high-resolution detection of a warm absorber in the Broad Line Radio Galaxy 3C 382

Abstract

Recent high-resolution measurements suggest that the soft X-ray spectrum of obscured radio galaxies exhibits signatures of photoionized gas (e.g. 3C 445 and 3C 33) similar to those observed in radio-quiet obscured active galactic nuclei. While signatures of warm absorbing gas covering a wide range of temperature and ionization states have been detected in about one-half of the population of nearby type 1 Seyfert galaxies, no traces of warm absorber gas have been reported to date in the high-resolution spectra of broad-line radio galaxies (BLRG). We present here the first detection of a soft X-ray warm absorber in the powerful Fanaroff-Riley type II BLRG 3C 382 using the Reflection Grating Spectrometer on-board XMM-Newton. The absorption gas appears to be highly ionized, with column density of the order of 1022 cm-2, ionization parameter log ξ > 2 erg cm s-1 and outflow velocities of the order of 103 km s-1. The absorption lines may come from regions located outside the torus, however, at distances less than 60 pc. This result may indicate that a plasma ejected at velocities near the speed of light and a photoionized gas with slower outflow velocities can coexist in the same source beyond the broad-line regions. © 2009 The Authors. Journal compilation © 2009 RAS.