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 logξ > 2 ergcms-1 and outflow velocities of the order of 103 kms-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.
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- January 2010
- galaxies: active;
- X-rays: galaxies;
- Astrophysics - High Energy Astrophysical Phenomena
- 5 pages, 3 figures, 1 table, accepted for publication in MNRAS Letters