A complete view of the broad-line radio galaxy 4C +74.26 with XMM-Newton
Abstract
This paper presents a timing study and broad-band spectral analysis of the broad-line radio galaxy 4C +74.26 based on a 35-ks XMM-Newton observation. As found in previous data sets, the source exhibits no evidence for rapid variability, and its 0.2-10 keV light curve is well fitted by a constant. An excellent fit to the pn 0.3-12 keV spectrum was found using a continuum that combines an ionized and a neutral reflector, augmented by both cold and warm absorption. There is no evidence for a soft excess. The column of cold absorption was greater than the Galactic value, with an intrinsic column of ~1.9 × 1021cm-2. Evidence for the warm absorber was found from OVII and OVIII absorption edges with maximum optical depths of τmaxOVII= 0.3 and τmaxOVIII= 0.03, respectively. A joint pn-MOS fit increased the OVIII optical depth to τmaxOVIII= 0.1. A simple, one-zone warm absorber model yielded a column of ~9 × 1020cm-2 and an ionization parameter of ~60. Partial covering models provide significantly worse fits than ones including a relativistically broadened Fe Kα line, strengthening the case for the existence of such a line. On the whole, the X-ray spectrum of 4C +74.26 exhibits many features typical of both a radio-loud quasar (excess absorption) and radio-quiet Seyfert 1 galaxies (Fe Kα emission and warm absorption). We also show that a spurious absorption line at ~8 keV can be created by the subtraction of an instrumental Cu Kα emission line.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- October 2005
- DOI:
- 10.1111/j.1365-2966.2005.09345.x
- arXiv:
- arXiv:astro-ph/0506673
- Bibcode:
- 2005MNRAS.362.1183B
- Keywords:
-
- galaxies: active;
- galaxies: individual: 4C +74.26;
- X-rays: galaxies;
- Astrophysics
- E-Print:
- 6 pages, 4 figures, accepted by MNRAS