2005MNRAS.362.1183B

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 ∼1.9x10²¹/cm2. Evidence for the warm absorber was found from Ovii and Oviii absorption edges with maximum optical depths of τ^max_OVII= 0.3 and τ^max_OVIII= 0.03, respectively. A joint pn-MOS fit increased the Oviii optical depth to τ^max_OVIII= 0.1. A simple, one-zone warm absorber model yielded a column of ∼9x10²⁰/cm2 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.