Suzaku View of the Swift/BAT Active Galactic Nuclei. IV. Nature of Two Narrow-line Radio Galaxies (3C 403 and IC 5063)

Abstract

We report the results of Suzaku broadband X-ray observations of the two narrow-line radio galaxies, 3C 403 and IC 5063. Combined with the Swift/Burst Alert Telescope (BAT) spectra averaged for 58 months, we are able to accurately constrain their spectral properties over the 0.5-200 keV band. The spectra of both nuclei are well represented with an absorbed cutoff power law, an absorbed reflection component from cold matter with an iron-K emission line, and an unabsorbed soft component, which gives a firm upper limit for the scattered emission. The reflection strength normalized to the averaged BAT flux is R ≡ Ω/2π ≈ 0.6 in both targets, implying that their tori have a sufficiently large solid angle to produce the reprocessed emission. A numerical torus model with an opening angle of ~50° well reproduces the observed spectra. We discuss the possibility that the amount of the normal gas responsible for Thomson scattering is systematically smaller in radio galaxies compared with Seyfert galaxies.