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

TL;DR

This study uses Suzaku and Swift/BAT data to analyze the X-ray spectra of two narrow-line radio galaxies, revealing their spectral properties and torus geometry, and comparing their gas content with Seyfert galaxies.

Contribution

First detailed broadband X-ray spectral analysis of 3C 403 and IC 5063 using Suzaku and Swift/BAT data, constraining torus geometry and scattering gas content.

Findings

Spectra are well modeled with absorbed cut-off power law and reflection components.

Reflection strength R ~ 0.6 indicates large torus solid angle.

Torus model with ~50° opening angle fits observed spectra.

Abstract

We report the results of Suzaku broad band X-ray observations of the two narrow-line radio galaxies (NLRGs), 3C 403 and IC 5063. Combined with the Swift/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 cut-off 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 = \Omega/2\pi ~ 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 deg 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.