An XMM-Newton View of the Radio Galaxy 3C 411

TL;DR

This study presents high-quality X-ray observations of the radio galaxy 3C 411, exploring its spectral properties and suggesting it may be more accurately classified as a flat-spectrum radio quasar due to its hard X-ray spectrum.

Contribution

First detailed XMM-Newton spectral analysis of 3C 411, proposing a possible reclassification as a flat-spectrum radio quasar based on spectral modeling.

Findings

Spectral models fit with absorbed double power-law and relativistic reflection.

The hard X-ray component resembles that of flat-spectrum radio quasars.

Inner disk radius estimated at at most 20 gravitational radii.

Abstract

We present the first high signal-to-noise XMM-Newton observations of the broad-line radio galaxy 3C 411. After fitting various spectral models, an absorbed double power-law continuum and a blurred relativistic disk reflection model (kdblur) are found to be equally plausible descriptions of the data. While the softer power-law component ($\Gamma$=2.11) of the double power-law model is entirely consistent with that found in Seyfert galaxies (and hence likely originates from a disk corona), the additional power law component is very hard ($\Gamma$=1.05); amongst the AGN zoo, only flat-spectrum radio quasars have such hard spectra. Together with the very flat radio-spectrum displayed by this source, we suggest that it should instead be classified as a FSRQ. This leads to potential discrepancies regarding the jet inclination angle, with the radio morphology suggesting a large jet inclination but the FSRQ classification suggesting small inclinations. The kdblur model predicts an inner disk radius of at most 20 r$_g$ and relativistic reflection.