X-ray spectral analysis of the low-luminosity active galactic nucleus NGC 7213 using long XMM-Newton observations

TL;DR

This study analyzes a long XMM-Newton observation of the low-luminosity AGN NGC 7213, revealing constant spectral shape, specific iron emission lines, and a spectrum modeled by a power-law plus thermal components.

Contribution

It provides detailed X-ray spectral analysis of NGC 7213, identifying emission lines and modeling the spectrum with thermal and power-law components, based on the longest observation of this source.

Findings

Detection of neutral and ionized iron emission lines.

Spectrum modeled by power-law and thermal components.

Constant spectral shape during observation.

Abstract

We present the X-ray spectral results from the longest X-ray multi-mirror mission-Newton observation, 133 ks, of the low luminosity active galactic nucleus NGC 7213. The hardness ratio analysis of the X-ray light curves discloses a rather constant X-ray spectral shape, at least for the observed exposure time, enabling us to perform X-ray spectral studies using the total observed spectrum. Apart from a neutral Fe K\alpha emission line, we also detect narrow emission lines from the ionised iron species, Fe xxv and Fe xxvi. Our analysis suggests that the neutral Fe K\alpha originates from a Compton-thin reflector, while the gas responsible for the high ionisation lines is collisionally excited. The overall spectrum, in the 0.3-10 keV energy band, registered by the European Photon Imaging Camera, can be modelled by a power-law component (with a slope of \Gamma\simeq1.9) plus two thermal components at 0.36 and 8.84 keV. The low-energy thermal component is entirely consistent with the X-ray spectral data obtained by the Reflection Grating Spectrometer between 0.35-1.8 keV.