Broadband spectral analysis of Mrk 926 using multi-epoch X-ray observations

TL;DR

This study analyzes multi-epoch X-ray spectra of Mrk 926 to investigate the origin of its soft X-ray excess, considering models like warm corona and relativistic reflection, and also explores its radio emission characteristics.

Contribution

It provides a comprehensive broadband spectral analysis of Mrk 926 across multiple epochs, assessing the origins of the soft excess and detecting a potential radio jet component.

Findings

Soft excess is variable and can be explained by warm corona or reflection.

A warm coronal component is slightly favored as the origin of the soft excess.

An optically-thin radio component consistent with a jet is detected.

Abstract

The X-ray spectra of some active galactic nuclei (AGN) show a soft X-ray excess, emission in excess to the extrapolated primary X-ray continuum below 2 keV. Recent studies have shown that this soft excess can be described well as originating from either a relativistic ionized reflection, the extreme blurring of the reprocessed emission from the innermost region of the accretion disk, or Comptonization from an optically thick and warm region called the 'warm corona', in which electron scattering is the dominant source of opacity. To constrain the origin of the soft excess in the Seyfert 1 galaxy Mrk 926, we carry out an multi-epoch X-ray spectral study using observations from Suzaku (2009), XMM-Newton and NuSTAR (2016), and NuSTAR and Swift-XRT (2021). The broadband X-ray spectra of Mrk 926 contains: a thermally Comptonized primary continuum, a variable soft excess, and distant reflection. We find that in Mrk 926 as in so many sources, it is difficult to make a definite statement as to what is causing the observed soft excess. A warm coronal-like component is slightly preferred by the data but a reflection origin is also possible. Using archival radio data, we detect an optically-thin radio component in our broadband study of Mrk 926. While this component is consistent with an optically-thin radio jet, future multi-wavelength observations including high spatial resolution radio observations at multiple frequencies are required to probe the origin of the radio emission in more detail.