On the relativistic iron line and soft excess in the Seyfert 1 galaxy Markarian 335

TL;DR

This study analyzes XMM-Newton data of Seyfert 1 galaxy Markarian 335, revealing a complex iron line and soft excess, with implications for accretion disc and torus models, and challenges to absorption-based explanations.

Contribution

It provides detailed spectral analysis showing the presence of a broad accretion disc line and narrow components, clarifying the origin of the iron features and soft excess in this galaxy.

Findings

Detection of a broad accretion disc line

Identification of narrow iron line components from distant material

Disfavoring of variable absorption as the soft excess origin

Abstract

We report on a 133 ks XMM-Newton observation of the Seyfert 1 galaxy Markarian 335. The 0.4-12 keV spectrum contains an underlying power law continuum, a soft excess below 2 keV, and a double-peaked iron emission feature in the 6-7 keV range. We investigate the possibility that the double-peaked emission might represent the characteristic signature of the accretion disc. Detailed investigations show that a moderately broad, accretion disc line is most likely present, but that the peaks may be owing to narrower components from more distant material. The peaks at 6.4 and 7 keV can be identified, respectively, with the molecular torus in active galactic nucleus unification schemes, and very highly ionized, optically thin gas filling the torus. The X-ray variability spectra on both long (~100 ks) and short (~1 ks) timescales disfavour the recent suggestion that the soft excess is an artifact of variable, moderately ionized absorption.