# Investigating the origin of the Fe emission lines of the Seyfert 1 galaxy Mrk~205

## TL;DR

This study analyzes X-ray observations of Seyfert galaxy Mrk 205 to understand the origin of Fe emission lines, revealing a complex reflection environment and suggesting a truncated accretion disk with low Eddington ratio.

## Contribution

It provides the first detailed analysis of Fe K lines in Mrk 205 using Suzaku and XMM-Newton, exploring the reflection components and disk structure.

## Key findings

- Detected narrow Fe Kα line and Compton reflection hump.
- Found evidence for ionized disk reflection in soft and hard X-rays.
- Suggested the accretion disk may be truncated at 6-12 gravitational radii.

## Abstract

We have investigated the nature and origin of the Fe K emission lines in Mrk~205 using observations with {\it Suzaku} and {\it XMM-Newton}, aiming to resolve the ambiguity between a broad emission line and multiple unresolved lines of higher ionization. We detect the presence of a narrow Fe K$\alpha$ emission line along with a broad band Compton reflection hump at energies $E>10 \rm \, keV$. These are consistent with reflected emission of hard X-ray photons off a Compton thick material of $N_{\rm H} \ge 2.15\times 10^{24} \rm cm^{-2}$. In addition we detect a partially covering ionized absorption with ionization parameter $\log(\xi/\rm erg\, cm\, s^{-1})=1.9_{-0.5}^{+0.1}$, column density $N_{\rm H}=(5.6_{-1.9}^{+2.0})\times 10^{22}\rm cm^{-2}$ and a covering factor of $0.22_{-0.06}^{+0.09}$. We detect the presence of emission arising out of ionized disk reflection contributing in the soft and the hard X-rays consistently in all the observations. We however, could not definitely ascertain the presence of a relativistically broadened Fe line in the X-ray spectra. Using relativistic reflection model, we found that the data are unable to statistically distinguish between the scenarios when the super-massive black hole is non-rotating and when it is maximally spinning. Using the disk reflection model we also find that the accretion disk of the AGN may be truncated at a distance $6R_{\rm G}<R<12R_{\rm G}$, which may suggest why there may not be any broad Fe line. The Eddington rate of the source is low ($\lambda_{\rm Edd}=0.03$), which points to an inefficient accretion, possibly due to a truncated disk.