X-ray warm absorber variability of the Seyfert Galaxy Arakelian 564

TL;DR

This study investigates the long-term variability of warm absorbers in the Seyfert galaxy Arakelian 564 through X-ray spectral analysis over eleven years, revealing changes in ionisation and soft excess properties.

Contribution

It provides the first detailed analysis of warm absorber variability in Arakelian 564 over an eleven-year period using XMM-Newton data.

Findings

Ionisation parameter varies between observations.

Soft X-ray excess characterized by two blackbody components.

Long-term spectral changes observed in ionised gas.

Abstract

The aim of this paper is to study the variability of the warm absorber "clouds of ionised gas within AGN", for the Seyfert 1 galaxies Arakelian 564. The X-ray spectra for four XMM-Newton observations of this object are analysed in EPIC and RGS instruments. These four observations covered a period of eleven years. There are some changes in the ionisation parameter ($ \xi $) of the absorbing matter from one observation to another( $\log\xi =0.889 \pm 3.11 \times 10^{-2}$ for year 2000 observation and $0.437 \pm 7.60 \times 10^{-2}$ for year 2001 ). Also the X-ray soft excess is studied for the four observation by using two blackbody parameters in EPIC spectra ( the first black-body temperature is $\sim $ $0.129 \pm 2.04 \times 10^{-3}$ Kev and the second is $\sim 1.74 \pm 7.6 \times {10^{-2}}$ Kev) and one black body parameter in RGS spectra.