New Active Galactic Nuclei Detected by the ART-XC and eROSITA Telescopes Onboard the SRG Observatory during an All-Sky X-ray Survey

TL;DR

This study identifies 17 X-ray sources detected by SRG's ART-XC and eROSITA telescopes, revealing their nature as Seyfert galaxies and analyzing their X-ray spectra, including absorption features, to enhance understanding of active galactic nuclei.

Contribution

First optical identification of 17 X-ray sources from SRG's all-sky survey, classifying them as Seyfert galaxies and analyzing their X-ray absorption properties.

Findings

All sources are Seyfert galaxies up to z≈0.15.

Three sources show significant intrinsic absorption.

Two sources are likely strongly absorbed.

Abstract

We present the results of our identification of 17 X-ray sources detected in the 4-12 keV energy range by the Mikhail Pavlinsky ART-XC telescope during the first year of the SRG all-sky survey. Three of them have been discovered by the ART-XC telescopes, while the remaining ones have already been known previously as X-ray sources, but their nature has remained unknown. We took optical spectra for nine sources located in the northern sky $\delta > -20$ deg with the 1.6-m AZT-33IK telescope at the Sayan Observatory (the Institute of Solar-Terrestrial Physics, the Siberian Branch of the Russian Academy of Sciences) and the 1.5-m Russian-Turkish telescope at the TUBITAK National Observatory. For the remaining objects we have analyzed the archival optical spectra taken during the 6dF survey. All of the investigated objects have turned out to be Seyfert galaxies (eight of type 1, seven of type 2, and two of intermediate type 1.8) at redshifts up to $z\approx 0.15$. Based on data from the eROSITA and ART-XC telescopes onboard the SRG observatory, we have obtained X-ray spectra in the energy range 0.2-20 keV for eight sources. A significant intrinsic absorption ($N_H > 10^{22}$ cm$^{-2}$) has been detected in three of them, with two of them being probably strongly absorbed ($N_H \sim 10^{23}$ cm$^{-2}$). This paper is a continuation of the series of publications on the optical identification of active galactic nuclei detected by the ART-XC telescope.