The Hosts of X-ray Absorption Lines Toward AGNs

TL;DR

This paper investigates the galaxies and galaxy groups near 15 AGN lines of sight to identify potential hosts of X-ray absorption lines, aiding future baryonic matter detection with upcoming spectroscopy missions.

Contribution

It provides a systematic method to identify and analyze potential galaxy hosts of X-ray absorption lines around AGNs, enhancing understanding of baryonic matter distribution.

Findings

Identified potential host galaxies and groups near 15 AGNs.

Mapped angular separation versus redshift for candidate hosts.

Established a framework for associating absorption lines with galaxy environments.

Abstract

Most baryonic matter in the universe exists in gaseous form and can be found in structures such as galactic halos and the low-density intergalactic medium. proposed-ray spectroscopy missions such as Athena, Arcus, and Lynx will have the capability to identify absorption lines in spectra toward bright active galactic nuclei (AGNs), which can be used as a tool to probe this missing matter. In this study, we examine the optical fields surrounding 15 primary observing targets and identify the foreground galaxies and galaxy groups that are potential hosts of absorption. We record the basic properties of the potential host and their angular and physical separation from the AGN line of sight. This process is done by marking the location of various galaxies and groups in optical images of the field surrounding the target and plotting their angular separation vs. redshift to gauge physical proximity to the background source. We identify the surrounding objects according to those which have measured redshifts and those that require them.