The circum-galactic medium of quasars: transverse and line-of-sight absorptions

TL;DR

This study uses optical spectroscopy of quasar pairs to investigate the circumgalactic medium of quasars, revealing MgII absorption lines and providing insights into the gas environment around quasars.

Contribution

It presents new spectroscopic observations of 14 quasar pairs, expanding understanding of quasar circumgalactic media through absorption line analysis.

Findings

MgII absorption lines found in 7 out of 14 pairs

Line-of-sight absorptions observed in 2 cases

Complementary to previous 30 QPPs study

Abstract

Quasar projected pairs (QPPs) can be used for investigating the circumgalactic medium of quasars through the study of intervening absorption lines in the spectrum of the background quasar that are at the same redshift of the foreground quasar. Here we report on optical spectroscopy, gathered at Gran Telescopio Canarias, of 14 QPPs. In 7 cases we find MgII absorption lines associated with the foreground quasar. Only for two cases line-of-sight absorptions (LOS) are revealed. These new observations complement our previous study performed on other 30 QPPs. A brief discussion of the properties of the intervening absorption lines associated with the foreground quasar for the full dataset is reported.