We present the results of the COS Intragroup Medium (COS-IGrM) Survey that used the Cosmic Origins Spectrograph on the Hubble Space Telescope to observe a sample of 18 UV bright quasars, each probing the intragroup medium (IGrM) of a galaxy group. We detect Lyα, C II, N V, Si II, Si III, and O VI in multiple sightlines. The highest ionization species detected in our data is O VI, which was detected in 8 out of 18 quasar sightlines. The wide range of ionization states observed provide evidence that the IGrM is patchy and multiphase. We find that the O VI detections generally align with radiatively cooling gas between 105.8 and 106 K. The lack of O VI detections in 10 of the 18 groups illustrates that O VI may not be the ideal tracer of the volume filling component of the IGrM. Instead, it either exists at trace levels in a hot IGrM or is generated in the boundary between the hotter IGrM and cooler gas.
@article{arxiv.2109.14080,
title = {Detection of a Multiphase Intragroup Medium: Results from the COS-IGrM Survey},
author = {Tyler McCabe and Sanchayeeta Borthakur and Timothy Heckman and Jason Tumlinson and Rongmon Bordoloi and Romeel Dave},
journal= {arXiv preprint arXiv:2109.14080},
year = {2022}
}