Presence of Ionized Gas Around Galaxies (IMAGE) Instituto de Astrofísica de Canarias (IAC) Caption The presence of ionized gas around galaxies with moves with them leaves a trace in the microwave background radiation (left panel) which can be detected knowing the pattern of velocities of the galaxies provided by the map of fluctuations in their redshift (right panel). Credit Carlos Hernández-Monteagudo (IAC). Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.