IUCAA Brochure 2024

Radio Galaxies The team also used the MeerKAT to study a galaxy towards PKS 1830-211, and discovered unexpected gas cloudsmade up of the largest hydrogen atoms in the universe - Rydberg The MeerKAT radio telescope in South Africa is currently the most sensitive radio telescope and IUCAA researchers are using it to detect millions of normal and active galaxies. The MeerKATAbsorption Line Survey (MALS) is a large survey that observes the sky and the team led by IUCAA has collected radio continuum images to make a catalog of 495325 radio sources detected over an area of 2289 square degrees from 391 telescope pointings at 1 - 1.4 GHz. The interplay between energetic output from AGN and cold gas in host galaxies is central to understanding the fueling of massive black holes and the evolution of galaxies hosting these. A majority of these radio sources were detected for the first time by MALS in 2023, and will be used to investigate the evolution of cold gas in active and normal galaxies via absorption lines. These may be used for a diverse range of scientific objectives by the astronomy community, and is among the first of several data releases to come fromMALS. atoms. It is the first time scientists have observed these atoms in a distant galaxy. This tells us that interstellar gas in this galaxy is much denser than what is found in the Milky Way. Moreover, they believe the large atoms are spread throughout the galaxy in ionized interstellar gas clouds. The discovery gives a new way to observe our Universe and possibly study the evolution of interstellar gas in galaxies over cosmic time. The research could also help us to understand how interstellar gas drives and inhibits the activity of SMBH.