Towards radio discovery of cosmic dawn

Abstract

As First Light from the first stars transforms the universe from the dark ages into cosmic dawn, the history may be traced in redshifted 21-cm from neutral hydrogen in the gas. Efforts to build precision radiometers over the 40-200 MHz band to detect this faint signal are beginning to yield results of significance to the theory, thus constraining the starlight of the earliest galaxies. I will present the progression in SARAS radiometers that have been deployed in remote sites in India – at the Timbaktu collective, in the trans-Himalayan plateau and, most recently, floated on a remote lake. I will then discuss the impact of the data on the astrophysics of the Epoch of Reionisation and Cosmic Dawn, our attempt to confirm the EDGES detection, and the road ahead.