Speaker
Description
Recent observations with the James Webb Space Telescope (JWST) indicate a higher-than-expected abundance of galaxies at high redshifts (z > 10), potentially suggesting galaxy formation models with an enhanced star formation efficiency during the Cosmic Dawn (CD). These galaxy formation models are expected to leave their imprints on the thermal and ionization history of the intergalactic medium (IGM) at high redshifts and the redshifted 21 cm signal from neutral hydrogen from the CD. In this work, we investigate these imprint using an upgraded version of the semi-numerical framework SCRIPT, which now self-consistently models spatial fluctuations in the hydrogen spin temperature by including the Lyman-α coupling and X-ray heating. With this framework, we explore models with and without enhanced star formation rate and and their impact on the shape of the 21 cm signal. We further assess the extent to which the combined measurements of the sky-averaged 21 cm signal and its power spectra can discriminate between various scenarios. With upcoming observations with the SKA1-LOW and other global and interferometric observations, the 21 cm signal can potentially be an independent probe to study the galaxy formation models at high redshifts.
