Probing the First Structures with the SKA

Abstract

The first stars in the universe started to appear at redshifts z$\\sim$30, the epoch of Cosmic Dawn. The IGM during this period was almost completely neutral. However since these structures were sources of ionizing radiation, the neutral IGM was converted into a highly ionized one, between z$\\sim$15 to z$\\sim$6 - the Epoch of Reionisation or EoR. Any detection of cosmological signal from this era can give valuable insights into characteristics of the first stars. Thus one of the major targets of the upcoming Square Kilometer Array (SKA) is to probe for the cosmological signals from this epoch. The main target signal for the SKA-low, the proposed low frequency SKA array, is the redshifted 21cm hyperfine spectral line of neutral hydrogen atom.