Colloquium

Precision measurements of the cosmic radio sky at short radio wavelengths, first ground based and later space based, helped refine the cosmological model and pin down cosmological parameters of our evolving universe.  Astrophysical evolution in Cosmic Dawn, leading to transformation of primordial gas to galaxy populations and an ionised intergalactic medium, continues to be an open problem.While JWST reveals the emerging sources of light, evolution in the gas may be traced by the departures in the CMB from Planck form arising from interactions with the hyperfine transition of atomic hydrogen.  This is a key motivation for bringing precision to long wavelength measurements of the radio sky.

I describe my work towards precision performance of the SKA Low telescope, under construction now with detection of EoR power spectrum as a key science goal, and a parallel complementary effort with the GINAN radiometer, towards precision measurement of the global evolution across Cosmic Dawn and subsequent Reionisation.