On the Prospects of Measuring the Cosmic Dawn 21-cm Power Spectrum using the Upgraded Giant Meterwave Radio Telescope (uGMRT)

Abstract

A recent observation by the EDGES collaboration shows a strong absorption signal in the global 21-cm spectrum from around a redshift of $z = 17$. This absorption is stronger than the maximum prediction by existing models and indicates that the spatial fluctuations of the \HI 21-cm brightness temperature at Cosmic Dawn could be an order of magnitude larger than previously expected. In this paper, we investigate the prospects of detecting the \HI 21-cm power spectrum from Cosmic Dawn using uGMRT. We find that a $10\sigma$ detection of the enhanced \HI 21-cm signal power spectrum is possible within $70, 140$ and $400$ Hours of observation for an optimistic, moderate and pessimistic scenario respectively, using the Band-1 of uGMRT. This could be an useful probe of the interaction between the baryon and dark matter particles in the early Universe. We also present a comparison of the uGMRT predictions with those for the future SKA-Low.