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

TL;DR

This paper evaluates the potential of the upgraded GMRT to detect the enhanced 21-cm power spectrum from Cosmic Dawn, which could shed light on baryon-dark matter interactions, with detection prospects depending on observation time and scenario.

Contribution

It assesses the detectability of the amplified 21-cm power spectrum using uGMRT and compares its capabilities with future SKA-Low observations.

Findings

A 10σ detection is possible within 70 hours in optimistic scenarios.

Detection is feasible within 140 hours in moderate scenarios.

Detection remains possible within 400 hours in pessimistic scenarios.

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.