BIGHORNS - Broadband Instrument for Global HydrOgen ReioNisation Signal

Understand

The redshifted 21cm line of neutral hydrogen (HI), potentially observable at low radio frequencies (~50-200 MHz), should be a powerful probe of the physical conditions of the inter-galactic medium during Cosmic Dawn and the Epoch of Reionisation (EoR).

• The sky-averaged HI signal is expected to be extremely weak (~100 mK) in comparison to the foreground of up to 10000 K at the lowest frequencies of interest.
• The detection of such a weak signal requires an extremely stable, well characterised system and a good understanding of the foregrounds.
• Development of a nearly perfectly (~mK accuracy) calibrated total power radiometer system is essential for this type of experiment.