Seminari
Thursday 25/11/2021 @ 11:30, JAC, Sala IV piano Battiferro (remote)
Nicholas Kern, "Exploring the High Redshift Frontier with Neutral Hydrogen: First Results from the Hydrogen Epoch of Reionization Array (HERA)"
The systematic mapping of neutral hydrogen over large cosmic volumes is a powerful probe of cosmology and astrophysics, and promises to shed new light on the formation of the first stars and galaxies during the Cosmic Dawn and Epoch of Reionization (EoR). Current and next-generation radio telescopes will use the HI 21 cm line to probe redshifts 6 < z < 20, providing an unprecedented view of early galaxy formation and the radiative processes that shaped the intergalactic medium. However, significant technical challenges stand in the way of these experiments, particularly the challenge of astrophysical foreground contamination that exceeds the cosmological signal by many orders of magnitude. In this talk, I will discuss the scientific goals of these 21 cm experiments, the technical challenges they face, and the work being done currently to surmount these challenges. I will focus on recent Phase I results from the Hydrogen Epoch of Reionization Array (HERA), a new radio telescope that will have unprecedented sensitivity to the 21 cm signal at the EoR, and will discuss future directions.