SO Webloquio: Cold gas constraints via HI Intensity Mapping in the SKA era

Intensity mapping surveys of neutral hydrogen (HI) are a new way to measure the large-scale matter distribution of our universe over a wide range of redshifts, and thus constrain cosmological parameters describing the universal expansion. The next generation of radio telescopes and interferometers - in particular the Square Kilometre Array (SKA) - are being designed and built to include optimising the detection of the HI line at low spatial resolution, allowing efficient mapping of large, previously unexplored, volumes of the universe, in both HI and continuum. The impact of instrumental systematics of radio observations on cosmological measurements can be significantly reduced by cross-correlating the HI signal with galaxy surveys. The cross-correlation also offers new ways to measure connections between HI and other properties of the optically-selected galaxy samples. I will give an overview of the status of the planned cosmological surveys to be observed with the SKA, with an emphasis on the HI intensity mapping technique and prospects of the on-going and future experiments with this technique. As well, I will showcase studies on the potential of future intensity mapping experiments in constraining HI properties, such as the global HI density, including HI scaling relations in galaxies.

21/07/2022 - 12:30
Dr. Laura Wolz
Jodrell-Bank Centre for Astrophysics at the University of Manchester