Conference Summary: HI Science in the Next Decade

TL;DR

The paper reviews the future of HI 21cm line research, highlighting technological advancements, upcoming experiments, and their potential to deepen understanding of galaxy evolution, dark matter, and cosmic reionization over the next decade.

Contribution

It provides a comprehensive overview of upcoming HI 21cm line experiments, technologies, and scientific goals, emphasizing the role of new instruments and surveys in advancing cosmology and galaxy studies.

Findings

First results on reionization expected in 2-3 years

HI surveys will reveal galaxy gas content and distribution

SKA will enable precision cosmology at high redshift

Abstract

The atomic hydrogen (HI) 21cm line measures the gas content within and around galaxies, traces the dark matter potential and probes volumes and objects that other surveys do not. Over the next decade, 21cm line science will exploit new technologies, especially focal plane and aperture arrays, and will see the deployment of Epoch of Reionization/Dark Age detection experiments and Square Kilometer Array (SKA) precursor instruments. Several experiments designed to detect and eventually to characterize the reionization history of the intergalactic medium should deliver first results within two-three years time. Although "precision cosmology" surveys of HI in galaxies at z ~ 1 to 3 require the full collecting area of the SKA, a coherent program of HI line science making use of the unique capabilities of both the existing facilities and the novel ones demonstrated by the SKA precursors will teach us how many gas rich galaxies there really are and where they reside and will yield fundamental insight into how galaxies accrete gas, form stars and interact with their environment.