Cosmological surveys with the Australian Square Kilometre Array Pathfinder

TL;DR

This paper evaluates the Australian SKA Pathfinder's potential for a comprehensive low-redshift hydrogen survey, WALLABY, demonstrating its capability to significantly constrain dark energy parameters when combined with Planck data.

Contribution

It provides a detailed design study of WALLABY, estimating its galaxy redshift yield and its potential to improve cosmological constraints using radio observations.

Findings

Full sky survey will measure approximately 0.6 million redshifts.

Combined with Planck data, it can constrain the Dark Energy equation of state to 20%.

Highlights the growing role of radio surveys in cosmology.

Abstract

This is a design study into the capabilities of the Australian Square Kilometre Array Pathfinder in performing a full-sky low redshift neutral hydrogen survey, termed WALLABY, and the potential cosmological constraints one can attain from measurement of the galaxy power spectrum. We find that the full sky survey will likely attain 0.6 million redshifts which, when combined with expected Planck CMB data, will constrain the Dark Energy equation of state to 20%, representing a coming of age for radio observations in creating cosmological constraints.