2014/12/31 by S. Yahya, Sahba Yahya, P. Bull +11 · 2 citations
Physics and Astronomy · #Astronomy #Astrophysics #Astrophysics and Cosmic Phenomena #Baryon #Baryon acoustic oscillations #Cosmology #Dark energy #Dark matter #Galaxies: Formation, Evolution, Phenomena #Galaxy #Physics #Radio Astronomy Observations and Technology #Redshift #Redshift survey #Sky #astro-ph.CO
paper · pdf · doi:10.1093/mnras/stv695
published as MNRAS 450 (2015) 2251-2260 · 11 pages, 7 figures, 5 tables. Minor revisions for improved clarity. Version accepted by MNRAS
arxiv created 2015/03/31 · openalex publication_date 2015/05/06 · arxiv updated 2015/05/08 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The Square Kilometre Array (SKA) will conduct the biggest spectroscopic galaxy survey ever, by detecting the 21 cm emission line of neutral hydrogen (H i) from around a billion galaxies over 3/4 of the sky, out to a redshift of z ∼ 2. This will allow the redshift-space matter power spectrum, and corresponding dark energy observables, to be measured with unprecedented precision. In this paper, we present an improved model of the H i galaxy number counts and bias from semi-analytic simulations, and use it to calculate the expected yield of H i galaxies from surveys with a variety of Phase 1 and 2 SKA configurations. We illustrate the relative performance of the different surveys by forecasting errors on the radial and transverse scales of the baryon acoustic oscillation (BAO) feature, finding that the full ‘billion galaxy survey’ with SKA2 will deliver the largest dark energy Figure of Merit of any current or future large-scale structure survey.