Cosmology with Phase 1 of the Square Kilometre Array Red Book 2018: Technical specifications and performance forecasts

• Published in: Publications of the Astronomical Society of Australia Vol. 37
• Main Authors: Bacon, David J., Battye, Richard A., Bull, Philip, Camera, Stefano, Ferreira, Pedro G., Harrison, Ian, Parkinson, David, Pourtsidou, Alkistis, Santos, Mário G., Wolz, Laura, Abdalla, Filipe, Akrami, Yashar, Alonso, David, Andrianomena, Sambatra, Ballardini, Mario, Bernal, José Luis, Bertacca, Daniele, Bengaly, Carlos A. P., Bonaldi, Anna, Bonvin, Camille, Brown, Michael L., Chapman, Emma, Chen, Song, Chen, Xuelei, Cunnington, Steven, Davis, Tamara M., Dickinson, Clive, Fonseca, José, Grainge, Keith, Harper, Stuart, Jarvis, Matt J., Maartens, Roy, Maddox, Natasha, Padmanabhan, Hamsa, Pritchard, Jonathan R., Raccanelli, Alvise, Rivi, Marzia, Roychowdhury, Sambit, Sahlén, Martin, Schwarz, Dominik J., Siewert, Thilo M., Viel, Matteo, Villaescusa-Navarro, Francisco, Xu, Yidong, Yamauchi, Daisuke, Zuntz, Joe
• Format: Journal Article
• Language: English
• Published: Cambridge University Press (CUP) 2020
• Subjects: Astrophysics; cosmology; galaxy redshift surveys; intensity mapping; Physics; radio telescopes; weak lensing; gravitation: lens; cosmology; general relativity; baryon: oscillation: acoustic; observatory; cosmological model; dark energy: equation of state; galaxy redshift surveys; radio telescopes; weak lensing; galaxy; statistical analysis; intensity mapping; non-Gaussianity
• ISSN: 1323-3580; 1448-6083; 1448-6083
• DOI: 10.1017/pasa.2019.51

Abstract We present a detailed overview of the cosmological surveys that we aim to carry out with Phase 1 of the Square Kilometre Array (SKA1) and the science that they will enable. We highlight three main surveys: a medium-deep continuum weak lensing and low-redshift spectroscopic HI galaxy survey over 5 000 deg 2 ; a wide and deep continuum galaxy and HI intensity mapping (IM) survey over 20 000 deg 2 from $z = 0.35$ to 3; and a deep, high-redshift HI IM survey over 100 deg 2 from $z = 3$ to 6. Taken together, these surveys will achieve an array of important scientific goals: measuring the equation of state of dark energy out to $z \sim 3$ with percent-level precision measurements of the cosmic expansion rate; constraining possible deviations from General Relativity on cosmological scales by measuring the growth rate of structure through multiple independent methods; mapping the structure of the Universe on the largest accessible scales, thus constraining fundamental properties such as isotropy, homogeneity, and non-Gaussianity; and measuring the HI density and bias out to $z = 6$ . These surveys will also provide highly complementary clustering and weak lensing measurements that have independent systematic uncertainties to those of optical and near-infrared (NIR) surveys like Euclid , LSST, and WFIRST leading to a multitude of synergies that can improve constraints significantly beyond what optical or radio surveys can achieve on their own. This document, the 2018 Red Book , provides reference technical specifications, cosmological parameter forecasts, and an overview of relevant systematic effects for the three key surveys and will be regularly updated by the Cosmology Science Working Group in the run up to start of operations and the Key Science Programme of SKA1.