Cosmology from SKA

Chairs: Changbom Park (KIAS) and David Parkinson (KASI)

Session Goal

The goal is to discuss the cosmological surveys that will be done by SKA and the pathfinders need, their needs and possible enhancements. This discussion will motivate people to get involved in science with SKA, and identify which science area they are interested in and can contribute to.

Session Structure

There will be a single talk given by David Parkinson, focussing on the Cosmology Red Book. Discussion and interuption is encouraged.

Discussion Document

Please add any comments or annotations to this Google doc during the presentations.

Background

The Cosmology Red book for SKA (https://arxiv.org/abs/1811.02743) really focussed on cosmology from wide area surveys, looking at the cosmology that can be done through the clustering statistics of:

However, by the time the SKA comes on line (late 2020s), a large number of optical surveys will have covered and measured similar area and redshift range to the planned cosmology surveys. DESI for example will have 3D power spectrum measurements out to z~1 and above, and QSO clustering at z~3.

What then, for SKA? It seems that a lot of what SKA has to offer as an advantage over optical surveys are a lack of systematics, or at least very different systematics to optical surveys. I would suggest that cross-correlation and cross-identification are the key to any successful radio cosmology survey.

Discussion Topics

Facilities

What facilities can Korea provide to 'value-add', or make possible cosmology surveys with SKA?
  1. High-resolution radio — if there was a VLBI facility in the south, could it be used to provide classification of radio galaxies, allow the continuum sample to be sub-divided
  2. Optical photometric — is there a role for KMTNet in cross-identifying bright, close radio sources
  3. Optical spectroscopic — can Korea help provide optical spectroscopic follow-up of radio sources in the southern hemisphere, to enchance photometric/clustering redshifts for continuum sources

Modelling

What large-volume simulations are needed?

Theory