The 6dF Galaxy Survey: cosmological constraints from the velocity power spectrum

Johnson, Andrew, Blake, Chris, Koda, Jun, Ma, Yin-Zhe, Colless, Matthew, Crocce, Martin, Davis, Tamara M., Jones, Heath, Magoulas, Christina, Lucey, John R., Mould, Jeremy, Scrimgeour, Morag I. and Springob, Christopher M. (2014) The 6dF Galaxy Survey: cosmological constraints from the velocity power spectrum. Monthly Notices of the Royal Astronomical Society, 444 4: 3926-3947. doi:10.1093/mnras/stu1615

Author Johnson, Andrew
Blake, Chris
Koda, Jun
Ma, Yin-Zhe
Colless, Matthew
Crocce, Martin
Davis, Tamara M.
Jones, Heath
Magoulas, Christina
Lucey, John R.
Mould, Jeremy
Scrimgeour, Morag I.
Springob, Christopher M.
Title The 6dF Galaxy Survey: cosmological constraints from the velocity power spectrum
Journal name Monthly Notices of the Royal Astronomical Society   Check publisher's open access policy
ISSN 0035-8711
Publication date 2014-11
Year available 2014
Sub-type Article (original research)
DOI 10.1093/mnras/stu1615
Open Access Status DOI
Volume 444
Issue 4
Start page 3926
End page 3947
Total pages 22
Place of publication Oxford, United Kingdom
Publisher Oxford University Press
Collection year 2015
Language eng
Formatted abstract
We present scale-dependent measurements of the normalized growth rate of structure fσ8(k, z = 0) using only the peculiar motions of galaxies. We use data from the 6-degree Field Galaxy Survey velocity sample together with a newly compiled sample of low-redshift (z < 0.07) Type Ia supernovae. We constrain the growth rate in a series of Δk ∼ 0.03 h Mpc−1 bins to ∼35 per cent precision, including a measurement on scales >300 h−1 Mpc, which represents one of the largest scale growth rate measurement to date. We find no evidence for a scale-dependence in the growth rate, or any statistically significant variation from the growth rate as predicted by the Planck cosmology. Bringing all the scales together, we determine the normalized growth rate at z = 0 to ∼15 per cent in a manner independent of galaxy bias and in excellent agreement with the constraint from the measurements of redshift-space distortions from 6-degree Field Galaxy Survey. We pay particular attention to systematic errors. We point out that the intrinsic scatter present in Fundamental Plane and Tully–Fisher relations is only Gaussian in logarithmic distance units; wrongly assuming it is Gaussian in linear (velocity) units can bias cosmological constraints. We also analytically marginalize over zero-point errors in distance indicators, validate the accuracy of all our constraints using numerical simulations, and demonstrate how to combine different (correlated) velocity surveys using a matrix ‘hyperparameter’ analysis. Current and forthcoming peculiar velocity surveys will allow us to understand in detail the growth of structure in the low-redshift universe, providing strong constraints on the nature of dark energy.
Keyword Surveys
Cosmological parameters
Cosmology: observations
Dark energy
Large scale structure of Universe
Digital Sky Survey
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: School of Mathematics and Physics
Official 2015 Collection
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Citation counts: TR Web of Science Citation Count  Cited 23 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 22 times in Scopus Article | Citations
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