The WiggleZ Dark Energy Survey: improved distance measurements to z = 1 with reconstruction of the baryonic acoustic feature
Abstract
We present significant improvements in cosmic distance measurements from the WiggleZ Dark Energy Survey, achieved by applying the reconstruction of the baryonic acoustic feature technique. We show using both data and simulations that the reconstruction technique can often be effective despite patchiness of the survey, significant edge effects and shotnoise. We investigate three redshift bins in the redshift range 0.2 < z < 1, and in all three find improvement after reconstruction in the detection of the baryonic acoustic feature and its usage as a standard ruler. We measure modelindependent distance measures D_{V}(r_{s}^{fid}/r_{s}) of 1716 ± 83, 2221 ± 101, 2516 ± 86 Mpc (68 per cent CL) at effective redshifts z = 0.44, 0.6, 0.73, respectively, where D_{V} is the volumeaveraged distance, and r_{s} is the sound horizon at the end of the baryon drag epoch. These significantly improved 4.8, 4.5 and 3.4 per cent accuracy measurements are equivalent to those expected from surveys with up to 2.5 times the volume of WiggleZ without reconstruction applied. These measurements are fully consistent with cosmologies allowed by the analyses of the Planck Collaboration and the Sloan Digital Sky Survey. We provide the D_{V}(r_{s}^{fid}/r_{s}) posterior probability distributions and their covariances. When combining these measurements with temperature fluctuations measurements of Planck, the polarization of Wilkinson Microwave Anisotropy Probe 9, and the 6dF Galaxy Survey baryonic acoustic feature, we do not detect deviations from a flat Λ cold dark matter (ΛCDM) model. Assuming this model, we constrain the current expansion rate to H_{0} = 67.15 ± 0.98 km s^{1}Mpc^{1}. Allowing the equation of state of dark energy to vary, we obtain w_{DE} = 1.080 ± 0.135. When assuming a curved ΛCDM model we obtain a curvature value of Ω_{K} = 0.0043 ± 0.0047.
 Publication:

Monthly Notices of the Royal Astronomical Society
 Pub Date:
 July 2014
 DOI:
 10.1093/mnras/stu778
 arXiv:
 arXiv:1401.0358
 Bibcode:
 2014MNRAS.441.3524K
 Keywords:

 cosmological parameters;
 distance scale;
 largescale structure of the universe;
 Astrophysics  Cosmology and Nongalactic Astrophysics
 EPrint:
 20 double column pages, 10 figures, 5 tables