The WiggleZ Dark Energy Survey: joint measurements of the expansion and growth history at z < 1
Abstract
We perform a joint determination of the distance-redshift relation and cosmic expansion rate at redshifts z = 0.44, 0.6 and 0.73 by combining measurements of the baryon acoustic peak and Alcock-Paczynski distortion from galaxy clustering in the WiggleZ Dark Energy Survey, using a large ensemble of mock catalogues to calculate the covariance between the measurements. We find that DA(z) = (1205 ± 114, 1380 ± 95, 1534 ± 107) Mpc and H(z) = (82.6 ± 7.8, 87.9 ± 6.1, 97.3 ± 7.0) km s-1 Mpc-1 at these three redshifts. Further combining our results with other baryon acoustic oscillation and distant supernovae data sets, we use a Monte Carlo Markov Chain technique to determine the evolution of the Hubble parameter H(z) as a stepwise function in nine redshift bins of width Δz = 0.1, also marginalizing over the spatial curvature. Our measurements of H(z), which have precision better than 7 per cent in most redshift bins, are consistent with the expansion history predicted by a cosmological constant dark energy model, in which the expansion rate accelerates at redshift z < 0.7.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- September 2012
- DOI:
- 10.1111/j.1365-2966.2012.21473.x
- arXiv:
- arXiv:1204.3674
- Bibcode:
- 2012MNRAS.425..405B
- Keywords:
-
- surveys;
- distance scale;
- large-scale structure of Universe;
- Astrophysics - Cosmology and Nongalactic Astrophysics
- E-Print:
- 11 pages, 11 figures, accepted for publication in MNRAS