Mon. Not. R. Astron. Soc. 425, 405–414 (2012) doi:10.1111/j.1365-2966.2012.21473.x

The WiggleZ Survey: joint measurements of the expansion and growth history at z < 1 Chris Blake,1 Sarah Brough,2 Matthew Colless,2 Carlos Contreras,1 Warrick Couch,1 Scott Croom,3 Darren Croton,1 Tamara M. Davis,4 Michael J. Drinkwater,4 Karl Forster,5 David Gilbank,6 Mike Gladders,7 Karl Glazebrook,1 Ben Jelliffe,3 Russell J. Jurek,8 I-hui Li,1 Barry Madore,9 D. Christopher Martin,5 Kevin Pimbblet,10 Gregory B. Poole,1 Michael Pracy,3 Rob Sharp,2,11 Emily Wisnioski,1 David Woods,12 Ted K. Wyder5 andH.K.C.Yee13 1Centre for Astrophysics and Supercomputing, Swinburne University of Technology, PO Box 218, Hawthorn, VIC 3122, 2Australian Astronomical Observatory, PO Box 296, Epping, NSW 1710, Australia 3Sydney Institute for , School of Physics, University of Sydney, NSW 2006, Australia 4School of Mathematics and Physics, University of Queensland, Brisbane, QLD 4072, Australia 5California Institute of Technology, MC 278-17, 1200 East California Boulevard, Pasadena, CA 91125, USA 6South African Astronomical Observatory, PO Box 9, Observatory 7935, South Africa 7Department of Astronomy and Astrophysics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637, USA 8Australia Telescope National Facility, CSIRO, Epping, NSW 1710, Australia 9Observatories of the Carnegie Institute of Washington, 813 Santa Barbara St., Pasadena, CA 91101, USA 10School of Physics, Monash University, Clayton, VIC 3800, Australia 11Research School of Astronomy and Astrophysics, Australian National University, Weston Creek, ACT 2611, Australia 12Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1, Canada 13Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4, Canada

Accepted 2012 June 7. Received 2012 May 25; in original form 2012 April 16

ABSTRACT We perform a joint determination of the distance– relation and cosmic expansion rate at 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 z = 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. Key words: surveys – distance scale – large-scale structure of Universe.

one of the most important observational tests of the cosmological 1 INTRODUCTION models which characterize the different components of the Universe One of the fundamental goals of observational cosmology is to de- and their evolution with time. In particular, a paramount problem termine the expansion rate of the Universe as a function of redshift. in cosmology is to understand the physical significance of the ‘dark Measurements of the expansion history, which can be described by energy’ which appears to dominate the cosmic energy density today, the evolution of the Hubble parameter H(z) = (1 + z)da/dt with as described by the phenomenology of the standard cosmological redshift z,wher