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Title

The WiggleZ Dark Energy Survey: testing the cosmological model with baryon acoustic oscillations at z = 0.6

Author(s)

Blake, Chris;  Davis, Tamara;  Poole, Gregory B.;  Parkinson, David;  Brough, Sarah;  Colless, Matthew;  Contreras, Carlos;  Couch, Warrick;  Croom, Scott;  Drinkwater, Michael J.;  Karl Forster;  Gilbank, David;  Gladders, Mike;  Glazebrook, Karl;  Jelliffe, Ben;  Jurek, Russell J.;  Li, I-hui;  Madore, Barry;  Martin, D. Christopher;  Pimbblet, Kevin;  Pracy, Michael;  Sharp, Rob;  Wisnioski, Emily;  Woods, David;  Wyder, Ted K.;  Yee, H. K. C.

Abstract

We measure the imprint of baryon acoustic oscillations (BAOs) in the galaxy clustering pattern at the highest redshift achieved to date, z= 0.6, using the distribution of N= 132 509 emission-line galaxies in the WiggleZ Dark Energy Survey. We quantify BAOs using three statistics: the galaxy correlation function, power spectrum and the band-filtered estimator introduced by Xu et al. The results are mutually consistent, corresponding to a 4.0 per cent measurement of the cosmic distance–redshift relation at z= 0.6 [in terms of the acoustic parameter ‘A(z)’ introduced by Eisenstein et al., we find A(z= 0.6) = 0.452 ± 0.018]. Both BAOs and power spectrum shape information contribute towards these constraints. The statistical significance of the detection of the acoustic peak in the correlation function, relative to a wiggle-free model, is 3.2σ. The ratios of our distance measurements to those obtained using BAOs in the distribution of luminous red galaxies at redshifts z= 0.2 and 0.35 are consistent with a flat Λ cold dark matter model that also provides a good fit to the pattern of observed fluctuations in the cosmic microwave background radiation. The addition of the current WiggleZ data results in a ≈30 per cent improvement in the measurement accuracy of a constant equation of state, w, using BAO data alone. Based solely on geometric BAO distance ratios, accelerating expansion (w < −1/3) is required with a probability of 99.8 per cent, providing a consistency check of conclusions based on supernovae observations. Further improvements in cosmological constraints will result when the WiggleZ survey data set is complete.

Publication type

Journal article

Research centre

Swinburne University of Technology. Faculty of Information and Communication Technologies. Centre for Astrophysics and Supercomputing

Source

Monthly Notices of the Royal Astronomical Society, Vol. 415, no. 3 (Aug 2011), pp. 2892-2909

Publication year

2011

FOR Code(s)

0201 Astronomical and Space Sciences

Keyword(s)

Baryon acoustic oscillations;  Cosmological parameters;  Large-scale structure of Universe;  Redshifts

Publisher

Wiley-Blackwell Publishing

ISSN

0035-8711

Publisher URL

http://dx.doi.org/10.1111/j.1365-2966.2011.19077.x

Copyright

Copyright © 2011 The Authors. Journal compilation copyright © 2011 Royal Astronomical Society. The accepted manuscript is reproduced in accordance with the copyright policy of the publisher. The definitive publication is available at www.interscience.wiley.com.

Full text

Peer reviewed