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

Date

2011

Authors

Blake, C.A.
Davis, Tamara
Poole, Gregory B
Parkinson, David
Brough, Sarah
Colless, Matthew
Contreras, Carlos
Couch, Warrick
Croom, Scott
Drinkwater, Michael John

Journal Title

Journal ISSN

Volume Title

Publisher

Blackwell Publishing Ltd

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= 132509 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.

Description

Keywords

Keywords: Cosmological parameters; Dark energy; Large-scale structure of Universe; Surveys

Citation

Source

Monthly Notices of the Royal Astronomical Society

Type

Journal article

Book Title

Entity type

Access Statement

Open Access

License Rights

DOI

10.1111/j.1365-2966.2011.19077.x

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