Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published August 2011 | Published
Journal Article Open

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

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.

Additional Information

© 2011 The Authors. Monthly Notices of the Royal Astronomical Society © 2011 RAS. Accepted 2011 May 14. Received 2011 May 13; in original form 2011 February 3. Article first published online: 23 Jun. 2011. We acknowledge financial support from the Australian Research Council through Discovery Project grants DP0772084 and DP1093738 funding the positions of SB, MP, GBP and TD. SC acknowledges the support of the Australian Research Council through a QEII Fellowship. MJD thanks the Gregg Thompson Dark Energy Travel Fund for financial support. The Galaxy Evolution Explorer (GALEX) is a NASA small explorer, launched in 2003 April. We gratefully acknowledge NASA's support for construction, operation and science analysis for the GALEX mission, developed in cooperation with the Centre National d'Etudes Spatiales of France and the Korean Ministry of Science and Technology. Finally, the WiggleZ survey would not be possible without the dedicated work of the staff of the Australian Astronomical Observatory in the development and support of the AAOmega spectrograph, and the running of the AAT.

Attached Files

Published - Blake2011p15716Mon_Not_R_Astron_Soc.pdf

Files

Blake2011p15716Mon_Not_R_Astron_Soc.pdf
Files (2.5 MB)
Name Size Download all
md5:bbc54a4c919a1d0d24cef3fc03e07e42
2.5 MB Preview Download

Additional details

Created:
August 22, 2023
Modified:
October 24, 2023