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The WiggleZ Dark Energy Survey: the transition to large-scale cosmic homogeneity

Scrimgeour, Morag I. and Martin, D. Christopher and Wyder, Ted K. (2012) The WiggleZ Dark Energy Survey: the transition to large-scale cosmic homogeneity. Monthly Notices of the Royal Astronomical Society, 425 (1). pp. 116-134. ISSN 0035-8711. http://resolver.caltech.edu/CaltechAUTHORS:20120927-132913439

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Abstract

We have made the largest volume measurement to date of the transition to large-scale homogeneity in the distribution of galaxies. We use the WiggleZ survey, a spectroscopic survey of over 200 000 blue galaxies in a cosmic volume of ∼1 h^(−3) Gpc^3. A new method of defining the ‘homogeneity scale' is presented, which is more robust than methods previously used in the literature, and which can be easily compared between different surveys. Due to the large cosmic depth of WiggleZ (up to z = 1), we are able to make the first measurement of the transition to homogeneity over a range of cosmic epochs. The mean number of galaxies N(< r) in spheres of comoving radius r is proportional to r^3 within 1 per cent, or equivalently the fractal dimension of the sample is within 1 per cent of D_2 = 3, at radii larger than 71 ± 8 h^(−1) Mpc at z ∼ 0.2, 70 ± 5 h^(−1) Mpc at z ∼ 0.4, 81 ± 5 h^(−1)  Mpc at z ∼ 0.6 and 75 ± 4 h^(−1) Mpc at z ∼ 0.8. We demonstrate the robustness of our results against selection function effects, using a Λ cold dark matter (ΛCDM) N-body simulation and a suite of inhomogeneous fractal distributions. The results are in excellent agreement with both the ΛCDM N-body simulation and an analytical ΛCDM prediction. We can exclude a fractal distribution with fractal dimension below D_2 = 2.97 on scales from ∼80 h^(−1) Mpc up to the largest scales probed by our measurement, ∼300 h^(−1) Mpc, at 99.99 per cent confidence.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1111/j.1365-2966.2012.21402.xDOIUNSPECIFIED
http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2966.2012.21402.x/abstract;jsessionid=3A59F3783A234B2E5B5EC81A1F0571F0.d03t04PublisherUNSPECIFIED
Additional Information:© 2012 The Authors. Monthly Notices of the Royal Astronomical Society © 2012 RAS. MIS would like to thank Florian Beutler for many helpful comments on the paper. We also thank Eyal Kazin, David Parkinson, Luigi Guzzo and Andy Taylor for helpful discussions. MIS acknowledges support from a Jean Rogerson Scholarship and a UWATop-up Scholarship from the University of Western Australia. GBP acknowledges support from two Australian Research Council (ARC) Discovery Projects (DP0772084 and DP1093738). The Centre for All-sky Astrophysics (CAASTRO) is an Australian Research Council Centre of Excellence, funded by grant CE11E0090. GALEX is a NASA Small Explorer, launched in 2003 April. We gratefully acknowledgeNASA’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. The WiggleZ survey would not have been 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.
Group:Space Astrophysics Laboratory
Funders:
Funding AgencyGrant Number
Jean Rogerson ScholarshipUNSPECIFIED
University of Western Australia UWATop-up ScholarshipUNSPECIFIED
Australian Research Council Discovery ProjectDP0772084
Australian Research Council Discovery ProjectDP1093738
Australian Research Council Centre of ExcellenceCE11E0090
Subject Keywords:surveys; galaxies: statistics; cosmology: observations; large-scale structure of Universe
Record Number:CaltechAUTHORS:20120927-132913439
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:20120927-132913439
Official Citation:Scrimgeour, M. I., Davis, T., Blake, C., James, J. B., Poole, G. B., Staveley-Smith, L., Brough, S., Colless, M., Contreras, C., Couch, W., Croom, S., Croton, D., Drinkwater, M. J., Forster, K., Gilbank, D., Gladders, M., Glazebrook, K., Jelliffe, B., Jurek, R. J., Li, I.-h., Madore, B., Martin, D. C., Pimbblet, K., Pracy, M., Sharp, R., Wisnioski, E., Woods, D., Wyder, T. K. and Yee, H. K. C. (2012), The WiggleZ Dark Energy Survey: the transition to large-scale cosmic homogeneity. Monthly Notices of the Royal Astronomical Society, 425: 116–134. doi: 10.1111/j.1365-2966.2012.21402.x
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:34516
Collection:CaltechAUTHORS
Deposited By: Jason Perez
Deposited On:01 Oct 2012 21:29
Last Modified:28 Aug 2016 20:24

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