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Title

The WiggleZ Dark Energy Survey: measuring the cosmic expansion history using the Alcock-Paczynski test and distant supernovae

Author(s)

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

Abstract

Astronomical observations suggest that today's Universe is dominated by a dark energy of unknown physical origin. One of the most notable results obtained from many models is that dark energy should cause the expansion of the Universe to accelerate: but the expansion rate as a function of time has proved very difficult to measure directly. We present a new determination of the cosmic expansion history by combining distant supernovae observations with a geometrical analysis of large-scale galaxy clustering within the WiggleZ Dark Energy Survey, using the Alcock-Paczynski test to measure the distortion of standard spheres. Our result constitutes a robust and non-parametric measurement of the Hubble expansion rate as a function of time, which we measure with 10-15 per cent precision in four bins within the redshift range 0.1 < z < 0.9. We demonstrate, in a manner insensitive to the assumed cosmological model, that the cosmic expansion is accelerating. Furthermore, we find that this expansion history is consistent with a cosmological-constant dark energy.

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. 418, no. 3 (Dec 2011), pp. 1725-1735

Publication year

2011

FOR Code(s)

0201 Astronomical and Space Sciences

Keyword(s)

Cosmic expansion;  Dark energy;  Distance scale;  History

Publisher

Wiley-Blackwell

ISSN

0035-8711

Publisher URL

http://dx.doi.org/10.1111/j.1365-2966.2011.19606.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.

Research Projects

The last 8 billion years of cosmic evolution, Australian Research Council grant number DP0772084
The fundamental physics governing the formation of cosmic structure, Australian Research Council grant number DP1093738
The formation and structure of distant galaxies, Australian Research Council grant number LX0881951

Full text

Peer reviewed