TY - JOUR
T1 - The WiggleZ Dark Energy Survey
T2 - The transition to large-scale cosmic homogeneity
AU - Scrimgeour, Morag I.
AU - Davis, Tamara
AU - Blake, Chris
AU - James, J. Berian
AU - Poole, Gregory B.
AU - Staveley-Smith, Lister
AU - Brough, Sarah
AU - Colless, Matthew
AU - Contreras, Carlos
AU - Couch, Warrick
AU - Croom, Scott
AU - Croton, Darren
AU - Drinkwater, Michael J.
AU - Forster, Karl
AU - Gilbank, David
AU - Gladders, Mike
AU - Glazebrook, Karl
AU - Jelliffe, Ben
AU - Jurek, Russell J.
AU - Li, I. hui
AU - Madore, Barry
AU - Martin, D. Christopher
AU - Pimbblet, Kevin
AU - Pracy, Michael
AU - Sharp, Rob
AU - Wisnioski, Emily
AU - Woods, David
AU - Wyder, Ted K.
AU - Yee, H. K.C.
PY - 2012/9/1
Y1 - 2012/9/1
N2 - 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 200000 blue galaxies in a cosmic volume of ∼1h-3Gpc3. 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 r3 within 1per cent, or equivalently the fractal dimension of the sample is within 1per cent of D2 = 3, at radii larger than 71 ± 8h-1Mpc at z ∼ 0.2, 70 ± 5h-1Mpc at z ∼ 0.4, 81 ± 5h-1Mpc at z ∼ 0.6 and 75 ± 4h-1Mpc 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 D2 = 2.97 on scales from ∼80h-1Mpc up to the largest scales probed by our measurement, ∼300 h-1Mpc, at 99.99per cent confidence.
AB - 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 200000 blue galaxies in a cosmic volume of ∼1h-3Gpc3. 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 r3 within 1per cent, or equivalently the fractal dimension of the sample is within 1per cent of D2 = 3, at radii larger than 71 ± 8h-1Mpc at z ∼ 0.2, 70 ± 5h-1Mpc at z ∼ 0.4, 81 ± 5h-1Mpc at z ∼ 0.6 and 75 ± 4h-1Mpc 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 D2 = 2.97 on scales from ∼80h-1Mpc up to the largest scales probed by our measurement, ∼300 h-1Mpc, at 99.99per cent confidence.
KW - Cosmology: observations
KW - Galaxies: statistics
KW - Large-scale structure of Universe
KW - Surveys
UR - http://www.scopus.com/inward/record.url?scp=84865356589&partnerID=8YFLogxK
U2 - 10.1111/j.1365-2966.2012.21402.x
DO - 10.1111/j.1365-2966.2012.21402.x
M3 - Article
SN - 0035-8711
VL - 425
SP - 116
EP - 134
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 1
ER -