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Michael Drinkwater for the team

Australia: Blake, Brough, Colless, Couch, Croom, Davis, Glazebrook, Jelliffe, Jurek, Li, Pimbblet, Poole,

Pracy, Sharp, WisniosikiU.S.A.: Foster, Gladders, Madore,

Martin, Small, Wyder Canada: Gilbank, Woods, Yee

The WiggleZ Dark Energy Survey

30/6/092 Unity of the Universe

1. Motivation2. Design &

Progress3. Large Scale

Structure Results

4. Other Results

1. Motivation

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Need to sample around redshift z=0.6 when acceleration starts

Survey aims:Measure BAO

scale to 2% in a sample of 240,000 galaxies at 0.3<z<0.9

Measure w to 10% to independently validate constant dark energy model

Motivation

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2. Design & Progress

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GALEX satellite imagingUV-selected galaxiesMedium Imaging Survey

extendedNUV < 22.8

Optical imaging: r < 22.5SDSS (North)RCS2 survey on CFHT

(South)AAT’s new AAOmega fibre

spectrograph220-night large projectMeasure 240,000 redshiftsStar forming galaxiesEmission line redshifts in

short 1-hour exposures

Example spectra

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Quality = 5 (high)Redshift z=0.57R = 21.4 mag

Quality = 3 (acceptable)Redshift z=0.86R = 21.2 mag

Survey coverage

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Design Improvements

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New spectrograph beam splitterMoved spectra

100 nm to the red

More reliable redshifts

Optical Colour SelectionIncreased

median redshift to zmed=0.6

Survey Status

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Progress Observations ¾ done Scheduled to run 2006 to 2010 August Over 140,000 galaxies measured Have doubled the number of known

z>0.5 galaxies from the two largest existing surveys (DEEP2 & VIMOS)

Galaxies in the 15-hour WiggleZ field… to 3.3 Gpc distance

3. Large scale clustering results

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The 2dF control system…

WiggleZ power spectrum

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5% accuracy indk = 0.01 bins

Linear model isgood fit to k = 0.3

WiggleZ power spectrum

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Divided by reference model with BAO signal removed.

Model divided by reference

Model convolved with survey window

Cosmological Parameters

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Predicted final sensitivity

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Predicted precision in measurement of (wconst, ΩM) combined with supernovae

4. Other results

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Small scale clustering (Blake et al. 2009)UV luminosity function (Russell Jurek’s PhD)Growth of structure (Carlos Contreras’ PhD)Super starburst galaxies (Emily Wisnioski’s

PhD)Future work

Neutrino massGalaxy bispectrumGenus statisticHomogeneity scale of Universe (vs LTB

models)

Small scale clustering

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Small scale clustering

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The UV galaxy luminosity function

N=9356 (photo-z)

N=1869 N=1039

N=2976

WiggleZN=47,747

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Russell Jurek’s PhD

First ever sample of bright end of UV luminosity function

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MN

UV

-18

-

20

-

22

0.2 0.6 1.0 redshift (z) 0

.01

0.0

2

0

.03

Fract

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un

ivers

al st

ar

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on

den

sity

• WiggleZ galaxies have the highest SF at any redshift• Their contribution peaks at z≈0.6

UV contribution to star formation

Growth of structure

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Super starburst galaxies

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Neutrino Mass

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Advantage of WiggleZGalaxies less

strongly clustered than LRGs

Higher redshift

Better power spectrum measurementHave many

more Fourier scales before it goes non linear

Non-linear growthof structure

Summary

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Aims of WiggleZSurvey the largest ever

volume of the z>0.5 Universe

240,000 galaxies in 1 Gpc3

Measure BAO scale to 2%Measure constant w to

10%BAO not measured until

observations finish 2010 May

Many other science applications

The technology behind WiggleZ: 2dF positioning fibres on the AAT

2dF on a bad day

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Note the special error message: “Too many errors.”