WiggleZ Dark Energy Survey

WiggleZ Dark Energy Survey
Name	WiggleZ Dark Energy Survey
Acronym	WiggleZ
Type	Redshift survey
Telescopes	Anglo-Australian Telescope
Instruments	AAOmega spectrograph
Start	2006
End	2011
Principal investigators	Darren Croton; Michael Drinkwater
Participants	Swinburne University of Technology; Australian Astronomical Observatory; University of Queensland

WiggleZ Dark Energy Survey The WiggleZ Dark Energy Survey was a large-scale extragalactic redshift survey that mapped emission-line galaxies to measure baryon acoustic oscillations and test cosmic acceleration. It connected observational programs at the Anglo-Australian Telescope with theoretical work from groups at Swinburne University of Technology, University of Queensland, Australian National University, and collaborators linked to the Max Planck Society, Harvard University, University of Cambridge, and the University of Oxford.

Overview

The project collected spectroscopic redshifts for hundreds of thousands of galaxies using the Anglo-Australian Telescope and the AAOmega spectrograph to trace large-scale structure across wide fields including regions near the South Galactic Cap and the Sloan Digital Sky Survey footprint. It utilized target selection informed by imaging from the Galaxy Evolution Explorer, the Two Micron All Sky Survey, the Dark Energy Survey preparatory catalogs, and legacy datasets from the Two-degree Field Galaxy Redshift Survey and the 6dF Galaxy Survey. The survey built on methods developed in projects such as the Sloan Digital Sky Survey and the 2dF Galaxy Redshift Survey while engaging researchers associated with institutions like Monash University, University of Melbourne, and International Centre for Radio Astronomy Research.

Objectives and Scientific Goals

WiggleZ aimed to measure the scale of baryon acoustic oscillations (BAO) at intermediate redshifts to constrain the expansion history associated with dark energy models such as the Lambda-CDM model and alternatives including quintessence frameworks explored at the Perimeter Institute and the Kavli Institute for Cosmology. Primary goals included testing predictions of the Cosmic Microwave Background analyses from WMAP and comparing distance measures with supernova programs like the Supernova Legacy Survey and the Sloan Supernova Survey. The collaboration sought to probe growth of structure predictions from simulations developed at the Max Planck Institute for Astrophysics and connect observational constraints to theoretical work by researchers at Princeton University, Caltech, and the Institute for Advanced Study.

Instrumentation and Observations

Observations were executed with the Anglo-Australian Telescope using the multi-fiber AAOmega spectrograph fed by the 2dF fiber positioner, leveraging instrument teams associated with the Australian Astronomical Observatory and technical expertise from groups at CARA and the United Kingdom Infra-Red Telescope. Target selection used ultraviolet photometry from the Galaxy Evolution Explorer and optical photometry cross-matched with catalogs from Sloan Digital Sky Survey imaging fields, coordinated alongside calibration programs referencing standards maintained by the European Southern Observatory and the National Optical Astronomy Observatory. Survey scheduling and time allocation were negotiated with the Australian National Telescope Allocation Committee and coordinated across semesters with teams at the Anglo-Australian Observatory.

Data Reduction and Analysis Methods

Data reduction employed pipelines developed by instrument teams at the Anglo-Australian Observatory and analysis toolkits inspired by software from the Sloan Digital Sky Survey and the CosmoMC frameworks from the University of Cambridge and the University of Oxford. Redshift determination used emission-line fitting routines validated against reference samples from the 2dF Galaxy Redshift Survey and cross-checked with photometric catalogs from the Two Micron All Sky Survey and the Galaxy Evolution Explorer. Statistical analyses of clustering and BAO signals applied methods from the Planck and WMAP analyses, incorporating covariance estimation techniques practiced by teams at Harvard University, Princeton University, and the Max Planck Institute for Astrophysics. Cosmological parameter inference used Markov Chain Monte Carlo software influenced by work at the Perimeter Institute and the Institute for Advanced Study.

Key Results and Cosmological Implications

WiggleZ produced robust BAO detections at redshifts around z~0.6, providing distance measurements that complemented lower-redshift results from the Sloan Digital Sky Survey and higher-redshift constraints from the Baryon Oscillation Spectroscopic Survey. The survey's measurements tightened limits on the dark energy equation-of-state parameter w, informing joint analyses with data from WMAP, Planck, and supernova compilations such as the Supernova Legacy Survey and the Union compilation. Results influenced theoretical interpretations at institutions including Princeton University, Caltech, and the Max Planck Institute for Astrophysics, and were cited in follow-up observational designs for projects at the European Southern Observatory and the Dark Energy Survey consortium.

Collaboration and Project Timeline

Initiated in the mid-2000s, WiggleZ ran observing campaigns from 2006 through 2011, coordinated by principal investigators associated with Swinburne University of Technology and University of Queensland and involving collaborators from Australian National University, University of Cambridge, Harvard University, Max Planck Society, and other institutions. Data releases were distributed to the community following internal validation protocols similar to those used by the Sloan Digital Sky Survey and inspired collaborations with programs at the Dark Energy Survey and future projects at the Anglo-Australian Telescope and European Southern Observatory. The survey legacy influenced planning at facilities including the Vera C. Rubin Observatory and the Square Kilometre Array precursor projects.

Category:Redshift surveys Category:Astrophysics projects Category:Cosmology