6dF Galaxy Survey

6dF Galaxy Survey The 6dF Galaxy Survey was a large-area, redshift and peculiar velocity survey of the southern sky carried out using the Six-degree Field instrument on the UK Schmidt Telescope at the Anglo-Australian Observatory. The survey produced a redshift catalog and a peculiar velocity sample that enabled measurements of the local large-scale structure, cosmography, and galaxy properties across the southern celestial hemisphere. It is widely used alongside other surveys and facilities for cosmological analyses, comparisons with simulations, and multiwavelength studies.

Overview

The survey mapped galaxies selected from the Two Micron All Sky Survey, the SuperCOSMOS Sky Survey, and other catalogs, providing redshifts, spectra, and velocity dispersions for hundreds of thousands of targets drawn from the southern sky, the Magellanic Clouds region, and fields overlapping with the Sloan Digital Sky Survey footprint. Key institutional partners included the Anglo-Australian Observatory, the Australian Astronomical Observatory, the University of Cambridge, the University of Sydney, and collaborators associated with the Royal Observatory, Edinburgh, the Max Planck Institute for Astrophysics, and the European Southern Observatory. The project tied into legacy programs such as the 2dF Galaxy Redshift Survey, the Sloan Digital Sky Survey, the Two Micron All Sky Survey, and the Infrared Astronomical Satellite catalogs.

Survey Design and Instrumentation

Survey strategy employed the Six-degree Field multi-fibre spectrograph mounted on the UK Schmidt Telescope at Siding Spring Observatory, enabling simultaneous spectroscopy for up to 150 targets over a field of view comparable to the Magellanic Clouds extent and to observing programs at the Anglo-Australian Telescope and the Cerro Tololo Inter-American Observatory. Target selection used photometry from Two Micron All Sky Survey and astrometric inputs from SuperCOSMOS and served scientific teams connected to the Australian National University, the University of Oxford, the University of Melbourne, the Smithsonian Astrophysical Observatory, and the Max Planck Society. The instrument design drew on multi-object spectroscopy concepts used by the Two-degree Field instrument, fiber positioner technology developed in collaboration with teams at the Rutherford Appleton Laboratory, and calibration practices similar to those at the European Southern Observatory and the National Optical Astronomy Observatory.

Data Reduction and Catalogs

Raw spectra were processed with pipelines developed by project teams at the Anglo-Australian Observatory, the Australian National University, and collaborators from the University of Cambridge and the University of Edinburgh, incorporating wavelength calibration methods used at the Royal Observatory, Greenwich, and flux calibration approaches comparable to those adopted by the Sloan Digital Sky Survey. Catalog products included redshift catalogs, peculiar velocity catalogs derived using Fundamental Plane and Tully–Fisher relations, and value-added tables cross-matched to photometric inputs from Two Micron All Sky Survey, SuperCOSMOS, the Wide-field Infrared Survey Explorer, and archival imaging from the Hubble Space Telescope and the European Southern Observatory. Data release protocols were coordinated with standards practiced by the International Virtual Observatory Alliance, the NASA/IPAC Infrared Science Archive, and data centers at the Centre de Données astronomiques de Strasbourg.

Scientific Results

Analyses of the redshift and peculiar velocity samples yielded measurements of the local galaxy luminosity function, environmental dependence studies linking galaxy properties to cluster and group membership identified in catalogs from the Australian Astronomical Observatory and the Max Planck Institute for Astrophysics, and constraints on the peculiar velocity field used to probe dark matter distribution inferred in comparisons with Lambda Cold Dark Matter simulations produced by teams at the University of California, Berkeley, the University of Cambridge, and the Max Planck Institute for Astrophysics. Results were compared with outcomes from the Sloan Digital Sky Survey, the 2dF Galaxy Redshift Survey, and the Galaxy And Mass Assembly project; they informed studies related to bulk flow measurements that involved groups at Princeton University, the University of Oxford, and the Kavli Institute for Cosmology. Publications involved authors affiliated with the Australian Research Council, the Royal Astronomical Society, and international consortia including participants from the Harvard–Smithsonian Center for Astrophysics.

Legacy and Impact

The survey legacy includes publicly available redshift and peculiar velocity catalogs used by researchers at institutions such as the Smithsonian Astrophysical Observatory, the Max Planck Institute, the University of Cambridge, and the Australian National University for follow-up observations with instruments at the Anglo-Australian Telescope, the European Southern Observatory, the Keck Observatory, and the Very Large Telescope. The 6dF data have been integrated into meta-analyses alongside datasets from the Two Micron All Sky Survey, the Sloan Digital Sky Survey, the Dark Energy Survey, and the Galaxy And Mass Assembly project, supporting ongoing research in cosmic flows, large-scale structure, galaxy evolution, and cross-correlation studies with microwave background experiments from the Wilkinson Microwave Anisotropy Probe and the Planck Collaboration. Its methodologies influenced instrument development at the Australian Astronomical Observatory and survey design decisions at institutions such as the European Southern Observatory, the National Astronomical Observatory of Japan, and the National Optical Astronomy Observatory.

Category:Astronomical surveys