The 2dF Galaxy Redshift Survey (2dFGRS) is a major spectroscopic
survey taking full advantage of the unique capabilities of the
2dF
facility built by the Anglo-Australian Observatory. The 2dFGRS is
integrated with the 2dF QSO survey.
The 2dFGRS obtained spectra for 245591 objects, mainly galaxies,
brighter than a nominal extinction-corrected magnitude limit of
bJ=19.45. Reliable (quality>=3) redshifts were obtained for
221414 galaxies. The galaxies cover an area of approximately 1500 square
degrees selected from the extended
APM Galaxy Survey
in three regions: an NGP strip, an SGP strip and random fields scattered
around the SGP strip. The arrangement of survey fields is shown below.
The 2dFGRS survey and its database are described in detail in
Colless et al.
(2001), with additional documentation and updates provided
here. The
figure below shows the map of the galaxy distribution produced from the
completed survey (other versions of this figure in various image formats
are accessible from the 2dFGRS
gallery).
The survey has been used to address a variety of fundamental problems
in galaxy formation and cosmology. The results emerging from the survey
to date include:
- An accurate measurement of the power spectrum of galaxy clustering
on scales up to 300h-1 Mpc, allowing precise
determinations of the total mass density of the universe and the
baryon fraction
(Percival et al.
2001).
- Measurements of the distortion of the clustering pattern in redshift
space, providing independent constraints on the total mass density
and the spatial distribution of dark matter
(Peacock et al.
2001 and
Hawkins et al.
2003).
- A strong new upper limit on the total neutrino mass
(Elgaroy et
al. 2002).
- In combination with observations of the cosmic microwave background
(CMB), precise measurements of the Hubble constant and the baryon
density, evidence for a non-zero cosmological constant (dark
energy), and constraints on the equation of state of the dark energy
(Efstathiou
et al. 2002 and
Percival et
al. 2002).
- The first direct measurements of the galaxy bias parameter, both
from higher-order correlations in the galaxy distribution
(Verde et al.
2002) and from comparison with the CMB power spectrum
(Lahav et al.
2002).
- A characterization of the galaxy luminosity function in both the
optical
(Norberg et
al. 2002) and near-infrared
(Cole et al.
2001), with the former yielding the mean current
star-formation rate and the latter the stellar mass function of
galaxies.
- The distribution of galaxies as a joint function of total luminosity
and central surface brightness
(Cross et al.
2001).
- The luminosity functions for galaxies with different spectral types,
both in the field
(Folkes et al.
1999 and
Madgwick et
al. 2001) and in clusters
(De Propris
et al. 2003).
- The variation in clustering properties of galaxies as functions of
luminosity
(Norberg et
al. 2002) and spectral type
(Madgwick
et al. 2003).
- Constraints on the cosmic star-formation history from the mean
galaxy spectrum in the local universe
(Baldry
et al. 2002) and the environmental dependence of
star-formation rates of galaxies around clusters
(Lewis
et al. 2002).
- The properties and luminosity functions of radio sources of various
types
(Sadler et
al. 2002 and
Magliocchetti
et al. 2002).
- The properties of previously-identified clusters of galaxies in the
survey, and dynamical estimates of the cluster masses
(De Propris et
al. 2001).
Further results emerging from the 2dFGRS are described in other
publications of the 2dFGRS
team.
The final release dataset
comprises the following elements:
- The input photometric
catalogues (source catalogues) for the full 2dFGRS survey,
containing data for 382323 objects, together with related material.
- The spectroscopic
catalogues for 245591 objects, containing the
spectroscopic parameters such as redshifts and spectral types.
- The mSQL
database, which allows searching and subsetting of the
public release data, and provides access to the FITS files
containing the spectra as well as all the other photometric and
spectroscopic parameters.
- The survey mask
software for determining whether a given position is in
the survey region, and the survey magnitude limit and redshift
completeness at that position; also
selection
software for extracting various types of subsamples and
creating corresponding mock catalogues.
- Documentation, both
on-line
and through links to survey
publications.
- Additional material such as
images,
movies and
stills,
media reports and
links to related topics.