Title: The 2dF Galaxy Redshift Survey
Speaker: Matthew Colless
Abstract:
The 2dF Galaxy Redshift Survey has now measured redshifts for over
140,000 galaxies and provides some of the most detailed
information to date on the intrinsic properties of galaxies
and the large-scale structure in the local universe. I present
results on the luminosity functions of galaxies and their
dependence on spectral type and surface brightness. I also
report some initial results on the statistical properties on
the structure of the galaxy distribution and the implications
for cosmological parameters.
The redshift-space anisotropy of the galaxy correlation
function is in excellent agreement with the predictions of the
gravitational instability paradigm for the growth of
large-scale structure. The preliminary estimate of the
distortion parameter has significantly higher precision than
previous determinations. Allowing for the effective redshift
and luminosity of the 2dFGRS sample, this result is in good
accord with recent CMB anisotropy results, and favours a
universe with a low mass density, Omega~0.3-0.4.
A preliminary measurement of the real-space power spectrum of
galaxy clustering, P(k), has been made on scales up to 300
h/Mpc (k>0.02). A comparison is presented between the 2dFGRS
power spectrum and previous estimates from the projected
galaxy distribution and earlier redshift surveys; the 2dFGRS
P(k) is also compared to predictions from the best-fitting
cosmological models derived from recent CMB anisotropy
measurements. Further work with the 2dFGRS will yield
higher-order clustering statistics for the galaxy
distribution. Amongst other things, these will test whether
the initial density fluctuations were a Gaussian random field,
and allow independent measurement of the mass density Omega
and the bias parameter b.
Reference for students:
"Redshift Surveys and Cosmology", Colless, M., 1999, astroph-11326
The 2dF Galaxy Redshift Survey Home Page
Lunch with the students will be on Friday, January 19th at 12:00 in A-101.