The 6dF Galaxy Survey: Peculiar Velocity Field and Cosmography
  We derive peculiar velocities for the 6dF Galaxy Survey (6dFGS) and describe
the velocity field of the nearby ($z<0.055$) southern hemisphere. The survey
comprises 8885 galaxies for which we have previously reported Fundamental Plane
data. We obtain peculiar velocity probability distributions for the redshift
space positions of each of these galaxies using a Bayesian approach. Accounting
for selection bias, we find that the logarithmic distance uncertainty is 0.11
dex, corresponding to $26\%$ in linear distance. We use adaptive kernel
smoothing to map the observed 6dFGS velocity field out to $cz \sim 16,000$
\kms, and compare this to the predicted velocity fields from the PSCz Survey
and the 2MASS Redshift Survey. We find a better fit to the PSCz prediction,
although the reduced $\chi^2$ for the whole sample is approximately unity for
both comparisons. This means that, within the observational uncertainties due
to redshift independent distance errors, observed galaxy velocities and those
predicted by the linear approximation from the density field agree. However, we
find peculiar velocities that are systematically more positive than model
predictions in the direction of the Shapley and Vela superclusters, and
systematically more negative than model predictions in the direction of the
Pisces-Cetus Supercluster, suggesting contributions from volumes not covered by
the models.
