The VLT LBG Redshift Survey I: Clustering and Dynamics of ~1000 Galaxies
  at z~3
  We present the initial imaging and spectroscopic data acquired as part of the
VLT VIMOS Lyman-break galaxy Survey. UBR (or UBVI) imaging covers five 36'x36'
fields centred on bright z>3 QSOs, allowing ~21,000 2<z<3.5 galaxy candidates
to be selected using the Lyman-break technique. We performed spectroscopic
follow-up using VIMOS, measuring redshifts for 1020 z>2 LBGs and 10 z>2 QSOs
from a total of 19 VIMOS pointings. From the galaxy spectra, we observe a
625+-510 km/s velocity offset between the ISM absorption and Ly-alpha emission
line redshifts. Using the photometric and spectroscopic catalogues, we have
analysed the galaxy clustering at z~3. In the photometric case, the angular
correlation function, w(theta), is well fit by a double power-law with
clustering scale-length, r_0 = 3.19+0.32-0.54 Mpc/h for r < 1 Mpc/h and r_0 =
4.59+0.31-0.33 Mpc/h at larger scales. Using the redshift sample we estimate
the semi-projected correlation function, w_p(sigma) and find r_0 =
3.67+0.23-0.24 Mpc/h for the VLT sample and r_0 = 3.98+0.14-0.15 Mpc/h for a
combined VLT+Keck sample. From the z-space correlation functions and assuming
the above xi(r) models, we find that the combined VLT and Keck surveys require
a galaxy velocity dispersion, <w_z^2>^1/2 ~ 700 km/s, higher than the ~400 km/s
found by previous authors. We also measure a value for the gravitational growth
rate parameter of beta(z=3) = 0.48+-0.17, implying a low value for the bias of
b = 2.06+1.1-0.5. This value is consistent with the galaxy clustering amplitude
which gives b = 2.22+-0.16, assuming the standard cosmology, implying that the
evolution of the gravitational growth rate is also consistent with Einstein
gravity. We have compared our LBG clustering amplitudes with lower redshift
measurements and find that the clustering strength is not inconsistent with
that of low-redshift L* spirals for simple 'long-lived' galaxy models.
