VLT LBG Redshift Survey II: Interactions between galaxies and the IGM at
  z ~3
  We have measured redshifts for 243 z ~3 quasars in nine VLT VIMOS LBG
redshift survey areas, each of which is centred on a known bright quasar. Using
spectra of these quasars, we measure the cross-correlation between neutral
hydrogen gas causing the Lya forest and 1020 Lyman-break galaxies at z ~3. We
find an increase in neutral hydrogen absorption within 5 h^-1 Mpc of a galaxy
in agreement with the results of Adelberger et al. (2003, 2005). The Lya-LBG
cross-correlation can be described by a power-law on scales larger than 3 h^-1
Mpc. When galaxy velocity dispersions are taken into account our results at
smaller scales (<2 h^-1 Mpc) are also in good agreement with the results of
Adelberger et al. (2005). There is little immediate indication of a region with
a transmission spike above the mean IGM value which might indicate the presence
of star-formation feedback. To measure the galaxy velocity dispersions, which
include both intrinsic LBG velocity dispersion and redshift errors, we have
used the LBG-LBG redshift space distortion measurements of Bielby et al.
(2010). We find that the redshift-space transmission spike implied in the
results of Adelberger et al. (2003) is too narrow to be physical in the
presence of the likely LBG velocity dispersion and is likely to be a
statistical fluke. Nevertheless, neither our nor previous data can rule out the
presence of a narrow, real-space transmission spike, given the evidence of the
increased Lya absorption surrounding LBGs which can mask the spike's presence
when convolved with a realistic LBG velocity dispersion. Finally, we identify
176 CIV systems in the quasar spectra and find an LBG-CIV correlation strength
on scales of 10 h^-1 Mpc consistent with the relation measured at ~Mpc scales.
