The evolution of galaxy clustering since z = 3 using the UKIDSS Ultra
  Deep Survey: the divergence of passive and star-forming galaxies
  We use the UKIDSS Ultra-Deep Survey to trace the evolution of galaxy
clustering to z = 3. Using photometric redshifts derived from data covering the
wavelength range 0.3 - 4.5 um we examine this clustering as a function of
absolute K-band luminosity, colour and star-formation rate. Comparing the
deprojected clustering amplitudes, we find that red galaxies are more strongly
clustered than blue galaxies out to at least z = 1.5, irrespective of
rest-frame K-band luminosity. We then construct passive and star-forming
samples based on stellar age, colour and star-formation histories calculated
from the best fitting templates. The clustering strength of star-forming
galaxies declines steadily from r_0 ~ 7 h^-1 Mpc at z ~ 2 to r_0 ~ 3 h^-1 Mpc
at z ~ 0, while passive galaxies have clustering strengths up to a factor of
two higher. Within the passive and star-forming subsamples, however, we find
very little dependence of galaxy clustering on K-band luminosity. Galaxy
`passivity' appears to be the strongest indicator of clustering strength. We
compare these clustering measurements with those predicted for dark matter
halos and conclude that passive galaxies typically reside in halos of mass M >
10^13 M_sun while luminous star-forming galaxies occupy halos an order of
magnitude less massive over the range 0.5 < z < 1.5. The decline in the
clustering strength of star-forming galaxies with decreasing redshift indicates
a decline in the hosting halo mass for galaxies of a given luminosity. We find
evidence for convergence of clustering in star-forming and passive galaxies
around z ~ 2, which is consistent with this being the epoch at which the red
sequence of galaxies becomes distinct.
