CFHTLenS: The relation between galaxy dark matter haloes and baryons
  from weak gravitational lensing
  We present a study of the relation between dark matter halo mass and the
baryonic content of host galaxies, quantified via luminosity and stellar mass.
Our investigation uses 154 deg2 of Canada-France-Hawaii Telescope Lensing
Survey (CFHTLenS) lensing and photometric data, obtained from the CFHT Legacy
Survey. We employ a galaxy-galaxy lensing halo model which allows us to
constrain the halo mass and the satellite fraction. Our analysis is limited to
lenses at redshifts between 0.2 and 0.4. We express the relationship between
halo mass and baryonic observable as a power law. For the luminosity-halo mass
relation we find a slope of 1.32+/-0.06 and a normalisation of
1.19+0.06-0.07x10^13 h70^-1 Msun for red galaxies, while for blue galaxies the
best-fit slope is 1.09+0.20-0.13 and the normalisation is 0.18+0.04-0.05x10^13
h70^-1 Msun. Similarly, we find a best-fit slope of 1.36+0.06-0.07 and a
normalisation of 1.43+0.11-0.08x10^13 h70^-1 Msun for the stellar mass-halo
mass relation of red galaxies, while for blue galaxies the corresponding values
are 0.98+0.08-0.07 and 0.84+0.20-0.16x10^13 h70^-1 Msun. For red lenses, the
fraction which are satellites tends to decrease with luminosity and stellar
mass, with the sample being nearly all satellites for a stellar mass of 2x10^9
h70^-2 Msun. The satellite fractions are generally close to zero for blue
lenses, irrespective of luminosity or stellar mass. This, together with the
shallower relation between halo mass and baryonic tracer, is a direct
confirmation from galaxy-galaxy lensing that blue galaxies reside in less
clustered environments than red galaxies. We also find that the halo model,
while matching the lensing signal around red lenses well, is prone to
over-predicting the large-scale signal for faint and less massive blue lenses.
This could be a further indication that these galaxies tend to be more isolated
than assumed. [abridged]
