CFHTLenS: Higher-order galaxy-mass correlations probed by
  galaxy-galaxy-galaxy lensing
  We present the first direct measurement of the galaxy-matter bispectrum as a
function of galaxy luminosity, stellar mass, and SED type. Our analysis uses a
galaxy-galaxy-galaxy lensing technique (G3L), on angular scales between 9
arcsec to 50 arcmin, to quantify (i) the excess surface mass density around
galaxy pairs (excess mass hereafter) and (ii) the excess shear-shear
correlations around single galaxies, both of which yield a measure of two types
of galaxy-matter bispectra. We apply our method to the state-of-the-art
Canada-France-Hawaii Telescope Lensing Survey (CFHTLenS), spanning 154 square
degrees. This survey allows us to detect a significant change of the bispectra
with lens properties. Measurements for lens populations with distinct redshift
distributions become comparable by a newly devised normalisation technique.
That will also aid future comparisons to other surveys or simulations. A
significant dependence of the normalised G3L statistics on luminosity within
-23<M_r<-18 and stellar mass within 5x10^9 M_sol<M_star<2x10^11 M_sol is found
(h=0.73). Both bispectra exhibit a stronger signal for more luminous lenses or
those with higher stellar mass (up to a factor 2-3). This is accompanied by a
steeper equilateral bispectrum for more luminous or higher stellar mass lenses
for the excess mass. Importantly, we find the excess mass to be very sensitive
to galaxy type as recently predicted with semi-analytic galaxy models: luminous
(M_r<-21) late-type galaxies show no detectable signal, while all excess mass
detected for luminous galaxies seems to be associated with early-type galaxies.
We also present the first observational constraints on third-order stochastic
galaxy biasing parameters.
