  Alignments in the angular momentum vectors of galaxies can induce large scale
correlations in their projected orientations. Such alignments arise from the
tidal torques exerted on neighboring proto-galaxies by the smoothly varying
shear field. Weak gravitational lensing can also induce ellipticity
correlations since the images of neighboring galaxies will be distorted
coherently by the intervening mass distribution. Comparing these two sources of
shape correlations, it is found that for current weak lensing surveys with a
median redshift of 1, the intrinsic signal is a contaminant on the order of
1-10% of the measured signal. However, for shallower surveys, the intrinsic
correlations dominate over the lensing signal. The distortions induced by
lensing are curl-free, whereas those resulting from intrinsic alignments are
not. This difference can be used to disentangle these two sources of
ellipticity correlations. When the distortions are dominated by lensing, as
occurs at high redshifts, the decomposition provides a valuable tool for
understanding properties of the noise and systematic errors.
