Weak gravitational lensing of intrinsically aligned galaxies
  Subject of this paper is the weak lensing effect on galaxies that show
intrinsically correlated ellipticities. In our model, we investigate the
distortion of the ellipticity field if the galaxies experience an apparent
shift in their position by weak lensing deflection and compare this effect to
the shearing effect induced by tidal fields. Starting with a derivation of
intrinsic ellipticity spectra by employing a tidal torquing model generating
galactic angular momenta, we model the galaxy ellipticity by assuming that the
galactic disk forms perpendicularly to the host halo angular momentum direction
and derive intrinsic ellipticity E-mode and B-mode spectra from the angular
momentum statistics. The lensing effect on the ellipticity field is modeled by
employing the methodology developed in the framework of lensing of the cosmic
microwave background polarisation. For EUCLID, ellipticity correlations are
altered by lensing deflection on multipoles l>1000 by ~5% for the ellipticity
E-modes and by ~30% for the B-modes, while a shallower survey would exhibit
larger changes on larger angular scales. In addition to the convolving effect
of lensing on the ellipticity spectra we investigate the E/B-mode conversion,
and discuss the possibility of measuring correlations between different
multipoles which is evoked by the homogeneity breaking effect of the lensing
displacement. Our conclusion is that although shape correlations generated by
weak gravitational shear is dominant, the shifting effect due to lensing is
shaping the ellipticity spectra on small angular scales and causes a number of
interesting phenomena, which might be observable by future surveys.
