effect has a lower amplitude; high mass haloes show a ratio between structure in the directions perpendicular and parallel to their angular momenta of about a $30\%$ excess (for the 3D case, this was above $50\%$) and low mass haloes show a $10\%$ effect (compared to $20-30\%$), which makes this detection a slightly more difficult task.

Observations
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Galaxies with spiral and flattened spheroidal shapes projected onto the sky give a handle on their orientation with respect to the line of sight and, therefore, it is possible to estimate in a statistical sense the direction of their angular momentum. Spiral galaxies with round projected shapes are likely discs seen face-on and therefore their angular momenta point in the direction perpendicular to the plane of the sky; elongated projected shapes indicate discs seen edge-on, and therefore their angular momenta point in the direction perpendicular to the long axis of the ellipsoid. On the other hand, elliptical galaxies with round projected shapes can either be nearly intrinsically spherical or flattened spheroids seen face-on; however, elongated ellipticals are more likely flattened spheroids seen edge-on since recent results on intrinsic elliptical shapes indicate that these are more commonly oblate rather than prolate spheroids (e.g. 