Refer to the Discussion and Concluding Remarks section. It says, "This result also indicates that the major axis of the M31 dark halo is perpendicular to its disk and nearly aligned with the planar distribution of a subgroup of its satellites."
Is this an isolated paper that states this, or is it an established fact that the major axis of the dark matter halo is perpendicular to the galactic plane of Andromeda?
What about other galaxies, like the Milky Way? Is this also observed in other galaxies?