Understanding Galactic Disc Warps: The Influence of Dark Matter and the Sagittarius Dwarf Galaxy

This paper by James Binney explores why spiral galaxies, like the Milky Way, often have warped outer discs. By revisiting and updating earlier models, Binney shows how galactic warps form and evolve, especially under the influence of the Sagittarius Dwarf Galaxy's gravitational pull during close encounters. His model suggests that these interactions cause the Milky Way’s disc to warp temporarily, gradually winding into spiral patterns. This work highlights that such warps provide insight into the dark matter halo’s density and shape, offering a new understanding of galactic dynamics and structure.