Probing the Shape of Milky Way Like Galaxies Using the TNG50 Simulation: Twisted and Twisted-Stretched Halos

One of the most intriguing properties of the dark matter (DM) and stellar distribution in the Milky Way galaxy is their morphological structures. We investigate the morphology of DM and stellar distribution in a sample of Milky Way (MW) like galaxies in the TNG50 simulation. Using a local in shell iterative method (LSIM), we explicitly show evidence of twisting and stretching in most galaxies in our sample. This is matched with the re-orientation observed in the eigenvectors of the inertia tensor and gives us a clear picture of having a re-oriented halo. We make a comparison between the shape profile of dark matter (DM) halo and stars and quite remarkably see that their radial profiles are fairly close, especially at small galactocentric radii where the stellar disk is located. This implies that the DM halo is somewhat aligned with the stellar disk in response to the baryonic potential. The level of alignment mostly decreases away from the center, though.