The Sphericalization of Dark Matter Halos by Galaxy Disks

Understand

Cosmological simulations indicate that cold dark matter (CDM) halos should be triaxial.

• Verifying observationally this theoretical prediction is, however, less than straightforward because the assembly of galaxies is expected to modify the halo shapes and to render them more axisymmetric.
• We use a suite of N-body simulations to investigate quantitatively the effect of the growth of a central disk galaxy on the shape of triaxial dark matter halos.
• As expected, the halo responds to the presence of the disk by becoming more spherical.