Are Halos of Collisionless Cold Dark Matter Collisionless?
Abstract
We study whether gravitational scattering of halo dark matter particles by subhalos can connect two seemingly independent problems: the abundance of subhalos in dark matter halos and the cuspiness of the halos' inner density profiles. Our numerical experiments indicate that subhalos can cause the collisionless dark matter particles in the centers of main halos to diffuse. Combined with tidal mass loss of the subhalos, this process introduces significant scatter in the inner density profiles and offers an explanation for the range of profiles seen in both observations and cosmological simulations.
- Publication:
-
Physical Review Letters
- Pub Date:
- July 2004
- DOI:
- 10.1103/PhysRevLett.93.021301
- arXiv:
- arXiv:astro-ph/0403102
- Bibcode:
- 2004PhRvL..93b1301M
- Keywords:
-
- 95.35.+d;
- 95.75.-z;
- 98.62.Gq;
- Dark matter;
- Observation and data reduction techniques;
- computer modeling and simulation;
- Galactic halos;
- Astrophysics;
- High Energy Physics - Phenomenology
- E-Print:
- 4 pages, 3 figures. Phys Rev Lett, in press on May 14