A DERIVATION OF (HALF) THE DARK MATTER DISTRIBUTION FUNCTION
- Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark)
All dark matter structures appear to follow a set of universalities, such as phase-space density or velocity anisotropy profiles; however, the origin of these universalities remains a mystery. Any equilibrated dark matter structure can be fully described by two functions, namely the radial and tangential velocity distribution functions (VDFs), and once these two are understood we will understand all the observed universalities. Here, we demonstrate that if we know the radial VDF then we can derive and understand the tangential VDF. This is based on simple dynamical arguments about properties of collisionless systems. We use a range of controlled numerical simulations to demonstrate the accuracy of this result. We therefore boil the question of the dark matter structural properties down to understanding the radial VDF.
- OSTI ID:
- 22092413
- Journal Information:
- Astrophysical Journal, Vol. 756, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
Similar Records
ON THE ORIGIN OF THE ANGULAR MOMENTUM PROPERTIES OF GAS AND DARK MATTER IN GALACTIC HALOS AND ITS IMPLICATIONS
Evolution of the phase-space density and the Jeans scale for dark matter derived from the Vlasov-Einstein equation