45 citations · 118 across the 4 of their papers we have counts for
4 papers · 1 filter
Characterizing stellar halo populations II: The age gradient in blue horizontal-branch stars
Payel Das, Angus Williams, James Binney
The distribution of Milky Way halo blue horizontal-branch (BHB) stars is examined using action-based extended distribution functions (EDFs) that describe the locations of stars in…
Made-to-Measure Dark Matter Haloes, Elliptical Galaxies and Dwarf Galaxies in Action Coordinates
A. A. Williams, N. W. Evans
We provide a family of action-based distribution functions (DFs) for the double-power law family of densities often used to model galaxies. The DF itself is a double-power law in c…
A Very Simple Cusped Halo Model
N. W. Evans, A. A. Williams
We introduce a very simple model of a dark halo. It is a close relative of Hernquist's model, being generated by the same transformation but this time applied to the logarithmic po…
Hamiltonians of Spherically Symmetric, Scale-Free Galaxies in Action-Angle Coordinates
A. A. Williams, N. W. Evans, A. Bowden
We present a simple formula for the Hamiltonian in terms of the actions for spherically symmetric, scale-free potentials. The Hamiltonian is a power-law or logarithmic function of…