The velocity distribution of SDSS satellites in MOND

TL;DR

This paper models the velocity distribution of SDSS satellite galaxies within MOND, demonstrating that observed velocity dispersions can be matched with realistic anisotropy profiles and consistent mass-to-light ratios.

Contribution

It shows that MOND can accurately reproduce satellite velocity dispersions with plausible anisotropy profiles and realistic galaxy parameters.

Findings

Velocity dispersions match observations with radially varying anisotropy.

Anisotropies are similar to those from MOND collapse simulations.

Mass-to-light ratios are physically reasonable.

Abstract

The recent SDSS measured velocity distribution of satellite galaxies has been modelled in the context of MOND. We show that even when the extra constraint of adhering to the projected satellite number density profile is added, the two line of sight (los) velocity dispersion profiles presented in Klypin & Prada (2007) can be matched simply with a radially varying anisotropy. Interestingly, the anisotropies required to fit the los velocity dispersions are remarkably similar to the anisotropies generated by dissipationless collapse simulations in MOND. The mass-to-light ratios of the two host galaxies used are sensible and positivity of the distribution function is satisfied.