Andromeda Dwarfs in Light of MOND. II. Testing Prior Predictions

TL;DR

This study tests MOND predictions against new velocity dispersion data of Andromeda's dwarf galaxies, finding good agreement and highlighting MOND's ability to distinguish between internal and external gravitational regimes.

Contribution

It provides empirical validation of MOND predictions for dwarf galaxy dynamics, emphasizing the theory's unique external-internal field distinction.

Findings

Data agree with MOND predictions for each dwarf galaxy.

MOND explains the observed velocity dispersions without dark matter.

External and internal field effects are supported by the data.

Abstract

We employ recently published measurements of the velocity dispersions in the newly discovered dwarf satellite galaxies of Andromeda to test our previously published predictions of this quantity. The data are in good agreement with our specific predictions for each dwarf made a priori with MOND, with reasonable stellar mass-to-light ratios, and no dark matter, while Newtonian dynamics point to quite large mass discrepancies in these systems. MOND distinguishes between regimes where the internal field of the dwarf, or the external field of the host, dominates. The data appear to recognize this distinction, which is a unique feature of MOND not explicable in LCDM.