Rotation of the Globular Cluster Population of the Dark Matter Deficient Galaxy NGC 1052-DF4: Implication for the Total Mass

TL;DR

This study investigates the rotation of globular clusters in NGC 1052-DF4 to assess its dark matter content, finding little evidence of rotation which supports its classification as a dark matter deficient galaxy.

Contribution

It provides the first Bayesian analysis of globular cluster rotation in NGC 1052-DF4, offering insights into its mass and dark matter deficiency.

Findings

Non-rotating model favored over rotating model

Rotation amplitude, if any, is small

Supports the galaxy's classification as dark matter deficient

Abstract

We explore the globular cluster population of NGC 1052-DF4, a dark matter deficient galaxy, using Bayesian inference to search for the presence of rotation. The existence of such a rotating component is relevant to the estimation of the mass of the galaxy, and therefore the question of whether NGC 1052-DF4 is truly deficient of dark matter, similar to NGC 1052-DF2 another galaxy in the same group. The rotational characteristics of seven globular clusters in NGC 1052-DF4 were investigated, finding that a non-rotating kinematic model has a higher Bayesian evidence than a rotating model, by a factor of approximately 2.5. In addition, we find that under the assumption of rotation, its amplitude must be small. This distinct lack of rotation strengthens the case that, based on its intrinsic velocity dispersion, NGC 1052-DF4 is a truly dark matter deficient galaxy.