Observational Constraints on the Modified Gravity Model (MOG) Proposed by Moffat: Using the Magellanic System

TL;DR

This study evaluates the Modified Gravity (MOG) model's ability to explain the Magellanic Stream's dynamics without dark matter, comparing it with CDM and TeVeS models using observational data and statistical analysis.

Contribution

It provides observational constraints on MOG's parameters and demonstrates its plausibility in modeling the Magellanic Stream's dynamics compared to other gravity theories.

Findings

MOG can fit the Magellanic Stream data with appropriate parameters.

MOG's performance is comparable to CDM and TeVeS models.

The study supports MOG as a viable alternative to dark matter in this context.

Abstract

A simple model for the dynamics of the Magellanic Stream (MS), in the framework of modified gravity models is investigated. We assume that the galaxy is made up of baryonic matter out of context of dark matter scenario. The model we used here is named Modified Gravity (MOG) proposed by Moffat (2005). In order to examine the compatibility of the overall properties of the MS under the MOG theory, the observational radial velocity profile of the MS is compared with the numerical results using the $\chi^2$ fit method. In order to obtain the best model parameters, a maximum likelihood analysis is performed. We also compare the results of this model with the Cold Dark Matter (CDM) halo model and the other alternative gravity model that proposed by Bekenstein (2004), so called TeVeS. We show that by selecting the appropriate values for the free parameters, the MOG theory seems to be plausible to explain the dynamics of the MS as well as the CDM and the TeVeS models.