Title: Comparing the dark matter models, modified Newtonian dynamics and modified gravity in accounting for the galaxy rotation curves,
Abstract: We compare six models (including the baryonic model, two dark matter models,
two modified Newtonian dynamics models and one modified gravity model) in
accounting for the galaxy rotation curves. For the dark matter models, we
assume NFW profile and core-modified profile for the dark halo, respectively.
For the modified Newtonian dynamics models, we discuss Milgrom's MOND theory
with two different interpolation functions, i.e. the standard and the simple
interpolation functions. As for the modified gravity, we focus on Moffat's MSTG
theory. We fit these models to the observed rotation curves of 9 high-surface
brightness and 9 low-surface brightness galaxies. We apply the Bayesian
Information Criterion and the Akaike Information Criterion to test the
goodness-of-fit of each model. It is found that non of the six models can well
fit all the galaxy rotation curves. Two galaxies can be best fitted by the
baryonic model without involving the nonluminous dark matter. MOND can fit the
largest number of galaxies, and only one galaxy can be best fitted by MSTG
model. Core-modified model can well fit about one half LSB galaxies but no HSB
galaxy, while NFW model can fit only a small fraction of HSB galaxies but no
LSB galaxy. This may imply that the oversimplified NFW and Core-modified
profiles couldn't well mimic the postulated dark matter halo.