  In this paper, we investigate the external field effect in the context of the
MOdified Newtonian Dynamics (MOND) on the surface brightness and velocity
dispersion profiles of globular clusters (GCs). Using N-MODY, which is an
N-body simulation code with a MOND potential solver, we show that the general
effect of the external field for diffuse clusters, which obey MOND in most of
their parts, is that it pushes the dynamics towards the Newtonian regime. On
the other hand, for more compact clusters, which are essentially Newtonian in
their inner parts, the external field is effective mainly in the outer parts of
compact clusters. As a case study, we then choose the remote Galactic GC NGC
2419. By varying the cluster mass, half-light radius, and mass-to-light ratio
we aim to find a model that will reproduce the observational data most
effectively, using N-MODY. We find that even if we take the Galactic external
field into account, a Newtonian Plummer sphere represents the observational
data better than MOND to an order of magnitude in terms of the total $\chi^2$
of surface brightness and velocity dispersion.

Astrophysics of Galaxies