English

NGC 2419 does not challenge MOND, Part 2

Cosmology and Nongalactic Astrophysics 2015-06-03 v1

Abstract

I argue that, despite repeated claims of Ibata et al., the globular cluster NGC 2419 does not pose a problem for modified Newtonian dynamics (MOND). I present a new polytropic model with a running polytropic index. This model provides an improved representation of the radial distribution of surface brightness while maintaining a reasonable fit to the velocity dispersion profile. Although it may be argued that the differences with these observations remain large compared to the reported random errors, there are several undetectable systematic effects which render a formal likelihood analysis irrelevant. I comment generally upon these effects and upon the intrinsic limitations of pressure supported objects as tests of gravity.

Keywords

Cite

@article{arxiv.1111.4334,
  title  = {NGC 2419 does not challenge MOND, Part 2},
  author = {R. H. Sanders},
  journal= {arXiv preprint arXiv:1111.4334},
  year   = {2015}
}

Comments

3 page, 2 figures

R2 v1 2026-06-21T19:38:02.157Z