NGC 2419 does not challenge MOND, Part 2

R. H. Sanders*

*Corresponding author for this work

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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.

Original languageEnglish
Pages (from-to)L21-L23
Number of pages3
JournalMonthly Notices of the Royal Astronomical Society
Volume422
Issue number1
DOIs
Publication statusPublished - May-2012

Keywords

  • gravitation
  • globular clusters: individual: NGC 2419
  • dark matter
  • MODIFIED NEWTONIAN DYNAMICS

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