A. Sollima, C. Nipoti, A. Mastrobuono Battisti, M. Montuori, R. Capuzzo-Dolcetta
We present the results of a detailed analysis of the projected velocity
dispersion of the globular cluster Palomar 14 performed using recent
high-resolution spectroscopic data and extensive Monte Carlo simulations. The
comparison between the data and a set of dynamical models (differing in
fraction of binaries, degree of anisotropy, mass-to-light ratio M/L, cluster
orbit and theory of gravity) shows that the observed velocity dispersion of
this stellar system is well reproduced by Newtonian models with a fraction of
binaries f_b<30% and a M/L compatible with the predictions of stellar evolution
models. Instead, models computed with a large fraction of binaries
systematically overestimate the cluster velocity dispersion. We also show that,
across the parameter space sampled by our simulations, models based on the
Modified Newtonian Dynamics theory can be reconciled with observations only
assuming values of M/L lower than those predicted by stellar evolution models
under standard assumptions.
View original:
http://arxiv.org/abs/1111.1689
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