A Monte Carlo analysis of the velocity dispersion of the globular cluster Palomar 14

Abstract

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.

13 pages, 13 figures, accepted for publication by ApJ

References in corpus (5)

• N-body simulations of gravitational dynamics
• Testing Fundamental Physics with Distant Star Clusters: Analysis of Observational Data on Palomar 14
• Globular Clusters in the Outer Galactic Halo: AM-1 and Palomar 14
• What a Local Sample of Spectroscopic Binaries can tell us about the Field-Binary Population
• Polytropic model fits to the globular cluster NGC 2419 in Modified Newtonian Dynamics

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• Asymmetrical tidal tails of open star clusters: stars crossing their cluster's prah challenge Newtonian gravitation
• Characterizing a cluster's dynamic state using a single epoch of radial velocities
• The velocity dispersion and mass function of the outer halo globular cluster Palomar 4
• Positrons from Primordial Black Hole Microquasars and Gamma-ray Bursts
• The Luminosity Function and stellar Mass to Light ratio of the massive globular cluster NGC2419
• Mass segregation in the outer halo globular cluster Palomar 14
• Mergers, tidal interactions, and mass exchange in a population of disc globular clusters: II. Long-term evolution
• Multiple stellar population mass loss in massive Galactic globular clusters
• The MOND External Field Effect on the Dynamics of the Globular Clusters: General Considerations and Application to NGC 2419
• Testing QUMOND theory with Galactic globular clusters in a weak external field