Testing fundamental physics with distant star clusters: theoretical models for pressure-supported stellar systems

Abstract

We investigate the mean velocity dispersion and the velocity dispersion profile of stellar systems in MOND, using the N-body code N-MODY, which is a particle-mesh based code with a numerical MOND potential solver developed by Ciotti, Londrillo and Nipoti (2006). We have calculated mean velocity dispersions for stellar systems following Plummer density distributions with masses in the range of $10^4{M}_{\odot }$ to $10^9{M}_{\odot }$ and which are either isolated or immersed in an external field. Our integrations reproduce previous analytic estimates for stellar velocities in systems in the deep MOND regime ($a_i,a_e\ll a_0$), where the motion of stars is either dominated by internal accelerations ($a_i\gg a_e$) or constant external accelerations ($a_e\gg a_i$). In addition, we derive for the first time analytic formulae for the line-of-sight velocity dispersion in the intermediate regime ($a_i\sim a_e\sim a_0$). This allows for a much improved comparison of MOND with observed velocity dispersions of stellar systems. We finally derive the velocity dispersion of the globular cluster Pal 14 as one of the outer Milky Way halo globular clusters that have recently been proposed as a differentiator between Newtonian and MONDian dynamics.

11 pages, 9 figures, Accepted in MNRAS

References in corpus (14)

• A direct empirical proof of the existence of dark matter
• Tidal dwarf galaxies as a test of fundamental physics
• Can MOND take a bullet? Analytical comparisons of three versions of MOND beyond spherical symmetry
• Evolution of spiral galaxies in modified gravity
• Testing modified gravity with globular cluster velocity dispersions
• Dwarf Spheroidals in MOND
• Escaping from MOND
• Dynamical friction in modified Newtonian dynamics
• Axisymmetric and triaxial MOND density-potential pairs
• Galaxy merging in MOND
• Loss of mass and stability of galaxies in MOND
• Dissipationless collapses in MOND
• Testing gravity with motion of satellites around galaxies: Newtonian gravity against Modified Newtonian Dynamics
• Tidal radii and escape speeds in dwarf spheroidal galaxies under MOND and dark halos compared

Cited by in corpus (40)

• Modified Newtonian Dynamics (MOND): Observational Phenomenology and Relativistic Extensions
• From galactic bars to the Hubble tension: weighing up the astrophysical evidence for Milgromian gravity
• Testing the Strong Equivalence Principle: Detection of the External Field Effect in Rotationally Supported Galaxies
• Halo globular clusters observed with AAOmega: dark matter content, metallicity and tidal heating
• The globular cluster NGC 2419: a crucible for theories of gravity
• The velocity dispersion and mass-to-light ratio of the remote halo globular cluster NGC 2419
• MOND effects in the inner solar system
• Declining rotation curves of galaxies as a test of gravitational theory
• MOND and the dynamics of NGC1052-DF2
• Direct N-body simulations of globular clusters: (I) Palomar 14
• A new formulation of the external field effect in MOND and numerical simulations of ultra-diffuse dwarf galaxies $-$ application to NGC 1052-DF2 and NGC 1052-DF4
• Asymmetrical tidal tails of open star clusters: stars crossing their cluster's prah challenge Newtonian gravitation
• The outskirts of globular clusters as modified gravity probes
• The velocity dispersion and mass function of the outer halo globular cluster Palomar 4
• Polytropic model fits to the globular cluster NGC 2419 in Modified Newtonian Dynamics
• MOND in galaxy groups: a superior sample
• Flattened velocity dispersion profiles in Globular Clusters: Newtonian tides or modified gravity?
• Globular clusters in modified Newtonian dynamics: velocity-dispersion profiles from self-consistent models
• Testing Dark Matter and Modifications to Gravity using Local Milky Way Observables
• Probing the radial acceleration relation and the strong equivalence principle with the Coma cluster ultra-diffuse galaxies
• On the tension between the Radial Acceleration Relation and Solar System quadrupole in modified gravity MOND
• Distant star clusters of the Milky Way in MOND
• Mass segregation in the outer halo globular cluster Palomar 14
• The dynamical phase transitions of stellar systems and the corresponding kinetimacs
• A Monte Carlo analysis of the velocity dispersion of the globular cluster Palomar 14
• Testing modified gravity with dwarf spheroidal galaxies
• Abundance analysis of the outer halo globular cluster Palomar 14
• Lopsidedness of self-consistent galaxies by the external field effect of clusters
• MONDian dynamical modeling of NGC 288 with $\beta \ne 0$
• Globular clusters as a probe for Weyl Conformal Gravity
• Dwarf Galaxies, MOND, and Relativistic Gravitation
• Isothermal distributions in MONDian gravity as a simple unifying explanation for the ubiquitous $\rho \propto r^{-3}$ density profiles in tenuous stellar halos
• The MOND External Field Effect on the Dynamics of the Globular Clusters: General Considerations and Application to NGC 2419
• Observational Constraints on the Modified Gravity Model (MOG) Proposed by Moffat: Using the Magellanic System
• Gravitational anomalies signaling the breakdown of classical gravity
• On the problem of deformed spherical systems in Modified Newtonian Dynamics
• The kinematics of star clusters undergoing gas expulsion in Newtonian and Milgromian dynamics
• Observational dynamics of low-mass stellar systems
• Formation of collisional ring galaxies in Milgromian dynamics
• Examining Baryonic Faber-Jackson Relation in Galaxy Groups