Modified Newtonian dynamics and the "dearth of dark matter in ordinary elliptical galaxies"

  title={Modified Newtonian dynamics and the "dearth of dark matter in ordinary elliptical galaxies"},
  author={Mordehai Milgrom and Robert H. Sanders},
  journal={The Astrophysical Journal},
The recent findings of Romanowsky et al., of an "unexpectedly" small mass discrepancy within 5 effective radii in several elliptical galaxies, are not surprising in the context of modified Newtonian dynamics (MOND). As we show here, they are, in fact, in full concordance with its predictions. One is dealing with high surface density galaxies with mean accelerations rather larger than the acceleration constant of MOND. These findings continue, and are now the extreme examples of, the trend… Expand

Figures from this paper

Planetary nebula in elliptical galaxies pose a problem in dark matter theory. Using data from the Planetary Nebula Spectrograph (PN. S), Romanowsky et al. (2003) reported that less dark matter thanExpand
MOdified Newtonian Dynamics (MOND) is an alternative to the dark matter paradigm. MOND asserts that when the magnitude of acceleration is smaller than the acceleration parameter a0, the response ofExpand
Modified Newtonian Dynamics (MOND): Observational Phenomenology and Relativistic Extensions
It is shown that many of these puzzling observations are predicted by one single relation — Milgrom’s law — involving an acceleration constant a0 on the order of the square-root of the cosmological constant in natural units. Expand
We investigate the possibility that the observed behavior of test particles outside galaxies, which is usually explained by assuming the presence of dark matter, is the result of the dynamicalExpand
Dynamics of elliptical galaxies with planetary nebulae in modified Newtonian dynamics
The dynamics of an elliptical galaxy within a couple of effective radii can be probed effectively by stars. However, at larger distances planetary nebulae (PNe) replace stars as the tracer of theExpand
MOND predictions of ‘halo’ phenomenology in disc galaxies
We examine two corollaries of MOND pertaining to properties of the equivalent dark matter halo. MOND predicts for pure exponential discs a tight relation involving the halo and disc scalelengths andExpand
Lost and found dark matter in elliptical galaxies
Using numerical simulations of disk-galaxy mergers, it is found that the stellar orbits in the outer regions of the resulting ellipticals are very elongated, which explains the observed low velocities even in the presence of large amounts of dark matter. Expand
The Acceleration Scale, Modified Newtonian Dynamics, and Sterile Neutrinos
General relativity is able to describe the dynamics of galaxies and larger cosmic structures only if most of the matter in the universe is dark, namely, it does not emit any electromagneticExpand
Understanding the internal dynamics of elliptical galaxies without non-baryonic dark matter
Assuming virial equilibrium and Newtonian dynamics, low-mass early-type galaxies have larger velocity dispersions than expected from the amount of baryons they contain. The conventionalExpand
Testing modified Newtonian dynamics through statistics of velocity dispersion profiles in the inner regions of elliptical galaxies
Modified Newtonian dynamics (MOND) proposed by Milgrom provides a paradigm alternative to dark matter (DM) that has been successful in fitting and predicting the rich phenomenology of rotating discExpand


A Dearth of Dark Matter in Ordinary Elliptical Galaxies
The kinematics of the outer parts of three intermediate-luminosity elliptical galaxies were studied with the Planetary Nebula Spectrograph. The galaxies' velocity-dispersion profiles were found toExpand
Modified Newtonian dynamics as an alternative to dark matter
▪ Abstract Modified Newtonian dynamics (MOND) is an empirically motivated modification of Newtonian gravity or inertia suggested by Milgrom as an alternative to cosmic dark matter. The basic idea isExpand
Dynamical Family Properties and Dark Halo Scaling Relations of Giant Elliptical Galaxies
Based on a uniform dynamical analysis of the line-pro—le shapes of 21 mostly luminous, slowly rotating, and nearly round elliptical galaxies, we have investigated the dynamical family relations andExpand
Dynamics of the Globular Cluster System Associated with M87 (NGC 4486). II. Analysis
We present a dynamical analysis of the globular cluster system associated with M87 (=NGC 4486), the cD galaxy near the dynamical center of the Virgo Cluster. The analysis utilizes a new spectroscopicExpand
MOND rotation curves for spiral galaxies with Cepheid-based distances
Rotation curves for four spiral galaxies with recently determined Cepheid-based distances are reconsidered in terms of modified Newtonian dynamics (MOND). For two of the objects, NGC 2403 and NGCExpand
Detection, photometry and slitless radial velocities of 535 planetary nebulae in the flattened elliptical galaxy ngc 4697
We have detected 535 planetary nebulae (PNs) in the flattened elliptical galaxy NGC 4697 using the classic on-band, off-band filter technique with the Focal Reducer and Spectrograph at the CassegrainExpand
Dynamics of the Globular Cluster System Associated with M49 (NGC 4472): Cluster Orbital Properties and the Distribution of Dark Matter*
Using the Low Resolution Imaging Spectrometer on the Keck I and II telescopes, we have measured radial velocities for 196 globular clusters (GCs) around M49 (NGC 4472), the brightest member of theExpand
Kinematics of elliptical galaxies with a diffuse dust component - III. A Monte Carlo approach to include the effects of scattering
This paper is the third one in a series, intended to investigate how the observed kinematics of elliptical galaxies are affected by dust attenuation. In Papers I and II, we investigated the effectsExpand
Multicolour CCD surface photometry for E and S0 galaxies in 10 clusters
CCD surface photometry for 232 E and S0 galaxies is presented. The galaxies are observed in Gunn r and Johnson B, or Gunn r and g. For 48 of the galaxies surface photometry in Johnson U is alsoExpand
Spectroscopy for E and S0 galaxies in nine clusters
Central velocity dispersions, Mg-2 line indices and radial velocities for 220 E and SO galaxies are derived on the basis of intermediate resolution spectroscopy. Galaxies in the following clustersExpand