The Third Law of Galactic Rotation

Abstract

I review the connection between dynamics and the baryonic mass distribution in rotationally supported galaxies. The enclosed dynamical mass-to-light ratio increases with decreasing galaxy luminosity and surface brightness. The correlation with surface brightness appears to be the more fundamental, with the dependence on luminosity following simply from the weaker correlation between luminosity and surface brightness. In addition to this global relation, there is also a local relation between the amplitude of the mass discrepancy and the acceleration predicted by the observed distribution of baryons. I provide an empirical calibration of this mass discrepancy-acceleration relation. The data are consistent with the operation of a singe effective force law in disk galaxies, making this relation tantamount to a natural law. I further provide formulae by which the radial dark matter distribution can be estimated from surface photometry. The form of the dark matter halo depends uniquely on the distribution of baryons in each galaxy, and in general is neither a cusp nor a core. It remains difficult to see how galaxy formation models can reproduce the observed behavior, which is uniquely predicted by MOND.

Accepted for publication in Galaxies. Solicited contribution to the Special Issue "Beyond Standard Gravity and Cosmology" (ed. A. Diaferio). 23 pages, 7 figures

References in corpus (15)

• High-Resolution Rotation Curves and Galaxy Mass Models from THINGS
• A common mass scale for satellite galaxies of the Milky Way
• High-resolution dark matter density profiles of THINGS dwarf galaxies: Correcting for non-circular motions
• Color--Mass-to-Light Ratio Relations for Disk Galaxies
• A Novel Test of the Modified Newtonian Dynamics with Gas Rich Galaxies
• HI holes and high-velocity clouds in the spiral galaxy NGC 6946
• The mass distribution in early-type disk galaxies: declining rotation curves and correlations with optical properties
• Dynamical Centers and Non-Circular Motions in THINGS Galaxies: Implications for Dark Matter Halos
• A Tale of Two Paradigms: the Mutual Incommensurability of LCDM and MOND
• Dwarf Galaxy Dark Matter Density Profiles Inferred from Stellar and Gas Kinematics
• Weighing the local dark matter with RAVE red clump stars
• Dwarf Spheroidals in MOND
• Andromeda Dwarfs in Light of MOND
• The high mass end of the Tully-Fisher relation
• Phenomenology of MOND and gravitational polarization

Cited by in corpus (15)

• One Law To Rule Them All: The Radial Acceleration Relation of Galaxies
• The universal rotation curve of dwarf disk galaxies
• A statistical investigation of the mass discrepancy-acceleration relation
• Cosmology and Convention
• Λ CDM is Consistent with SPARC Radial Acceleration Relation
• Predictions and Outcomes for the Dynamics of Rotating Galaxies
• Tests and problems of the standard model in Cosmology
• The formation of exponential disk galaxies in MOND
• Tracing the Dynamical Mass in Galaxy Disks Using HI Velocity Dispersion and its Implications for the Dark Matter Distribution in Galaxies
• The mass discrepancy acceleration relation in early-type galaxies: extended mass profiles and the phantom menace to MOND
• Emergent gravity in galaxies and in the Solar System
• Galaxy rotation curves and universal scaling relations: comparison between phenomenological and fermionic dark matter profiles
• Radial acceleration relation and dissipative dark matter
• The radial acceleration relation and dark baryons in MOND
• On the radial acceleration of disk galaxies