The distribution of dark and luminous matter inferred from extended rotation curves

Abstract

A better understanding of the formation of mass structures in the universe can be obtained by determining the amount and distribution of dark and luminous matter in spiral galaxies. To investigate such matters a sample of 12 galaxies, most with accurate distances, has been composed of which the luminosities are distributed regularly over a range spanning 2.5 orders of magnitude. Of the observed high quality and extended rotation curves of these galaxies decompositions have been made, for four different schemes, each with two free parameters. For a "maximum disc fit" the rotation curves can be well matched, yet a large range of mass-to-light ratios for the individual galaxies is required. For the alternative gravitational theory of MOND the rotation curves can be explained if the fundamental parameter associated with MOND is allowed as a free parameter. Fixing that parameter leads to a disagreement between the predicted and observed rotation curves for a few galaxies. When cosmologically motivated NFW dark matter halos are assumed, the rotation curves for the least massive galaxies can, by no means, be reproduced; cores are definitively preferred over cusps. Finally, decompositions have been made for a pseudo isothermal halo combined with a universal M/L ratio. For the latter, the light of each galactic disc and bulge has been corrected for extinction and has been scaled by the effect of stellar population. This scheme can successfully explain the observed rotations and leads to sub maximum disc mass contributions. Properties of the resulting dark matter halos are described and a ratio between dark and baryonic mass of approximately 9 for the least, and of approximately 5, for the most luminous galaxies has been determined, at the outermost measured rotation.

Accepted for publication in the Monthly Notices of the RAS, 31 pages, 14 figures, 8 tables

References in corpus (7)

• Wilkinson Microwave Anisotropy Probe (WMAP) Three Year Results: Implications for Cosmology
• High-Resolution Rotation Curves and Galaxy Mass Models from THINGS
• Concentration, Spin and Shape of Dark Matter Haloes as a Function of the Cosmological Model: WMAP1, WMAP3 and WMAP5 results
• THINGS about MOND
• The high mass end of the Tully-Fisher relation
• The Araucaria Project: Distance to the Local Group Galaxy NGC 3109 from Near-Infrared Photometry of Cepheids
• Dark matter halo response to the disk growth

Cited by in corpus (7)

• Dark matter concentrations in galactic nuclei according to polytropic models
• The Quest for the Nature of the Dark Matter: The Need of a New Paradigm
• Exact semianalytical calculation of rotation curves with Bekenstein-Milgrom nonrelativistic MOND
• HI 21 cm observation and mass models of the extremely thin galaxy FGC 1440
• Low-mass disc galaxies and the issue of stability: MOND vs dark matter
• On the radial acceleration of disk galaxies
• Understanding disk galaxy rotation velocities without dark matter contribution--a physical process for MOND?