Are Dwarf Galaxies Dominated by Dark Matter?

R. A. Swaters*, R. Sancisi, T. S. van Albada, J. M. van der Hulst

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

52 Citations (Scopus)

Abstract

Mass models for a sample of 18 late-type dwarf and low surface brightness galaxies show that in almost all cases the contribution of the stellar disks to the rotation curves can be scaled to explain most of the observed rotation curves out to two or three disk scale lengths. The concept of a maximum disk, therefore, appears to work as well for these late-type dwarf galaxies as it does for spiral galaxies. Some of the mass-to-light ratios required in our maximum disk fits, however, are high, up to about 15 in the R band, with the highest values occurring in galaxies with the lowest surface brightnesses. Equally well-fitting mass models can be obtained with much lower mass-to-light ratios. Regardless of the actual contribution of the stellar disk, the fact that the maximum disk can explain the inner parts of the observed rotation curves highlights the similarity in shapes of the rotation curve of the stellar disk and the observed rotation curve. This similarity implies that the distribution of the total mass density is closely coupled to that of the luminous mass density in the inner parts of late-type dwarf galaxies.

Original languageEnglish
Article number118
Number of pages10
JournalAstrophysical Journal
Volume729
Issue number2
DOIs
Publication statusPublished - 10-Mar-2011

Keywords

  • galaxies: dwarf
  • galaxies: irregular
  • galaxies: kinematics and dynamics
  • SURFACE BRIGHTNESS GALAXIES
  • NEUTRAL HYDROGEN OBSERVATIONS
  • RESOLUTION ROTATION CURVES
  • SCULPTOR GROUP GALAXIES
  • WESTERBORK HI SURVEY
  • SPIRAL GALAXIES
  • IRREGULAR GALAXIES
  • MASS-DISTRIBUTION
  • GALACTIC DISKS
  • MAGELLANIC-CLOUD

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