Are Dwarf Galaxies Dominated by Dark Matter?

Understand

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 are high, however, 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.