The dark blue compact dwarf galaxy NGC 2915

Abstract

Recent results on NGC 2915, the first blue compact dwarf galaxy to have its mass distribution modeled, are summarized. NGC 2915 is shown to have HI well beyond its detected optical extent. Its rotation curve is well determined and fit with maximum disk mass models. The dark matter halo dominates the mass distribution at nearly all radii, and has a very dense core compared to normal galaxies. High mass star formation energizes the HI in the centre of the galaxy, but appears to be maintained in virial equilibrium with the dark matter halo. The implications of these results are briefly discussed.