We have discovered three globular clusters beyond the Holmberg radius in Hubble Space Telescope Advanced Camera for Surveys images of the gas-rich dark matter dominated blue compact dwarf galaxy NGC 2915 .
The clusters , all of which start to resolve into stars , have M _ { V 606 } = -8.9 to –9.8 mag , significantly brighter than the peak of the luminosity function of Milky Way globular clusters .
Their colors suggest a metallicity [ { Fe / H } ] \approx - 1.9 dex , typical of metal-poor Galactic globular clusters .
The specific frequency of clusters is at a minimum normal , compared to spiral galaxies .
However , since only a small portion of the system has been surveyed it is more likely that the luminosity and mass normalized cluster content is higher , like that seen in elliptical galaxies and galaxy clusters .
This suggests that NGC 2915 resembles a key phase in the early hierarchical assembly of galaxies - the epoch when much of the old stellar population has formed , but little of the stellar disk .
Depending on the subsequent interaction history , such systems could go on to build-up larger elliptical galaxies , evolve into normal spirals , or in rare circumstances remain suspended in their development to become systems like NGC 2915 .