Thus, they are also useful for comparing the star formation histories of dwarf and giant galaxies. The upper limit to the effective radii of the cluster candidates is 3.5 pc, in good agreement with Galactic globulars. They find that the specific GC frequency, S N , in dEs is more like the values found in giant ellipticals rather than in spirals, and the mean S N for nucleated dEs is roughly a factor of 2 higher than for non-nucleated dEs. Also, S N increases with M V . This could be due to the inhibition of star formation by supernovae in low mass galaxies.
Colors suggest that most of the GCs are more metal-poor than the nuclei or the galaxies themselves.
This implies that the GCs formed before the bulk of the stars in the galaxies. The pattern speed is arguably the most important parameter describing a bar and its effects on a host galaxy. NGC 2915 is a unique object, possessing a blue compact dwarf galaxy core and a HI disk with a bar and spiral arms pattern extending far beyond the optical galaxy. The group demonstrated that the spiral pattern could not be due to interactions, be sustained by swing amplification, or be driven by the bar. Because the disk of NGC 2915 is dominated by dark matter, they considered the possibility of dark matter distributed in a disk, but showed that it was unlikely.