Deep Hubble Space Telescope Observations of Blue Star Clusters in NGC 3597
Ballester, Gilda E.; Crisp, David; Grillmair, Carl J.; Holtzman, Jon A.; Trauger, John T.; Gallagher, John S., III; Hester, J. Jeff; Westphal, James A.; Mould, Jeremy R.; Hoessel, John G.; Clarke, John T.; Evans, Robin W.; Stapelfeldt, Karl R.; Burrows, Christopher J.; Griffiths, Richard E.; Scowen, Paul A.; Watson, Alan M.; Carlson, Matthew N.
Abstract
We have analyzed HST/WFPC2 images of NGC 3597 and find ~700 compact objects surrounding the galaxy with an average (B-R)_0~0.6. We propose that the majority of these objects are young globular clusters. They have a spread in colors that is consistent with that expected for a population of young clusters with a common age and spread induced by photometric errors and reddening within NGC 3597. If these objects were similar to the Galactic globular cluster system seen at a younger age, we would predict a turnover in the luminosity function at B~23. However, we find that the luminosity function for the clusters is increasing to the limits of our photometry (B~27).