Masses of Star Cluster in the Nuclei of Bulgeless Spiral Galaxies
Publication date: 05 January 2005
Authors: Walcher, C.J., et al.
Journal: The Astrophysical Journal
Copyright: The American Astronomical Society
In the last decade star clusters have been found in the centers of spiral galaxies across all Hubble types. We here present a spectroscopic study of the exceptionally bright (106108 LSun) but compact (re ~ 5 pc) nuclear star clusters in very late type spirals with the Ultraviolet and Visual Echelle Spectrograph at the VLT. We find that the velocity dispersions of the nine clusters in our sample range from 13 to 34 km s-1. Using photometric data from the Hubble Space Telescope WFPC2 and spherically symmetric dynamical models, we determine masses between 8 x 105 and 6 x 107 MSun. The mass-to-light ratios range from 0.2 to 1.5 in the I band. This indicates a young mean age for most clusters, in agreement with previous studies.Link to publication