SIMBAD references

Using high-dispersion spectra from the HIRES echelle spectrograph on the Keck I telescope, we measure velocity dispersions for four globular clusters (GCs) in M33. Combining the velocity dispersions with integrated photometry and structural parameters derived from King-Michie model fits to Wide Field Planetary Camera 2 images, we obtain mass-to-light ratios for the clusters. The mean value is M/L_V=1.53±0.18, very similar to the M/L_Vof Milky Way and M31 GCs. The M33 clusters also fit very well into the fundamental plane and binding energy-luminosity relations derived for Milky Way GCs. Dynamically and structurally, the four M33 clusters studied here appear virtually identical to Milky Way and M31 GCs.