The Integrated Light of M67 and the Spectroscopic CMD''
Session 49 -- Star Clusters in the Milky Way and Other Galaxies
Display presentation, Thursday, June 15, 1995, 9:20am - 4:00pm

## [49.04] The Integrated Light of M67 and the Spectroscopic CMD''

Lewis A. Jones, James A. Rose (University of North Carolina at Chapel Hill), Nelson Caldwell (F.L. Whipple Observatory), Michael J. Tripicco (University of Maryland)

We present intermediate resolution spectroscopic data on M67 in the 4800--5400 \AA~ region. We have spectra of 55 stars extending from the tip of the giant branch down to one magnitude below the turnoff. This data has been applied to the study of stellar populations in elliptical galaxies in two very powerful ways. First, as a 5 Gyr, solar abundance population, M67 represents a prototypical old open cluster which is a likely analog, both in age and metal abundance, to the intermediate'' age populations being found in integrated light studies of elliptical galaxies. We have formed an integrated spectrum of M67 and present it as a fiducial calibrator for the evolutionary synthesis models of Worthey (1994 ApJS, 95, 107). Second, as we have spectra covering a representative CMD for M67 we can examine empirically the behavior of specific spectral features as a function of position along an isochrone. This will begin to provide a much needed understanding of what aspects of stellar populations are being measured by these spectral indices. We present results for 8 Lick spectral indices including H$\beta$, Mg$_{2}$, and several Fe features.