Program: GN-2010B-Q-88

Massive star clusters are the breeding grounds for stars of all masses, and the primary birthplaces of the most massive stars in galaxies. The Quintuplet cluster is one of the most massive resolved young clusters in the Local Group and is a test bed for studying the star formation history of the region and inferring the possibility of top-heavy scenario by means of measuring the alpha-elements and iron absolute abundances and their corresponding ratios. We have recently developed two different techniques to derive metallicity from infrared observations of LBVs and WR stars. For LBVs, absolute alpha-elements (Si, Mg) and iron abundances may be obtained while for WRs it is possible to derive the alpha-element (oxygen) abundance of the natal cloud. The Quintuplet cluster offers a unique site to validate the consistency of such techniques. We propose to obtain near-infrared NIFS spectra of the high-mass stars in the Quintuplet cluster and isolated massive stars in the inner Galactic Center region in order to extract stellar properties, ages, and abundances and hence address the top heavy dilema. The unique capabilities of NIFS will also provide constraints, both spatial and spectroscopic, on the multiplicity of the most massive stars (LBVs).