Program: GS-2005A-Q-48

This is a pilot program to obtain spectra of the central regions of six nearby elliptical galaxies with a resolution of R=2000 (from 0.9 to 2.5 microns) with GNIRS in order to test the effect of the age onto the NIR spectra of elliptical galaxies. Surprisingly enoug very few near-infrared spectra of elliptical galaxies have been published in the literature so far. Five of the six galaxies we plan to observe are suspected to have stellar populations between 2 and 5 Gyr, from their optical spectroscopic properties. The sixth galaxy is an old "normal" elliptical galaxy and will be used as a "control field'" galaxy. Several modelers (e.g. Maraston 2004, MNRAS) predict that elliptical galaxies with young stellar populations have a distinct NIR spectrum from older elliptical galaxies. It is therefore possible to recognize young populations in galaxies by the different indices in a much larger dynamic range enabled by the introduction of the NIR bands. We wish to compare ages derived in the optical with those derived in the NIR.