Description
Near-infrared spectra were obtained for 117 red giants in the Fornax dwarf spheroidal galaxy with the FORS1 spectrograph on the VLT, in order to study the metallicity distribution of the stars and to lift the age-metallicity degeneracy of the red giant branch (RGB) in the color-magnitude diagram (CMD). Metallicities are derived from the equivalent widths of the infrared calcium triplet lines at 8498, 8542, and 8662{AA} calibrated with data from globular clusters, the open cluster M67, and the LMC. For a substantial portion of the sample, the strength of the calcium triplet is unexpectedly high, clearly indicating that the main stellar population of Fornax is significantly more metal-rich than could be inferred from the position of its RGB in the CMD.
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