Star formation histories of nearby elliptical galaxies. II. Merger remnant sample

This work presents high signal-to-noise spectroscopic observations of a sample of six suspected merger remnants, selected primarily on the basis of H I tidal debris detections. Single stellar population analysis of these galaxies indicates that their ages, metallicities, and alpha-enhancement ratios are consistent with those of a representative sample of nearby elliptical galaxies. The expected stellar population of a recent merger remnant, a young age combined with low [alpha/Fe], is not seen in any H I-selected galaxy. However, one galaxy (NGC 2534) is found to deviate from the Z-plane in the sense expected for a merger remnant. Another galaxy (NGC 7332), selected by other criteria, best matches the merger remnant expectations.