Spectrophotometric Evolution of Spiral Galaxies with Truncated Star Formation: An Evolutionary Link between Spirals and S0s in Distant Clusters

Abstract

A one-zone chemospectrophotometric model is used to investigate the time evolution of disk galaxies whose star formation is truncated and to determine the dependence of this evolution on the previous star formation history and the truncation epoch. Truncated spirals show red colors D1 Gyr after trunca-tion and evolve spectrally from an e(b) type, down through the e(a), a]k, and k]a classes, to Ðnally become a k type. The exact behavior in this phase depends on the truncation epoch and the star forma-tion history prior to truncation. For example, earlier type disks show redder colors and do not show a]k-type spectra after truncation of star formation. We also discuss a possible evolutionary link between the k-type galaxies with spiral morphology found in distant clusters and present-day S0s by investigating whether truncated spirals reproduce the infrared color-magnitude relation of Coma gal-axies. We suggest that only less luminous, later-type disk galaxies whose star formation is truncated at intermediate and high redshifts can reproduce the red I[K colors observed for S0s in the Coma cluster.