2007ApJ...655L..29D

We present empirical H II region oxygen abundances for a sample of low-luminosity starburst galaxies that are in a short-lived evolutionary state. All five galaxies are characterized by centrally concentrated star formation that is embedded in smooth stellar envelopes resembling dE-like systems. The galaxies also have small gas contents with typical M_HI_/LB_≲0.1, resulting in gas exhaustion timescales of less than 1 Gyr, even when molecular gas is considered. We find that compared to other morphologically similar systems, the galaxies of this sample have surprisingly high oxygen abundances, with 12+log(O/H)∼9.0. We propose that these objects are a subclass of evolved blue compact dwarfs that have exhausted most of their gas supply while retaining their metals. We further propose that we are seeing these objects during a short phase in which they are nearing the end of their starburst activity, and could become early-type dwarfs.