Mass transfer and star formation in the early-type galaxy of a mixed pair, am 0327-285

Abstract

We present evidence for a young stellar population component in the early-type member of the E+S galaxy pair AM 0327-285. This young population is consistent with the occurrence of cross-fueling in this interacting system. We used spectroscopy, optical imaging, IRAS data, and stellar population synthesis to study the stellar content in the early-type galaxy. We also attempted to date episodes of star formation in its nuclear region, from population synthesis and basic dynamical considerations. The dominant population is old and metal-rich ([Z/Z]Θ=0.3) while ~ 10% of the flux at 5870 Å arises from a superimposed young stellar population with age <_ 5 x 10⁸ yr. This age is close to several estimates of the characteristic timescale of the interaction, suggesting that the mass influx associated with this star formation occurred as a result of an earlier phase of the interaction and not as a result of the present geometry of the pair.