The nuclear starburst activity in the Seyfert 2 galaxy NGC 7679

Abstract

We present our recent spectrophotometric results of the infrared luminous Seyfert 2 galaxy NGC 7679. We find compelling evidence of the presence of a recent nuclear starburst, revealed by the observations of a) the spectral features of high order Balmer absorption lines, b) the weak equivalent widths for CaIIK $λ$3933, CN $λ$4200, G-band $λ$4300 and MgIb $λ$5173, and c) the suggested UV stellar wind resonance lines (N V $λ$1240, Si IV $λ$1400 and C IV $λ$1550) in the IUE spectrum. Using the simple stellar population synthesis model, we find that in the nuclear 2" $\times$ 2" region, the contributions from the old, intermediate and young components are 21.7%, 42.9% and 35.4%, respectively. These nuclear starburst activities might be triggered by the close encounter with NGC 7682, as suggested by recent numerical simulations.