A minor-merger model for NGC 7479

The overall morphology of the barred spiral galaxy NGC 7479 is modelled in numerical simulations of a minor merger, Special attention is paid to the m orphology and velocity field of the asymmetric spiral structure and the str ong stellar bar. The mass of the satellite galaxy is 1/10 of the mass of th e primary disc, or 1/30 of the total mass of the primary. The satellite is placed initially in a circular prograde orbit at six disc scale lengths fro m the centre of the primary. We follow the evolution of the merger until th e secondary galaxy reaches the nuclear region of the primary. A comparison between the modelled and observed morphologies of the stellar and the ioniz ed and neutral gas distributions and velocity fields supports the hypothesi s that the transient look of NGC 7479 is a result of a minor merger. We var y several of the initial parameters of the merger and discuss their effects on the resulting morphology. The merging satellite galaxy is likely to lie within the bar of NGC 7479. We identify a possible candidate in the observ ational data, We discuss briefly the most probable future evolution of NGC 7479 in the light of our minor-merger simulations, and conclude that NGC 74 79 is likely to evolve toward an earlier Hubble type.