The physical properties and evolution of the interacting system AM 1204−292

ABSTRACT We investigate interaction effects in the stellar and gas kinematics, population, ionized properties of interacting galaxy pair AM 1204−292,composed NGC 4105 4106. The data consist long-slit spectra range 3000–7050 Å. massive E3 presents a flat velocity profile, while is strong rotation, suggesting an external origin. Its companion, 4106, shows asymmetries radial field, likely due to interaction. dynamics were modelled using P-Gadget3 treepm/sph code, from which we show that system has just passed first perigalacticum, triggered outbreak star formation, currently at full maximum. characterized population synthesis code starlight and, on average, both galaxies are predominantly composed old populations. slightly negative age gradient, comparable with most elliptical galaxies, but steeper metallicity gradient. SB0 4106 smaller variations comparison intermediate-mass early-type galaxies. These gradients have not been disturbed by interaction, since formation happened very recently was extensive mass. Electron density estimates for systematically higher than those obtained isolated central O/H abundances photoionization models combination emission-line ratios, resulted 12 + log(O/H) = 9.03 ± 0.02 8.69 0.05 respectively.