Ultraluminous starbursts in major mergers

摘要: We use numerical simulation to investigate the triggering of starbursts in merging disk galaxies. The properties merger-driven are sensitive structure progenitor galaxies; specifically, amount material a dense central bulge. Galaxies without bulges develop bars shortly after their first close passage, driving significant gas inflow and subsequent centers These significantly deplete star-forming gas, so that only relatively weak arise during final merger. By contrast, models galaxies with show bulge acts stabilize against until actually merge. At this time, strong dissipation leads formation massive mass an ensuing star-formation rate two orders magnitude greater than our isolated models. very short duration, typically approximately 50 Myr, suggesting rarity ultraluminous infrared is result being evolutionary phase, rather special rare conditions. fact these mergers display many galaxies--tidal features, double nuclei, compact concentrations, extreme levels starburst activity--suggets can explain emission from active nucleus.