Ultraluminous Starbursts in Major Mergers

dc.creatorMihos, Chris
dc.creatorHernquist, Lars
dc.date1994-05-16
dc.date.accessioned2026-07-07T02:19:11Z
dc.date.available2026-07-07T02:19:11Z
dc.descriptionWe use numerical simulation to investigate the triggering of starbursts in merging disk galaxies. The properties of the merger-driven starbursts are sensitive to the structure of the progenitor galaxies; specifically, to the amount of material in a dense central bulge. Galaxies without bulges develop bars shortly after their first close passage, driving significant gas inflow and subsequent starbursts in the centers of the galaxies. These starbursts significantly deplete the star-forming gas, so that only relatively weak starbursts arise during the final merger. By contrast, models of galaxies with central bulges show that a bulge acts to stabilize the galaxies against inflow and starbursts until the galaxies actually merge. At this time, strong dissipation leads to the formation of a massive central gas mass and an ensuing star formation rate two orders of magnitude greater than that in our isolated disk models. These starbursts are very short in duration, typically $\sim$ 50 Myr, suggesting that the rarity of ultraluminous infrared galaxies is a result of their being in a very short evolutionary phase, rather than special and rare formation conditions. The fact that these mergers display many of the properties of ultraluminous infrared galaxies -- tidal features, double nuclei, massive compact gas concentrations, and extreme levels of starburst activity -- suggests that merger-driven starbursts can explain the emission from many ultraluminous infrared galaxies without an active nucleus.
dc.description9 pages, uuencoded compressed postscript, accepted to ApJ Letters
dc.identifierhttps://arxiv.org/abs/astro-ph/9405039
dc.identifierhttp://arxiv.org/abs/astro-ph/9405039
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/9764
dc.subjectAstrophysics
dc.titleUltraluminous Starbursts in Major Mergers
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