Stellar Populations in Gas-rich Galaxy Mergers. I. Dependence on Star Formation History

摘要: We investigate the nature of stellar populations major galaxy mergers between late-type spirals with considerably abundant interstellar medium by performing numerical simulations designed to solve both dynamical and chemical evolution in a self-consistent manner. particularly consider that star formation history is crucial determinant merger remnants, therefore we how difference affects mergers. found rapidity formation, which defined as ratio timescale gas consumption most important for number fundamental characteristics remnants. The main results obtained this study are following. 1. A more rapid becomes elliptical larger mean metallicity. This primarily because, smaller amount metal-enriched tidally stripped away during merging, and, consequently, can be converted components. demonstrates cause color-magnitude relation galaxies closely associated details merging dynamics depend on 2. negative metallicity gradient fitted reasonably well power law reproduced dissipative formation. magnitude an formed less 3. absolute correlates age sense remnant steeper likely show gradient. 4. outer part population older than nucleus Moreover, gaseous component some models appreciably result implies origin metal-poor hot X-ray halos real essentially ascribed merging. 5. Irrespective epoch remnants: later become ellipticals younger populations. reflects fact mergers, preferentially into stars period triggered These five clearly demonstrate even strongly affected furthermore determined In particular, tidal stripping total dissipation demonstrated play vital roles determining properties Based these results, adopt specific assumption luminosity dependence thereby discuss successfully present model reproduce chemical, photometric, spectroscopic galaxies.