Composite star formation histories of early-type galaxies from minor mergers: prospects for WFC3

摘要: The star formation history of nearby early-type galaxies is investigated via numerical modelling. Idealized hydrodynamical N-body simulations with a prescription are used to study the minor merger process between giant galaxy (host) and less massive spiral (satellite) reasonable assumptions for ages metallicities progenitors. We find that evolution rate extended over several dynamical times shows peaks which correspond pericentre passages satellite. newly formed stars mainly located in central part satellite remnant while older initial disk deposited at larger radii shell-like structures. After final plunge satellite, can continue Gyrs depending on efficiency. Although mass fraction new small, we half-mass radius differs from half-light V H bands. Moreover synthetic 2D images J, H, NUV, Hb bands, using characteristic filters Wide Field Camera 3 (WFC3) Hubble Space Telescope (HST), reveal residual induced by gas-rich mergers be clearly observed during after plunge, especially NUV band, interacting systems (z<0.023) moderate numbers orbits (~2 typical exposure ~3600 sec). This suggests WFC3 has potential resolve these substructures, characterize plausible past episodes, give clues galaxies.