G. Schaller, D. Schaerer, G. Meynet, A. Maeder, "New grids of stellar models from 0.8 to 120M; at Z=0.020 and Z=0.001," Astronomy & Astrophysics Supplement Series, 96:269-331, 1992.
Georges Meynet (Geneva Observatory, University of Geneva): "The evolution of galaxies is intimately related to the evolution of one of their main components--the stars. Stellar evolution is responsible for the different colors of galaxies. When the galaxy presents no sign of recent star formation, most of its luminosity is due to red giant stars. Inversely, a young stellar population manifests itself through the presence of numerous blue stars as O-type and/or Wolf-Rayet stars. In starburst galaxies, one can even observe stellar populations that are completely dominated by very young stars born a few million years ago.
"The chemical composition of the galaxies is also mainly due to the enrichment of the interstellar gas by new material synthesized in stars. Again, the metallicity ...
