How to Determine the Star Formation Histories in Spiral Disks
نویسندگان
چکیده
With the help of the multiphase chemical evolution model (Mollá, Hardy & Beauchamps 1999) we have derived the evolutionary histories of the galaxies NGC 4303, NGC 4321 y NGC 4535. With these histories and an evolutionary synthesis model, we were able to reproduce their observed radial distributions of the spectral indices Mg2 and Fe5270. Chemical evolution models however may fit well the present day observational characteristics of galaxies without discriminating among very different star formation histories. Furthermore, the spectral indices Mg2 and Fe5270 exhibit the age-metallicity degeneracy problem, implying that discriminating ages from metallicity with only these indices in single stellar populations might be impossible. Our objective here is to make sure that the implied evolutionary histories represent well these galaxies.
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