ADEMIS: A Library of Evolutionary Models for Emission-Line Galaxies: I- Dustfree Models

Abstract

We present an extensive set of stellar population synthesis models, which self-consistently include the (optical--far-UV) continuum emission from stars as well as the resulting emission-line spectrum from photoionized gas surrounding massive stars during their main sequence life-time. The models are presented as a compiled library, ADEMIS, available electronically. ADEMIS contains the equivalent widths and the intensities of the lines [OII]3727, Hbeta, [OIII]5007, Halpha, [NII]6584, which were calculated assuming a metallicity of 0.2, 0.4, 1.0, and 1.5 Zo and a wide range of ionization parameters. We investigate the regime of continuous star formation, assuming a Salpeter initial mass function, whose upper mass limit is an input parameter. The calculated equivalent width models, which are function of the burst age, are compared with the Jansen et al. atlas of integrated spectra for nearby galaxies. We reproduce the observed properties of galaxies along the full Hubble sequence and suggest how the metallicity and age of such galaxies might be be roughly estimated.