Significado de la función de luminosidad Hα en galaxias australes

Abstract

By means of CCD frames and image processing techniques we measured the luminosity function of H-alpha of HII regions of nearby galaxies with a high S/N. Several studies were done recently assuming that the shape of the observed luminosity function can be use to determine physical parameters (e.g. mass distribution, stellar evolution, stellar mass distribution, etc) of the hidden stellar population. Some of the models only consider the distribution of the integrated stellar mass of the HII regions and others only the evolution of the stellar ionizating population of H11 region. In this work we consider the two effects simultaneously plus the effect of taking in account different stellar formation rate for the host galaxy. This a summary of the results: - The turnover point discover by Kennicutt et al. (1989) appears to have an explanation as the convolution of the stellar formation rate and the stellar mass distribution. - From comparison with observational data (from Feinstein et al. - 1992, this issue and Thesis) some galaxies NGC 2997, NGC 6070, NGC 6384, NGC 7552 seem to have luminosity functions compatible with a constant SFR. NGC 1672 exhibits to have a more complex situation, not compatible with a constant SFR. - In the case of constant SFR, the slope of-2 (Kennicutt et al., 1989, Apj 337,761) can only fit the luminosity function in the bright side of the distribution.