The elliptical galaxy NGC 5044: Stellar population and ionized gas

In this work we investigate the stellar population, metallicity distribution and ionized gas in the elliptical galaxy NGC 5044, using long-slit spectroscopy and a stellar population synthesis method. We found differences in the slope of metalline profiles along the galaxy which suggests an enhancement of a elements, particularly towards the central region. The stellar population synthesis showed that the component with [Z/Z.] similar to 0.0 dominates the lambda5870 Angstrom flux in the central region of NGC 5044, contributing with similar to42% of the total flux, while in the external regions the contribution decreases to similar to8.0%. The component with [Z/Z.] similar to -0.4 contributes with similar to32% in the central region, and similar to55% in the external regions. The component with [Z/Z.] similar to -1.1 contributes with similar to26% in the central region, and similar to37% in the external regions. The three components have similar to10(10) years. The presence of a non-thermal ionization source, such as a low-luminosity AGN and/or shock ionization, is implied by the large values of the ratio [NII]/Halpha observed in all sampled regions. However, the emission lines observed in the external regions indicate the presence of an additional ionization source, probably hot, post-AGB stars.