We present a study of the ionized gas in a sample of 65 nearby early-type galaxies, for which we have acquired optical intermediate-resolution spectra. Emission lines are detected in ~89 % of the sample. The incidence of emission appears independent from the E or S0 morphological classes. According to classical diagnostic diagrams, the majority of the galaxies are LINERs. However, the galaxies tend to move toward the "Composites" region (at lower [NII]/Halpha values) as the emission lines are measured at larger galacto-centric distances. This suggests that different ionization mechanisms may be at work in LINERs.
@article{arxiv.0909.3866,
title = {The nature of ionized gas in early-type galaxies},
author = {F. Annibali and A. Bressan and R. Rampazzo and W. W. Zeilinger},
journal= {arXiv preprint arXiv:0909.3866},
year = {2009}
}
Comments
Proceeding of the Conference "Galaxies in Isolation", Granada, 12-15 May 2009