2009/09/21 by F. Annibali, A. Bressan, Annibali, F. +5
Physics and Astronomy · #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences #astro-ph.CO
paper · pdf · doi:10.48550/arxiv.0909.3866
Proceeding of the Conference "Galaxies in Isolation", Granada, 12-15 May 2009
arxiv created 2009/09/21 · arxiv updated 2009/12/01
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.