J/A+A/519/A40 Spectroscopic study of 65 nearby galaxies (Annibali+, 2010) ================================================================================ Nearby early-type galaxies with ionized gas. IV. Origin and powering mechanism of the ionized gas. Annibali F., Bressan A., Rampazzo R., Zeilinger W.W., Vega O., Panuzzo P. =2010A&A...519A..40A ================================================================================ ADC_Keywords: Galaxies, nearby ; Galaxies, optical ; Galaxies, spectra Keywords: galaxies: elliptical and lenticular, cD - galaxies: ISM - galaxies: active - galaxies: abundances Abstract: With the aim of constraining the source of excitation and the origin of the ionized gas in early-type galaxies (ETGs), we analyzed intermediate resolution optical spectra of a sample of 65 ETGs mostly located in low density environments. Optical emission lines are detected in 89% of the sample. The incidence and strength of emission do not correlate either with the E/S0 classification, or with the fast/slow rotator classification. Comparing the nuclear r Annibali et al., Paper II 2006A&A...445...79A, Cat. Annibali et al., Paper III 2007A&A...463..455A, Cat. ================================================================================ (End) Francesca Annibali [INAF-OAPd], Patricia Vannier [CDS] 01-Jul-2010