Nearby early-type galaxies with ionized gas

II. Line-strength indices for 18 additional galaxies

¹ SISSA, via Beirut 4, 34014 Trieste, Italy e-mail: annibali@sissa.it, annibali@stsci.edu
² INAF – Osservatorio Astronomico di Padova, vicolo dell'Osservatorio 5, 35122 Padova, Italy
³ Institut für Astronomie der Universität Wien, Türkenschanzstraße 17, 1180 Wien, Austria

Received: 4 July 2005
Accepted: 4 August 2005

Abstract

We previously presented a data-set of line-strength indices for 50 early-type galaxies in the nearby Universe. The galaxy sample is biased toward galaxies showing emission lines, located in environments corresponding to a broad range of local galaxy densities, although predominantly in low density environments. The present addendum enlarges the above data-set of line-strength indices by analyzing 18 additional early-type galaxies (three galaxies, NGC 3607, NGC 5077 and NGC 5898 were presented in the previous set). We measured 25 line-strength indices, defined by the Lick IDS “standard” system (Trager et al. 1998, ApJS, 116, 1; Worthey & Ottaviani 1997, ApJS, 111, 377), for 7 luminosity weighted apertures and 4 gradients of each galaxy. This addendum presents the line-strength data-set and compares it with the available data in the literature.