1 Introduction

A longstanding issue in galaxy evolution is whether galaxies evolve according to a given set of initial conditions or whether the environment in which they reside is decisive for their evolution; i.e. whether galaxy evolution depends on nature or nurture. In order to search for environmental effects in galaxy properties, we have obtained optical and millimetric data for galaxies in dense regions of the Southern sky and in the field. In de Mello et al. (2002, hereafter Paper II) we present an extensive analysis of the data. The main results we found are: intermediate type spirals in dense environments have on average less molecular gas per blue luminosity, lower current SFR, the same SFE and higher atomic gas fraction when compared with field galaxies. Although none of the above results stand out as a single strong diagnostic, given their statistical significance (see Table 3 of Paper II), taken together they suggest a trend for diminished gas content and star formation activity in galaxies in high density environments. We also found that SFR per blue luminosity increases linearly as the total amount of gas increases in LINERs. This result, based on a small sample, suggests that LINERs are powered by star formation rather than an AGN. We refer the reader to Paper II for a more detailed analysis of these results.

In this paper we present the optical and millimetric data; it is organized as follows. Section 2 describes the sample, Sect. 3 describes the optical data, Sect. 4 describes the millimetric data, Sect. 5 describes general properties, and a comparison with other samples, Sect. 6 presents a summary and conclusions. A database of optical and millimetric spectra together with digitized images are shown in Appendix A (only available in electronic form).