Global Analysis of a Southern Planetary Nebulae Sample

Abstract

In this work we present a summary of the results of a long term observational program aimed to derive physical parameters and chemical abundances of southern PNe developed in the last years at the University of São Paulo, Brazil. Results shown here were derived from 74 nebulae, all of them observed (at least twice) with the 1.60m telescope at the Pico dos Dias Observatory, Brazil, using a Cassegrain spectrograph, a 300 lines/mm (4.4 Å/pixel) grating, and UV-coated CCD detectors. Observational runs took place between 1988 and 1995. Data reduction followed the standard procedure of bias and flat-field corrections, extraction of the spectrum, wavelength calibration, and flux calibration through spectrophotometric standard stars observed each night. The table below summarizes our results. Nebulae were classified among the Peimbert types and mean abundances are shown for each type, using the notation ε(X)=log(X/H)+12.