Spectroscopic study of the planetary nebulae with Wolf-Rayet nuclei in the Magellanic Clouds.

Abstract

UV and optical spectrophotometric data of planetary nebulae with WR nuclei in the Magellanic Clouds are presented. Analysis of the nebular characteristics shows that the ionized gas, in all the objects, is extremely C-rich, probably due to contamination with freshly-made C from stellar nucleosynthesis. Very high electron densities are found (N_e_>=10^4^cm^-3^) which are interpreted as an indication of youth. The central stars are C-rich, with spectral types in the range from WC4-5 to WC 8. The spectral type distribution is totally different from that found for galactic planetary nebulae with WR nuclei. Estimates of the stellar visual magnitudes and temperatures are presented. Stellar temperatures over 60000K were derived for all the objects, with some cases exceeding 100000K. These high temperatures however do not produce high excitation nebulae.