49 citations · 93 across the 5 of their papers we have counts for
5 papers
Chemical evolution of the galactic bulge: single and double infall models
R. D. D. Costa, W. J. Maciel, A. V. Escudero
Recent work has produced a wealth of data concerning the chemical evolution of the galactic bulge, both for stars and nebulae. Present theoretical models generally adopt a limited…
Planetary nebulae and the chemical evolution of the galactic bulge
Roberto D. D. Costa, Andre V. Escudero, Walter J. Maciel
Electron temperatures, densities, ionic and elemental abundances of helium, nitrogen, oxygen, argon, sulfur and neon were derived for a sample of bulge planetary nebulae, represent…
The populations of planetary nebulae in the direction of the Galactic bulge
S. K. Gorny, G. Stasinska, A. V. Escudero +1
We have observed 44 planetary nebulae (PNe) in the direction of the Galactic bulge, and merged our data with published ones. We have distinguished, in the merged sample of 164 PNe,…
New abundances of planetary nebulae in the Galactic Bulge
A. V. Escudero, R. D. D. Costa, W. J. Maciel
New observations and derived chemical abundances are reported for a sample of 57 bulge planetary nebulae (PN). Together with our previous results, a total of over a hundred objects…
Abundances of Recently Discovered Planetary Nebulae Towards the Galactic Bulge
A. V. Escudero, R. D. D. Costa
In this work we report spectrophotometric observations of a planetary nebula sample towards the galactic bulge. A total of 45 PNe was observed and their physical parameters (electr…