The optically bright post-AGB population of the LMC
Abstract
The detected variety in chemistry and circumstellar shell morphology of the limited sample of Galactic post-AGB stars is so large, that there is no consensus yet on how individual objects are linked by evolutionary channels. The evaluation is complicated by the fact that the distances and hence luminosities of these objects are poorly known. In this contribution we report on our project to overcome this problem by focusing on a significant sample of post-AGB stars with known distances: those in the LMC. Via cross-correlation of the infrared SAGE-SPITZER catalogue with optical catalogues we selected a sample of 322 LMC post-AGB candidates based on their position in the various colour-colour diagrams. We determined the fundamental properties of 82 of them, using low resolution optical spectra that we obtained at Siding Spring and SAAO. We selected a subsample to be studied at high spectral resolution in order to obtain accurate abundances of a wide range of species. This will allow us to connect the theoretical predictions with the obtained surface chemistry at a given luminosity and metallicity. By this, we want to constrain important structure parameters of the evolutionary models. Preliminary results of the selection process are presented.
- Publication:
-
The Magellanic System: Stars, Gas, and Galaxies
- Pub Date:
- March 2009
- DOI:
- 10.1017/S1743921308028809
- Bibcode:
- 2009IAUS..256..415V
- Keywords:
-
- stars: AGB and post-AGB;
- circumstellar matter;
- stars: evolution;
- Hertzsprung-Russell diagram;
- galaxies: individual (LMC);
- Magellanic Clouds