2003/12/19 by Maarten Reyniers, H. Van Winckel, Hans Van Winckel +4 · 1 citation
Physics and Astronomy · #Astronomical and nuclear sciences #Astrophysics and Star Formation Studies #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1051/0004-6361:20034397
published as Astron.Astrophys. 417 (2004) 269-281 · 14 pages, 10 figures, accepted for publication in A&A; Table 4 is available at ftp://ftp.ster.kuleuven.ac.be/dist/maarten/filescds/ pending upload to CDS
arxiv created 2003/12/19 · openalex publication_date 2004/03/15 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/31
In an effort to extend the still limited sample of s-process enriched post-AGB stars, high-resolution, high signal-to-noise VLT+UVES spectra of the optical counterparts of the infrared sources IRAS 06530–0213 and IRAS 08143–4406 were analysed. The objects are moderately metal deficient by and -0.4 respectively, carbon-rich and, above all, heavily s-process enhanced with a [ls/Fe] of 1.8 and 1.5 respectively. Especially the spectrum of IRAS 06530–0213 is dominated by transitions of s-process species, and therefore resembling the spectrum of IRAS 05341+0852, the most s-process enriched object known so far. The two objects are chemically very similar to the 21 μm objects discussed in [CITE]. A homogeneous comparison with the results of these objects reveals that the relation between the third dredge-up efficiency and the neutron nucleosynthesis efficiency found for the 21 μm objects, is further strengthened. On the other hand, a detailed comparison with the predictions of the latest AGB models indicates that the observed spread in nucleosynthesis efficiency is certainly intrinsic, and proves that different 13C pockets are needed for stars with comparable mass and metallicity to explain their abundances.