A window on the efficiency of the s-process in AGB stars: chemical abundances of n-capture elements in the planetary nebula NGC 3918
Abstract
The chemical content of the planetary nebula NGC 3918 is investigated through deep, high-resolution (R∼40,000) UVES at VLT spectrophotometric data. We identify and measure more than 750 emission lines, making ours one of the deepest spectra ever taken for a planetary nebula. Among these lines we detect very faint lines of several neutron-capture elements (Se, Kr, Rb, and Xe), which enable us to compute their chemical abundances with unprecedented accuracy, thus constraining the efficiency of the ph s-process and convective dredge-up in the progenitor star of NGC 3918.
- Publication:
-
Memorie della Societa Astronomica Italiana
- Pub Date:
- 2016
- DOI:
- 10.48550/arXiv.1510.04548
- arXiv:
- arXiv:1510.04548
- Bibcode:
- 2016MmSAI..87..299M
- Keywords:
-
- Stars: AGB and post-AGB;
- ISM: abundances;
- ISM: planetary nebulae;
- individual: NGC 3918;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 4 pages, 5 figures, 1 table. To appear in the Memorie della Societ\`a Astronomica Italiana. Proceedings of the EWASS 2015 Special Session "AGB stars: a key ingredient in the understanding and interpretation of stellar populations"