Nils Ryde
Professor
Carbon stars in local group dwarf galaxies: C and O abundances
Author
Summary, in English
We present abundances of carbon and oxygen as well as abundance ratios 12C/13C for a sample of carbon stars in the LMC, SMC, Carina, Sculptor and Fornax dwarf galaxies. The overall metallicities in these dwarf galaxies are lower than in the galactic disc. The observations cover most of the AGB and we discuss the abundance patterns in different regions along the AGB. The abundances are determined from infrared spectra obtained with the ISAAC spectrometer on VLT (R=1500) and the Phoenix Spectrometer on Gemini South (R=50000). The synthetic spectra used in the analysis were computed with MARCS model atmospheres. We find that the oxygen abundance is decreasing with decreasing overall metallicity of the system while the C/O ratio at a given evolutionary phase is increasing with decreasing oxygen abundance.
Based on observations collected at the European Southern Observatory, Paranal, Chile (ESO Programme 70.D-0414 & 072.D-0501)
Based on observations collected at the European Southern Observatory, Paranal, Chile (ESO Programme 70.D-0414 & 072.D-0501)
Publishing year
2006
Language
English
Pages
955-960
Publication/Series
Memorie della Societa Astronomica Italiana
Volume
77
Document type
Journal article
Topic
- Astronomy, Astrophysics and Cosmology
Keywords
- Stars: carbon
- Stars: abundances
- Galaxies: dwarf
- Stars: AGB and post-AGB
- Local Group
- Infrared: stars
Status
Published