VizieR Online Data Catalog: Synthetic spectra of galactic globular clusters (Sbordone+, 2011)
Abstract
We considered a reference isochrone from the BaSTI database (http://www.oa-terqmo.inaf.it/BASI) (Pietrinferni et al. 2006ApJ...642..797P), with the following characteristics: an age of 12Gyr, helium mass fraction Y=0.246 and metal mass fraction Z=0.001, which results in an iron abundance of [Fe/H]=-1.62 for the alpha-enhanced metal mixture of the BaSTI models ([alpha/Fe]~0.4). Such an isochrone is representative for the first generation population in a typical Galactic GC.
Three metal mixtures are considered. The alpha-enhanced mixture employed in the BaSTI database (Pietrinferni et al. 2006ApJ...642..797P), which corresponds to typical first-generation subpopulations in Galactic GCs, is labelled as 'reference'. The first mixture representative of second-generation stars is labelled 'CNONa1', and displays - compared to the reference alpha-enhanced mixture - enhancements of N and Na by 1.8dex and 0.8dex by mass, respectively, together with depletions of C and O by 0.6dex and 0.8dex, respectively. This is the same metal distribution already used in the calculations by Salaris et al. (2006ApJ...645.1131S) and Pietrinferni et al. (2009ApJ...697..275P). An alternative composition for second-generation stars is labelled 'CNONa2'; it is the same as the CNONa1 mixture but for the enhancement of N that in this case is equal to 1.44dex by mass. The important difference between CNONa1 and CNONa2 'second-generation' mixtures is that in the first case, at fixed Fe abundance, the C+N+O mass fraction is enhanced by a factor of 2 compared to the reference composition, whereas the CNONa2 mixture has the same CNO content (in both number and mass fractions) as the reference composition, within 0.5%. ************************************************************************** * * * The synthetic fluxes (FITS files) will be available later * * * ************************************************************************** (1 data file).- Publication:
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VizieR Online Data Catalog
- Pub Date:
- September 2011
- DOI:
- 10.26093/cds/vizier.35340009
- Bibcode:
- 2011yCat..35340009S
- Keywords:
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- Models: evolutionary;
- Spectroscopy;
- Clusters: globular