1999/05/26 by T. Lejeune, Thierry Lejeune, Lejeune, T. +2
Physics and Astronomy · #Astrophysics (astro-ph) #FOS: Physical sciences #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9905336
4 pages, to appear in the PASP Conference Proceedings series of the Workshop "Spectrophotometric dating of stars and galaxies", Annapolis, Maryland (U.S.A.), eds. I. Hubeny, S. Heap, and R. Cornett
arxiv created 1999/05/26 · openalex publication_date 1999/05/26 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In view of the important contributions of red giants to the integrated light in evolutionary synthesis calculations of old stellar populations in clusters and galaxies, we provide a comparison of theoretical isochrones computed from the Padova, Geneva, and Yale evolutionary tracks, respectively. Using the most recent version of the color-calibrated library of theoretical stellar spectra by Lejeune et al. (1999), the isochrones are converted in a uniform manner to the observational color-magnitude diagrams, (M(T1), C-T1) and (M(I), V-I), and compared with observed giant branches of typical globular clusters spanning a large range of metallicities. We find that the three different isochrones of the red giant branch provide significantly different slopes and curvatures, where in general, the differences tend to be larger for metallicities decreasing below [M/H] ~ -1. Throughout the full metallicity range (~ -2