A large stellar evolution database for population synthesis studies. I. Scaled solar models and isochrones

Abstract

We present a large and updated stellar evolution database for low-, intermediate- and high-mass stars in a wide metallicity range, suitable for studying Galactic and extragalactic simple and composite stellar populations using population synthesis techniques. The stellar mass range is between \sim0.5Mo and 10Mo with a fine mass spacing. The metallicity [Fe/H] comprises 10 values ranging from -2.27 to 0.40, with a scaled solar metal distribution. The initial He mass fraction ranges from Y=0.245, for the more metal-poor composition, up to 0.303 for the more metal-rich one, with Delta Y/Delta Z\sim 1.4. For each adopted chemical composition, the evolutionary models have been computed without and with overshooting from the Schwarzschild boundary of the convective cores during the central H-burning phase. The whole set of evolutionary models can be used to compute isochrones in a wide age range, from \sim30 Myr to \sim15Gyr. Both evolutionary tracks and isochrones are available in several observational planes, employing updated set of bolometric corrections and color-Te relations computed for this project. The number of points along the models and the resulting isochrones is selected in such a way that interpolation for intermediate metallicities not contained in the grid is straightforward. We compare our isochrones with results from different stellar evolution databases and perform some empirical tests for the reliability of our models. Since this work is devoted to scaled solar compositions, we focus our attention on the Galactic disk populations, employing multicolor photometry of unevolved field MS stars with precise Hipparcos parallaxes, well-studied open clusters and one eclipsing binary system with precise measurements of masses, radii and [Fe/H] of both components.