Evolutionary tracks and isochrones for low- and intermediate-mass stars: From 0.15 to 7 $M_{\odot}$, and from $Z=0.0004$ to 0.03

Abstract

We present a large grid of stellar evolution- ary tracks, which are suitable to modelling star clusters and galaxies by means of population synthesis. The tracks are presented for the initial chemical compositions (Z = 0:0004;Y =0 :23), (Z =0 :001;Y =0 :23), (Z =0 :004;Y = 0:24), (Z =0 :008;Y =0 :25), (Z =0 :019;Y =0 :273) (solar composition), and (Z =0 :03;Y =0 :30). They are com- puted with updated opacities and equation of state, and a moderate amount of convective overshoot. The range of initial masses goes from 0:15 M to 7 M ,a nd the evo- lutionary phases extend from the zero age main sequence (ZAMS) till either the thermally pulsing AGB regime or carbon ignition. We also present an additional set of mod- els with solar composition, computed using the classical Schwarzschild criterion for convective boundaries. From all these tracks, we derive the theoretical isochrones in the Johnson-Cousins UBVRIJHK broad-band photometric system.