Evolutionary tracks and isochrones for low- and intermediate-mass stars: From 0.1.5 to 7 M-circle dot and from Z=0.0004 to 0.03

We present a large grid of stellar evolutionary tracks, which are suitable to modelling star clusters and galaxies by means of population synthesis. T he 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 = 0.2 5], [Z = 0.019, Y = 0.273] (solar composition), and [Z = 0.03,Y = 0.30]. Th ey are computed with updated opacities and equation of state, and a moderat e amount of convective overshoot. The range of initial masses goes from 0.1 5 M-. to 7 M-. and the evolutionary phases extend ii om the zero age main s equence (ZAMS) till either the thermally pulsing AGB regime or carbon ignit ion. We also present an additional set of models with solar composition, co mputed using the classical Schwarzschild criterion for convective boundarie s. From all these tracks, we derive the theoretical isochrones in the Johns on-Cousins UBVRIJHK broad-band photometric system.