Continuous stellar mass-loss in N-body models of galaxies

We present an N-body computer code-aimed at studies of galactic dynamics - with a CPU-efficient algorithm for a continuous (i.e. time-dependent) stell ar mass-loss. First, we summarize available data on stellar mass-loss and d erive the long-term (20 Gyr) dependence of mass-loss rate of a coeval stell ar population. We then implement it through a simple parametric form into a particle-mesh code with stellar and gaseous particles. We perform several tests of the algorithm reliability and show an illustrative application: a 2D simulation of a disk galaxy, starting as purely stellar but evolving as two-component due to gradual mass-loss from initial stars and to star forma tion. In a subsequent paper we will use the code to study changes that are induced in galactic disks by the continuous gas recycling compared to the i nstantaneous recycling approximation, especially the changes in star format ion rate and radial in ow of matter.