Spherically symmetric hydrodynamic model calculations on the evolution of interstellar matter and on stellar evolution in the cove of spiral-galaxies

A numerical model is presented for a galactic core with radial symmetry, describing the mechanism of repeated bursts of stellar evolution. Repeated burst occur under the condition that energy is transfered by stellar winds and supernovae explosions from the massive stars, formed in the bursts at high gas pressures, to the interstellar medium. Thus the gas component of the model core expands until massive stars are no longer available. The following contraction of the gas distribution, caused by energy dissipation, results in a new burst, thus starting a new evolutional cycle. In the numerical model a large part of massive stars results in a high production rate for turbulent kinetic energy, so that a repeated excitation of bursts becomes possible. (orig./WB)