Mathematical Model of Star Formation in the Presence of External Perturbations.

This paper investigates a mathematical model of a star formation system, including in-fall of gas from the local environment and out-flow of gas due to supernovae explosions and perturbations. In particular, the objective is to study how the variable density of interstellar components of the system namely atomic, molecular, and stellar components, interact in the star formation cycle. Under special parametric conditions, both limit cycle and stationary state behavior are observed. This indicates a stable star formation cycle in discrete episodes and an unstable star formation cycle converging to a stationary state. Observations of duty cycles under various parameters with varying intensity of supernovae shockwaves for dwarf galaxies, showed that the system adopts a self-regulatory oscillation state beyond a particular value. Analysis of giant galaxies showed decreased oscillatory periods for higher values. This is implied by the low production rate of supernovae in dwarf galaxies, increased production of cold gas, continuation of the cyclic behavior for a longer time. Stronger shockwaves increase the rate of dissipation of gases, resulting in shredding of mass, to get transferred into a precipitous lower mass. Star-forming rate (SFR) of high-mass star systems was found to vary against higher-order perturbations of supernovae shockwave but remained the same in the case of low-mass star systems. [ABSTRACT FROM AUTHOR]