view Abstract Citations (10) References (24) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Galactic Evolution with Self-regulated Star Formation: Stability of a Simple One-Zone Model Parravano, Antonio ; Rosenzweig, Patricia ; Teran, Manuel Abstract In a simple one-zone model of mass exchange between three components (stars, clouds, and diffused gas), we include a self-regulating mechanism based on the sensitivity of the condensation of small cool clouds upon the radiation density in the 912-1100 A band. This mechanism is capable of affecting the large-scale structure of the galaxies due to the fact that it acts at a large scale in a very short time. Even in the most favorable models for the production of nonlinear oscillations, the inclusion of this mechanism of self-regulation leads, in many cases, to the progressive damping of the oscillations. Parravano has demonstrated that a sample of 70 isolated galaxies of different types and dimensions presents a strong tendency to have a rate of star formation that produces a UV radiation density that maintains the state of warm gas close to the state of marginal stability for the condensation of small clouds due to thermochemical instabilities in the isobaric mode. Here we reinforce this result by showing that in our one-zone model the system tends toward this marginal state. The one-zone model shows a pattern of evolution in which the global SFR has small variations in long periods of time. When we add the regulating mechanism in multizone models, the zones are forced to oscillate out of phase. Consequently, even when the SFR oscillates locally, the global SFR tends to maintain a nearly constant value. The present model also alleviates the gas consumption, which makes it easier to explain the presence of gas in evolved galaxies. Publication: The Astrophysical Journal Pub Date: June 1990 DOI: 10.1086/168820 Bibcode: 1990ApJ...356..100P Keywords: Galactic Evolution; Star Formation; Ultraviolet Radiation; Interstellar Gas; Numerical Integration; Star Formation Rate; Stellar Mass; Astrophysics; GALAXIES: EVOLUTION; GALAXIES: STELLAR CONTENT; STARS: FORMATION; ULTRAVIOLET: SPECTRA full text sources ADS |