A law of star formation in disk galaxies - Evidence for self-regulating feedback

Abstract

view Abstract Citations (96) References (37) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS A law of star formation in disk galaxies : evidence for self-regulating feedback. Dopita, M. A. Abstract The assumption that the pressure in the interstellar medium is derived from energetic processes associated with star formation and with the older stellar population is shown to lead to a law of star formation which is applicable to all disk galaxies. This states that the rate of star formation per unit total mass is linearly related to the ratio of gas to total surface densities. The star formation rate decreases exponentially in a given galaxy, but the gas content declines to a finite limit. The solution is characterized by two natural time scales, a gas depletion time scale, tau0, and an equipartition time scale, tau1, which is the inverse of the specific rate of star formation at which the pressure produced by young stars in the interstellar medium matches the pressure generated by the older population. Real galaxies appear to obey this law of star formation and it is found that tau0 = (2-4) x 10 to the 9th yr, tau1/tau sub 0 = 0.005 (+0.002, -0.003) gives the best fit to the data. In galaxies in which the rate of star formation determines the pressure of the disk medium, it is also shown that the rate of star formation is directly proportional to the product of the total mass and the mean surface density of gas. Publication: The Astrophysical Journal Pub Date: August 1985 DOI: 10.1086/184526 Bibcode: 1985ApJ...295L...5D Keywords: Disk Galaxies; Galactic Structure; Interstellar Matter; Star Formation; Depletion; Early Stars; Gas Density; Star Formation Rate; Astrophysics full text sources ADS | data products SIMBAD (5) NED (5)