Rate of star formation in normal disk galaxies

Journal Article · Thu Sep 01 04:00:00 EDT 1983 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/161261· OSTI ID:5599940

Kennicutt, Jr, R C

Photometry of the integrated H..cap alpha.. emission in a large sample of field spiral and irregular galaxies has been used to obtain quantitative estimates of the total star formation rate (SFR) in the galaxies. The photoionization properties of a stellar population have been modeled for a variety of choices for the initial mass function (IMF). The observed UBV colors and H..cap alpha.. emission equivalent widths place tight constraints on the slope of the IMF between 1 M /sub sun/ and 50 M /sub sun/ in the galaxies; excellent agreement with the observed galaxy colors and H..cap alpha.. emission is obtained with models using an IMF slope close to Salpeter's original value. The properties of late-type galaxies are not well reproduced by the Miller-Scalo solar neighborhood IMF. The extinction-corrected star formation rates are large, as high as 20 M /sub sun/ yr/sup -1/ in giant Sc galaxies (H/sub 0/ = 50 km s/sup -1/ Mpc/sup -1/). The current rates in late-type galaxies are comparable to the past rates averaged over the age of the disk; late-type disk galaxies have evolved at a nearly constant rate, confirming earlier models by Searle, Sargent, and Bagnuolo. Little evidence is found for a strong correlation between the SFR and average gas density; if the SFR proportional rho/sup n/, then the exponent n must be much less than 1, corroborating earlier studies of star formation in the solar neighborhood by Miller, Scalo, and Twarog. Comparison of the present SFRs with the remaining supply of interstellar gas yields consumption time scales of only a few times 10/sup 9/ years in most cases, in agreement with the model estimates of Larson, Tinsley, and Caldwell.

• Research Organization: University of Minnesota, Department of Astronomy
• OSTI ID: 5599940
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 272:1; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640102 -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BALMER LINES
CHARGED PARTICLES
COSMIC GASES
EMISSION SPECTRA
FLUIDS
GALACTIC EVOLUTION
GALAXIES
GASES
INTERGALACTIC SPACE
IONIZATION
IONS
MORPHOLOGY
NITROGEN IONS
PHOTOIONIZATION
PHOTOMETRY
SPACE
SPECTRA
STAR ACCRETION
STAR EVOLUTION