The physical processes which control star formation histories and evolution in noninteracting irregular galaxies are investigated in the star-forming region properties of a sample of 15 irregulars actively engaged in star formation. H II region kinematics, sizes and distributions are obtained from H-alpha velocity profiles taken from high dispersion echelle spectra and from b, y, I and H-alpha bandpasses of a video camera. The young star-forming regions are found to dominate the light at all optical wavelengths, and the observed colors are redder than predicted from most theoretical population models of young systems. Young galaxies with high star formation rates would therefore not be expected to be very blue. Although there is no compelling evidence for it, star formation propagation due to mechanical energy returned by young stars is considered as a possible star formation history mechanism in irregular galaxies.
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Deidre A. Hunter (1982) studied this question.