Chemical and Photometric Evolution Models for Disk, Irregular, and Low Mass Galaxies
(a) Dependence of the collapse time scale, , in natural logarithmic scale, (in Gyr) on the galactocentric radius, , in kpc. Each line represents a given maximum rotation velocity, , or radial mass distribution as labeled. The dashed (gray) and dotted (black) lines show the time corresponding to 2 and 5 times, respectively, the age of the Universe, Gyr. (b) Comparison of the radial dependence of the collapse time scale, , in natural logarithmic scale, for our MWG model, corresponding to , shown by the solid red line, with the radial functions used by Chang et al. , Boissier and Prantzos , Chiappini et al. , Renda et al. , Carigi and Peimbert , and Marcon-Uchida et al.  labeled CHA99, BP99, CHIA01, REN05, CAR08, and MAR10, respectively.