Fig. 1. 2d chemodynamical evolution of a 10⁹ M_sun - dIrr with dark matter halo: mass density of high mass stars (HMS, upper part of images) and of low mass stars (LMS, lower part of images) after 0.5, 1.5, 3.0, 5.0, 7.0 and 9.0·10⁹ years. LMS densities are reduced by a factor of 10⁵ for better perceptibility. The size of the images is equivalent to 6.8 kpc. See the main text for further details