Surviving dust mass fractions as a function of the mass of nonrotating progenitor stars. The left and right panels represent the metallicity of [Fe/H] = 0 and −1, respectively. In each panel, the dotted, dashed, and dash-dotted lines correspond to rev1, rev2, and rev3 models. The green and purple colors indicate the minimum and maximum mass fractions corresponding to grain sizes with a < a_{ave, no-rev} and a ≥ a_{ave, no-rev}, respectively. a_{ave, no-rev} is the dust-mass weighted average grain size for each nonrotating progenitor star in the no-rev model shown in Fig. 5. The symbols and shaded areas represent the minimum and maximum mass fractions for each progenitor mass. We shall note here that η can be interpreted as the true surviving fraction for large grains. For smaller grains, instead, this quantity does not reflect the fraction of pre-shock small grains that survives the reverse shock; rather, it compares the post-shock mass in small grains – which also results from partial destruction of larger grains – to the initial pre-shock value (see text).