The impact of metallicity-dependent dust destruction on the
  dust-to-metals ratio in galaxies
  The ratio of the mass of interstellar dust to the total mass of metals (the
dust-to-metals/DTM ratio) tends to increase with metallicity. This can be
explained by the increasing efficiency of grain growth in the interstellar
medium (ISM) at higher metallicities, with a corollary being that the low DTM
ratios seen at low metallicities are due to inefficient stellar dust
production. This interpretation assumes that the efficiency of dust destruction
in the ISM is constant, whereas it might be expected to increase at low
metallicity; the decreased cooling efficiency of low-metallicity gas should
result in more post-shock dust destruction via thermal sputtering. We show that
incorporating a sufficiently strong metallicity dependence into models of
galaxy evolution removes the need for low stellar dust yields. The contribution
of stellar sources to the overall dust budget may be significantly
underestimated, and that of grain growth overestimated, by models assuming a
constant destruction efficiency.
