The Minimal Astration Hypothesis -- a Necessity for Solving the Dust
  Budget Crisis?
  Assuming that gas and dust separate in the interstellar medium (ISM) so that
high-density regions, where stars can form, are almost devoid of dust, the
amount of metals being removed from the ISM can be significantly reduced
(minimized astration). Here, it is shown by simple analytical models that this
may increase the total metal budget of a galaxy considerably. It is suggested
that these extra metals may increase the mass of dust such that the "dust
budget crisis", i.e., the fact that there seems to be more dust at high
redshifts than can be accounted for, can be ameliorated. Reducing the amount of
astration, the metal budget can be more than doubled, in particular for systems
that evolve under continuous gas accretion.
