A Mechanism for the Oxygen and Iron Bimodal Radial Distribution
  Formation in the Disc of our Galaxy
  Recently it has been proposed that there are two types of SN Ia progenitors
-- short-lived and long-lived. On the basis of this idea, we develope a theory
of a unified mechanism for the formation of the bimodal radial distribution of
iron and oxygen in the Galactic disc. The underlying cause for the formation of
the fine structure of the radial abundance pattern is the influence of spiral
arms, specifically, the combined effect of the corotation resonance and
turbulent diffusion. From our modelling we conclude that to explain the bimodal
radial distributions simultaneously for oxygen and iron and to obtain
approximately equal total iron output from different types of supernovae, the
mean ejected iron mass per supernova event should be the same as quoted in
literature if maximum mass of stars, that eject heavy elements, is $50
M_{\odot}$. For the upper mass limit of $70 M_{\odot}$ the production of iron
by a supernova II explosion should be increased by about 1.5 times.
