On the radial oxygen distribution in the Galactic disc - II. Effects of local streams

We analyse the idea that the local dips (similar to 1 kpc along the Galactic radius) observed in oxygen abundance are associated with the infall of intergalactic low-abundant gas (similar to 0.2 Z(circle dot)) on to the Galactic disc during the last similar to 100 Myr. We term such infall events local streams. The derived masses of the falling gas (of the order of several times 10(8) M-circle dot) are close to the observed ones (e.g. in the Magellanic Stream). Such local streams do not change the mean mass of oxygen ejected per core-collapse supernova (CC SN) event, so that our previous inference on probable upper initial masses for progenitors of CC SNe remains valid.