The infall time-scale in the solar neighborhood

Abstract

The Galactic disk is supposed to have been formed from gas condensing out from the halo. The rate at which this infall of gas occurs, the amount of infall, and the time scales over which gas falls on to the disc have important consequences for the chemical evolution of the Galaxy. However there are large uncertainties in the observed data about infall, and even basic questions like the actual origin of the gas, the amount of infall etc., have not been answered. In this work, we have used the observed metallicity distribution of low mass stars (the G-dwarf distribution) and the age-metallicity relation (AMR) to constrain the amount of infall and the infall time scale. Along with the infall time scales the history of star formation in the solar neighborhood can also be determined