The Initial Mass Function for the Solar Neighborhood Stars

The Wielen dip over the range of 6 < M_v < 9 in the luminosity function (LF) for the solar neighborhood stars could be explained by the combination of two different IMFs which yields the age of 13 billion years of the solar neighborhood. This smaller age than the Galactic age of 15 billion years, indicates the slow collapse model of the Galaxy, solving the G-dwarf problem. Two different IMFs suggest two different mechanisms for star formation in the solar neighborhood.