DETERMINATION OF THE IMF ON THE BASIS OF A RECENTLY DERIVED SFR HISTORY IN THE SOLAR NEIGHBORHOOD

The initial mass function (IMF) in the solar neighbourhood is determin ed on the basis of a recently derived history of the star formation ra te (SFR) which shows the presence of a star formation burst about 8 Gy r ago. The observed present-day mass function (PDMF) is considered, an d the average past distribution of stars of a given mass is estimated. Two cases are considered, namely (i) constant SFR, and (ii) variable SFR as derived from the new metallicity distribution of G dwarfs. The resulting IMF is compared with previous determinations by Scale and Kr oupa et al., and the variation with stellar mass of the slope of the I MF is compared with reference determinations in the Literature.