ИСТИНА

We present the novel technique for the determination of the low-mass end slope of the present day stellar mass function (PDMF) of unresolved stellar populations using pixel fitting of spectra integrated along the line of sight. In stellar systems with long dynamical relaxation timescales, where one can neglect the effects of the dynamical evolution, the PDMF is identical to the IMF at low masses. Our method achieves precision of ~0.1 in MF slope value and hence outperforms classical IMF determination techniques which use direct star counts in open clusters and HII associations. We used our method to obtain IMF for a few GCs and UCDs and 3000 giant elliptical galaxies. We do not see any evidence that the low mass IMF slope in giant ellipticals depends on their mass.