ИСТИНА

We present new estimates of the stellar initial mass function (IMF) in massive compact stellar systems which have not been affected by dynamical evolution. These estimates were made by new technique that determines low-mass end slope of the present day stellar mass function (PDMF) of unresolved stellar populations using pixel fitting of spectra integrated along line of sight. This 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 note that biases may be introduced to the MF measurements from integrated light spectra by significantly non-solar abundance ratios.