The nature of starburst activity in M 82

Results of near-infrared integral field spectroscopy of the starburst galax y M82, obtained with the MPE (Max-Planck-Institut fur Extraterrsstrische Ph ysik, Garching, Germany) 3D instrument, are presented. These data provide t he spatial distribution of key diagnostics (e.g. HI and HeI nebular emissio n lines, atomic and molecular stellar absorption features) for the composit ion of the populations of hot massive stars and cool evolved stars, on scal es of 20-25 pc. Together with mid-infrared spectroscopy from the Short Wave length Spectrometer (SWS) on board the ISO satellite (ISO is an ESA project with instruments funded by ESA member States (especially the PI countries: France, Germany, the Netherlands and the United Kingdom) with the particip ation of ISAS and NASA. SWS is a joint project of SRON and MPE) and data fr om the literature, the 3D data are analyzed with a starburst model to const rain quantitatively the cutoffs of the initial mass function, and the spati al and chronological evolution of starburst activity. (C) 2000 Elsevier Sci ence B.V. All rights reserved.