Diffuse Thermal Emission from Very Hot Gas in Starburst Galaxies:   Spectral Results
  New BeppoSAX observations of the nearby archetypical starburst galaxies (SBGs) NGC253 and M82 are presented. The main observational result is the unambiguous evidence that the hard (2-10 keV) component is (mostly) produced in both galaxies by thermal emission from a metal-poor (~ 0.1-0.3 solar), hot (kT \~ 6- 9 keV) and extended (see companion paper: Cappi et al. 1998) plasma. Possible origins of this newly discovered component are briefly discussed. A remarkable similarity with the (Milky Way) Galactic Ridge's X-ray emission suggests, nevertheless, a common physical mechanism. 
M.Cappi (ITeSRE-CNR, Bologna), M.Persic (Trieste Astronomical   Observatory), S.Mariani (Univ. of Bologna), L.Bassani, L.Dan...