  We suggest that non-thermal emission can be produced by multiple scatterings
of the photons between the supernova ejecta and pre-shock material in supernova
shock breakout. Such bulk-Comptonization process may significantly change the
original thermal photon spectrum, forming a power-law non-thermal component at
higher energies. We then show that the luminous X-ray outburst XRO081009
associated with SN2008D is likely to be such shock breakout emission from an
ordinary type Ib/c supernova.

Astrophysics