SURPRISINGLY HIGH-PRESSURE SHOCKS IN THE SUPERNOVA REMNANT IC-443

The intensities of several lines of molecular hydrogen have been measured from two regions of the supernova-remnant/molecular-cloud shock in IC443. The lines measured have upper-state energies ranging from 7000 K to 23 000 K. Their relative intensities differ in the two regions, but are consistent with those predicted from the post-shock regions of simple jump-type shocks of different pressure. The pressures so derived are far higher than the pressure in the supernova remnant itself, and a possible reason for this discrepancy is discussed.