A near-IR [Fe II] line imaging survey of supernova remnants in M33
  We report on the first near-IR [Fe II] line imaging survey of extragalactic   SNRs.   Observations of a sample of 42 objects drawn from an optically-selected catalogue of SNRs in M33 provide evidence for a wide range in the [Fe II] 1.644 microns luminosities. This can be understood as being primarily due to variations in the chemical abundances and density of the local ISM, although shock conditions may also play a significant role. We briefly discuss how these results may be used to better calibrate the supernova rate of star-forming galaxies. 
T. Morel (1), R. Doyon (2), N. St-Louis (2) ((1) Imperial College,   London, UK; (2) Universite de Montreal, Canada)