Near-Infrared Spectroscopy of Young Galactic Supernova Remnants
  Young Galactic supernova remnants (SNRs) are where we can observe closely the
supernova (SN) ejecta and its interaction with circumstellar/interstellar
medium. Therefore, they provide an opportunity to explore the explosion and the
final stage of the evolution of massive stars. Near-infrared (NIR) emission
lines in SNRs mostly originate from shocked dense material. In shocked SN
ejecta, forbidden lines from heavy ions are prominent, while in shocked
circumstellar/interstellar medium, [Fe II] and H2 lines are prominent. [Fe II]
lines are strong in both media, and therefore [Fe II] line images provide a
good starting point for the NIR study of SNRs. There are about twenty SNRs
detected in [Fe II] lines, some of which have been studied in NIR spectroscopy.
We will review the NIR [Fe II] observations of SNRs and introduce our recent
NIR spectroscopic study of the young core-collapse SNR Cas A where we detected
strong [P II] lines.
