Integral Field Spectroscopy of Supernova Remnant 1E0102-7219 Reveals
  Fast-moving Hydrogen and Sulfur-rich Ejecta
  We study the optical emission from heavy element ejecta in the oxygen-rich
young supernova remnant (SNR) 1E 0102.2-7219 (1E 0102) in the Small Magellanic
Cloud. We have used the Multi-Unit Spectroscopic Explorer (MUSE) optical
integral field spectrograph at the Very Large Telescope (VLT) on Cerro Paranal
and the wide field spectrograph (WiFeS) at the ANU 2.3 m telescope at Siding
Spring Observatory to obtain deep observations of 1E 0102. Our observations
cover the entire extent of the remnant from below 3500{\AA} to 9350{\AA}. Our
observations unambiguously reveal the presence of fast-moving ejecta emitting
in [S II], [S III], [Ar III], and [Cl II]. The sulfur-rich ejecta appear more
asymmetrically distributed compared to oxygen or neon, a product of
carbon-burning. In addition to the forbidden line emission from products of
oxygen burning (S, Ar, Cl), we have also discovered H{\alpha} and H{\beta}
emission from several knots of low surface brightness, fast-moving ejecta. The
presence of fast-moving hydrogen points towards a progenitor that had not
entirely shed its hydrogen envelope prior to the supernova. The explosion that
gave rise to 1E 0102 is therefore commensurate with a Type IIb supernova.
