SOME FEATURES OF INFRARED-SPECTRUM OF NGC7027 AND AN ESTIMATE OF ITS SULFUR ABUNDANCE

Observations of NGC 7027 in the range 10-12 p are presented, with a spectral resolution of AA/A = 0-005. The S iv line at 10-5 /x is clearly seen, and also the feature at 11-3 ft which has been observed by Gillet, Forrest & Merrill and which may be due to thermal emission from Mg CC>3 grains. A previously unobserved sharp feature is seen at 119 ft. A sulphur abundance between 6-86 and 7-12 (relative to H = 12-00) is deduced from the intensity of the S iv line, and the possibility that the 11-3 and/or the 119 ft features are due to unresolved clusters of lines is briefly discussed. © Royal Astronomical Society