Australia Telescope Observations of the CTB 33 Complex

We present high-resolution radio continuum, H I absorption, and H90α recombination line observations of the CTB 33 complex and nearby sources ( l = 337°, b = 0°) taken with the Australia Telescope Compact Array. We estimate distances to several discrete sources on the basis of H I absorption spectra. Radio recombination lines are detected for two sources in the field. The compact source G337.0-0.1 in the CTB 33 complex, whose nature was previously in doubt, is identified as a supernova remnant with a diameter of ~5 pc. This classification is based on several contributing features: a nonthermal spectral index (-0.6), a shell structure, and the absence of detectable recombination lines. In addition, a 1720 MHz OH maser is probably associated with G337.0-0.1. We conclude that the CTB 33 region is a supernova remnant-H II complex at a distance of ~11 kpc.