NEAR-INFRARED LINE AND RADIO-CONTINUUM IMAGING OF THE CIRCINUS GALAXY

We have imaged the Circinus galaxy in the near-infrared [Fe II] 1.64-m u m and H-2 2.12-mu m lines, and derived velocity maps for the emissio n, The morphologies are strikingly different, but the velocity maps ar e very similar and consistent with simple rotation. We also present ne w radio continuum maps at 3 and 6 cm, which show a partially resolved nucleus with a flat spectral index. This suggests free-free absorption rather than self-absorption in a compact source. There is some eviden ce of radio jets close to the nucleus, The H-2 emission, rather than t he [Fe II] as in NGC 1068, is extended along the jet axis and may be e xcited by jet-induced shocks either in a low-density medium or with ra ther slow shock speeds (v less than or similar to 50 km s(-1)). We fin d that the star formation in the ring 10 arcsec from the nucleus began less than a few x 10(7) yr ago. Nearer the AGN, perhaps in and around the inferred torus, we detect extended [Fe II] emission (including on e prominent peak about 2 arcsec north of the AGN which could be due to a single young remnant), from which we derive a modest star formation rate of <1 M. yr(-1).