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We have made observations of the \ion{H}{1} in the southern ringed barredspiral galaxies NGC~1433 and NGC~6300 with the Australia Telescope CompactArray (ATCA), the main goal being to test the resonance theory for the originof these rings. NGC~1433 is the prototypical ringed barred spiral, and displaysdistinct \ion{H}{1}~counterparts to its nuclear ring, inner ring, outerpseudoring, and plume-like features. The $L_{4}$ and $L_{5}$ regions atcorotation, as well as the bar itself, are relatively devoid of neutral atomichydrogen. By associating the inner ring of NGC~1433 with the inner secondharmonic resonance, and its outer pseudoring with the outer Lindblad resonance,we are able to infer a bar pattern speed for NGC~1433 of$26\pm5$~km~s$^{-1}$~kpc$^{-1}$. By way of contrast, NGC~6300 possesses a muchmore extended \ion{H}{1}~disk than NGC~1433. There is a gas ring underlying theinner pseudoring, but it is both broader and slightly larger in diameter thanthe optical feature. By again linking this inner ring feature to the innersecond harmonic resonance, we derive a bar pattern speed for NGC~6300 of$27\pm8$~km~s$^{-1}$~kpc$^{-1}$, but in this case, neither the outer pseudoringnor the nuclear ring predicted by the resonance-ring theory can be identifiedin NGC~6300. Although it may be the case that the ring in NGC~6300 is notrelated to a resonance with the bar at all, we postulate instead that NGC~6300is merely a less well-developed example of a resonance-ring galaxy than isNGC~1433.

Neutral Hydrogen in the Ringed Barred Galaxies NGC 1433 and NGC 6300