The morphology of the stars, atomic gas, and ionized gas in the barred spiral galaxy NGC 1530

We present observations of the barred spiral galaxy NGC 1530 that we use to investigate the overall structure and gas content of the galaxy. We use sensitive H alpha Fabry-Perot observations of the ionized gas to determine the star forming rates in various regions of the galaxy. Westerbork H I observations are used to investigate the morphology of the atomic gas and combined with the H alpha Fabry-Perot to determine the rotation curve. From the rotation curve we derive a pattern speed of the bar of approximately 20 km s(-1) kpc(-1) that predicts resonances at locations that coincide with prominent morphological features, including three gaseous rings mapped in these observations: an outer ring of atomic hydrogen at a radius consistent with the outer Lindblad resonance, an inner ring seen in both atomic hydrogen and H alpha, and a nuclear ring of dust and molecular gas. These rings combined with the very strong spiral arms dominate the morphology of the galaxy. (C) 1996 American Astronomical Society.