High-resolution imaging of stars, dust, and star formation in nuclear rings in galaxies

Nuclear rings in barred spiral galaxies offer an opportunity to study starburst properties, as well as the evolution of star formation in the central regions of galaxies. To further our understanding in these areas, a large imaging survey of over 80 galaxies with previous evidence for the existence of nuclear ring structure has been performed in the Ha emission line and the B and I broad bands using the William Herschel Telescope. Here, we present images of a subset of these galaxies, which reveal well-resolved nuclear rings in Ha. The rings consist of numerous "hotspots" (i.e., Ha-bright star-forming regions). For each hotspot we calculate Ha equivalent widths and compare the results to population synthesis models to obtain age estimates. Typical cluster ages are no more than 10 Myr.