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D. Maoz, A. Sternberg (Tel-Aviv University), L. C. Ho (Carnegie Observatories)
``Super star clusters'' (SSCs) represent an important mode of star formation in starburst environments. Our previous HST/FOC ultraviolet (UV) images have discovered a sizable population of SSCs in the circumnuclear rings (radii ~300 pc) of the barred galaxies NGC 1512 and NGC 5248. Here we present images of these systems taken with the HST/NICMOS camera using broad-band (F160W, F187W) and narrow-band (F187N = Paschen-alpha) filters. The near-IR images reveal many clusters not detected previously in the UV data. We use the observed UV/near-IR ratio to constrain the duration of the star-formation burst in these SSCs. Comparison of the UV and Pashen-alpha measurements allows us to estimate the amount of dust extinction and the timescale for the dispersal of dust and gas. The ring in NGC 1512 contains several candidate objects that resemble large-scale wind-blown bubbles, giant shells of ionized nebulae surrounding a stellar cluster.