Massive star formation in Luminous Infrared Galaxies
  We present HST/NICMOS observations of a sample of LIRGs. We show that active star formation appears to be occurring not only in the bright nuclei of these galaxies, but also in luminous super-star clusters and giant HII regions with ages of up to 20-40Myr. This population of bright clusters and HII regions is unprecedented in normal galaxies and emphasizes the effects of the extreme star formation in LIRGs. 
A. Alonso-Herrero (1), G. H. Rieke (1), M. J. Rieke (1), N. Z.   Scoville (2)((1) Steward Observatory, (2) Caltech)