NICMOS Imaging of Infrared-Luminous Galaxies

We present near-infrared images obtained with the HST NICMOS camera for a sample of 9 luminous (LIGs: L_IR (8-1000 microns) >~ 10^11 L_sun) and 15 ultra-luminous (ULIGS: L_IR >~ 10^12 L_sun) infrared galaxies. The sample includes representative systems classified as warm (f_25/f_60 > 0.2) and cold (f_25/f_60 <~ 0.2) based on the mid-infrared colors and systems with nuclear emission lines classified as HII (i.e. starburst), QSO, Seyfert and LINER. The morphologies of the sample galaxies are diverse and provide further support for the idea that they are created by the collision or interactions of spiral galaxies. Although no new nuclei are seen in the NICMOS images, the NICMOS images do reveal new spiral structures, bridges, and circumnuclear star clusters..