2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/12855HST is used to study the power sources and the interaction-induced tidal disturbances within the most luminous galaxies in the local universe -- the Ultra-Luminous IR Galaxies (ULIRGs) -- through the use of I-band images with WFPC2 and H-band images with NICMOS. Such images are probing for the first time the fine-scale structures in the strong collision-disturbed morphologies of these rare and exotic galaxies.To appear in "Astrophysics with Infrared Surveys: A Prelude to SIRTF," PASP Conference Proceedings, 4 pages, 2 figuresAstrophysicstext