We have observed 14 nearby (z<0.16) Ultraluminous Infrared Galaxies (ULIRGs)
with Spitzer at 3.6-24 microns. The underlying host galaxies are well-detected,
in addition to the luminous nuclear cores. While the spatial resolution of
Spitzer is poor, the great sensitivity of the data reveals the underlying
galaxy merger remnant, and provides the first look at off-nuclear mid-infrared
activity.Comment: To appear in the conference proceedings for Spitzer New Views of the
Universe, held Nov. 2004 in Pasadena, C
