Ultra-luminous galaxy mergers: ellipticals in formation?

Reinhard Genzel
Max-Planck-Institute for Space Physics &
University of California Berkeley

Ultra-luminous infrared galaxies (ULIRGs) are mergers of gas rich disk
galaxies. They may be the local counterparts to the distant submillimeter
sources that make up a significant part of the high-z far-infrared
background and star formation. A key question is whether ULIRGs evolve
into elliptical galaxies.

We have carried out 0.5" resolution, near-infrared spectroscopy of the in
a sample of a dozen late stage, compact ULIRGs. The new Keck and VLT data
give high quality information on the merger stellar dynamics. We find that
ULIRG mergers fall on the fundamental plane of hot galaxies. They resemble
intermediate mass, disky ellipticals. We discuss the impact of our work on
the evolution of elliptical galaxies.