THE HOST GALAXIES OF IRAS-SELECTED QUASI-STELLAR OBJECTS

We present Hubble Space Telescope (HST) images of three QSOs selected on the basis of their IRAS properties. The data were taken with the Pl anetary Camera primarily in order to examine the host galaxies. All th ree QSOs appear embedded in spectacular interactions between two or mo re luminous galaxies, probably spirals. We discuss the evolutionary co nnection, if any, between these three objects and the far more numerou s ultraluminous infrared galaxies. We argue that these three objects a re probably young and therefore do not fit a scenario in which QSOs em erge only in the later stages of an interaction when most of the dust has been blown away. It may be that we are simply viewing them from a fortuitous angle that allows a clear view into the cores.