Submillimeter observations of the ultraluminous broad absorption line quasar APM 08279+5255

With an inferred bolometric luminosity of 5 x 10(15) L., the recently identified z = 3.87, broad absorption line quasar APM 08279+5255 is apparently the most luminous object currently known. Since half of its prodigious emission occurs in the infrared, APM 08279+5255 also represents the most extreme example of an ultraluminous infrared galaxy. Here we present new submillimeter observations of this phenomenal object; while indicating that a vast quantity of dust is present, these data prove to be incompatible with the current models of emission and reprocessing mechanisms in ultraluminous systems. The influence of gravitational lensing on these models is considered, and we find that while the emission from the central continuum-emitting region may be significantly enhanced, lensing-induced magnification cannot easily reconcile the models with the observations. We conclude that further modeling, including the effects of any differential magnification, is required to explain the observed emission from APM 08279+5255.