Submillimeter Observations of the Ultraluminous Broad Absorption Line Quasar APM 08279+5255

Abstract

With an inferred bolometric luminosity of 5x10^{15} Lsolar, the recentlyidentified z=3.87 , broad absorption line quasar APM 08279+5255 isapparently the most luminous object currently known. Since half ofits prodigious emission occurs in the infrared, APM 08279+5255 alsorepresents the most extreme example of an ultraluminous infraredgalaxy. Here we present new submillimeter observations of this phenomenalobject; while indicating that a vast quantity of dust is present,these data prove to be incompatible with the current models of emissionand reprocessing mechanisms in ultraluminous systems. The influenceof gravitational lensing on these models is considered, and we findthat while the emission from the central continuum-emitting regionmay be significantly enhanced, lensing-induced magnification cannoteasily reconcile the models with the observations. We conclude thatfurther modeling, including the effects of any differential magnification,is required to explain the observed emission from APM 08279+5255.