Resolved Dust Emission in a Quasar at z=3.65
  We present submillimetre observations of the z=3.653 quasar SDSS160705+533558
together with data in the optical and infrared. The object is unusually bright
in the far-IR and submm with an IR luminosity of ~10^14 L_sun. We ascribe this
luminosity to a combination of AGN and starburst emission, with the starburst
forming stars at a rate of a few thousand solar masses per year. Submillimetre
Array (SMA) imaging observations with a resolution ~1" show that the submm (850
micron) emission is extended on scales of 10--35kpc and is offset from the
optical position by ~10 kpc. This morphology is dissimilar to that found in
submm galaxies, which are generally un- or marginally resolved on arcsecond
scales, or submm-luminous AGN where the AGN lies at the peak of the submm or
molecular emission. The simplest explanation is that the object is in the early
stages of a merger between a gas rich galaxy, which hosts the starburst, and a
gas-poor AGN-host galaxy, which is responsible for the quasar emission. It is
also possible that jet induced star formation might contribute to the unusual
morphology.
