PMN J0134-0931: A gravitationally lensed quasar with unusual radio morphology

The radio-loud quasar J0134-0931 was discovered to have an unusual morphology during our search for gravitational lenses. In Very Large Array and MERLIN images, there are five compact components with a maximum separation of 0″.7. All of these components have the same spectral index from 5 to 43 GHz. In a Very Long Baseline Array image at 1.7 GHz, a curved arc of extended emission joins two of the components in a manner suggestive of gravitational lensing. At least two of the radio components have near-infrared counterparts. We argue that this evidence implies that J0134-0931 is a gravitational lens, although we have not been able to devise a plausible model for the foreground gravitational potential. Like several other radio-loud lenses, the background source has an extraordinarily red optical counterpart.