The complex gravitational lens system B1933+503
Pearson, T. J.; Bremer, M.; Blandford, R. D.; Fassnacht, C. D.; Readhead, A. C. S.; Miley, G. K.; Nair, S.; Browne, I. W. A.; Wilkinson, P. N.; Schilizzi, R. T.; Womble, D. S.; Myers, S. T.; Jackson, N. J.; Marlow, D. R.; Sykes, C. M.; De Bruyn, A. G.; Cohen, J.; Hogg, D.
United Kingdom, United States, Netherlands
Abstract
We report the discovery of the most complex arcsec-scale radio gravitational lens system yet known. B1933+503 was found during the course of the CLASS survey and MERLIN and VLA radio maps reveal up to 10 components. Four of these are compact and have flat spectra; the rest are more extended and have steep spectra. The background lensed object appears to consist of a flat-spectrum core (quadruply imaged) and two compact `lobes' symmetrically disposed relative to the core. One of the lobes is quadruply imaged while the other is doubly imaged. An HST observation of the system with the WFPC2 shows a galaxy with an axial ratio of 0.5, but none of the images of the background object is detected. A redshift of 0.755 has been measured for the lens galaxy.