High-resolution CCD imaging and derived gravitational lens models of 2237+0305

Images of the gravitational lens 2237+0305 acquired in good seeing (FWHM <= 1") resolve the system into several components. At least five components reside in the central few arcseconds of the object: the nucleus of the galaxy (lens) and four point sources in a ringlike formation approximately centered on the galaxy. The diameter of this "ring" is ~1.7". The four point sources are all distinctly bluer than the galaxy, but do not have identical colors. A simple model that assumes that these four objects are indeed images of the quasar and treats the lens as a constant mass-to-light ratio, elliptical, de Vaucouleurs bulge reproduces the observed configuration remarkably well. The true position of the quasar is less than 0.1" from the center of the galaxy, and the blue mass-to-light ratio of the lens is 9.4 +/- 2.0 (H_0_ = 100, q_0_ = 1/2). While monitoring of the images is unlikely to produce a definitive time-delay measurement (the expected delays between the images are ~1 day), such observations should reveal variations due to microlensing; 2237+0305 may well prove to be the best object that will ever be found for this purpose. It is exceedingly improbable that any more examples of this type of lens exist; the a posteriori probability of finding such a close alignment between a relatively bright quasar and a nearby (z < 0.04) galaxy is of order 10^-4^. ###########################################################################

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