What is a Lensed Galaxy?
The Very Large Array (VLA) looked at a galaxy more than 12 billion light-years from Earth. Between this galaxy and Earth lies another distant galaxy, so perfectly aligned along the line of sight that its gravity bends the light and radio waves from the farther object into a circle, or “Einstein Ring.” Gravitational lenses were predicted, based on Albert Einstein’s General Theory of Relativity, in 1919. Einstein himself showed in 1936 that a perfectly-aligned gravitational lens would produce a circular image, but felt that the chances of actually observing such an object were nearly zero. The first gravitational lens was discovered in 1979, and the first Einstein Ring was discovered by researchers using the VLA in 1987.
Credit: Bill Saxton, NRAO/AUI/NSF
