The image is a remarkable testament to one of the predictions of general relativity. Einstein claimed that any massive object would warp space-time around itself, which could turn the object into a cosmic magnifying glass. This phenomenon was observed for the first time in 1919 by Eddington and it was the first test for general relativity.
The purple glow in the photo represents the extent of hot intergalactic gas within the group. Hydrogen gas is being heated to millions of degrees by the powerful supermassive black holes within the "left eye" and it indicates that the galaxies are racing towards each other at 1,350 kilometers per second (more than 3 million miles per hour)."
See more @ IFLS
- Photo @ SETI Twitter
- Space Photos of the Week: The Smiling Cheshire Cat Galaxy @ Wired
- @Earth Sky
- Where Alice in Wonderland meets Albert Einstein @ Phys (dot) org - "A key result of Einstein’s theory is that matter warps space-time, and thus a massive object can cause an observable bending of light from a background object. The first success of the theory was the observation, during a solar eclipse, that light from a distant background star was deflected by the predicted amount as it passed near the sun."
- Gemini Characterizes Cheshire Cat