What is the line of light in galaxy cluster MACS J1206? I noticed this in a thread from world building, what is the continuous line of light in MACS J1206 slightly right of center in this picture? The only thing I could think of would be the side view of a galaxy, but it's much longer than any other galaxies pictured.
I have highlighted the feature I believe you are talking about. It looks like a galaxy that has been repeated (smaller green oval). There are several foreground objects that appear to be causing additional gravitational lensing (red arrows). Due to the shapes of the objects causing the lensing effect, the apparent image can be affected in many different ways, such a image duplication (multiple identical images of a galaxy, etc.), magnification, distortion, etc. The universe is massive and three-dimensional and we still don't understand that much of it yet.