https://www.aanda.org/articles/aa/pd...aa28297-16.pdf
the above paper identified a huge bright gravitational arc down near the SCP so I tried to image it. Local conditions limited the data to a selection of about 12 hours of very variable quality, but there was enough to show this extraordinary object. The arc lensing is so efficient that it is possible to detect photons that have been travelling for most of the life of the universe - they started their journey only ~3 billion years after the big bang and ~7 billion years before the solar system came into being. The source galaxy - if it still exists - is now way across the other side of the universe. It is really exciting and a great privilege to be able to observe photons this ancient and in a way that clearly shows the reality of spacetime warping.
The arc itself has 3 main sections (one quite small) and a fourth segment on the opposite side of the lensing mass - the fourth is not visible on this image. Most interesting is that the source galaxy is now quite blue, so it must have been rich in hard UV to be even visible at redshift >2. The discovery paper also shows blue in false colour near IR, again indicating a UV bias in the spectrum.
The image is cosmetically pretty ghastly - had to dig right down in the bones of the data and found lots of noise. Maybe next year there will be more data
For now though, best fun for a long time.
thanks for looking. Cheers Ray
lum 188x2min
R 56x3min
G 26x3min
B 20x5min
10inch f4, asi1600
upscaled 150%