The Cartwheel galaxy is 500 million lightyears away. It has a striking ring structure which is thought to be the results of a head-on collision with a smaller galaxy. This resulted in a powerful gravitational shockwave that expanded outwards through the galaxy creating its unique structure. This shockwave swept up and compressed dust and gas, resulting in starburst activity which can been seen in the blue outer ring.
The Cartwheel galaxy is part of a group of 4, with its 3 companions (named G1-3) visible in the image. G3 is the more distant galaxy positioned at ~10 o’clock to the main group and is thought to be the galaxy that plunged through the Cartwheels disc causing the gravitational disruption.
For this image I captured 20 hours of data and this was processed using drizzle integration. I did use BlurX set to a fairly high 0.70 and used some Unsharp Mask sharpening in PS. The final image was also upsized in PS using nearest neighbour resampling. While there aren’t a lot of finer scale features resolved, I did manage to resolve the inner nucleic ring, the outer ring and the connecting spokes which is better than I initially expected. The image could do with some additional integration time to help control noise and better resolve the numerous groups of faint distant galaxies that are visible across the field.
Astrobin Link: https://www.astrobin.com/vzqx3y/