Wow, so that's an approximately 250k light year tail on CGCG254-021. So beautiful! I could get lost looking at images of far away galaxies, stars, you name it. Maybe some day, in my life, we will get a distributed optical telescope in space that allows us to image extrasolar planets! How exciting would that be?!

Credit: X-ray: NASA/CXC/University of Bonn/G. Schellenberger et al; Optical: INT

Read all about it in The Long X-ray Tail in Zwicky 8338," G. Schellenberger & T. H. Reiprich, 2015 November, Astronomy and Astrophysics G.
Schellenberger et al. The long X-ray tail in Zwicky 8338, Astronomy & Astrophysics (2015). DOI: 10.1051/0004-6361/201527317