PGC 2248: Cartwheel Galaxy
Lying about half a billion light-years away, the cartwheel shape of this PGC 2248 is the result of a violent galactic collision. A smaller galaxy has passed through the larger disc of this galaxy and produced shock waves that swept up gas and dust — much like the ripples produced when a stone is dropped into a lake. As well, this traumatic event sparked regions of intense star formation which appear blue here. The outermost ring of the galaxy marks the shock wave’s leading edge. This object is one of the most dramatic examples of the small class of ring galaxies. First discovered in in 1941 by astronomer Fritz Zwicky, he declaimed that this is "one of the most complicated structures awaiting its explanation on the basis of stellar dynamics." It took a few decades to unravel this cosmic mystery.
Using both ESA/ESO/NASA provided software and Photoshop I combined three b&w Hubble Telescope images (courtesy NASA and MAST) taken with blue, yellow-orange and red-infrared filters to create this image. Enjoy.