Click on image for full size view.
NGC 3628 sports a tidal tail and loops caused by gravitational interaction with it closeby neighbors, M65 and M66.
Taken from New Mexico Skies with an AP160, STL 11K, AstroDon filters:
Exposure: L = 20 hours R ,G, B 1 hour (each). All 20-minute intregrations.
Most of the processing was done by my friend Ken Crawford. Thanks, Ken!