Warped galaxy UGC 3697, composite radio-optical image. Also known as the 'Integral Sign' galaxy, this is an edge-on spiral galaxy with an unusually pronounced warp in both its stellar and gaseous disks. The neutral hydrogen gas, represented in blue, is overlaid on an optical image of the stars of the galaxy. Unlike in normal spiral galaxies, the brightest concentration of neutral hydrogen is not found near the centre of UGC 3697 but along its western edge, where the Very Large Array (VLA) has detected a bright, extended region of L-band emission. In addition, plumes of gas extend to considerable height above and below the disk of the galaxy. UGC 3697 is around 151 million light-years away in the constellation of Camelopardalis. Optical data from the Schmidt telescope. Images obtained in 2000 and 2017.