UGC 3697 (PGC 20348) is a low-mass, Scd spiral galaxy about 159 million ligh-years away in the constellation Camelopardis. It shows a super thin disk morphology. Rather than having a flat disk like other super-thin spirals, the two ends of UGC 3697’s galactic plane curl slightly in opposite directions, like an integral sign (∫) or a wavy potato chip. Some degree of warping is observed in a large fraction of galaxies, but only few are warped as much as UGC 3697. In contrast to normal edge-on spirals, where the brightest concentration of H-I is typically found near the central regions of the galaxy, UGC 3697 shows a bright blob of emission near its western edge. Gas filaments also extend from this location, reaching up to ∼7 kpc from the plane. Neither the filaments nor the bright midplane clump have any obvious optical counterparts.
UGC 3697 is part of a small galaxy group that includes the peculiar elliptical galaxy UGC 3714 (PGC 20398) and several dwarf galaxies. UGC 3714, at a projected distance of 39 kpc from UGC 3697, is the optically brightest group member, and has long been presumed to be responsible for exciting the warp of UGC 3697 via tidal effects. However, tides are rather inefficient warp drivers. New observations have revealed strong evidence that the galaxy recently merged with a satellite dwarf galaxy.
