Merging?

http://legacysurvey.org/viewer?ra=204.0605&dec=-1.0398&zoom=15&layer=decals-dr5

Yes, this group of galaxies is definitely merging/interacting! If you look under the “Spectroscopy” menu in the viewer, and turn on the “SDSS Spectra” layer, you can see that SDSS took spectra of two of these galaxies, and they’re at basically the same redshift and both are classified as “starburst” galaxies – a burst of star formation often happens after one galaxies passes by another. The long “tidal tail” at the bottom left is another good hint.

Very nice!
–dustin