Strange asymmetric halo around galaxy

http://legacysurvey.org/viewer?ra=172.2987&dec=-5.1261&zoom=14&layer=decals-dr5

This almost looks like the “bubble” that forms after a supernova blast - but this is around a galaxy!

It could also be that the little blue galaxy there just flew through the big guy and got partly disrupted. That often results in “shells”, or sometimes “umbrellas”, depending on the geometry.

cheers,
–dustin