The astronomer got angry and told me they weren't going to throw away theories based on some isolated phenomenon.
In 1966, world renowned astronomer, Halton Arp, collected his observations of 338 such unusual galaxies in a book entitled, "Atlas of Peculiar Galaxies".
Most all of the galaxies presented in the book are of the type you describe.
In most cases, those galaxies and their conjoined companions were observed to have very different red shifts, which caused Arp to conclude that red shift is not an indicator of speed or distance, but an indicator of age.
Naturally, the astronomical community, which had already accepted the Big Bang theory as gospel, thoroughly rejected Arp's findings out of hand, and labeled him a kook heretic. They did so (and continue to do so) despite the clear associations between these objects and the wild variances in their red shifts.
In subsequent decades, thousands of such objects have been added to Arp's original catalog.
The ramifications of these observations can't be overstated. Arp essentially disproved the Big Bang theory.
That probably explains the apoplexy of the astronomer I asked. Thanks for the info.