I don’t think it’s real, folks. I never have. And you won’t find it in my writings.
I’m thinking this article explains why spiral galaxies behave as they do. Because they’re simply a lot more massive than we thought them to be. And I’d guess that’s a feature unique to spirals. That elliptical and irregular galaxies have had that halo torn away by the gravitational interaction that made them elliptical or irregular in the first place.