The dual symmetric Spiral Arms of Galaxies are the streamer remnants of Dual Herbig Haro Black Holes based self propelled evaporating Tadpole black holes. creating stars by dual baby Herbig Haro Black Hole evaporation. Creating a White Hole in the middle. (Q-FFF Model)
Equal sized (spliced) Tadpole-Dual Black Holes of all sizes seem to be responsible at all scales, for all star and galaxy formation in the universe.