At https://phys.org/news/2022-10-flips-galaxies-cosmic-web.html … we are told that the alignment between galaxy spin and the large scale structure of the universe reveals the process by which different components of the galaxy form. Galaxies form a ‘cosmic web‘ consisting of giant filamentary structures linking up to massive clusters of galaxies. Galaxies which are mostly disks, with a low mass bulge, tend to have their spin axes parallel to the nearest filament. This is because they form mainly from gases falling on to the filament which rolls it up – into a disc. Galaxy bulges grow when galaxies merge, they suggest, also traveling along the filament. So, mergers appear to flip the alignment between galaxy spin and filament from parallel to perpendicular – we think, they add. The authors of the research paper say it is more likely as galaxies move along the filament towards each other. The motivation behind the research came about as they tried to understand why galaxies spin and how they require angular momentum from the material that forms them. Interesting paper to read – see https://doi.org/10.1093/mnras/stac2405 …
From a different angle see Donald Scott’s new book, available from SIS for £24 plus postage.