Shedding light on Galaxies' rotation secrets. Spiral galaxies are found to be strongly rotating, with an angular momentum higher by a factor of about 5 than ellipticals. In a new study, the researchers have traced back the dichotomy in the angular momentum of spiral and elliptical galaxies to their different formation history. In particular, the low angular momentum of ellipticals is mainly originated by nature in the central regions during the early galaxy formation process. Source 4u.