RE: APOD: 2008 July 28 - SDSSJ1430: A Galaxy Einstein Ring by Stefanie at 9:06 am EDT, Jul 29, 2008
...their multiple properties allow astronomers to determine the mass and dark matter content of the foreground galaxy lenses. Given these determinations, SLACS data has now been used, for example, to show that dark matter fraction increases with overall galaxy mass.
