I get excited when I see astronomers using novel techniques to study more distant and more difficult problems in astronomy. In this case, we have a galaxy cluster acting as a lens and some high-resolution spectroscopy to get a 3-dimensional view of a quasar.

A typical quasar is dominated by a point of light coming from the very center of the distant galaxy, specifically from the accretion disk around a supermassive black hole that is pulling matter into it. That bright central quasar can often act as a background light for probing what is in front of that quasar along our line of sight, including the structures within the very same galaxy.
SNIP---------------------------------------------------------

More: http://news.discovery.com/space/gala...ens-130221.htm



Artist conception, where paths A, B, and C correspond to the image at top.
However, typically, a quasar only allows one, piercing line of sight through the outflow region. J1029+2623 is different because it is being lensed by a whole galaxy cluster that lies somewhere in front of it along our line of sight. So there are three different images of the quasar widely separated apart. This means, as the diagram above shows, you get several different lines of sight through the outflow and can begin to discern its shape and properties.