For a very long time now, astronomers have wondered how galaxies replenish their supply of gas, but they now have a method for doing so, Space.com reported.

If a galaxy were to run on only the supply of gas that they were formed with, they would run dry just from creating stars. While astronomers have often theorized that galaxies refuel themselves, it has been hard to prove due to poor lighting.

Observers have begun using the light emitted from background galaxies to show the best view to date of how the refueling process takes place.

The team of astronomers observed two objects from the Tucana constellation using the European Southern Observatory's Very Large Telescope in Chile. Light from a quasar, a super-luminous galactic light source, reveals the flow of material from the fuel source to the galaxy, as well as the actual motion and composition.

WATCH an artists interpretation of the galaxy's feeding process.


"The cold gas - mostly hydrogen atoms - is very tenuous, so difficult to detect," lead author Nicolas Bouché, of the Research Institute in Astrophysics and Planetology in Toulouse, France, told SPACE.com in an e-mail.

Using the ultra-bright quasar is a big upgrade from the previous practice of using ordinary galaxies to light the scene.

"We can study the gas around any galaxy, regardless of its brightness," Bouché said. "This is a very young galaxy, seen only 2 billion years after the Big Bang, still in its early stages of formation."

The young galaxy is approximately 11 billion light years away from our Milky Way galaxy, which is good for 80 percent of the way across the visible universe.

While very beneficial to astronomers, the event of finding a quasar in such close proximity to a galaxy is uncommon.

"Unfortunately, the number of such 'apparent pairs,' where a background quasar happens to be situated a short distance on the sky from the galaxy, is a rare event," Bouché said.

The team will continue their study and, in late 2013 or early 2014, will have a brand new instrument to use. Bouché said the ESO's Multi Unit Spectroscopic Explorer will help them "map out the intergalactic gas thanks to the unprecedented sensitivity of this instrument."