Galaxies Get Fuel From Outside Sources [VIDEO]

Astronomers have long suspected galaxies capture resources from the universe around them in order to sustain themselves, because if they were limited to the gases they formed with, they would have quickly used up their entire supply when they started forming stars.

However, finding proof of degrees of consumption has been hard to find.

Then researchers used the European Southern Observatory's Very Large Telescope in Chile to study two objects located within the southern sky's Tucana constellation.

Using the illumination from a quasar, an extremely bright source powered by a supermassive black hole and located at the center of another background galaxy, the team made the best observations to date of a galaxy refueling itself.

Shining through the foreground galaxy, the light from the quasar revealed the flow of interstellar material into the galaxy, as well as its movement and composition.

"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 by email.

In the past, researchers used other regular galaxies as background flashlights, though the illumination supplied by those previous sources was much dimmer than the quasar involved in the latest study.

"We can study the gas around any galaxy, regardless of its brightness," lead author Nicolas Bouché from the Research Institute in Astrophysics and Planetology in Toulouse, France, told SPACE.com by email.

The quasar-aided viewpoint also reveals the location of the gas, what Bouché called "a critical piece of information," and makes the study of more distant galaxies much easier.

The galaxy that was the focus of the study lies approximately 11 billion light-years from the Milky Way, about 80 percent of the way across the visible universe.

"This is a very young galaxy, seen only two billion years after the Big Bang, still in its early stages of formation," Bouché said.

Past observations revealed the presence of gas around other galaxies, but Bouché's team was able to demonstrate that gas surrounding the foreground galaxy was being drawn in, rather than flowing out of it.

It was also revealed that the gaseous mixes contain more complex elements than previously thought, formed in the hearts of stars and cast wide during the explosive deaths of stars and sometimes ending up far outside their galaxies of origin.

The new observation method offers the potential for much more detailed studies, but suffers its own limitations.

"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," said Bouché, whose team plans to continue studies of similar galaxies using a variety of telescopes and instruments.

The researchers also plan to take a closer look at the galactic pairing through the European Southern Observatory's Multi Unit Spectroscopic Explorer, which will come online later this year or in early 2014.

"This means we will be able to map out the intergalactic gas thanks to the unprecedented sensitivity of this instrument," Bouché said.