These optical images from the NOAO Deep Wide-Field Survey are from a section of the Boötes field. Covering roughly 7 percent of the total survey area, this region contains about 300,000 galaxies and stars.

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A long time ago in a galaxy far, far away. . . .

A report from the National Optical Astronomy Observatory in Tucson has revealed a hitherto largely unseen stage in galactic evolution.

The galaxies observed have quickly expanding black holes at their center and are producing stars more quickly than occurs in present-day galaxies.

This discovery will help scientists better understand the evolution of galaxies, including our own.

Using the Spitzer Space Telescope, an infrared telescope launched into orbit in 2003, researchers have been able to make observations of galaxies 10 billion light-years away.

This means the light being seen is 10 billion years old, from when the universe was relatively (pun intended) young, roughly 3 billion years old.

"It's an early stage of their formation," said Arjun Dey, an astronomer at NOAO and a co-author of a paper published on the research in The Astrophysical Journal recently.

"We caught them in their growth phase," he said.

Dey estimated that this "phase of galactic evolution" lasts between 100 million and 200 million years, incomprehensibly long in human terms, but a very brief period for a galaxy.

"It's less than a year in human terms," said Buell Jannuzi, director of Kitt Peak National Observatory and another author of the paper. "Spitzer is the only one that could make these kinds of observations," he said.

Optical telescopes are unable to see these galaxies, because the amount of dust present reddens the light they emit to beyond the optical range when it reaches Earth. It's the same way that atmospheric dust creates red sunsets, only more so.

Around 2,600 of this type of galaxy were discovered in the area observed — nine square degrees of the sky in the constellation Boötes, Dey said. Based on the observations, Dey said it is possible thousands of stars are being formed in each galaxy every year, as opposed to the one to three stars formed yearly in the Milky Way.

This has a direct relation on how quickly the black hole in the center of each galaxy grows.

"Each limits the formation of the other," he said.

If a black hole becomes energetic enough to heat up the gas clouds that could become stars to 1,000,000 Kelvin (1,799,540.6 degrees Fahrenheit), it prevents the formation of the stars. And if stars form very quickly, there will not be enough mass falling into the black hole to heat up the clouds to that threshold.

Somehow, this manages to affect the entire galaxy, although "nobody's really clear on how this works," and models to simulate the process have to "fudge that aspect," Dey said.

Research on how long this phase lasts, as well as what the galaxies actually look like at this point, is the next phase of the research, he said.

"We've started getting images with Hubble (Space Telescope)," he said.

Unlike the Milky Way, these galaxies don't seem to have a spiral form or the elliptical shape also common in mature galaxies. They are more nebulous in shape.

Dey said it may be that they take on a more recognizable shape as they age and move past their current, energetic phase and become more like our own galaxy.