Washington, Oct 22 : Astronomers from the University of Florida (UF) and University of California-Santa Cruz have discovered the onset of a huge flow of gas from a quasar, or the super-bright core of an extremely remote young galaxy still being formed.
The gas was expelled from the quasar and its enormous black hole sometime in the space of four years around 10 billion years ago - an extremely brief and ancient blip noticed by the unlikely convergence of two separate observational efforts.
"It was completely serendipitous," said Fred Hamann, a UF astronomy professor. "In fact, the only way it could have happened is through serendipity," he added.
Quasars are enormously bright cores of very distant galaxies thought to contain "super-massive" black holes a billion times larger than our sun.
They are seen only in the centers of very distant galaxies that formed long ago - galaxies whose light is just now reaching Earth after billions of years in transit.
The quasar in question occurred about 10.3 billion years ago.
The black holes within quasars are invisible, but the cosmic material cascading toward them builds up and forms hot "accretion" disks, the source of quasars' intense light.
Some of the incoming material also can be expelled from quasars to form enormous gas clouds that zoom out at extremely high speeds.
"With the quasar in question, the gas is flowing at an astonishing rate of 58 million mph," Hamann said.
But while astronomers had observed the presence of such gas clouds with other quasars, they had never witnessed one actually coming into being - until now.
Hamann said the discovery was initiated when Kyle Kaplan, an undergraduate at UC-Santa Cruz, earlier this spring noticed peculiarities in the spectra, or wavelengths of light, that had been observed and recorded from the quasar.
The spectra were gathered in 2006 as part of an effort to study the galaxies between the quasar and Earth.
When Hamann and other astronomers checked the spectra against the spectra of the same region recorded in a separate sky survey in 2002, they were surprised to discover that there were zero indications of the gas cloud.
"So that's how we know this appeared between 2002 and 2006," he said.
Daniel Progra, a physics professor at the University of Nevada, Las Vegas and an expert on gas outflows from astronomical objects, indicated the discovery is a lucky one.
"I am most excited about this work," he said. "We humans cannot directly monitor changes in quasars as they take very many years. Therefore, a discovery of a change over a few years is very interesting. It is not unexpected, but chances are very small," he added.