Researchers Detect A Mysterious Flash Of X-Rays From A Faraway Galaxy (nytimes.com)

"It was a spark in the night. A flash of X-rays from a galaxy hovering nearly invisibly on the edge of infinity. Astronomers say they do not know what caused it." Slashdot reader schwit1 quotes the New York Times: The orbiting Chandra X-ray Observatory, was in the midst of a 75-day survey of a patch of sky known as the Chandra Deep Field-South, when it recorded the burst from a formerly quiescent spot in the cosmos. For a few brief hours on Oct 1, 2014, the X-rays were a thousand times brighter than all the light from its home galaxy, a dwarf unremarkable speck almost 11 billion light years from here, in the constellation Fornax. Then whatever had gone bump in the night was over and the X-rays died.

The event as observed does not fit any known phenomena, according to Franz Bauer, an astronomer at Pontifical Catholic University of Chile, and lead author of a report to be published in Science.
He described some possible explanation in a blog post this week -- for example, a star being torn apart by a black hole, or the afterglow from a gamma ray burst seen sideways -- but the spectrum readings aren't a match, according to the Times. "None of the usual cosmic catastrophe suspects work."

Comments

The universe is expanding...Re:When did it happen?

[Geoffrey.landis]

X-rays, of course, are a form of electromagnetic radiation (as is light), and travel at the speed of light

I wonder how long it takes light to travel 11 billion light years. Maybe if someone could figure that out, we could tell when the event happened.

An interesting thing to note is that the source wasn't 11 billion light years away when the light was emitted-- it was only 2.2 billion light years away back then. It took the light 11 billion years to travel that 2.2 billion light year distance at the speed of light.

Sounds paradoxical, doesn't it! That's the expansion of the universe in a nutshell.