NASA astronomers have discovered an unexpected “signal” coming from outside our galaxy that they cannot explain. “An unexpected and still unexplained feature outside our galaxy”

https://m.stacker.news/12547

NASA astronomers have discovered an unexpected “signal” coming from outside our galaxy that they cannot explain.

Scientists were analyzing 13 years of data from the Fermi Gamma-ray Space Telescope when they noticed the mysterious signal.

It was “an unexpected and still unexplained feature outside our galaxy,” wrote Francis Reddy of NASA’s Goddard Space Flight Center.

The powerful telescope can detect gamma rays, which are huge bursts of energetic light, thousands to hundreds of billions of times larger than our eyes can see. They are often created when stars explode or a nuclear explosion occurs. They stumbled upon the alternate signal while looking for something entirely different.

“It's a completely fortuitous discovery,” said Alexander Kashlinsky, a cosmologist at the University of Maryland and NASA's Goddard Space Flight Center, when presenting the findings to the American Astronomical Society.

"We found a much stronger signal and in a different part of the sky than we were looking for."

They were looking for one of the oldest characteristics of gamma rays to create the first atoms – known as cosmic microwave background radiation or CMB.

The CMB has a dipole structure, where one end is hotter and more occupied than the other. Astronomers generally think that the movement of our solar system creates the structure.

Instead, researchers detected a signal coming from a similar direction and with a nearly identical magnitude to another unexplained feature, which contained some of the most energetic cosmic particles they had ever detected.

"We found a gamma-ray dipole, but its peak is located in the southern sky, far from the CMB, and its magnitude is 10 times greater than we would expect from our motion," said Chris Shrader, an astrophysicist at Goddard.

This week, a paper describing the findings was published in The Astrophysical Journal Letters.

They think the discovery may be linked to a cosmic gamma-ray feature observed by the Pierre Auger Observatory in Argentina in 2017.

Astronomers believe that the two phenomena may originate from a single unidentified source, given their similar structure.

They hope to locate the mysterious source or develop alternative explanations for both features.

NASA's unexpected discovery could help astronomers confirm or challenge ideas about how the dipole structure is created.

"A disagreement with the size and direction of the CMB dipole could provide us with a glimpse into the physical processes operating in the very early universe, potentially even when it was less than a trillionth of a second old," said Fernando Atrio-Barandela, co-author of the paper. search.