Discovery of a “galactic bubble” measuring a billion light-years across

Astronomers have discovered the first “galactic bubble,” an almost unimaginably massive cosmic structure believed to be fossilized remains from just after the Big Bang, located in our galaxy’s backyard.

The bubble spans a billion light-years, making it 10,000 times wider than the Milky Way.

However, this giant bubble, which cannot be seen with the naked eye, is relatively 820 million light-years away from our home galaxy, in what astronomers call the Nearby Universe.

The bubble can be considered a “spherical shell with a core,” Daniel Bomarede, an astrophysicist at the French Atomic Energy Authority, told AFP.

Within this core is the Botts supercluster of galaxies, surrounded by a vast void sometimes called the Great Nothing.

The crust contains several other giant galaxy clusters already known to science, including the massive structure known as Sloan’s Great Wall.

Bommaredi said the discovery of the bubble was described in research he co-authored that was published in 2016 Astrophysical Journal This week was “part of a very long scientific process.”

It confirms a phenomenon first described in 1970 by American cosmologist – and future Nobel Prize winner in physics – Jim Peebles.

He hypothesized that in the primordial universe—which was then a mixture of hot plasma—the ripple of gravity and radiation created sound waves called baryon acoustic oscillations (BAOs).

When sound waves rippled through the plasma, they created bubbles.

About 380,000 years after the Big Bang, the process stopped when the universe cooled, causing the bubbles to freeze in shape.

The bubbles then grew larger as the universe expanded, similar to other fossilized remains from the time after the Big Bang.

Astronomers previously discovered BAOs signals in 2005 when looking at data from nearby galaxies.

But the newly discovered bubble is the first single acoustic baryon oscillation, according to the researchers.

‘unexpected’

The astronomers named their bubble Ho’oleilana — meaning “sent out blasts of awakening” — taking the name from the Hawaiian creation hymn.

The name came from the study’s lead author, Brent Tully, an astronomer at the University of Hawaii.

The bubble was discovered by chance, as part of Tully’s work searching through new catalogs of galaxies.

“It was something unexpected,” Bomarede said.

The bubble “is so massive that it extends to the edges of the strip of sky we were analyzing,” Tully said in a statement.

The duo enlisted the help of Australian cosmologist and BAO expert Colan Howlett, who “mathematically determined the spherical structure that best matched the data provided,” Bomareddy said.

This allowed the trio to visualize the 3D shape of Holliana, and the location of the galactic archipelago within it.

This may be the first time, but more bubbles could soon be spotted all over the universe.

Europe’s Euclid Space Telescope, which launched in July, is taking a wide view of the universe, which could enable it to catch more bubbles.

Large radio telescopes called the Square Kilometer Array, which are being built in South Africa and Australia, could also provide a new picture of galaxies from the viewpoint of the Southern Hemisphere, Bomareddy said.