Bubble of Galaxies

• 11 Sep 2023

In a remarkable astronomical find, scientists have recently stumbled upon the first known "bubble of galaxies," an enormous cosmic structure believed to be a fossilized remnant from the early universe, nestled in our cosmic neighborhood.

Key Points

• Bubble Description: Astronomers have identified a colossal "bubble of galaxies" spanning a staggering billion light-years, dwarfing the Milky Way galaxy by a factor of 10,000.
• Proximity: This immense cosmic bubble, although invisible to the naked eye, resides relatively close, at a distance of 820 million light-years from our own Milky Way galaxy, classified as part of the nearby universe.
• Bubble Anatomy: The structure resembles a "spherical shell with a heart" and encompasses the Bootes super cluster of galaxies within its core, surrounded by a vast expanse known as "the Great Nothing."
• Galactic Neighbours: Inside the bubble, several galaxy superclusters are already familiar to science, including the immense Sloan Great Wall.
• Historic Discovery: The bubble's existence confirms a phenomenon initially proposed in 1970 by renowned US cosmologist Jim Peebles, who theorized the formation of bubbles during the early universe's hot plasma phase.
• Baryon Acoustic Oscillations (BAOs): The churning interplay of gravity and radiation during the primordial universe generated sound waves, known as baryon acoustic oscillations (BAOs), which created these cosmic bubbles.
• Frozen in Time: Approximately 380,000 years after the Big Bang, as the universe cooled, the process ceased, preserving the bubble shapes.
• Expanding Bubbles: These cosmic relics grew in size as the universe expanded, similar to other remnants from the aftermath of the Big Bang.
• First of Its Kind: The newly discovered bubble stands as the inaugural single baryon acoustic oscillation recognized by astronomers.
• Significance: This remarkable discovery opens a window into the early universe, shedding light on the formation and preservation of these colossal cosmic structures.