Scientists Discover Massive ‘Bubble of Galaxies’ from Early Universe
Astronomers have made a groundbreaking discovery—a massive “bubble of galaxies” believed to be a fossilized remnant from the early universe, just after the Big Bang. This enormous cosmic structure spans a billion light years and is approximately 10,000 times wider than our Milky Way galaxy. While invisible to the naked eye, the bubble resides a relatively close 820 million light years away from Earth, within the nearby universe.
The bubble, named Ho’oleilana, is described as a spherical shell with a heart. Inside the heart lies the Bootes supercluster of galaxies, surrounded by a vast void known as “the Great Nothing.” The shell encapsulates various other galaxy superclusters, including the Sloan Great Wall, already known to scientists. The discovery of Ho’oleilana is the result of meticulous research and confirms a concept first theorized by Jim Peebles, a US cosmologist and future Nobel laureate, in 1970.
Peebles proposed that sound waves called baryon acoustic oscillations (BAOs) were formed in the early universe due to the interaction between gravity and radiation. These sound waves created bubbles as they rippled through the hot plasma. Around 380,000 years after the Big Bang, the universe cooled down, causing the bubbles to freeze in shape. These fossilized remnants then expanded alongside the universe. In 2005, astronomers detected signals of BAOs from nearby galaxies, but Ho’oleilana is the first known single baryon acoustic oscillation.
The discovery of Ho’oleilana was unexpected and came about during astronomer Brent Tully’s search through new catalogs of galaxies. Tully, from the University of Hawaii, named the bubble Ho’oleilana, which means “sent murmurs of awakening” in Hawaiian. The shape and position of the galaxies within the bubble were determined mathematically by Australian cosmologist Cullan Howlett. With this breakthrough, scientists believe that more bubbles could be identified across the universe.
Excitingly, the recently launched Euclid space telescope and the Square Kilometre Array, currently under construction in South Africa and Australia, have the potential to reveal more about the structure and formations of galaxies in our universe. The research on Ho’oleilana, titled “Ho’oleilana: An Individual Baryon Acoustic Oscillation?” was published in The Astrophysical Journal. These new findings contribute valuable insights to the study of our universe’s origins and evolution.
Reference:
R. Brent Tully et al, Ho’oleilana: An Individual Baryon Acoustic Oscillation?, The Astrophysical Journal (2023). DOI: 10.3847/1538-4357/aceaf3
R. Brent Tully et al, Cosmicflows-4, The Astrophysical Journal (2023). DOI: 10.3847/1538-4357/ac94d8