A team of astronomers from the University of Hawaii have found traces of a giant cosmic bubble 820 million light-years away. They called her Ho’oleilana. According to the researchers, it is one acoustic baryon oscillation (BAO), an example of the state of matter at the beginning of the universe.
The bubble they identified is a billion light-years across. Inside are the gigantic structures of the galaxies closest to Earth. The Harvard/Smithsonian Great Wall, which includes the Coma Cluster, the Hercules Cluster, and the Sloan Great Wall, the Bootes Supercluster, and the dark strip called the Bootes Void, are some collections of millions of stars and planets that are native to Ho’oleilana .
An acoustic baryon vibration?
A baryon acoustic oscillation is a trace on the cosmic map, similar to a fold, created by the violent interactions between photons (radiation) and neutrons and protons (baryonic matter) in the early stages of the universe. BAOs are one of the key predictions of the Big Bang theory, the currently dominant cosmic model. This says that before the universal expansion event, all existing matter and radiation had condensed into a primordial superhot plasma.
While baryon matter and radiation were connected, they collided with each other, producing acoustic waves that propagated throughout the plasma. When they separated, photons and protons stopped interacting with each other and the bubbles they caused froze. When the universe as we know it began, BAOs, like the microwave background, remained recognizable ghosts.
A group of scientists have discovered cosmic filaments that point to and surround the Milky Way’s supermassive black hole, and they can’t yet provide a concrete explanation for it.
Only recently have scientists learned to find traces of these vibrations in the visible universe. BAOs became visible when cosmologists studied the distribution of galaxies in space. When mapped in 3D, they were found to be assembled in a specific pattern. Clusters and superclusters tend to group in filament-like structures, condense at a center, have “walls,” and are separated by areas of voids. Galaxy clusters maintain certain distances, which in turn correspond to the predicted size of the baryons’ acoustic oscillations.
Ho’oleilana, an unexpected discovery
Hawaii scientists believe the structure found in the observatory is a new BAO. They used the Cosmicflows-4 database, the largest collection of galaxy distance information to date. Ho’oleilana has been identified since 2016 by the Sloan Digital Sky Survey project. At that time it was not given BAO status and was only described as a bowl-shaped structure. This is the first time that the total extent has been calculated and given an official designation.
Visualizing “Ho’oleilana” in three dimensions helps us understand its content and its relationship to the environment. “It was an amazing process to create this map and see how the giant shell structure of Ho’oleilana is made up of elements that have been identified in the past as some of the largest structures in the universe,” concluded Daniel Pomarede of CEA University Paris. Saclay, cartographer of the group responsible for discovering the bubble.
