In a recent astronomical breakthrough, scientists have unveiled a colossal cluster of galaxies that may hold clues to the birth of our universe, often referred to as the Big Bang.
This expansive celestial formation, known as “Ho’oleilana,” can be found roughly 820 million light-years away from our home planet. What’s truly mind-boggling is its staggering width, spanning an astonishing one billion light-years. To put it simply, it’s an unimaginably vast expanse in the cosmos.
The name “Ho’oleilana” draws its inspiration from the Hawaiian creation chant called Kumulipo. This chant tells the story of how the cosmos and everything within it came into existence, including stars and the moon.
Baryon Acoustic Oscillations
Huge formations like Ho’oleilana are expected to form in the universe due to tiny ripples that once existed in the early universe. Think of it as the universe’s starting point when everything was hot, dense, and mostly even.
These ripples in density are called Baryon Acoustic Oscillations, or simply BAOs. They are like tiny waves in a cosmic sea. These waves got bigger as the universe went through a super-fast expansion phase known as the Big Bang. As they grew, they played a key role in shaping significant cosmic structures and how galaxies are spread out in space.
Ho’oleilana is the very first example we’ve found of a massive structure directly linked to one of these Baryon Acoustic Oscillations. It’s like discovering the missing puzzle piece that helps us understand how the universe’s grand structures came to be.
Group of clusters of galaxies
The bubble is actually made up of structures we’ve known about before, and these are some of the most enormous gatherings of stuff in the whole universe. These structures include what we call superclusters, which are groups of clusters of galaxies.
Imagine a supercluster as a big family of galaxies. Each of these superclusters contains about 10 galaxy clusters, and they stretch across an incredible distance of up to 200 million light-years.
Right at the center of this bubble is something called the Bootes supercluster, and it’s surrounded by what we call the Bootes void. This void is basically a massive empty space in the universe, and it is 330 million light-years wide.
The bubble was so incredibly huge that it spilled over the area of the sky we were studying. Brent Tully, the leader of the study and an astronomer from the University of Hawaii, said, “We were not looking for it. It is so huge that it spills to the edges of the sector of the sky that we were analyzing.”
He also pointed out that this bubble is a lot more powerful and way bigger than we ever expected. Its diameter is a staggering one billion light-years, which is way beyond what the smart folks in theory-land thought was possible.
Astronomers discover the 1st 'bubble of galaxies', 10,000x wider than the Milky Way. Named Ho'oleilana, it's a fossil-like remnant of the Big Bang, 820 million light years away. 🔭💥 pic.twitter.com/rB4Zs9kopN
— CuriosityMint (@curiositymint) September 8, 2023
Beginning of the universe
Roughly 380,000 years after the universe began, space was a bustling, hot place. It was filled with tiny particles called electrons and protons. When these particles cooled down a bit, they stuck together to form atoms, just like the ones we’re made of.
At the same time, some places in space became crowded and started collapsing under their own gravity. But there was a twist – there was also something pushing things apart, like a cosmic tug of war. This back-and-forth action caused the plasma to create ripples that spread out in space.
The size of the largest ripples depended on how fast sound could move through that plasma-filled space. And guess what? These ripples turned out to be about 500 million light-years wide. When the plasma cooled down, it left behind these enormous 3D ripple marks, much like footprints in the cosmic sand.
As the universe continued to age after the Big Bang, galaxies started appearing in places where many other galaxies already existed. These gatherings of galaxies formed large bubble-like spaces.
Here’s why this is important: by examining how galaxies are spread out in these bubbles, we can learn more about those ripples we mentioned earlier – the Baryon Acoustic Oscillations (BAOs). It’s akin to reading the universe’s story by observing how galaxies huddle together.
In 2014, the same group of scientists pinpointed something called the Laniakea Supercluster. It’s a place where our Milky Way resides, along with roughly 100,000 other galaxies.
Surprisingly, the Laniakea Supercluster is only about 500 million light-years wide, which is just half the width of Ho’oleilana, the massive cosmic structure we’re talking about. The Laniakea Supercluster stretches all the way to the edge of this larger cosmic bubble.
Researchers had found signs of Ho’oleilana before. Back in 2016, the Sloan Digital Sky Survey identified a part of its shell-like shape. However, the true size of this cosmic bubble remained hidden until now.
Daniel Pomarede, a researcher at CEA Paris-Saclay University and the group’s mapmaker, stated, “I am the cartographer of the group, and mapping Ho’oleilana in three dimensions helps us understand its content and relationship with its surroundings.”
He further said, “It was an amazing process to construct this map and see how the giant shell structure of Ho’oleilana is composed of elements that were identified in the past as being themselves some of the largest structures of the universe.”