Gamma-ray bursts show that the universe's greatest structure is closer to Earth and larger than previously thought: "The meaning of this is still up for debate.

The Hercules-Corona Borealis Great Wall, the largest structure in the universe, was already difficult to explain with models of the universe because of its enormous size. Now, astronomers have found that the structure is even larger than they previously thought thanks to Gamma-Ray Bursts (GRBs), the universe's most potent energy explosions. Additionally, the scientists discovered that portions of the Great Wall of Hercules-Corona Borealis are actually closer to Earth than previously thought.

The Corona Borealis and Hercules The initial galaxies in the universe congregated and expanded around the Great Wall, a filament of the cosmic web that is known as a "supercluster" of galaxies. Johndric Valdez, a teenage Filipino who wants to become an astronomer, came up with the name. But that's not a very literal name. This is due to the fact that the spherical Great Wall encompasses not only the Hercules and Corona Borealis constellations but also the area of the celestial sphere that extends from Boötes to Gemini.

István Horváth, Jon Hakkila, and Zsolt Bagoly headed the team that made the first discovery of the Hercules-Corona Borealis Great Wall in 2014. They also lead the team that has now more precisely measured the structure's dimensions than ever before. Specifically, the group discovered that it covers a wider radial range than was previously estimated. Prior to this study, scientists were unaware that this vast structure also includes some nearby gamma-ray bursts.

The discovery is remarkable since it was previously known that the Hercules-Corona Borealis Great Wall covered an area that was over 1 billion light-years thick and 10 billion light-years wide by 7.2 billion light-years. To put that in perspective, that is enough space to accommodate more than 94,000 Milky Way galaxies arranged side by side along the longest side of the Great Wall, which makes up around 10% of the entire observable universe's breadth.

The University of Alabama in Huntsville's Jon Hakkila told Space.com, "The most interesting finding is that the closest parts of the Hercules-Corona Borealis Great Wall lie closer to us than had previously been identified, since the most distant extent is hard to verify."

The Hercules–Corona Borealis Great Wall dwarfs the Milky Way, our home galaxy, which is a part of a separate supercluster named Laniakea, which is 500 million light-years wide. Actually, according to the team, it is currently unknown how much of the latter structure there is.

"Our gamma-ray burst sample is not large enough to place better upper limits on the maximum size of the Hercules-Corona Borealis Great Wall than we already have," Hakkila stated. However, it very likely stretches beyond the 10 billion light-years that we had previously determined. It is bigger than the majority of things that may be compared to it.

How gamma-ray bursts can be used a a measuring tool

GRBs played a crucial role in the 2014 discovery of the Great Wall of Hercules-Corona Borealis and, more recently, in the more thorough study of this enormous cosmic structure. Two distinct forms of GRBs are believed to come from two mechanisms of stellar-mass black hole development, making them the universe's most bright and intense explosions, according to Hakkila.

High-energy gamma ray bursts lasting more than two seconds are known as long-duration GRBs, and they are produced when the core of large stars collapses, resulting in a supernova explosion. However, in double-star systems, short-duration GRBs are believed to be the result of the collision and merger of two ultradense stellar remnants known as neutron stars.

"The enormous energies created by the star system's collapse are released in both situations as relativistic particle jets. The particles react to produce X-rays and gamma-rays far from a jet's nozzle," Hakkila stated. "Gamma-ray bursts can be seen at incredibly large distances because they are so luminous."

According to Hakkila, gamma-ray bursts can also serve as indicators of the location of galaxies because they are associated with dying stars or the collision of two dead stars, and stars are found in galaxies. GRBs are so bright that they can reveal the existence of a galaxy even when it is too faint to be observed.

"The tremendous brightness of gamma-ray bursts allows them to be markers of where matter can be found in the universe," Hakkila said.