Identify the largest cluster of galaxies of the early Universe – Tiempo.hn

The early universe was a chaotic mixture of gas and matter that only began to come together to form galaxies several hundred million years after the Big Bang. They took several billions of years for these first galaxies were grouped in large clusters. Or at least that’s what scientists thought.

Now, a team of astronomers from the Massachusetts Institute of Technology (MIT), and the Universities of Florida and Missouri, have detected a huge and limp heap of galaxies that formed “only” 3,800 million years after the Big Bang. It is 10,000 million light years from Earth and is home to thousands of individual galaxies. This gigantic structure is about 250 billion times the mass of the Sun and is 1,000 times more massive than the Milky Way, our own galaxy.

The cluster, named IDCS J1426.5 + 3508 (for short, IDCS 1426) is the largest cluster of galaxies ever discovered in the first 4,000 million years after the Big Bang. These results were presented at the 227 meeting of the American Astronomical Society held in Kissimmee, Florida, and will be published in The Astrophysical Journal.

IDCS 1426 seems to be experiencing a major upheaval. Researchers have indeed seen a bright knot of X-rays, near the center of the cluster, indicating that the core light of its center some hundreds of thousands of years could have moved. Scientists believe that the core may have been evicted from their central position by a violent collision with another massive cluster of galaxies, which caused the gauze inside the core splashed around, like wine in a glass that had moved from suddenly.

Michael McDonald, MIT, believes that a collision can thus explain how IDCS 1426 could form so quickly in the early universe, in an era in which even if individual galaxies were just beginning to take shape.

“In the grand scheme of things probably assures McDonald- galaxies began to form not until the universe was relatively cold, and yet this’cosa’ suddenly emerged and Little time. Our guess is that another massive cluster similarly appeared on the scene and changed everything. Which would explain why (IDCS 1426) is so massive and grew so rapidly. Basically, it is the first in line. “

Cities in space

The galaxy clusters are conglomerations of hundreds (even thousands) of individual galaxies They stay together due to gravity. They are the largest structures of matter in the universe and those closest to us, as the Virgo cluster, are extremely bright and easy to locate in the sky.

“They are like a kind of cities in the space in which all these galaxies live side by side McDonald- explains. In the nearby Universe, if you see a cluster is as if you had seen all, and they all have a similar appearance. But the farther you look more differences begin to appear. “

However, the search for galaxy clusters that are far removed in space and time, is a difficult and full of uncertainties task. In 2012, a group of NASA researchers, using the Spitzer Space Telescope detected the first signs of IDCS 1426 and undertook the first estimates of its mass. “We then had the basics of how massive it was and how far it was McDonald- recalls but we were not entirely convinced. These new results are’clavo in ataud’ and proof that it was really what we suspected. “

For a more precise mass of the galaxy cluster, McDonald and his colleagues used data from estimate several major NASA observatories, including the Hubble Space Telescope, the Keck Observatory and the Chandra X-ray telescope. “Basically explains the researcher used three different methods to weigh the cluster.”

Both Hubble and Keck observatories recorded the optical data, the researchers analyzed in detail to determine the amount of light that curved around the cluster due to gravity, a phenomenon called “gravitational lensing.” The higher it is an accumulation, plus gravity exerts on its surroundings and the greater the curvature of light rays that pass near it.

With the space telescope Chandra, scientists examined data from the X-ray have an estimate of the prevailing temperature in the cluster. The objects at very high temperatures emit X-rays, and the hotter a mass, more gas is compressed inside, making it more massive. From the data of X, McDonald and his team-rays also calculated the amount of gas present in IDCS 1426, which is an indication to also know the amount of matter and its mass.

Zone works

Using the three methods, the team reached with each of them, practically the same results. about 250 billion times the mass of the Sun. Now, researchers try to identify individual galaxies within the cluster to try to understand how this huge mega-structure was able to be formed in the early universe.

“This cluster is a kind of jobsite declares McDonald- . It’s dirty, noisy and full of things incomplete. But observe what is incomplete is precisely the way to get an idea of ​​how clusters grow. So far, only if we have located a dozen individual galaxies, but this is just the beginning, the tip of the iceberg “.

McDonald hopes that things will change with the launch, in 2018, the James Space Telescope Webb, an instrument that operates in the infrared and is hundreds of times more sensitive than current Spitzer, with which the cluster was discovered.