IDCS J1426.5+3508 (IDCS 1426 for short) is an extremely massive young

galaxy cluster A galaxy cluster, or a cluster of galaxies, is a structure that consists of anywhere from hundreds to thousands of galaxies that are bound together by gravity, with typical masses ranging from 1014 to 1015 solar masses. They are the second-lar ...

. It is the most massive galaxy cluster detected at such an early age. This rare galaxy cluster, which is located 10 billion light travel distance years from Earth, weighs almost 500 trillion

Sun The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radi ...

s. This object has important implications for understanding how these mega-structures formed and evolved early in the

Universe The universe is all of space and time and their contents, including planets, stars, galaxies, and all other forms of matter and energy. The Big Bang theory is the prevailing cosmological description of the development of the universe. ...

Astronomer An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They observe astronomical objects such as stars, planets, moons, comets and galaxies – in either ...

s have observed IDCS 1426 when the universe was less than a third of its current age. First discovered by the Spitzer Space Telescope in 2012, IDCS 1426 was then observed using the

Hubble Space Telescope The Hubble Space Telescope (often referred to as HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the first space telescope, but it is one of the largest and most vers ...

and the

Keck Observatory The W. M. Keck Observatory is an astronomical observatory with two telescopes at an elevation of 4,145 meters (13,600 ft) near the summit of Mauna Kea in the U.S. state of Hawaii. Both telescopes have aperture primary mirrors, and when co ...

to determine its distance. About 90% of the mass of the cluster is in the form of dark matter, the substance that has been detected only through its gravitational pull on normal matter composed of atoms. There is a region of bright

X-ray An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10 picometers to 10 nanometers, corresponding to frequencies in the range 30&nb ...

emission near the middle of the cluster, but not exactly at the center. The location of this “core” of gas suggests that the cluster had a collision or interaction with another massive system of galaxies, perhaps within about the last 500 million years. This would cause the core to become offset. IDCS 1426 is being observed from when the Universe was only 3.8 billion years old. For an enormous structure to form rapidly, mergers with smaller clusters would likely play a role in a large cluster’s growth. This core, while still extremely hot, contains cooler gas than its surroundings. This is the most distant galaxy cluster where such a “cool core” of gas has been observed. These cool cores are important in understanding how quickly hot gas cools off in clusters, influencing the rate of stars at which stars are born. This cooling rate can be slowed by outbursts from a

supermassive black hole A supermassive black hole (SMBH or sometimes SBH) is the largest type of black hole, with its mass being on the order of hundreds of thousands, or millions to billions of times the mass of the Sun (). Black holes are a class of astronomical ob ...

in the center of the cluster. Apart from the cool core, the hot gas in the cluster is remarkably symmetrical and smooth. This is another piece of evidence that IDCS 1426 formed very rapidly and quickly in the early Universe. Despite the high mass and rapid evolution of this cluster, its existence does not pose a threat to the standard model of cosmology.

References

{{2016 in space IDCS 1426 Boötes