The GRANTECAN discovers the largest cluster of galaxies known in the early universe


Share post:

A study, led by researchers at the Instituto de AstrofĂ­sica de Canarias (IAC) and carried out with OSIRIS, an instrument on the Gran Telescopio Canarias (GTC), has found the most densely populated galaxy cluster in formation in the primitive universe. The researchers predict that this structure, which is at a distance of 12.5 billion light years from us, will have evolved becoming a cluster similar to that of Virgo, a neighbour of the Local Group of galaxies to which the Milky Way belongs. The study is published in the specialized journal Monthly Notices of the Royal Astronomical Society.

The GRANTECAN discovers the largest cluster of galaxies known in the early universe
The studied galaxy cluster in formation, 12.5 billion light years from us. The circles indicate the new
 members discovered with the GTC, 4 of them are shown in detail [Credit: NASA/ESA/GOODS-
N+3DHST+CANDELS Team/Daniel Lopez/IAC]

Clusters of galaxies are groups of galaxies which remain together because of the action of gravity. To understand the evolution of these “cities of galaxies” scientists look for structures in formation, the so-called galaxy protoclusters, in the early universe.

In 2012 an international team of astronomers made an accurate determination of the distance of the galaxy HDF850.1, known as one of the galaxies with the highest rate of star formation in the observable universe. To their surprise, the scientists also discovered that this galaxy, which is one of the most studied regions on the sky, known as the Hubble Deep Field/GOODS-North, is part of a group of around a dozen protogalaxies which had formed during the first thousand million years of cosmic history. Before its discovery only one other similar primordial group was known.

Now, thanks to a new piece of research with the OSIRIS instrument on the Gran Telescopio Canarias (GTC, or GRANTECAN), the team has shown that it is one of the most densely populated regions populated with galaxies in the primitive Universe, and have for the first time carried out a detailed study of the physical properties of this system. “Surprisingly we have discovered that all the members of the cluster studied up to now, around two dozen, are galaxies with normal star formation, and that the central galaxy appears to dominate the production of stars in this structure” explains Rosa Calvi, formerly a postdoctoral researcher at the IAC and first author of the article.

Witnesses to the infancy of the local Universe

This recent study shows that this cluster of galaxies in formation is made up of various components, or “zones” with differences in their evolution. The astronomers predict that this structure will change gradually until it becomes a galaxy cluster similar to Virgo, the central region of the supercluster of the same name in which is situated the Local Group of galaxies to which the Milky Way belongs. “We see this city in construction just as it was 12,500 million years ago, when the Universe had less than 10% of its present age, so we are seeing the childhood of a cluster of galaxies like those which are typical in the local Universe” notes Helmut Dannerbauer, an IAC researcher who is co-author of this article.

The GRANTECAN discovers the largest cluster of galaxies known in the early universe
Gran Telescopio Canarias [Credit: Daniel Lopez/IAC]

The distance measured to these studied sources agrees perfectly with the predictions based on photometric observations taken previously on GRANTECAN by Pablo Arrabal Haro, formerly a doctoral student at the IAC, supervised by JosĂ© Miguel RodrĂ­guez Espinosa, an IAC researcher and Assistant General Secretary of the International Astronomical Union (IAU), and Casiana Muñoz-Tuñón, a researcher and Deputy Director of the IAC, all of them co-authors of the present article. Arrabal developed a method for selecting galaxies with normal star formation rates, based on the photometric survey SHARDS (Survey for High-z Absorption Red and Dead Sources), a Large Programme of the European Southern Observatory (ESO) carried out on the GTC. “I am very happy to see that the method developed during my doctoral thesis works so well in finding and confirming a region highly populated with galaxies in the distant Universe” states Arrabal.

The SHARDS programme has been led by Pablo PĂ©rez-GonzĂĄlez, researcher at the Centro de AstrobiologĂ­a (CAB, CSIC-INTA) and also author of the paper. As PĂ©rez-GonzĂĄlez explains, “measuring exactly how these structures are forming, especially at the beginning of the Universe, is not easy, and we need exceptional data such as those we are taking with the GTC telescope as part of the SHARDS and SHARDS Frontier Fields projects, which allow us to determine distances to galaxies and between galaxies at the edge of the Universe with a precision never achieved before.”

In addition, Stefan Geier, GTC support astronomer and co-author of the paper points out that “this highly surprising result would not have been possible without the extraordinary capacity of OSIRIS together with the large colllecting area of the GRANTECAN, the largest optical and infrared telescope in the world.”

The Gran Telescopio Canarias and the Observatories of the Instituto de AstrofĂ­sica de Canarias (IAC) are part of the network of Singular Scientific and Technical Infrastructures of Spain.

Source: Instituto de AstrofĂ­sica de Canarias [February 26, 2021]

Support The Archaeology News Network with a small donation!



Related articles

Mysterious 'Galaxy X' around Milky Way may soon be found

A dwarf galaxy that is too dim to see but is suspected to orbit our own Milky Way...

Tune your radio: Galaxies sing when forming stars

A team led from the Instituto de AstrofĂ­sica de Canarias (IAC) has found the most precise way ever...

Viking Landers found organics on Mars, experiment confirms

More than 30 years after NASA's Viking landers found no evidence for organic materials on Mars, scientists say...

Iron integral to the development of life on Earth – and the possibility of life on other planets

Iron is an essential nutrient that almost all life requires to grow and thrive. Iron's importance goes all...

Seeds of giant galaxies formed in the early universe

An international research team has shown that the largest galaxies in the Universe may have started out as...

Black holes like to eat, but have a variety of table manners

All supermassive black holes in the centers of galaxies appear to have periods when they swallow matter from...

Pressure runs high at edge of solar system

Out at the boundary of our solar system, pressure runs high. This pressure, the force plasma, magnetic fields...

Powerful new tool for looking for life beyond Earth

NASA has developed an innovative new spectroscopy instrument to aid the search for extraterrestrial life. The new instrument...