Using XMM space telescope that is capable of detecting signatures of extremely hot gasses, researchers from the University of Geneva examined Abell 27444 which is a large cluster of galaxies with an unusual distribution of luminous dark matter at its center. Although ordinary matter makes up only 5 percent of the universe and approximately half of this amount, the “missing baryons”, has eluded the detection of scientists thus far, the study found that the rest of this percentage is in the form of a “cosmic web” of hot gas that associates with intergalactic filaments that exist at temperatures between 100,000 and 10 million degrees. As well as galaxies, they contain large amounts of hot gas and even larger amounts of invisible dark matter.
The object that the researchers studied during their study is Abell 2744, which has been nicknamed as the Pandora Cluster. In order to understand the origin of this formation, it was vital to discover in what form and where the ordinary matter that we do not perceive – known as the “missing baryons” – is found. To do this, the astrophysicists from UNIGE and the Ecole polytechnique fédérale de Lausanne (EPFL) took an interest in Abell 2744, a massive cluster of galaxies with a complex distribution of dark and luminous matter at its center. It is composed of at least four smaller components that are merging.
The team, from the Institute for Computational Cosmology, said its findings helped confirm its theories about how structures form in the universe. The discovery came after almost nearly 30 hours of observation by the observatory.
The Durham University staff belonged to a worldwide group of experts who spotted three massive filaments containing gas in the web that is believed to link galaxies and galaxy clusters together across the universe.
In the end, the researchers measured for the first time ever the temperature and density of these filaments.
In the past few decades, astronomers have detected the threadlike structure of the Cosmic Web in the large-scale distribution of galaxies and found hints that diffuse gas is arranged in a similar way.
The researchers observed this cluster with the XMM space telescope in order to detect very hot gas. He added that we must now verify that Abell 2744’s missing baryons, presently discovered are applicable to the whole universe. The findings also validated earlier predictions that mysterious percentage of the ordinary matter is comprised in a “cosmic web”, says the lead researcher Dominique Eckert.
For more in-depth investigations, astronomers will have to wait for ESA’s Athena X-ray telescope, planned for launch in 2028.
This work is based on X-ray data collected with ESA’s XMM-Newton X-ray observatory and on optical observations from the NASA/ESA Hubble Space Telescope, the CanadaFranceHawaii Telescope and the European Southern Observatory’s 2.2 m-diameter telescope.
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