Using the eROSITA X-ray telescope, astronomers have spotted a filament of intergalactic matter spanning almost fifty million light-years. It is the longest ever discovered.
The distribution of matter is not uniform in the Universe. If you take a long, long step back, you will indeed notice that its structure resembles a gigantic cosmic web. In this painting, clusters of galaxies (held together by gravity) are positioned at the intersections of gigantic filaments of incandescent matter that extend into the observable Universe. For your information, note that more than half of all baryonic matter of our Universe (which makes up the stars, the planets or even yourself) is contained in these stringy structures.
That said, a team of astronomers announces that they have observed one of these filaments of matter. Details of the study can be found in the journal Astronomy &Astrophysics .
Because these structures are very stretched, the particles that compose them are incredibly diffuse, which makes them extremely difficult to spot. To give you an idea, note that these filaments only contain ten particles per m3 .
As part of this work, researchers from the University of Bonn, Germany, therefore relied on the eROSITA space telescope, an X-ray telescope built by the Max Planck Institute in Germany. " eROSITA has very sensitive detectors for the type of X-ray radiation that emanates from the gas of these filaments " , explains Thomas Reiprich, lead author of the study." It also has a wide field of vision. In fact, it is then able to capture a relatively large part of the sky in a single measurement and at a very high resolution ” .
For this research, astronomers focused on the system Abell 3391/95 . Composed of three clusters of galaxies, you will find it about700 million light-years away of the Earth.
With this instrument, they were not only able to isolate the clusters and many of the individual galaxies that compose them, but also two gas filaments connecting the two main parts of the system, of which one measures 49 million light years . It is the longest ever discovered to date.
These new observations are also consistent with the results of a simulation, developed by these same researchers and responsible for reconstructing the evolution of the Universe. “ The images of eROSITA are indeed strikingly similar to computer-generated graphics ” , points out Thomas Reichrich. " Suggesting that the widely accepted standard model for the evolution of the Universe is correct " .
