They (lastly) discovered the lacking materials of the universe! | EUROtoday

On Jun 27, 2025

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UThe worldwide scientific group has lastly simply flushed out the strange “ghost” matter of the universe. Florian Pacaud, astrophysicist on the University of Bonn and co -author of this research revealed in Astronomy & Astrophysicsexplains to Point This discovery which resolves a thriller of a number of many years and validates our cosmological fashions.

The level: What is that this lacking materials in query in your research?

Florian Pacaud:When we are saying “normal matter”, it’s distinguished from unique substances launched in cosmology, corresponding to darkish matter or darkish vitality. It is strange matter: protons, neutrons, electrons, the kind of matter which constitutes us and which constitutes the celebs. But our cosmological fashions, which remarkably reproduce our observations, require a really exact amount of this strange materials to function. This amount is notably decided by the abundance of sunshine components – deuterium, lithium – created throughout Big Bang by nuclear response.

The drawback is that, after we observe this materials within the present universe – within the stars, the chilly fuel of galaxies, the recent fuel of galaxies -, we’re missing between a 3rd occasion and half. Since the Nineties, digital simulations have given us a believable clarification: this diffuse materials has collapsed on the filaments of the cosmic canvas, between the clusters of galaxies. By compressing herself, it was heated to very excessive temperatures and was fully ionized, which makes it nearly invisible with our common statement strategies.

How did you proceed to handle it?

It is a course of that spans a number of years, we’re not the one ones. First there have been strategies the place this materials was noticed via the absorption it produced on very shiny sources within the background. Then statistical methods the place we “stack” many filaments recognized based on the presence of galaxies clusters to extend the sign. Now we’re on the stage in detecting particular person filaments.

To obtain this, it takes devices that observe in X -rays – this extremely popular ionized plasma naturally emits on this vary, even very weakly. But the radiation is so weak that an instrument is critical that mixes good sensitivity and completely mastered instrumental background; Otherwise, errors can conceal or imitate the sign that we’re on the lookout for. In our group, we first used the German satellite tv for pc Erosita, which had the benefit of getting mapped the entire sky and a really steady background. This allowed us to publish our first particular person filament detections since 2021.

For this new research, nevertheless, we used the Japanese SUZAKU satellite tv for pc, which has this property of getting an especially properly characterised background. However, its restricted spatial decision posed an issue: different astrophysical sources may contaminate the sign. We due to this fact mixed it with Xmm-Newton, of ESA, which has an excellent angular decision and which is to this point essentially the most delicate in XMM XMM. XMM-Newton has allowed us to very exactly establish these contaminating sources-in explicit lively nuclei of galaxies-and to exclude them from the evaluation of Suzaku. It was this affiliation of the 2 satellites that allowed us to detect this new filament.

What can this discover carry to our understanding of the universe?

What is especially passable with this new filament is that it lastly validates our theoretical fashions. In our first observations of particular person filaments, we had an issue: the density and the temperature noticed have been superior to what was anticipated. It raised a vital query: had we merely noticed the poorest and hottest-so the best to detect-or have been our digital simulations false?

To uncover

The kangaroo of the day

Answer

This new filament responds to this query. It has a density a lot decrease than the others, of an element 5, it corresponds precisely to what our digital simulations count on. This means that we really solely observe the tail of the distribution, in different phrases, the exceptionally dense filaments, and that our cosmological fashions are truthful. Indeed, after we mix all observational beams of latest years, we are able to now reproduce the quantity of lacking matter. It is there, distributed in these cosmic filaments, representing 30 to 50 % of strange matter.

This analysis additionally permits us to higher perceive the cosmic canvas. With galaxies, we already observe this huge -scale construction – clusters, filaments, empty -, however the galaxies characterize solely a small fraction of the overall mass. By observing the remainder of the Baryonic matter in these filaments, we begin to have a whole mapping of matter within the universe. Unfortunately, with the judgment of Suzaku and Erosita, we are going to now have to attend for the New Athena satellite tv for pc of ESA, scheduled for 2037, to go additional and research the chemical composition of those filaments with unequaled precision.

https://www.lepoint.fr/astronomie/ils-ont-enfin-retrouve-la-matiere-manquante-de-l-univers-27-06-2025-2593122_1925.php