The matter and dark energy are some of the great mysteries that astrophysicists, physicists and astronomers are still trying to solve. As we know, the Universe is rich in various types of structures (from galaxies to black holes) but still now the 95% of matter and energy escapes the eyes of the instruments. Part of the matter may be hidden in gigantic cosmic filaments .

On the left a computer simulation, on the right the actual observation of eROSITA

Could cosmic filaments solve one of the mysteries of the Universe?

The University of Bonn recently published a new study that may have found part of that 95% which is missing from our conventional observation. As always, a single study is not enough to answer complex questions, but more evidence will be needed in the future. Despite everything, what the German astrophysicists did deserves a read.

According to what reported, part of the matter that we usually do not see would be enclosed in gigantic cosmic filaments made up of extremely hot gas that surround and unite galaxies or clusters of galaxies. German scholars have observed one of these filaments with a length of well 50 millions of light years (the Milky Way should have a diameter of 160 thousand light years).

The explanation given ( and which seems to agree with computer simulations) is that after the Big Bang the expansion of the gas had an almost uniform distribution. That “almost” allowed the formation of areas with a slightly higher density which then led to stars, galaxies, planets and the Universe that we know.

It is theorized, however, that “in the course of well 13 billions of years a kind of spongy structure has developed: large holes devoid of matter, with intermediate areas in which thousands of galaxies are gathered in a small space, the so-called clusters of galaxies “. These structures would in turn be connected by cosmic filaments which could contain more than half of the baryon matter of the Universe .

On the right the computer simulation, on the right the observation of eROSITA

Huge but elusive filaments in the Universe

How come it was not possible to see all this matter even with very sophisticated instruments? The explanation would be given by the fact that in all this time the particles would have been “diluted” in the cosmic void (approx. 10 particles / m ³ ). This complicated its identification.

Thanks to eROSITA, however, it was possible to find traces of this very diluted but also very common gas. This probe was placed in L2 (second Lagrange point), observe the X-rays up to 10 keV . It also uses a wide-angle lens to allow you to frame a large portion of the sky at once.

eROSITA was aimed in the area of ​​ Abell 3391 / 95 where there are three clusters of galaxies a 700 millions of light years from Earth. Thanks to the large viewing angle you can frame large objects. As written above, the comparison between computer simulation and instrument images gave very similar results. However, this is only part of the puzzle and we will have to wait for further confirmation before having a final answer.