Science. – Missing baryonic matter is hidden between galaxies as a gas

Madrid, 25 (Europe Press)

A new astrophysical technique has discovered that the missing baryonic matter in the universe is found filling the intergalactic void in the form of low-density hot gas.

Scientists estimate that dark matter and dark energy account for 95% of the universe and that the remaining 5% is made up of baryonic matter, that is, the ordinary matter from which living things, planets, and stars are made. However, for decades, nearly half of this issue wasn’t found either.

According to the report of the Canary Islands Astronomical Institute (IAC), which was involved in the discovery, to design the new technology, changes in the electromagnetic spectrum of galaxies, and their redshift caused by the redness of light coming from, the galaxies moving away from us were analyzed.

In the universe, sources that move away from the spectrum appear redder, and those that approach us the most are blue. This process was essential to the development of modern cosmology. Nearly a hundred years ago, Edwin Hubble discovered that the redshift of galaxies increases with their distance, providing the first observational support for the Big Bang theory. Since then, redshift has been used to map the distances of galaxies and create 3D maps of their densities in the universe.

On this occasion, a new methodology has been developed that studies the statistics of redshift maps of galaxies, ignoring the transformation into distances. In the first work, the team showed that these maps are sensitive to the gravitational pull between galaxies on cosmic scales. In another case, the same team compares these maps with observations of the cosmic microwave background radiation, and is able to make a complete count of ordinary matter for 90% of the life of the universe.

“Most ordinary matter is invisible to us because it is not hot enough to emit energy. However, using redshift maps of galaxies, we found that all of this matter fills the space between galaxies.” Explains Jonas Chaves Monteiro, researcher at the Donostia International Center for Physics (DIPC) and lead author of this work.

Finally, in a third study, the researchers also used redshift maps of galaxies to study the nature of gravity. “Unlike previous methods, our new method does not rely on any remote redshift transformation and is robust against noise and impurities in the data. As a result, it allows us to conclude with great accuracy that the observations are compatible. With Einstein’s theory of gravity,” says Carlos Hernández -Monteagudo, IAC researcher and lead author of this article.

All three studies have been published in the Monthly Notices of the Royal Astronomical Society (MNRAS).