(ORDO NEWS) — One of the most difficult space puzzles was used to explore another. Astronomers used powerful bursts of radio waves traced from distant galaxies to explore the space between stars – and discovered where the missing matter of the Universe is hiding.
In the vast voids that extend between the galaxies, gas is so rarefied that it cannot be detected by other instruments.
From measurements, astronomers have found that extremely rarefied gas can make up all the missing “normal” matter in the universe.
“The discovery of fast radio bursts and their localization in distant galaxies were key discoveries needed to solve this mystery,” said astronomer J. Xavier Prochaska of the University of California at Santa Cruz.
The problem of lack of matter has long puzzled astronomers. We approximately know the material and energy composition of the Universe. About 68 percent of the universe is dark energy, and 27 percent is dark matter. This is something we cannot directly detect (nor do we know what it is at all).
The remaining 5 percent is what we can detect – normal or baryonic matter, consisting of baryonic particles. Stars, planets, nebulae, plasma, even black holes – all this consists of baryonic matter. People from baryonic matter. This is the building block of everything we can see.
The radiation left over from the Big Bang, which can be found throughout the Universe – the cosmic microwave background – allows us to find out how much baryonic matter was in the early Universe. But a few decades ago, when astronomers began comparing these values with baryonic matter, which we can find now, they found only about half of the matter.
Where the rest went was a mystery. Methods such as analyzing light propagating from distant quasar galaxies have revealed very specific small amounts of atomic hydrogen.
“The intergalactic space is very rarefied. The missing substance was equivalent to only one or two atoms in a room the size of a middle office, ”explained astronomer Jean-Pierre Macquart of Curtin University, Australia, International Center for Radio Astronomy Research.
“So it was very difficult to detect it using traditional methods and telescopes.”
This is a place where astronomers come to the aid of fast radio bursts. Extremely powerful bursts of radio waves from deep space, erupted by radiation equivalent to hundreds of millions of Suns, packed in a period of time of only milliseconds. Most of them flare up at a time. Thus, they are extremely difficult to predict and difficult to localize.
We do not know what it is (although evidence increasingly points to magnetars as one of the reasons), but only last year did astronomers figure out and specify how to track the source of radio bursts.
This means that we can calculate the distance that they have covered. In turn, whether we know what makes them or not, bursts have become a valuable tool for exploring outer space.
This is because we know that radiation leaves its source in the form of a compact beam over the entire radio spectrum. But when it reaches the Earth, the signal is stretched, and some wavelengths reach fractions of milliseconds. This can be analyzed in the context of the distance traveled to calculate how much matter the signal has traveled to create the resistance needed for such a wavelength dispersion.
The team used this technique on a number of such recently localized signals of fast radio bursts, some of which are located at a distance of billions of light years, to calculate the gas content in the intergalactic medium.
There are not enough radio signals to determine the composition of matter (probably mainly hydrogen and helium), but the amount of matter corresponded to the amount of matter predicted from measurements of the cosmic microwave background.
This is an amazing result, the best proof that the missing matter is hiding in space, which is not so empty. But there is still a lot of work ahead. This result is based on several signals – analysis of a larger number of them will help to more fully characterize the issue, providing not only detection, but also the location and mode of propagation of matter.
Where the missing substance is most concentrated — around or far away from the galaxies — it can provide important information that will help us understand how the universe evolved.
Contact us: [email protected]