Last of the ordinary matter missing from the found universe

WASHINGTON: The last tank of ordinary matter that had so far escaped detection was located in the gap between existing galaxies in the form of extremely hot gaseous oxygen filaments, say the scientists. Ordinary matter, or "baryons", make up all the existing physical objects, from stars to the nuclei of black holes.

However, until now, astrophysicists had only been able to locate about two-thirds of the material that theorists predict was created by the Big Bang.

Researchers at the University of Colorado at Boulder, United States, located the missing third, finding it in the space between galaxies. This lost material exists in the form of gaseous oxygen filaments at temperatures of about 1 million degrees Celsius, according to the study published in the journal Nature.

"It is one of the main pillars of the experimentation of the Big Bang theory, namely the baryonic census of hydrogen and helium and all the rest in the periodic table, "said Shull.

Researchers have a good idea of ​​where to find most of the ordinary matter in the universe not to be confused with dark matter, which scientists have not yet located: about 10 % are found in galaxies and nearly 60% in gas clouds that lie between galaxies. In 2012, the researchers predicted that the missing 30% of baryons were probably in a canvas-like pattern called Warm Warm Intergalactic Space (WHIM).

To search for missing atoms in this region between galaxies, the team pointed a series of satellites on a quasar called 1ES 1553, a black hole in the center of a galaxy that consumes and spits out huge quantities of gas. "It's essentially a very bright lighthouse in the space," Shull said.

Scientists can collect a lot of information by recording how the radiation of a quasar crosses the space.

First, the researchers used the Cosmic Origins spectrograph on the Hubble Space Telescope to get an idea of ​​where they could find the missing baryons. Then they settled on these baryons using the XMM-Newton satellite (X-Ray Multi-Mirror Mission) of the European Space Agency. The team found the signatures of a type of highly ionized oxygen gas located between the quasar and our solar system and at a density high enough to be extrapolated to the entire universe, accounting for 30% of ordinary matter.

"We found the missing baryons," said Shull.

Galaxies and quasars have blown this gas in deep space for billions of years. Shull added that researchers will have to confirm their findings by pointing satellites at brighter quasars.