The Search for the Missing Baryons

🌟The missing baryons refer to the ordinary matter that should make up 5% of the universe but was only found to be 2.5%. This is known as the missing baryon problem.

🔭Fast radio bursts (FRBs) are intense pulses of radio waves that come from galaxies far away. By analyzing their dispersion, astronomers can estimate the amount of ionized baryons in the universe.

🌌The warm-hot intergalactic medium (WHIM) is a sparsely spread ionized region between galaxies. It accounts for approximately 50% of the missing baryons.

📈Computer simulations run decades ago accurately predicted the location of the missing baryons in the WHIM, validating the scientific understanding of the distribution of baryonic matter.

🧪The finding highlights the inefficiency of the formation of stars and galaxies, as only a small percentage of the ordinary matter from the Big Bang ends up in these structures.

What are baryons?

—Baryons are the ordinary matter particles made up of protons and neutrons, which include everything we can see.

What are fast radio bursts (FRBs)?

—Fast radio bursts are short-duration pulses of intense radio waves that come from other galaxies. The cause of these bursts is still unknown.

What is the warm-hot intergalactic medium (WHIM)?

—The WHIM is an ionized region between galaxies that consists of sparsely spread particles with temperatures between 100,000 and 10 million Kelvin.

How did scientists estimate the missing baryons using fast radio bursts?

—Scientists measured the dispersion of fast radio bursts and correlated it with the redshift of their host galaxies. This allowed them to estimate the total baryonic matter, including the ionized particles in the WHIM.

What does this finding reveal about the formation of stars and galaxies?

—The finding shows that the formation of stars and galaxies is an inefficient process, as only a small percentage of the ordinary matter from the Big Bang ends up in these structures.

00:00Half the universe's ordinary matter, known as baryons, has been missing.

10:51Using fast radio bursts (FRBs) from galaxies far away, scientists estimated the amount of ionized baryons in the universe.

11:53Approximately 50% of the missing baryons were found in the warm-hot intergalactic medium (WHIM) between galaxies.

13:45The research validates previous computer simulations and highlights the inefficiency of star and galaxy formation.

14:02This finding challenges the perception that most of the ordinary matter from the Big Bang ends up in stars and galaxies.