A new study published in the journal Nature explains how a group of astronomers accidentally discovered dark matter while out searching for the earliest stars of the universe. The team was led by Prof. Judd Bowman of Arizona State University.





A second paper recently published in Nature suggests that the signal detected by the Arizona group is proof that interactions between the dark matter of today and the dark matter of the early universe do take place. This paper was published by Prof. Rennan Barkana of Tel Aviv University.

“Dark matter is the key to unlocking the mystery of what the universe is made of”, says Prof. Barkana, Head of the Department of Astrophysics at TAU’s School of Physics and Astronomy. “We know quite a bit about the chemical elements that make up the earth, the sun, and other stars, but most of the matter in the universe is invisible and known as dark matter.”

The radio wave signal that was detected by Prof. Bowman and colleagues measured in at a frequency of 78 megahertz. While they found it to be a similar width to what they’d expected, they found it had a larger amplitude than predicted. This was an indication that the primordial gas was much colder than predicted. Prof. Barkana suggests that could be because of the interaction between hydrogen and dark matter. “I realized that this surprising signal indicates the presence of two actors: the first stars, and dark matter,” he says. “The first stars in the universe turned on the radio signal, while the dark matter collided with the ordinary matter and cooled it down. Extra-cold material naturally explains the strong radio signal.”





From what’s previously been learned about dark matter, physicists were expecting the dark matter particles to be heavy, but they were in fact very low in mass. However, Prof. Barkana argues that, based on the radio signal, dark matter particles are not as heavy as once suggested. “This insight alone has the potential to reorient the search for dark matter,” says Barkana.

According to Barkana, dark matter produces a unique pattern of radio waves that can be picked up by a large array of radio antennas such as the SKA which is under construction at this very moment. “Such an observation with the SKA would confirm that the first stars indeed revealed dark matter,” says Prof. Barkana.

Related Links;





More News to Read

Comments

comments