Israeli astrophysicist says 'first concrete proof' of the existence of dark matter found

A group of astronomers came across dark matter whilst trying to detect the earliest stars in the universe. The primordial gas was colder than expected. For the Israeli researcher, this is due to the interaction with dark matter. If confirmed, the results could change the orientation of scientific research.

Jerusalem (AsiaNews/Agencies) – If correct, the insight of an Israeli astrophysicist could open a whole new window on one of the greatest mysteries of modern science: dark matter.

In an article published on Wednesday in the journal Nature, Prof Rennan Barkana of Tel Aviv University, explains how a team of astronomers, led by Prof Judd Bowman, of the University of Arizona, unexpectedly came across upon dark matter whilst using cosmic radio wave signals in an attempt to detect the earliest stars in the universe.

Recorded using the novel EDGES radio telescope in Australia, the radio signal dates to 180 million years after the Big Bang that created our universe, which occurred some 13.7 billion years ago.

This, according to Barkana, is the first direct proof of the existence of dark matter, and shows that it is composed of low-mass particles – and can interact with other forms of matter.

Bowman and his colleagues detected a radio wave signal at a frequency of 78 megahertz, which was largely consistent with expectations.

But they also found it was much stronger than predicted, indicating that the primordial gas was colder than expected, about -263 degrees, or about 10 degrees Celsius above absolute zero.

Barkana’s contribution was to propose that the gas cooled through the interaction of hydrogen with cold, dark matter long before the first stars formed.

This is the first concrete evidence of the existence of dark matter. “Once stars formed in the early universe, their light was predicted to have penetrated the primordial hydrogen gas, altering its internal structure,” Barkana writes.

The observation matches this prediction except for the unexpected depth of the absorption. Physicists expected that any such dark matter particles would be heavy, but the discovery indicates low-mass particles.

This alone has the potential or reorienting the search for dark matter. The theory now is that the behaviour of the universe can be explained by 4.9 per cent matter and energy that we know about, around 26 per cent matter that we don't know about – dark matter, and 69 per cent energy we don't know about – dark energy.

The results are very preliminary and will require many more years of follow-up work, but if they do pan out, they will change the scientific understanding of dark matter and the universe, and lead to new directions in scientific research.

• israel
• dark matter
• science
• astrophysics
• rennan barkana
• judd bowman
• tel aviv university
• university of arizona