Physicists discover the oldest dark matter to date using microwaves

The Hubble telescope image shows a gravitational lensing next to a filter image showing where dark matter is likely to be.

Researchers have just studied the lens of the oldest light we can see and discovered the oldest dark matter observed so farsurrounding galaxies that are 12 billion years old.

They discovered this dark matter by looking at how some galaxies distort the light of the cosmic microwave background, the oldest detectable radiation just after the Big Bang, which unleashed the universe as we know it. Team research is published In physical review letters.

“Most researchers use source galaxies to measure the distribution of dark matter from the present to eight billion years ago,” said Yuichi Harikan, an astronomer at the University of Tokyo’s Cosmic Ray Research Institute and co-author of the latest paper. Nagoya University Release. However, we can look back further because we used the farthest CMB to measure dark matter. For the first time, we’ve been measuring dark matter from roughly the very first moments of the universe.”

Dark matter makes up about 27% of the universe, although we cannot detect it directly. Since we don’t know what it is, dark matter is really an umbrella term for this unknown mass, which we see on massive scales thanks to its gravitational effects.

An illustration of how dark matter distorts light from the cosmic microwave background.

Some of the main candidates for dark matter are Small particles called WIMPs (double massive particle interaction) and Even more small particles are called axions; It is entirely possible that both WIMPs and axions form dark matter. Searches for dark matter Ongoing, but in the meantime, astronomers can search and see its effects at huge scales.

The dark matter acts as a kind of invisible glue, Groups of galaxies together. It also acts as a lens for far light, Zoom in on old things for our observation. As much as it is a mystery, dark matter is also a boon for studying the early universe.

For this reason, when The Webb Telescope recently imaged the galaxy cluster SMACS 0723was actually looking for all the ancient galaxies zoomed in by SMACS 0723, including the oldest galaxy seen so far, which formed 300 million years after the Big Bang.

Previous work has generally looked at shorter wavelengths through a gravitational lens, Mostly objects in visible and infrared wavelengths. But the light we see from the cosmic background – the oldest light we see – is in the microwave portion of the electromagnetic spectrum. This ultra-high-energy light started out but has been stretched over time by the expansion of the universe, and today we see it just a faint glow from the microwave.

In recent work, researchers identified 1.5 million lens galaxies in visible light. Then they looked at them with a telescope that sees microwave light – the European Space Agency’s Planck satellite – and measured how much dark matter around nearby galaxies distorted ancient microwave light.

Cosmic microwave background and satellite Planck.

Study co-author Nita Bahkal, an astronomer at Princeton University, said in the same issue.

The team also found that dark matter in certain regions of space was less lumpy than it should be according to the standard theory of cosmology.

“Our discovery remains uncertain,” Hironao Miyatake, an astronomer at Nagoya University and lead author of the research paper, said in the statement. “But if true, it suggests that the entire model is flawed and you go back in time. This is exciting because if the result persists after uncertainties are reduced, it could indicate an improvement to the model that may provide insight into the nature of dark matter itself.”

In the future, data from the upcoming Rubin Observatory will help by accurately imaging large swaths of the night sky that makes it easier to see more ancient parts of space.

MORE: The world’s largest digital camera is almost ready to go back in time