Researchers have just studied the oldest lensing of light we can see and discovered the oldest dark matter ever observed.surrounding galaxies 12 billion years old.
They detected this dark matter by looking at how some galaxies warp light from the cosmic microwave background, the earliest detectable radiation just after the Big Bang, which started the universe as we know it. The team’s investigation 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 Harikane, an astronomer at the University of Tokyo Cosmic Ray Research Institute and co-author of the recent paper. at a university in nagoya release. “However, we could look further back into the past because we use the more distant CMB to measure dark matter. For the first time, we were measuring dark matter from almost the earliest moments of the universe.”
Dark matter makes up about 27% of the universe., although we cannot detect it directly. Because we don’t know what it is, dark matter is really a general term for this unexplained mass, which we see on massive scales thanks to its gravitational effects.
Some prime candidates for dark matter are small particles called WIMPs (weakly interacting massive particles) and even smaller particles called axions; it is entirely possible that both WIMPs and axions constitute dark matter. dark matter searches they are ongoing, but in the meantime, astronomers can look up and see their effects on huge scales.
Dark matter acts as a kind of invisible glue, holding galaxy clusters together. It also acts as a lens for more distant light, magnifying glass of ancient objects for our observation. As much of an enigma as it is, dark matter is also a boon to studying the early universe.
That’s why when the The Webb telescope recently captured an image of the galaxy cluster SMACS 0723it was actually looking at all the oldest galaxies magnified 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 gravitational lensing, mostly objects in visible and infrared wavelengths. But the light we see from the cosmic background, the oldest light we can see, is in the microwave portion of the electromagnetic spectrum. This light started out ultra-energetic, but spread over time by the expanding universe, and today we see it simply as a faint microwave glow.
In the recent work, the researchers identified 1.5 million lensed galaxies in visible light. They then observed them using a telescope that sees microwave light, ESA’s Planck satellite, and measured how much older microwave light distorted the dark matter around nearby galaxies.
“This result provides a very consistent picture of galaxies and their evolution, as well as the dark matter in and around galaxies, and how this picture evolves over time,” said study co-author Neta Bahcall, an astronomer at the Princeton University, at Princeton University. same release.
The team also found that dark matter in certain regions of space was less clumpy than it should be according to the standard theory of cosmology.
“Our finding is still uncertain,” Hironao Miyatake, an astronomer at Nagoya University and lead author of the paper, said in the statement. “But if true, it would suggest that the whole model is flawed as you go back in time. This is exciting because if the result holds after uncertainties are reduced, it could suggest an improvement to the model that can provide insights into the nature of dark matter itself.”
In the future, data from the upcoming Rubin Observatory will help image large swaths of the night sky at resolutions that will make it easier to see even older parts of space.
More: The world’s largest digital camera is almost ready to look back in time