Key idea: An international team of astrophysicists and cosmologists have spent the past year teasing out the secrets of dark matter, using sophisticated computer simulations and the observations from the one of the most powerful astronomical cameras in the world.
Original author and publication date: Princeton University – April 7, 2023
Futurizonte Editor’s Note: Should we try to see the invisible? Yes, of course. But let’s me mindful we may not like what we see.
From the article:
It feels like a classical paradox: How do you see the invisible? But for modern astronomers, it is a very real challenge: How do you measure dark matter, which by definition emits no light?
The answer: You see how it impacts things that you can see. In the case of dark matter, astronomers watch how light from distant galaxies bends around it.
An international team of astrophysicists and cosmologists have spent the past year teasing out the secrets of this elusive material, using sophisticated computer simulations and the observations from the one of the most powerful astronomical cameras in the world, the Hyper Suprime-Cam (HSC). The team is led by astronomers from Princeton University and the astronomical communities of Japan and Taiwan, using data from the first three years of the HSC sky survey, a wide-field imaging survey carried out with the 8.2-meter Subaru telescope on the summit of Maunakea in Hawai’i. Subaru is operated by the National Astronomical Observatory of Japan; its name is the Japanese word for the cluster of stars we call the Pleiades.
The team presented their findings at a webinar attended by more than 200 people, and they will share their work at the “Future Science with CMB x LSS” conference in Japan.
“Our overall goal is to measure some of the most fundamental properties of our universe,” said Roohi Dalal, a graduate student in astrophysics at Princeton.
“We know that dark energy and dark matter make up 95% of our universe, but we understand very little about what they actually are and how they’ve evolved over the history of the universe. Clumps of dark matter distort the light of distant galaxies through weak gravitational lensing, a phenomenon predicted by Einstein’s General Theory of Relativity. This distortion is a really, really small effect; the shape of a single galaxy is distorted by an imperceptible amount. But when we make that measurement for 25 million galaxies, we’re able to measure the distortion with quite high precision.”