Astronomers using the Hubble Space Telescope have turned up a ghostly ring of dark matter, surrounding the aftermath of a collision between two galaxy clusters. This is one of the strongest pieces of evidence ever found for the existence of dark matter; a shadowy substance that only interacts with regular matter through gravity.
Researchers discovered the ring while they were mapping the distribution of dark matter inside the galaxy cluster Cl 0024+17, which is located about 5 billion light-years from Earth. The ring itself is 2.6 million light-years across.
Since dark matter is invisible, the researchers discovered the ring by its gravitational influence on background galaxies. The more dark matter concentrated into an area, the more the light from background objects is distorted, like ripples on a pond of water. We’re fortunate that the head-on collision between the galaxy clusters provided us with a perfect view from our perspective here on Earth.
So how did this ring form? Simulations have shown that when galaxy clusters collide, the dark matter falls into the centre of the combined cluster, and then sloshes back out. As it heads back out, mutual gravity slows it back down, and the dark matter piles up into a ring.
Original Source: Hubble News Release
NASA's TESS mission has turned up thousands of exoplanet candidates in almost as many different…
Many people think of the James Webb Space Telescope as a sort of Hubble 2.…
On November 26th, 2018, NASA's Interior Exploration using Seismic Investigations, Geodesy, and Heat Transport (InSight)…
Black holes are incredible powerhouses, but they might generate even more energy thanks to an…
According to the United Nations, the world produces about 430 million metric tons (267 U.S.…
As we saw with JWST, it's difficult and expensive to launch large telescope apertures, relying…