Melbourne: Galaxies in a cluster roughly 300 million light years from Earth could contain 100 times more dark matter than visible matter, a new study has found.
Researchers used powerful computer simulations to study galaxies that have fallen into the Coma Cluster, one of the largest structures in the universe in which thousands of galaxies are bound together by gravity.
"The galaxies could have fallen into the cluster as early as seven billion years ago, which, if our current theories of galaxies evolution are correct, suggests they must have lots of dark matter protecting the visible matter from being ripped apart by the cluster," researchers said.
Dark matter cannot be seen directly but the mysterious substance is thought to make up about 84 per cent of the matter in the universe.
International Centre for Radio Astronomy Research (ICRAR) PhD student Cameron Yozin, who led the study, said that the study demonstrates for the first time that some galaxies that have fallen into the cluster could plausibly have as much as 100 times more dark matter than visible matter.
Mr Yozin, who is based at The University of Western Australia, said that the galaxies he studied in the Coma Cluster are about the same size as our own Milky Way but contain only one per cent of the stars.
He said that the galaxies appear to have stopped making new stars when they first fell into the cluster between seven and ten billion years ago and have been dead ever since, leading astrophysicists to label them "failed" galaxies.
This end to star formation is known as "quenching".
"Galaxies originally form when large clouds of hydrogen gas collapse and are converted to stars - if you remove that gas, the galaxy cannot grow further," Mr Yozin said.
"Falling into a cluster is one way in which this can happen. The immense gravitational force of the cluster pulls in the galaxy, but its gas is pushed out and essentially stolen by hot gas in the cluster itself," he said.
"For the first time, my simulations have demonstrated that these galaxies could have been quenched by the cluster as early as seven billion years ago," Mr Yozin said.
"They have however avoided being ripped apart completely in this environment because they fell in with enough dark matter to protect their visible matter," he said.
Researchers used powerful computer simulations to study galaxies that have fallen into the Coma Cluster, one of the largest structures in the universe in which thousands of galaxies are bound together by gravity.
"The galaxies could have fallen into the cluster as early as seven billion years ago, which, if our current theories of galaxies evolution are correct, suggests they must have lots of dark matter protecting the visible matter from being ripped apart by the cluster," researchers said.
International Centre for Radio Astronomy Research (ICRAR) PhD student Cameron Yozin, who led the study, said that the study demonstrates for the first time that some galaxies that have fallen into the cluster could plausibly have as much as 100 times more dark matter than visible matter.
Advertisement
He said that the galaxies appear to have stopped making new stars when they first fell into the cluster between seven and ten billion years ago and have been dead ever since, leading astrophysicists to label them "failed" galaxies.
Advertisement
"Galaxies originally form when large clouds of hydrogen gas collapse and are converted to stars - if you remove that gas, the galaxy cannot grow further," Mr Yozin said.
Advertisement
"For the first time, my simulations have demonstrated that these galaxies could have been quenched by the cluster as early as seven billion years ago," Mr Yozin said.
Advertisement
COMMENTS
Advertisement
Samsung Galaxy M35 5G With 50-Megapixel Rear Camera, 6,000mAh Battery Launched in India: Price, Offers Samsung Galaxy Tab S10 Series to Be Launched in October, Tipster Claims Samsung Galaxy S25 Ultra Tipped to Get an Asymmetrical Design With Narrower ‘Visual’ Bezels Amid Huge Row, Karnataka Pauses Bill For Reservation In Private Sector Firms Travel Influencer Aanvi Kamdar Dies After Falling Off A Waterfall Near Mumbai BJP Subtly Asking Ajit Pawar To Quit "Mahayuti": Sharad Pawar's NCP Biden Tests Positive For Covid As Age Worries Mount Biden Says Could Drop Election Bid If "Medical Condition" Emerged Russia Says It's Ready To Work With Any US Leader Track Latest News Live on NDTV.com and get news updates from India and around the world.