Cosmic robbery could explain lack of dark matter in some galaxies
By Samantha Mathewson published about 16 hours ago
Large galaxies may steal dark matter from smaller galaxies they nearly collide with.
Computer simulations showed large galaxies may steal dark matter from smaller galaxies when they collide. The close-up views reveal two galaxies lacking dark matter, compared to the brighter regions in the image. (Image credit: Moreno et al. )
Large galaxies may steal dark matter from smaller galaxies they nearly collide with, new research suggests.
Scientists from the University of California, Irvine and Pomona College used computer models to simulate the evolution of a corner of the universe about 60 million light-years across. The new computer models, which weren't designed to do so, created seven galaxies deprived of dark matter, a sight that had previously puzzled scientists. The strange simulations arose after near-collisions with massive neighboring galaxies, according to a statement from the University of California, Irvine.
Dark matter is the invisible stuff that makes up to 85% of all matter in the universe. Astronomers can't study it directly, but believe it must exist to make sense of the behavior of stars, planets and galaxies. Therefore, in a universe full of dark matter, the new computer simulations help explain how some galaxies might lose this vital material.
The recent study follows earlier observations made in 2018 by Shany Danieli, co-author of the latest study and currently an astrophysicist at Princeton University. Those observations showed two galaxies that appeared to be missing most of their dark matter — something once thought impossible, according to the statement.
More:
https://www.livescience.com/larger-galaxies-steal-dark-matter
