Hints that a galactic collision knocked the invisible mass askew are disproven
Richard Massey/Durham Univ., ESA, NASA
Dark matter is still the shyest particle in physics. New observations show that dark matter in galaxy cluster Abell 3827 stubbornly ignores all other kinds of matter — including itself, astronomers reported April 6 at the European Week of Astronomy and Space Science in Liverpool, England.
The research, also posted online at arXiv.org, negates an earlier finding that stars were separated from their dark matter in Abell 3827, a cluster including four colliding galaxies about 1.3 billion light-years from Earth (SN: 5/16/15, p. 10). At the time, cosmologist Richard Massey and colleagues suggested the dark matter may have lagged behind its galaxy because it was interacting with another clump of dark matter — something dark matter is not supposed to do, according to standard theory. Dark matter, which makes up most of