Scientists have found dark matter interacting with other dark matter in an entirely new way other than just the force of gravity. This first potential signs of self-interacting dark matter suggests that dark matter may not be completely dark after all.
Astronomers used a technique known as gravitational lensing to deduce the location of dark matter and using the MUSE instrument on ESO’s very Large Telescope along with images from the ASA/ESA Hubble Space Telescope which is in orbit, they were able to study simultaneous collision of four other galaxies in a cluster known as Abell 3827, but with a relatively slower speed. Of course, these collisions took place over hundred of millions of years in the far-flung corners of the Universe.
As a result, the collisions severely distorted space-time. Also as calculation suggests, the distance between the clump of dark matter and that of four galaxies associated with collisions is currently 5000 light-years (50,000 million kilometers), this would take NASA’s Voyager spacecraft some 90 million years to travel that far.
Based on the assumption acquired as a result of observation that dark matter apparently slow down after interacting with other dark matter and its lag with the galaxy it surrounds, scientists came to the conclusion that dark matter is capable of engaging with a force other than gravity, presumably by interacting with itself.
This is for the first time dark matter has been found to show signs of self-interacting other than interacting with the force of gravity.
“We used to think that dark matter just sits around, minding its own business, except for its gravitational pull. But if dark matter were being slowed down during this collision, it could be the first evidence for rich physics in the dark sector — the hidden Universe all around us.” said lead author of the study, Richard Massey at Durham University.