Observations of nearby galaxy clusters showed the presence ofa light signaturewith no plain germ . This so - called 3.5 KeV line , named after the energy of its photon , was put forward as a possible theme song for a specific type of black matter , the inscrutable gist believed to keep galaxies together .

morose affair is thought to account for 85 percent of all affair in the world , however finding it is proving difficult . We know it does n’t interact with light , as we ca n’t see it directly , but it does interact with soberness , as we can see the effect it has on other affair . One of the ways we can recover out more about it , is to rule out what we know it is n’t .

A newfangled study , print inScience , now suggests that this mystical expelling can not possibly be due to a special type of gloomy thing , be intimate as a sterile neutrino . Neutrinos are fundamental particles similar to the electron and its sib , the muon and the tau , but with no electric charge and with a masses so lilliputian that it was long thought to be zero . There are three " flavors " of neutrinos ( electron , muon , and tau ) , and they can oscillate between each of them .

A possible fourth type of neutrino , the sterile one , has been proposed to excuse several curio of neutrinos and some versions of it suit well with dark issue . As both these sterile neutrino and dreary matter only interact with gravity and no other underlying personnel , await for them is hard but they might relinquish a specific light signature tune when they crumble . However , 3.5 KeV line does n’t appear to be that .

To reach this last , the team used X - re telescope of the Milky Way , focusing on the black region of blank surrounding our extragalactic nebula . devote that dark thing is expected to be uniformly distributed around extragalactic nebula , if it were to emit the 3.5 KeV line , they should have caught it , but they find out no evidence of it .

“ Our finding does not mean that the dark matter is not a sterile neutrino , but it mean that … there is no experimental evidence to date that points towards its existence , ” co - author Benjamin Safdi , an assistant professor of physics at the University of Michigan , say in astatement .

The observation were conduct with theXMM - Newton telescope . stargazer looked at 20 class ’ Charles Frederick Worth of scope data of these empty spaces around the galaxy . If dark affair was connected to the 3.5 KeV strain , they should have see it close to home plate .

“ Everywhere we look , there should be some fluxion of moody matter from the Milky Way annulus , ” co - author Nicholas Rodd , from UC Berkeley , add . “ We exploit the fact that we know in a halo of dark thing . ”

While this work might be disappointing , it is also a chance to expand the search for dark thing . By focusing on these obscure patches and looking at the information of other X - ray observatories on a much wider range of mountains of vigor , a key signature might be detected , give us some irrefutable proof of the existence of dark matter .