Fermi Data Hinders Dark Matter Research

For many years, physicists have been trying to determine what dark matter is, ever since it was proposed that its influence was the one holding galaxies together. Experts have attempted to find the particles that make up the elusive substance, thought to form much of the known Universe, though we can't seem to be able to observe it. When they failed to do so, researchers turned to finding out what dark matter was not, but, now, new data from the NASA Fermi Gamma-ray Space Telescope makes a dent in the most widely accepted theoretical models on the issue, ScienceNow reports.

According to a newly published study, the hefty range of masses in which dark matter particles were thought to be included may not be accurate. The investigation was not conducted by researchers handling Fermi, but by another team of astrophysicists peering through sets of pieces of information gathered from the telescope. This line of research is very important, because being able to confirm the existence of dark matter would confirm many theories on which modern astronomy and astrophysics are based. At this point, dark matter is only visible to us through the gravitational pull it exerts on galaxies.

The best possible candidate for being named the principal component of dark matter is a class of elementary particles known as weakly interacting massive particles, or WIMPs. Physicists determined through complex calculations that these elements should have a mass somewhere in the 1-to-200 gigaelectronvolts (GeV) range, which would make them have 1 to 200 times the mass of an average proton. The new investigation literally punches a hole in the new model, shaving off about 10 GeV of range from this hypothetical detection interval.

The work was conducted at the University of Maryland in College Park, under the supervision of particle cosmologist Kevork Abazajian. The expert presented the discovery at the April meeting of the American Physical Society (APS). He reveals that masses ranging from 5 to 15 GeV have been removed from the hypothetical models of WIMP masses. “In a lot of these different scenarios he's considered of how dark matter can annihilate […] he's started to rule out well-motivated theoretical models. I'm just really curious to see the actual paper and see how the analyses differ,” Fermi Large Area Telescope (LAT) collaboration member and Ohio State University astrophysicist Jennifer Siegal-Gaskins says.