Milky Way galaxy's 'mysterious' glowing center could be dark matter: Report

The mysterious red glow from the excess gamma radiations at the center of the Milky Way galaxy could be radiating from the ‘dark matter’ and pulsars, a physicist Mattia Di Mauro of the National Institute for Nuclear Physics in Italy has stated in a new study. The illuminated mystical center of the Milky Way dubbed as Galactic Center GeV Excess (GCE) was first discovered by physicists Lisa Goodenough and Dan Hooper in 2009 and it has, since then, stunned the scientists who have been trying to find the source of the single brightest source of light. NASA’s Fermi Gamma-Ray Space Telescope has now detected dark matter inside the galactic halo of the gamma radiation cluster of the Milky Way, according to the study published in The Astrophysical Journal. 

A Fermi-LAT collaboration team of astrophysicists investigated the previously proposed theories related to the potential sign of dark matter, which comprises 85 percent of all the universe. Di Mauro, an astrophysicist at Kavli Institute for Particle Astrophysics and Cosmology, a joint institute of Stanford University, and the US Department of Energy's SLAC National Accelerator Laboratory said that the researchers did not need dark matter specifically to decipher the gamma-ray emissions of the Milky Way galaxy.  “Instead, we identified a population of pulsars in the region around the galactic center, which sheds new light on the formation history of the Milky Way.” 

[Credit: NASA Goddard; A. Mellinger, CMU; T. Linden, Univ. of Chicago]

Di Mauro led the investigation after gamma radiation was caught on the Large Area Telescope (LAT) on NASA’s Fermi Gamma-ray Space Telescope and his team tried to establish the glow in the Milky Way galaxy’s center.  “We search for this radiation with the LAT in regions of the universe that are rich in dark matter, such as the center of our galaxy,” Seth Digel, head of KIPAC’s Fermi group explained. He stated that when the dark matter particles either decay or collide such gamma rays are produced.

While the galactic is extremely complicated, astrophysicists had earlier detected the charged particles produced in powerful star explosions called supernovae and its remnants known as pulsars. Meanwhile, “Two recent studies by teams in the US and the Netherlands showed that the gamma-ray excess at the galactic center is speckled, not smooth as we would expect for a dark matter signal,”  KIPAC’s Eric Charles said. 

[Credits: NASA, ESA and L. Hustak STScI]

"The analysis clearly shows that the excess of gamma rays is concentrated in the galactic center, exactly what we would expect to find in the heart of the Milky Way if dark matter is in fact a new kind of particle," Di Mauro said.

Collision of dark matter particles WIMPS

“Pulsars have very distinct spectra—that is, their emissions vary in a specific way with the energy of the gamma rays they emit. Using the shape of these spectra, we were able to model the glow of the galactic center correctly,” Di Mauro said. The astrophysicists established  Goodenough and Hooper’s speculative theory that if the dark matter particles called WIMPS (weakly interacting massive particles) and their antiparticles were to collide, it would destroy particles, including gamma-ray photons. The latter was studied by Pamela cosmic ray detector aboard the Resurs-DK No.1 satellite and the Alpha Magnetic Spectrometer experiment aboard the ISS.

(Image Credit: NASA)