For nearly a century, astronomers have been searching for dark matter, the invisible structure thought to hold galaxies together. While there is abundant indirect evidence for this mysterious substance’s existence, no one has yet been able to directly detect it. However, a new study suggests that progress may finally be being made. University of Tokyo professor Tomonori Totani claims to have identified gamma-ray emissions thought to originate from dark matter using data from NASA’s Fermi Gamma-ray Space Telescope.
New discovery with NASA data: Strongest candidate for dark matter found
Totani’s findings, published in the Journal of Cosmology and Astroparticle Physics, suggest that this radiation is emitted by colliding WIMPs (weakly interacting massive particles). It has long been suspected that WIMPs, a leading candidate for dark matter, emit gamma rays by annihilating each other. Totani explains that he discovered these emissions using 15 years of Fermi satellite data and focusing on the halo region rather than the galactic center. This region is a large spherical area surrounding the Milky Way and containing stars and gas.
The resulting gamma-ray emission intensities match those expected by astronomers from WIMP annihilation. Totani also calculated the frequency of WIMP annihilation from the measured intensity, and this was within the range of theoretical predictions. This raises the possibility that a signal produced by dark matter WIMPs has been detected. However, experts remain cautious and warn that this signal could be cosmic noise or another false positive rather than dark matter.
Other physicists interviewed on the subject indicate that gamma rays can originate from many different sources, from pulsars to supernovae. The distinctive feature of the detected gamma rays is their high photon energy of 20 gigaelectronvolts. However, experts caution that there are other phenomena in space, such as neutron star collisions, that could also produce such high-energy gamma rays. Dan Hooper, a physics professor at the University of Wisconsin-Madison, notes that the data Totani used has been previously examined by others, but no similar emission excess was found.
Hooper also believes Totani didn’t look anywhere within 10 degrees of the galactic center, which may have influenced the results. Physicists expect the majority of the dark matter signal to come from the galactic center. Totani emphasizes that it’s too early to say for sure that these gamma rays originate from dark matter, but that they are the most promising candidate radiation known to date. For definitive proof, gamma rays with the same parameters need to be detected from other parts of the sky.
What are your thoughts on this new study? Is the mystery of dark matter close to being solved, or is it just another cosmic illusion?
