Overview
- University of Tokyo astrophysicist Tomonori Totani reports a halo-shaped gamma-ray excess peaking near 20 GeV in Fermi data from the Milky Way’s direction, published in JCAP.
- Modeling points to a spectrum consistent with annihilating WIMPs with an estimated particle mass around 0.51 TeV, with uncertainties allowing higher values.
- The method masked the bright galactic plane and subtracted modeled astrophysical backgrounds, yielding a small yet statistically significant excess across roughly 2–200 GeV.
- Scientists including Dan Hooper, Kinwah Wu, and Silvia Manconi caution that unmodeled astrophysical sources or analysis systematics could explain the signal, noting past Fermi excesses were reinterpreted as pulsars or neutron-star populations.
- Critiques highlight background-model sensitivities and the abundance of gamma-ray emitters, and call for confirmation via independent analyses and searches for the same spectral feature in dark-matter–dominated dwarf galaxies.