Electron-positron annihilation lines and decaying sterile neutrinos

Man Ho CHAN, M.-C. CHU

Research output: Contribution to journalArticle


If massive sterile neutrinos exist, their decays into photons and/or electron-positron pairs may give rise to observable consequences. We consider the possibility that MeV sterile neutrino decays lead to the diffuse positron annihilation line in the Milky Way center, and we thus obtain bounds on the sterile neutrino decay rate Γ ₑ ≥10⁻²⁸ s⁻¹ from relevant astrophysical/cosmological data. Also, we expect a soft gamma flux of 1.2×10⁻⁴–9.7×10⁻⁴ ph cm⁻² s⁻¹ from the Milky Way center which shows up as a small MeV bump in the background photon spectrum. Furthermore, we estimate the flux of active neutrinos produced by sterile neutrino decays to be 0.02–0.1 cm⁻² s⁻¹ passing through the earth. Copyright © 2011 Springer Science+Business Media B.V.
Original languageEnglish
Pages (from-to)313-317
JournalAstrophysics and Space Science
Issue number2
Publication statusPublished - Apr 2012



Chan, M. H., & Chu, M.-C. (2012). Electron-positron annihilation lines and decaying sterile neutrinos. Astrophysics and Space Science, 338(2), 313-317. doi: 10.1007/s10509-011-0929-x


  • Dark matter
  • Milky way