- First Name: Hasan
- Last Name: Yuksel
- Working Group Presenter
- Title:Constraints on Galactic Positrons
- Presentation Type:Talk
- Presentation Work Group:Dark Matter
- Abstract:I will discuss implications of the observed Galactic positron annihilation gamma-ray line at 511 keV and constraints from INTEGRAL observations on some galactic positron production models, including MeV dark matter. The intense 0.511 MeV gamma-ray line emission from the Galactic Center observed by INTEGRAL requires a large annihilation rate of nonrelativistic positrons. If these positrons are injected at even mildly relativistic energies, higher-energy gamma rays will also be produced. We calculate the gamma-ray spectrum due to inflight annihilation and compare to the observed diffuse Galactic gamma-ray data. Even in a simplified but conservative treatment, we find that the positron injection energies cannot be above about 3 MeV,
which strongly constrains models for Galactic positron production.