The Galactic Positron Annihilation Radiation & The Propagation of Positrons in the Interstellar Medium

Abstract

We consider positron propagation in the interstellar medium and show that the positrons from the beta-plus decay chains of the radioactive nuclei Ni-56, Ti-44, and Al-26, produced in Galactic supernovae, can fully account for all the features of the diffuse Galactic 511 keV annihilation radiation observed by INTEGRAL/SPI. We also predict additional measurable features that can further test the origin of positrons and provide new information on the nature of the interstellar medium.

40 pages, 4 postscript figures, 7 tables, accepted for publication in the Astrophysical Journal, volume 698, June 2009

References in corpus (10)

• Spatial distribution of interstellar gas in the innermost 3 kpc of our Galaxy
• Studies of regular and random magnetic fields in the ISM: statistics of polarization vectors and the Chandrasekhar-Fermi technique
• Dynamic Alignment in Driven Magnetohydrodynamic Turbulence
• Strong Imbalanced Turbulence
• The sky distribution of positronium annihilation continuum emission measured with SPI/INTEGRAL
• Energy spectra stemming from interactions of Alfven waves and turbulent eddies
• Results of SPARO 2003: Mapping Magnetic Fields in Giant Molecular Clouds
• Microquasars as sources of positron annihilation radiation
• Folded Fields as the Source of Extreme Radio-Wave Scattering in the Galactic Center
• MHD Turbulent Mixing Layers: Equilibrium Cooling Models

Cited by in corpus (14)

• Wild at Heart:-The Particle Astrophysics of the Galactic Centre
• Nonabelian dark matter: models and constraints
• Filament formation in wind-cloud interactions. II. Clouds with turbulent density, velocity, and magnetic fields
• The Positron Puzzle
• Imaging the 511 keV positron annihilation sky with COSI
• Is There a Dark Matter Signal in the Galactic Positron Annihilation Radiation?
• Scalar Dark Matter Candidates -- Revisited
• Dust ion acoustic solitary structures in presence of nonthermally distributed electrons and positrons
• Positron Annihilation in the Nuclear Outflows of the Milky Way
• Galactic Positrons from Thermonuclear Supernovae
• Dynamical generation of macroscale magnetic fields and fast flows in a four-component astrophysical plasma
• Measuring the smearing of the Galactic 511 keV signal: positron propagation or supernova kicks?
• Galactic Electron-Positron Annihilation Emission from X-Ray Binaries with Transient and Persistent Jets
• Updated Constraints on the Injection Energy of Positrons Generating the Galactic 511 keV $\gamma$-ray line