Updated supernova ALP production rates including semi-Compton and pair-annihilation channels yield revised bounds on electron couplings, dominated by the decay a to e+ e- gamma at small couplings.
The 511 keV emission from positron annihilation in the Galaxy
3 Pith papers cite this work. Polarity classification is still indexing.
3
Pith papers citing it
abstract
The first gamma-ray line originating from outside the solar system that was ever detected is the 511 keV emission from positron annihilation in the Galaxy. Despite 30 years of intense theoretical and observational investigation, the main sources of positrons have not been identified up to now. Observations in the 1990's with OSSE/CGRO showed that the emission is strongly concentrated towards the Galactic bulge. In the 2000's, the SPI instrument aboard ESA's INTEGRAL gamma-ray observatory allowed scientists to measure that emission across the entire Galaxy, revealing that the bulge/disk luminosity ratio is larger than observed in any other wavelength. This mapping prompted a number of novel explanations, including rather "exotic ones (e.g. dark matter annihilation). However, conventional astrophysical sources, like type Ia supernovae, microquasars or X-ray binaries, are still plausible candidates for a large fraction of the observed total 511 keV emission of the bulge. A closer study of the subject reveals new layers of complexity, since positrons may propagate far away from their production sites, making it difficult to infer the underlying source distribution from the observed map of 511 keV emission. However, contrary to the rather well understood propagation of high energy (>GeV) particles of Galactic cosmic rays, understanding the propagation of low energy (~MeV) positrons in the turbulent, magnetized interstellar medium, still remains a formidable challenge. We review the spectral and imaging properties of the observed 511 keV emission and we critically discuss candidate positron sources and models of positron propagation in the Galaxy.
verdicts
UNVERDICTED 3representative citing papers
Non-thermal photon cascades via Compton reprocessing and positron annihilation in stars create a broad photon spectrum that substantially boosts photon-coupled WISP production, as shown for solar dark photons.
The paper supplies an introductory lecture-style summary of observational techniques, astronomical sources, and physical processes across the four main messengers in multi-messenger astronomy.
citing papers explorer
-
Supernova production of axion-like particles coupling to electrons, reloaded
Updated supernova ALP production rates including semi-Compton and pair-annihilation channels yield revised bounds on electron couplings, dominated by the decay a to e+ e- gamma at small couplings.
-
Enhanced Stellar Production of Weakly Interacting Slim Particles from Non-Thermal Nuclear Cascades
Non-thermal photon cascades via Compton reprocessing and positron annihilation in stars create a broad photon spectrum that substantially boosts photon-coupled WISP production, as shown for solar dark photons.
-
Introduction to multi-messenger astronomy
The paper supplies an introductory lecture-style summary of observational techniques, astronomical sources, and physical processes across the four main messengers in multi-messenger astronomy.