Journal article
Diffuse Galactic antimatter from faint thermonuclear supernovae in old stellar populations
Nature astronomy, Vol.1(6), 0135
06/01/2017
DOI: 10.1038/s41550-017-0135
Abstract
Our Galaxy hosts the annihilation of a few 1043 low-energy positrons every second. Radioactive isotopes capable of supplying such positrons are synthesized in stars, stellar remnants and supernovae. For decades, however, there has been no positive identification of a main stellar positron source, leading to suggestions that many positrons originate from exotic sources like the Galaxy’s central supermassive black hole or dark matter annihilation. Here we show that a single type of transient source, deriving from stellar populations of age 3–6 Gyr and yielding ∼0.03 M⊙ of the positron emitter 44Ti, can simultaneously explain the strength and morphology of the Galactic positron annihilation signal and the Solar System abundance of the 44Ti decay product 44Ca. This transient is likely the merger of two low-mass white dwarfs, observed in external galaxies as the sub-luminous, thermonuclear supernova known as SN 1991bg-like.The origin of Galactic positrons that produce gamma ray emission when annihilated is still debated. Mergers of two white dwarfs are likely to be the main source of these positrons. Such mergers produce sub-luminous, thermonuclear supernovae.
Details
- Title: Subtitle
- Diffuse Galactic antimatter from faint thermonuclear supernovae in old stellar populations
- Creators
- Roland Crocker - Australian National UniversityAshley Ruiter - Australian National UniversityIvo Seitenzahl - ARC Centre of Excellence for All-sky AstrophysicsFiona Panther - ARC Centre of Excellence for All-sky AstrophysicsStuart Sim - Queen's University BelfastBaumgardt HolgerMöller AnaisDavid Nataf - Johns Hopkins UniversityFerrario LiliaJ Eldridge - University of AucklandMartin White - The University of AdelaideBrad Tucker - ARC Centre of Excellence for All-sky AstrophysicsAharonian Felix
- Resource Type
- Journal article
- Publication Details
- Nature astronomy, Vol.1(6), 0135
- DOI
- 10.1038/s41550-017-0135
- ISSN
- 2397-3366
- eISSN
- 2397-3366
- Publisher
- Nature Publishing Group
- Language
- English
- Date published
- 06/01/2017
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984701831402771
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