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Portal:Radiation astronomy/Resource/14

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Positrons edit

Main articles: Radiation astronomy/Positrons and Positron astronomy
 
Observation of positrons from a terrestrial gamma ray flash is performed by the Fermi gamma ray telescope. Credit: NASA Goddard Space Flight Center.

"Positron astronomy is 30 years old but remains in its infancy."[1]

"[P]ositron astronomy results ... have been obtained using the INTEGRAL spectrometer SPI".[2] The positrons are not directly observed by the INTEGRAL space telescope, but "the 511 keV positron annihilation emission is".[2]

During solar flares “[s]everal radioactive nuclei that emit positrons are also produced; [which] slow down and annihilate in flight with the emission of two 511 keV photons or form positronium with the emission of either a three gamma continuum (each photon < 511 keV) or two 511 keV photons."[3]

References edit

  1. ↑ P.A.Milne; J.D.Kurfess; R.L.Kinzer; M.D.Leising; D.D.Dixon (April 2000). Investigations of positron annihilation radiation, In: Proceedings of the 5th COMPTON Symposium. 510. Washington, DC: American Institute of Physics. pp. 21-30. doi:10.1063/1.1303167. Bibcode: 2000AIPC..510...21M. http://arxiv.org/pdf/astro-ph/9911184. Retrieved 2011-11-25. 
  2. ↑ 2.0 2.1 G. Weidenspointner; G.K. Skinner; P. Jean; J. Knödlseder; P. von Ballmoos; R. Diehl; A. Strong; B. Cordier et al. (October 2008). "Positron astronomy with SPI/INTEGRAL". New Astronomy Reviews 52 (7-10): 454-6. doi:10.1016/j.newar.2008.06.019. http://www.sciencedirect.com/science/article/pii/S1387647308001164. Retrieved 2011-11-25. 
  3. ↑ Gerald H. Share; Ronald J. Murphy (January 2004). Andrea K. Dupree, A. O. Benz. ed. Solar Gamma-Ray Line Spectroscopy – Physics of a Flaring Star, In: Stars as Suns: Activity, Evolution and Planets. San Francisco, CA: Astronomical Society of the Pacific. pp. 133-44. ISBN 158381163X. Bibcode: 2004IAUS..219..133S. http://heseweb.nrl.navy.mil/gamma/solar/papers/share_iau_04.pdf. Retrieved 2012-03-15. 
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