Universe  ID: 10567

How Cosmic-ray Protons Make Gamma rays

Released on February 13, 2010
In the simplest and most common interaction, a cosmic-ray proton strikes another proton. The protons survive the collision, but their interaction creates an unstable particle — a pion — with only 14 percent the mass of a proton. In 10 millionths of a billionth of a second, the pion decays into a pair of gamma-ray photons. More complex scenarios occur when cosmic-ray protons strike nuclei containing greater numbers of particles.
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Simple animation of proton-proton interaction resulting in netural pion that decays into two gamma rays.
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This animation shows a more dynamic view of the pion and gamma ray creation process.

Credits

Scott Wiessinger (UMBC): Lead Animator
Scott Wiessinger (UMBC): Producer
Francis Reddy (SPSYS): Writer
Please give credit for this item to:
NASA/Goddard Space Flight Center

Short URL to share this page:
https://svs.gsfc.nasa.gov/10567

Mission:
Fermi Gamma-ray Space Telescope

This item is part of this series:
Astrophysics Animations

Keywords:
SVS >> HDTV
GCMD >> Earth Science >> Spectral/Engineering >> Gamma Ray
SVS >> Astrophysics
SVS >> Universe
SVS >> Fermi
SVS >> Supernova
NASA Science >> Universe

GCMD keywords can be found on the Internet with the following citation: Olsen, L.M., G. Major, K. Shein, J. Scialdone, S. Ritz, T. Stevens, M. Morahan, A. Aleman, R. Vogel, S. Leicester, H. Weir, M. Meaux, S. Grebas, C.Solomon, M. Holland, T. Northcutt, R. A. Restrepo, R. Bilodeau, 2013. NASA/Global Change Master Directory (GCMD) Earth Science Keywords. Version 8.0.0.0.0