Dictionary of Space Concepts

Short Definition:

Gamma rays are very high frequency electromagnetic radiation emitted as an outcome of radioactivity. Due to high frequency, gamma rays have very high energy. Natural sources of gamma emission originating on Earth are mainly an effect of radioactive decay and secondary radiation from atmospheric interactions among cosmic ray particles.

Detailed Definition:

A gamma ray, also known as gamma radiation, is a penetrating form of electromagnetic radiation originating from the radioactive decay of atomic nuclei. Gamma rays from radioactive decay are within the energy range starting at few kiloelectronvolts (keV) to roughly 8 megaelectronvolts (MeV), matching to the usual energy levels in nuclei among reasonably long lifetimes. The energy spectrum of gamma emission can be utilized to recognize the decaying radionuclides with a technique called gamma spectroscopy. Very-high-energy gamma rays in the 100–1000 teraelectronvolt (TeV) range have been observed from sources such as the Cygnus X-3 microquasar.

Etymology:

gamma - The third letter of the Greek alphabet (Γ, γ),
radiation - From the past participle stem of Latin radiare (“to gleam, shine, beam”).

Sample Sentence(s):

"Solar flares emit across the entire electromagnetic spectrum, including gamma rays."
"Gamma rays originating from far-distant quasars are used to estimate the extragalactic background light in the universe."

Translations:

French: 

Rayon gamma

German:

Gammastrahlung

Polish:

Promieniowanie gamma, promienie gamma

Swedish:

Gammastrålning

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