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It has a half-life of 30 years, and decays by beta decay without gamma ray emission to a metastable state of barium-137 (137m Ba). Barium-137m has a half-life of a 2.6 minutes and is responsible for all of the gamma ray emission in this decay sequence. The ground state of barium-137 is stable. The photon energy (energy of a single gamma ray) of ...
Gamma-ray telescopes collect and measure individual, high energy gamma rays from astrophysical sources. These are absorbed by the atmosphere, requiring that observations are done by high-altitude balloons or space missions. Gamma rays can be generated by supernovae, neutron stars, pulsars and black holes.
In astrophysics, gamma rays are conventionally defined as having photon energies above 100 keV and are the subject of gamma-ray astronomy, while radiation below 100 keV is classified as X-rays and is the subject of X-ray astronomy. Gamma rays are ionizing radiation and are thus hazardous to life.
Significant gamma-ray emission from our galaxy was first detected in 1967 [9] by the detector aboard the OSO 3 satellite. It detected 621 events attributable to cosmic gamma rays. However, the field of gamma-ray astronomy took great leaps forward with the SAS-2 (1972) and the Cos-B (1975–1982) satellites. These two satellites provided an ...
Pages in category "Gamma rays" The following 14 pages are in this category, out of 14 total. This list may not reflect recent changes. ...
List of Solar System objects most distant from the Sun; List of Solar System objects by size; Lists of geological features of the Solar System; List of natural satellites (moons) Lists of small Solar System bodies; Lists of comets; List of meteor showers; Minor planets. List of minor planets. List of exceptional asteroids; List of minor planet ...
Pages in category "Gamma-ray telescopes" The following 41 pages are in this category, out of 41 total. This list may not reflect recent changes. ...
67 Ga is used because, like 99m Tc, it is a gamma-ray emitter and various ligands can be attached to the Ga 3+ ion, forming a coordination complex which may have selective affinity for particular sites in the human body. An extensive list of radioactive tracers used in hydraulic fracturing can be found below.