the branch of astronomy that deals with the study of celestial objects by means of the gamma rays that come from them.
Origin of gamma-ray astronomy
First recorded in 1960–1965
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the investigation of cosmic gamma rays, such as those from quasars
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012