Positrons and electrons annihilated each other, emittinggamma rays detected by Fermi's gamma-ray burst detector, researchers said.
正电子和电子会相互湮灭而发射出的伽玛射线，再由费米的爆发检测器所检测到，研究人员说。
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A radioactive process in which an atomic nucleus loses energy by emitting a gamma ray without a change in its atomic or mass Numbers.
原子核的一种放射性过程，在这种过程中由于放出一个伽马射线而损失能量，但并不改变原子序数或质量。
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Giant bubbles of gamma-ray-emitting materials surrounding the Milky Way are created by our galaxy's central black hole - and its appetite for stars - according to an international team of astronomers.