星系中的射电辐射

星系中的射电辐射主要有三种

1. 同步辐射 （低频，幂律谱）
2. 自由-自由散射 (HII区：低频是接近于热谱，光学厚，高频光学薄，平谱）

https://www.cv.nrao.edu/course/astr534/FreeFreeEmission.html

1. AME

Anomalous Microwave Emission (AME) is a component of diffuse Galactic radiation observed at frequencies in the range ≈ 10–60 GHz. AME was first detected in 1996 and recognised as an additional component of emission in 1997