1 Radio Continuum (408 MHz)

図: Radio $0.4 \rm{GHz}$

Intensity of radio continuum emission from high-energy charged particles in the Milky Way,from surveys with ground-based radio telescopes (Jodrell Bank Mark I and Mark IA, Bonn 100-meter, and Parkes 64-meter). At this frequency, most of the emission is from electrons moving through the interstellar magnetic field at nearly the speed of light. Shock waves from supernova explosions accelerate electrons to such high speeds, producing especially intense radiation near these sources. Emission from the supernova remnant Cas A near 110° longitude is so intense that the diffraction pattern of the support legs for the radio receiver on the telescope is visible as a cross shape.

$$408 {\rm MHz = 0.734785 {\rm m} = 734 {\rm mm}}$$