What produces radio emission from space?
1. Thermal radiation from solid bodies such as the planets, ionized gas from stars, or dust in molecular clouds. 2. Synchrotron radiation from high-speed electrons traveling in magnetic fields. 3. Spectral line radiation from atomic and molecular gas in the interstellar medium or in the gaseous envelopes around stars. 4. Pulsed radiation resulting from the rapid rotation of neutron stars surrounded by an intense magnetic field and energetic electrons.
