Lesson Three Topics

Lesson Three Overview
Types of Radiation
Thermal Radiation
Synchrotron Radiation
Planetary Radio Sources
Radio Stars
Radio Galaxies
Quasars
Black Holes
The Milky Way: Our Own Radio Galaxy

	Activities and Quizzes

Lesson Three : Radio Galaxies

Radio galaxies are galaxies that emit large amounts of radio waves from their centers. Radiation that astronomers can detect from radio galaxies is primarily synchrotron radiation. While all galaxies emit some radio waves, radio galaxies emit almost a million times more radio energy than normal galaxies. The structure of radio galaxies consists of a galaxy surrounded by two huge lobes on either side of it. These radio lobes are created by narrow streams of matter called radio jets ejected into space from the center of the galaxy. We can detect synchrotron radiation from within these radio lobes and jets.

Radio jets are much larger than the active galaxies that emit them. Typical galaxies are usually around 100,000 light years across. The lobes of many radio galaxies are over 3,000,000 light years wide and the distance between the two radio lobes can span over 30,000,000 light years.