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 : Synchrotron Radiation

The other type of radiation that radio astronomers study is synchrotron radiation. Many objects in space generate a magnetic field. If a charged particle (like an electron) enters a magnetic field, it will begin to move in a circular path. If the particle is moving circularly, it is accelerating and is giving off electromagnetic radiation. Under ordinary circumstances, this radiation is known as cyclotron radiation and is not strong enough to be astronomically significant.

If the speed of the particle approaches the speed of light, however, its emitted radiation becomes much, much stronger and is known as synchrotron radiation. The amount of energy that the particles emit depends upon the radius of their circular path through the magnetic field. If that radius is small, the particle can radiate a tremendous amount of energy.

The most widespread source of radio waves in our galaxy is synchrotron radiation. In the sources that follow, this emission mechanism will appear numerous times.

An electron, moving at relativistic speeds (near the speed of light) begins to spiral in the presence of a magnetic field (represented in this diagram by a series of field lines). As it spirals, the electron emits cones of synchrotron radiation.