Beaming equation of Relativistic beaming

In the simple jet model of a single homogeneous sphere the observed luminosity is related to the intrinisic luminosity as

where

The observed luminosity therefore depends on the speed of the jet and the angle to the line of sight through the Doppler factor, , and also on the properties inside the jet, as shown by the exponent with the spectral index.

The beaming equation can be broken down into a series of three effects:

• Relativistic aberration
• Time dilation
• Blue- (or Red-) shifts