Astrophysical Jets

Simulates the bulk motion of relativistic jets coming out of a microquasar. The jets are modeled here as a pair of jets moving away from a central source. The two jets always move in opposite directions. The size and color of the blobs indicates the relative brightness.

Interesting to note:

the further the motion is from transverse, the greater the differences in the two jets.
the increase in brightness for the approaching jet can be very high when the motion is nearly face-on.
the decrease in brightness of the receding jet often makes it too dim to be detected (this sometimes called Doppler favoritism in favor of the approaching jet).
for pure transverse motion, the brightness is not the same as the central source, even when the brightness is input as 1. This is because the doppler factor is 1/Γ for transverse motion.

Here is the above diagram for GRS1915+105, a black hole about 11,000 parsecs distant. Note that if the approaching jet were more face-on, it would be much brighter. (More info here).

Explanatory Notes

Brightness Exponent
The change in brightness depends on the Doppler factor raised to a certain power (exponent). That exponent takes different values, depending on the character of the emitter.

θ, sp, bri
The apparent angle, apparent speed, and relative apparent brightness of the blob.

β
θ
Blob brightness
Brightness limit
Show invisibles
Brightness exponent
Distance
Animate