Black Hole Jets

1
Black Hole Jets

• Acceleration of jets
• Collimation of jets
• Superluminal motion
• Evolution of jets

2
A black hole is observed at a luminosity of
60,000 solar luminosities. The black hole mass
must be

• at least 2 solar masses
• less than 2 solar masses
• exactly 2 solar masses
• impossible to determine

3
Jets
-- Size of our Galaxy --
4
Jets
5
Acceleration of a jet
6
Collimation of a jet
7
Origin of jets is an unsolved problem

• The production and propagation of jets is a major
  topic in current research. See, for example
  http//www.aas.org/meetings/aas206/

8
About how large is the radius of a 1 million
solar mass black hole such as those which may
exist at the centers of many galaxies?

• a few km
• a few thousand km
• a few million km
• a few billion km

9
Rotating black holes

• For non-rotating black holes
• - event horizon is at the Schwarzschild radius
• - inner edge of the disk is at 3 Schwarzschild
  radii
• For maximally rotating black holes
• - event horizon is at ½ Schwarzschild radius
• - inner edge of the disk is at ½ Schwarzschild
  radius
• Schwarzschild radius 3 km (M/MSun)

10
Superluminal motion
11
What is the lifetime of this jet?
------------------ 150,000 light years
12
Evolution of Jets

• Jets from active galaxies are large and change
  slowly.
• Jets from solar-mass black holes are smaller, by
  the ratio of the black hole masses, and change
  more rapidly.
• It is possible to study the evolution of jets
  from solar-mass black hole.
• Show movie and then animation.

13
Review Questions

• How are jets accelerated?
• How are jets collimated?
• Do superluminal jets really move faster than the
  speed of light?
• Do the jets of stellar-mass black holes evolve
  faster or slower than the jets of supermassive
  black holes?