1. Black Hole Jets Acceleration of jets Collimation of jets
Superluminal motion
Evolution of jets

2. Jets
| -- Size of our Galaxy -- |

3. Jets

4. Acceleration of a jet

5. Collimation of a jet
Production of jets is not well understood and is a major topic in current research.

6. Superluminal motion

7. What is the lifetime of this jet?
| | = 150,000 light years

8. 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.

9. Jets of XTE J
Show movie then animation.

10. First direct observation of gradual deceleration of BH jet.
Jet deceleration
Approaching jet decelerates gradually.
Receding jet brightens only after sharp deceleration.
First direct observation of gradual deceleration of BH jet.

11. Intermediate Mass Black Holes
Eddington limit
Beaming
Nebula around a black hole

12. A black hole is observed at a luminosity of 3,000,000 solar luminosities. The black hole mass must be
at least 100 solar masses
less than 100 solar masses
exactly 100 solar masses
impossible to determine

13. Black hole masses Two types of black holes
Stellar mass black holes are up to 20 solar masses, formed in collapse of stars
Supermassive black holes are solar masses, found only in the nuclei of galaxies
Is there anything in between?

14. Starburst galaxy – M82

15. Starburst galaxy M82 in X-rays
Green cross is center of galaxy
Bright X-ray source is 15,000,000 solar luminosities
From Eddington limit, looks like a 500 solar mass black hole

16. Beaming
Is the source really as luminous as it looks or are the X-rays in a beam pointing towards us?

17. Nebula surrounding a BH
X-rays from the BH ionize Helium in the nebula which causes the Helium to emit one particular spectral line
By counting the number of photons in this spectral line of Helium, we can count the number of X-rays and find the true X-ray luminosity in all directions

18. Nebula around a black hole
Image from “slit-less” spectrograph
Horizontal axis shows position
Vertical axis shows combination of position and wavelength

19. Nebula around a black hole
Black hole is at least 750,000 solar luminosities.
Mass is at least 25 solar masses.

20. 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?
Estimating the mass of a black from its observed flux depends on what assumption?