Announcements Observing Monday-Thursday of this week counts on the third exam. Fourth exam is Wednesday, November 17 Review will be Monday, November 15

Black Holes Observed properties of black holes Eddington luminosity Accretion disks Jets Reading 24.3

The light from a quasar is emitted from a region 10 light-days across The light from a quasar is emitted from a region 10 light-days across. What does this tell us about the quasar? The brightness will change every day. The brightness will change every 20 days. The brightness will not change in less than 10 days. The brightness will not change in less than 100 days.

Accretion disk

In Active Galaxies the disk is surrounded by a dusty torus

Accretion disks

Varieties of Active Galaxies Radio Galaxies – big jets, no obvious BH Quasars – jets and BH Blazars – mainly see the jet

Orientation

Eddington Luminosity Limit on the brightness of a black hole

Eddington Luminosity

Accretion disks Disks form because infalling matter has angular momentum. Accretion leads to release of gravitational energy. Inner regions of disks rotate very rapidly – near the speed of light. The luminosity of a black hole is limited by its mass. Accretion disks of solar-mass and supermassive BHs are similar.

Jets | -- Size of our Galaxy -- |

Jets

Acceleration of a jet

Collimation of a jet

Superluminal motion

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

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