 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
The
torus of gas and dust can block part of our view
|
|
|
| • |
Seyfert
2 galaxies: Edge on view
|
|
|
Only gas well above and below disk is
visible
|
|
|
See only “slow” gas narrow emission lines
|
|
|
| • |
Seyfert
1 galaxies: Slightly tilted view
|
|
|
Hot high velocity gas close to black
hole is visible
|
|
High velocities broad
emission lines
|
|
|
| • |
BL
Lac objects: Pole on view
|
|
|
Looking right down the jet at central
region
|
|
|
Extremely bright – vary on time
scales of hours
|
|
|
| • |
Quasars: Very active AGN at large distances
|
|
|
Can barely make out the galaxy
surrounding them
|
|
Were apparently more common in
distant past
|
|