UV, Opt, X-ray, ...
Accretion Disk
“Torus” Obscurer
<0.1pc
10pc
10 kpc
Galactic Center gas
Star forming regions
e.g. in spiral arms
1 kpc
Nuclear obscuration
Galaxy-scale obscuration
How is it stable and extended?
Density? Substructure? Feeding of AGN?
First constraint:
- Column density
- Covering fraction