1. The AGN Obscuring Torus
Moshe Elitzur
University of Kentucky
& LAOG, Grenoble

2. Happy Birthday, young man!

3. Coupled Escape Probability optical depth zone # tz = tt z tz-1 ti i
i,i Ti Ci pi  ni1 ni2
ij = |i – j|
ti-1 t2 2 t1
Coupled
Escape
Probability 1
t0 = 0

4. Elitzur & Asensio Ramos 2006, MNRAS 365, 779
2-level Atom
 = 10-3 :
Semi-infinite Atmosphere
(10-3    107)
Slab t = 500
Time
%error
zones
ALI
CEP 20
0.39 
36.3
104 40
1.10
23.9
45.7
100
4.39
0.06
10.9
14.0
200
11.6
0.89
5.5
5.4
600
44.9
1.70
1.6
1.2
Time
%error, S
zones
ALI
CEP 1
0.03 
99.5
55.5 20
1.02
88.2
23.0 40
3.29
79.8
15.5
100
12.6
.033
62.5
6.5
200
28.1
.085
46.4
2.2
Elitzur & Asensio Ramos 2006, MNRAS 365, 779

5. Toroidal Obscuration Required by Unification Schemes
Unified Scheme for AGN
Toroidal
Obscuration
Required by
Unification
Schemes

6. General folklore: R  100 pc
Torus Properties
From the statistics of type 1 vs type 2: H/R ~ 1 (Schmitt et al ’01)
R = ? Must rely on IR emission
General folklore: R  100 pc

7. Origin of the 100’s pc Torus – Modeling IR emission
Pier & Krolik 92
5-10 pc
Pier & Krolik 93
~100 pc
Dearth of IR emission in smooth-density models T  r
Granato et al ’94, ‘97:
Uniform density
Rout ~ 100 – 300 pc
 = 45°

8. Observations – NGC 1068, CO at R ~ 70 pc, H ~ 9 – 10 pc  H/R ~ 0.15
Schinnerer et al ’00
at R ~ 70 pc, H ~ 9 – 10 pc  H/R ~ 0.15

9. Observations – NGC 1068, CO & H2
20 pc
140 pc
Galliano et al ’03: H/R ~ 0.15

10. IR – Observations
NGC1068: 2m imaging – R ~ 1 pc (Weigelt et al 04) 10m interferometry – R ~ 2 pc (Jaffe et al 04)
Cen A: 2m – R < 0.5 pc (Prieto et al 04) & 10m – R ~ 1.5 pc (Karovska et al 03)
Circinus: 2m – R ~ 1pc (Prieto et al 04) & 18m – R < 2 pc (Packham et al 05)
NGC1097 & NGC5506: 2m – R < 5 pc (Prieto et al 04)

11. The Torus Size Crisis Observations – compact (pc-size) torus
Theory – extended (100’s pc) torus
r  1.7 pc: T = 320 K
Jaffe et al ‘04
VLTI – NGC1068:
Poncelet et al ‘06
Lbol = 2·1045 erg s (Mason et al ’06)
T(r = 2pc) = 960 K
r(T = 320 K) = 26 pc
r(T = 226 K) = 57 pc

12. Temperature in Clumpy Medium
Tmax
Tmin
Nenkova et al 2006

13. Temperature–Distance Relation
Smooth density – T & R uniquely related
Clumpy density – different T at same R different R, same T

14. AGN Clumpy Torus: Size Effect
Ri = 0.9 pc L½ Y = Ro/Ri
N  N0r -q exp(-2/2)
N0 = 5  = 45º V = 60
Clumping solves the compact emission problem!

15. Dynamic Origin of Vertical Structure
Cloud accretion from the galaxy?
No need in a compact torus!

16. The Torus as a Disk-Wind Region
Bottorff et al 97

17. Unification Scheme

18. Grand Unification Scheme
masers
BLR
Torus
BAL
Emmering, Blandford & Shlosman 92

19. Cloud Properties in Torus-Wind
Size – shear resistance:
Density:
Mass:
Magnetic field:
Elitzur & Shlosman 2006

20. Water Masers – Glimpse of Torus Clouds?
NGC 3079
Kondratko, Greenhill & Moran ‘05
High-latitude features – disk rotational imprint: uplifted clouds

21. Outflow and Accretion Torus disappearance at L  1043 erg s-1 !
Narrow-line Seyfert 1 radio galaxies?
Chiaberge et al ’99; Whysong & Antonucci ‘04

22. Conclusions
No bagel
Toroidal Obscuration Required by Unified Scheme – just a region in the disk-wind