Download The AGN obscuring torus

The AGN Obscuring Torus
Moshe Elitzur
University of Kentucky
& LAOG, Grenoble
Happy Birthday, young man!
optical depth
zone #
tz = tt
tz-1
z
i
Coupled
Escape
Probability
2
1
ti,i-1
Ti Ci pi  ni1 ni2
ti
ti-1
t2
t1
t0 = 0
tij = |ti – tj|
2-level Atom
=
S  (1 )J  B(T)
10-3 :
Semi-infinite Atmosphere

tt = 500
Slab
(10-3  t  107)
Time
zones ALI
Time
%error
CEP ALI
CEP


C
N
 21 1  e E21 / kT  '
1   A 21
Ncr
zones ALI
%error, S
CEP ALI
CEP
20 0.39

36.3
104
1 0.03

99.5
55.5
40 1.10

23.9
45.7
20 1.02

88.2
23.0
100 4.39
0.06
10.9
14.0
40 3.29

79.8
15.5
200 11.6
0.89
5.5
5.4
100 12.6
.033
62.5
6.5
600 44.9
1.70
1.6
1.2
200 28.1
.085
46.4
2.2
Elitzur & Asensio Ramos 2006, MNRAS 365, 779
Unified Scheme for AGN
Toroidal
Obscuration
Required by
Unification
Schemes
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
Origin of the 100’s pc Torus – Modeling IR emission
Pier & Krolik 92
Pier & Krolik 93
5-10 pc
~100 pc
Dearth of IR emission in smooth-density models T  r


Granato et al ’94, ‘97:
•
Uniform density
•
Rout ~ 100 – 300 pc
•
 = 45°
Observations – NGC 1068, CO
Schinnerer et al ’00
at R ~ 70 pc, H ~ 9 – 10 pc  H/R ~ 0.15
Observations – NGC 1068, CO & H2
20 pc
140 pc
Galliano et al ’03:
H/R ~ 0.15
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)
9 & 10m – R ~ 1.5 pc (Karovska et al 03)
 Circinus: 2m – R ~ 1pc (Prieto et al 04)
8 & 18m – R < 2 pc (Packham et al 05)
 NGC1097 & NGC5506: 2m – R < 5 pc (Prieto et al 04)
The Torus Size Crisis
 Observations – compact (pc-size) torus
 Theory – extended (100’s pc) torus
VLTI – NGC1068:
Jaffe et al ‘04
r  1.7 pc: T = 320 K
Poncelet et al ‘06
Lbol = 2·1045 erg s-1
T(r = 2pc) = 960 K
r(T = 320 K) = 26 pc
r(T = 226 K) = 57 pc
(Mason et al ’06)
Temperature in Clumpy Medium
Tmax
Tmin
Nenkova et al 2006
Temperature–Distance Relation
 Smooth density – T & R uniquely related
 Clumpy density – different T at same R
different R, same T
AGN Clumpy Torus: Size Effect
Ri = 0.9 pc L½12
Y = Ro/Ri
N  N0r -q exp(-2/2)
N0 = 5
 = 45º
tV = 60
Clumping solves the compact emission problem!
Dynamic Origin of Vertical Structure
Cloud accretion from the galaxy?
No need in a compact torus!
The Torus as a Disk-Wind Region
Bottorff et al 97
Unification Scheme
Grand Unification Scheme
masers
BLR
Torus
BAL
Emmering, Blandford & Shlosman 92
Cloud Properties in Torus-Wind
3
NH,23 rpc
Size – shear resistance:
R c  1016 cm 
Density:
n  10 cm
Mass:
Mc  7  103 M  NH,23 Rc2,16
7
3
M7
NH,23

R c,16
1/ 2
Magnetic field:
NH,23 T2 
B  2 mG  

R
 c,16 
Elitzur & Shlosman 2006
Water Masers – Glimpse of Torus Clouds?
NGC 3079
Kondratko, Greenhill & Moran ‘05
High-latitude features – disk rotational imprint: uplifted clouds
Outflow and Accretion
1

M

0
.
02
L
/

M
yr
acc
45


M
out  1  NT
H,23 v 6  I
1
/
2

Macc L 45
T
2
L 45  (  NH
v
I
)
,23 6


 M
out  Macc
Torus disappearance at L  1043 erg s-1 !
Narrow-line Seyfert 1 radio galaxies?
Chiaberge et al ’99; Whysong & Antonucci ‘04
Conclusions
 No bagel
 Toroidal Obscuration Required by Unified Scheme
– just a region in the disk-wind