interferometric observations of the nuclear dust in active ...€¦interferometric observations of...
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Interferometric observationsof the nuclear dust inactive galactic nuclei
Obscured AGN Across Cosmic Time
Konrad R. W. Tristram
Collaborators:K. Meisenheimer, M. Schartmann (MPIA),
W. Jaffe, D. Raban (Sterrewacht Leiden), Bill Cotton (NRAO)
06.06.2007 Konrad R. Tristram Page 2
• Torus size: ~ 1 pcAngular sizes for the nearest AGN: < 20 mas
continuous torus modelλ=10 μm, i=60°
Schartmann (2005)
Introduction: Which instrument?
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• Torus size: ~ 1 pcAngular sizes for the nearest AGN: < 20 mas
• Need MIR instruments with highest resolution!Find this only at the VLTI: MIDI
VLT with the ResidenciaFebruary 2005
Introduction: Which instrument?
06.06.2007 Konrad R. Tristram Page 4
• Torus size: ~ 1 pcAngular sizes for the nearest AGN: < 20 mas
• Need MIR instruments with highest resolution!Find this only at the VLTI: MIDI
• MIDI– Dispersed fringes in the
N-band (8 to 13 μm)– NaCl prism (R ~ 30)– Grism (R ~ 240)
MIDI in the VLTI lab
Introduction: Which instrument?
06.06.2007 Konrad R. Tristram Page 5
• Essentially Young’s experiment
O
δ
S
P
r1r2
H1 H2
D
I
Introduction: MIR interferometry
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• Essentially Young’s experiment
• Correlated flux Fcor:flux in fringes
• Resolution:λφ
2 BL=
⋅
The VLTI interferometer
BL
Introduction: MIR interferometry
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List of all AGN observed to date:
GTO5.0 JyCircinus
GTO0.6 JyNGC 1365
GTO0.4 JyNGC 7469
GTO0.3 JyMCG -05-23-016
GTO0.6 JyIC 4329A
TimeFlux (10 µm)Name
GTO
GTO
OT
GTO
SDT / OT
0.6 JyNGC 5128 (Centaurus A)
13.0 JyNGC 1068 (M77)
0.3 Jy
0.4 Jy
0.5 Jy
3C 273
Mrk 1239
NGC 3783
Introduction: Target list
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List of all AGN observed to date:
GTO5.0 JyCircinus
GTO0.6 JyNGC 1365
GTO0.4 JyNGC 7469
GTO0.3 JyMCG -05-23-016
GTO0.6 JyIC 4329A
TimeFlux (10 µm)Name
GTO
GTO
OT
GTO
SDT / OT
0.6 JyNGC 5128 (Centaurus A)
13.0 JyNGC 1068 (M77)
0.3 Jy
0.4 Jy
0.5 Jy
3C 273
Mrk 1239
NGC 3783
Introduction: Target list
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• Spiral galaxy SA(s)b, i = 65°
• Seyfert type 2
• 4 × 106 M nucleus
• Distance ~4 Mpc50 mas ~ 1 pc
• Circumnuclear starburst
2MASS J, H, Ks colour mosaic
Circinus: General properties
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Period 72, 04-02 (U3-U2)Period 73, 04-06 (U3-U2)Period 74, 05-02 (U3-U4)Period 75, 05-05 (U2-U3)Period 77, 06-05 (U2-U3)
-80-60-40-2020406080
u in m
-80
-60
-40
-20
20
40
60
80 v in mU2-U4GTO observations from P72 to P77:• 21 fringe tracks
• 16 photometries
Circinus: UV coverage
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8 9 10 11 12 13Wavelength λ in μm
0
5
10
15
20
25To
tal f
lux
F tot
in J
y
Circinus: Total flux
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GTO observations from P72 to P77:
Period 72, 04-02 (U3-U2)Period 73, 04-06 (U3-U2)Period 74, 05-02 (U3-U4)Period 75, 05-05 (U2-U3)Period 77, 06-05 (U2-U3)
-80-60-40-2020406080
u in m
-80
-60
-40
-20
20
40
60
80 v in mU2-U4
• 21 fringe tracks
• 16 photometries
Circinus: UV coverage
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0.0
0.5
1.0
1.5
2.0Circinus, observed 2005-02-28
8 9 10 11 12 13Wavelength λ [μm]
Cor
rela
ted
flux
F cor
[Jy]
PA = 44.6°, BL = 49.3 mPA = 53.6°, BL = 51.0 mPA = 56.6°, BL = 51.6 mPA = 88.4°, BL = 58.1 mPA = 120.0°, BL = 62.0 mPA = 130.5°, BL = 62.4 m
Circinus: Correlated flux
ozon
e ba
nd
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334 KT1 =Temperature:
298 KT2 = Temperature:
1.18τ1 =Silicate depth:
2.21τ2 =Silicate depth:
Position angle:Covering factor:
Axis ratio:Size:Covering factor:
Axis ratio:Size:
61°α =0.20f2 =
0.97r2 =97 masΔ2 =1.0f1 =
0.21r1 =21 masΔ1 =
Flux distribution
200 100 0 -100 -200RA in mas
-200
-100
0
100
200
λ = 11.0 μm
DE
C in
mas
Two blackbody Gaussians:
Log of model flux distribution at 11µm Tristram et al.
Circinus: Gaussian fit
06.06.2007 Konrad R. Tristram Page 15
Flux distribution
200 100 0 -100 -200RA in mas
-200
-100
0
100
200
λ = 11.0 μm
DE
C in
mas
334 KT1 =Temperature:
298 KT2 = Temperature:
1.18τ1 =Silicate depth:
2.21τ2 =Silicate depth:
Position angle:Covering factor:
Axis ratio:Size:Covering factor:
Axis ratio:Size:
61°α =0.20f2 =
0.97r2 =97 masΔ2 =1.0f1 =
0.21r1 =21 masΔ1 =
Two blackbody Gaussians:
Log of model flux distribution at 11µm Tristram et al.
Circinus: Clumpiness
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Hydrodynamicaltorus model
Schartmann et al.
Simulations of AGN tori
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Hydrodynamicaltorus model
Schartmann et al.
Simulations of AGN tori
Brightness distribution (in logarithmic scaling, axis in pc):
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Known geometry
1’’~ 20 pc
O[III]
Wilson et al. 2000
Circinus: Geometry
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Expected torus configuration
Circinus: Geometry
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0.4 pc
2.0 pc
RA in mas
DEC in mas
-50-25255075
-75
-50
-25
25
50
75
-75
Greenhill et al. 2000
Circinus: Geometry
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NGC 1068: General properties
• Messier M77
• barred spiral galaxy (R)SA(rs)b, i = 51°
• Seyfert type 2
• 1 × 107 M nucleus
• Distance ~14 Mpc14 mas ~ 1 pc
SDSS (http://www.wikisky.org)
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NGC 1068: UV coverage
OT observations in period P76:
• grism
• 15 fringe tracks
Period 76, 05-11
150 100 50 -50 -100 -150
-150
-100
-50
50
100
150
u in m
v in m
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NGC 1068: Modelling
-50-252550
-50
-25
25
50
1.4 pc
3.9 pc
2 blackbody Gaussians:
Raban et al.
0°α ≈Position angle:
−42°α1 =Position angle:700 KT1 ≈Temperature:
300 KT2 ≈Temperature:
5τ1 ≈Silicate depth:
4τ2 ≈Silicate depth:Axis ratio:Size:
Axis ratio:
Size:
0.75r2 =57 masΔ2 =
0.34r1 =
20 masΔ1 =
06.06.2007 Konrad R. Tristram Page 24
NGC 1068: Modelling
-50-252550
-50
-25
25
50
1.4 pc
3.9 pc
2 blackbody Gaussians:
Raban et al.
0°α ≈Position angle:
−42°α1 =Position angle:700 KT1 ≈Temperature:
300 KT2 ≈Temperature:
5τ1 ≈Silicate depth:
4τ2 ≈Silicate depth:Axis ratio:Size:
Axis ratio:
Size:
0.75r2 =57 masΔ2 =
0.34r1 =
20 masΔ1 =
06.06.2007 Konrad R. Tristram Page 25
NGC 1068: Geometry
Gallimore et al.2004
06.06.2007 Konrad R. Tristram Page 26
Centaurus A: Properties
• elliptical galaxy• recent merger• dust lane, edge-on• FR 1 radio galaxy• narrow line RG• 6 × 107 M nucleus• distance ~4 Mpc
50 mas ~ 1 pc
06.06.2007 Konrad R. Tristram Page 27
Centaurus A: UV coverage
GTO observations in P74 and P75:
-80 -60 -40 -20 20 40 60 80
-80
-60
-40
-20
20
40
60
80Period 74, 05-02 (U3-U4)Period 75, 05-05 (U2-U3)
u in m
v in m
• 4 independent visibility points
• problems with photometry
06.06.2007 Konrad R. Tristram Page 28
Centaurus A: Fluxes
8 9 10 11 12 130.0
0.5
1.0
1.5
2.0Fl
ux in
F [J
y]
PA~108°, BL~60.3mPA~ 37°, BL~45.3m
Total Photometry
Wavelength λ [μm]
N
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Centaurus A: Results
Horiuchi et al. 2006 Meisenheimer et al. 2007
C1/C2C2
C2/C3C3
Core
CJ2
CJ1
40 20 0 -20Right Ascension (mas)
4020
0-2
0R
elat
ive
Dec
linat
ion
(mas
)
10 mas
127° ± 9°
50° jet axis
0.19 pc
baselineorientation
Feb
28
May 26
N
E
06.06.2007 Konrad R. Tristram Page 30
Other targets: Mrk 1239, MCG -05-..
8 9 10 11 12 13wavelength λ [μm]
0.0
0.2
0.4
0.6
0.8
1.0
8 9 10 11 12 13wavelength λ [μm]
0.0
0.2
0.4
0.6
0.8
1.0correlated flux Fcortotal flux Ftottotal flux Ftot
correlated flux Fcor
Mrk 1239 (Seyfert 1)MCG -05-23-016 (Seyfert 2)oz
one
band
ozon
e ba
nd
06.06.2007 Konrad R. Tristram Page 31
Conclusions
• Circinus & NGC 1068:– dusty tori perpendicular to ionisation cone– trace maser locations
• Centaurus A– dust disk – synchrotron source
• Weaker targets:– hardly resolved
VLT on Cerro Paranal, May 2005
06.06.2007 Konrad R. Tristram Page 32
Prospects
• Long baselines for unresolved targets• Shorter baselines for
highly resolved targets• Look at the phases
imaging• Comparison to simula-
tions• Extension of sample
One of the galaxies tobe observed: NGC 1365