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Mapping the circumnuclear dust in nearby AGN with MIDI. Konrad R.W. Tristram, Klaus Meisenheimer Max-Planck-Institut für Astronomie Heidelberg, Germany Collaborators: Walter Jaffe, David Raban, Bill Cotton. Motivation. Unified AGN model:
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Mapping the circumnuclear dust in nearby AGN with MIDI Konrad R.W. Tristram, Klaus Meisenheimer Max-Planck-Institut für Astronomie Heidelberg, Germany Collaborators: Walter Jaffe, David Raban, Bill Cotton
Motivation • Unified AGN model: Geometrical effects lead to different manifesta-tions (e.g. Seyfert 1 & 2) • Our goal: Resolve the dust distri-bution directly for nearby AGN Ionisation Cone Accretion Disk Obscuring Torus Broad Line Region Black Hole Konrad R. Tristram
Circinus: the galaxy • Spiral galaxy SA(s)b, i = ~65° • RA = 14h 13m, DEC = −65° 20’ • Seyfert type 2 • 4 × 106 M nucleus • Distance ~4 Mpc → 50 mas ~ 1 pc • unresolved in MIR 2MASS J, H, Ks colour mosaic Konrad R. Tristram
v in m 80 U2-U4 Period 72, 04-02 (U3-U2) Period 73, 04-06 (U3-U2) Period 74, 05-02 (U3-U4) 60 Period 75, 05-05 (U2-U3) Period 77, 06-05 (U2-U3) 40 20 u in m 80 60 40 20 -20 -40 -60 -80 -20 -40 -60 -80 Circinus: MIDI observations • The Circinus UV coverage: 21 fringe tracks, 16 photometries Konrad R. Tristram
Circinus: total flux Circinus, total flux from all observations 20 15 Flux in Jy 10 5 0 8 9 10 11 12 13 Wavelength in µm Konrad R. Tristram
Circinus: correlated flux Circinus, observed: 2005-02-28 2.0 N PA= 44°, BL=49.4m PA= 54°, BL=51.1m PA= 57°, BL=51.7m 1.5 PA= 88°, BL=58.2m PA=120°, BL=62.0m PA=131°, BL=62.4m Flux in Jy 1.0 0.5 0.0 8 9 10 11 12 13 Wavelength in µm Konrad R. Tristram
Circinus: modeling Two blackbody Gaussians: 200 0 DEC in mas -200 -200 0 200 11 µm RA in mas Log of model flux distribution at 11µm Konrad R. Tristram
O[III] 1’’~ 20 pc Circinus: environment Known geometry Expected torus configuration Wilson et al. 2000 Konrad R. Tristram
75 50 25 75 50 25 -25 -50 -75 -25 -50 -75 Circinus: model result DEC in mas Dust torus in Circinus supports unified scheme RA in mas 1.9 pc 0.4 pc Konrad R. Tristram
Centaurus A (NGC 5128) • Elliptical galaxy • RA = 13h 25m • DEC = −43° 01’ • Radio jet • 6 × 107 M nucleus • Distance 3.8 Mpc → 53 mas ~ 1 pc • Merger Konrad R. Tristram
Centaurus A: results 2.0 N Total Photometry PA~108°, BL~60.3m PA~ 37°, BL~45.3m 1.5 No dusty torus in Centaurus A Flux in Jy 1.0 0.5 0.0 8 9 10 11 12 13 Wavelength in µm Konrad R. Tristram
Conclusions • Circinus: • small hot and large cold component • orientation perpendicular to ionisation cone • Centaurus A • Centaurus A • weak extended dust component • major emitter in MIR: synchrotron source • Weaker targets: • hardly resolved Paranal, February 2005 Konrad R. Tristram