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The dust covering factor in AGN:The dust covering factor in AGN:What's wrong and how to fix it
Marko Stalevski1,2,3
with
Claudio Ricci4,5, Yoshihiro Ueda5, Paulina Lira1, Jacopo Fritz6, Maarten Baes3
1 Universidad de Chile, Santiago, Chile2 Astronomical Observatory, Belgrade, Serbia
3 Sterrenkundig Observatorium, Universiteit Gent, Belgium4 Pontificia Universidad Catolica de Chile, Santiago, Chile
5 Kyoto University, Kyoto, Japan 6 Centro de Radioastronomıa y Astrofısica, UNAM, Morelia, Mexico
The dust covering factor in AGN:The dust covering factor in AGN:What's wrong and how to fix it
Ltorus/LAGN = CF
(e.g. Fritz+06; Hatziminaoglou+09; Mor+09; Mor & Trakhtenbrot11; Alonso-Herrero+11; Ramos-Almeida+11; Mor & Netzer12; Mateos+15,
16). (S. Mateos talk)
IR SED fitting → CF
(e.g. Maiolino+07, Treister+08, Calderone+12, Lusso+13, Netzer+16)
The dust covering factor in AGN:The dust covering factor in AGN:What's wrong and how to fix it
Ltorus/LAGN = CF
(e.g. Fritz+06; Hatziminaoglou+09; Mor+09; Mor & Trakhtenbrot11; Alonso-Herrero+11; Ramos-Almeida+11; Mor & Netzer12; Mateos+15,
16). (S. Mateos talk)
IR SED fitting → CF
(e.g. Maiolino+07, Treister+08, Calderone+12, Lusso+13, Netzer+16)
ΔΔ
Δ –Δ – opening angle opening angle
ΔΔ
Covering Factor ≈ sinΔ
Wada 2012 Stalevski+16
f*LAGN
f*LAGN
(1-f)*LAGN = Ltorus
f*LAGN
(1-f)*LAGN = Ltorus
f*LAGN
Covering Factor = sinΔ ≈ Ltorus/LAGN
(1-f)*LAGN = Ltorus
f*LAGN
Covering Factor = sinΔ ≈ Ltorus/LAGN
Ltorus/LAGN = sinΔ · DA · TA
f (cosθ, Δ )f (τ,p,q,R,RadTrans,... )
Monte Carlo Radiative Transferhttp://www.skirt.ugent.be/
Baes+11; Baes & Camps 15; Camps & Baes 15
L ~ cosθ(1+2cosθ)
Anisotropic accretion disk:
Optical depth map (V-band) of the AGN sky
The two-phase torus model: high-density
clumps + low-density interclump
dust.
Density map of the xz plane.
Stalevski+12, 16
Stalevski+12, 16
Monte Carlo Radiative Transferhttp://www.skirt.ugent.be/
https://sites.google.com/site/skirtorus/
face-on view edge-on view
Ltorus/LAGN vs. CF: dust optical depth
Ltorus/LAGN vs. CF: disk-torus misalignment
Consequence forobscured AGN fraction vs. luminosity
Consequence forobscured AGN fraction vs. luminosity
Consequence forobscured AGN fraction vs. luminosity
Consequence forobscured AGN fraction vs. luminosity
IR vs X-ray CF discrepancy ?
XR
Ueda+14
Hasinger08
(e.g. Ueda+03; Hasinger08, Beckmann+09; Burlon+11; Ricci+13; Merloni+14; Ueda+14; Buchner+15;...)
IR vs X-ray CF discrepancy ?
IR
XR
Stalevski+16 Netzer+16
Ueda+14
Hasinger08
IR vs X-ray CF discrepancy ?
IR
XR
Stalevski+16 Netzer+16
Ueda+14
Hasinger08
IR vs X-ray CF discrepancy ?
– Sazonov+15:
– negative bias in finding obscured AGN in hard X-ray flux limited survey
– positive bias in finding unobscured AGN, due to Compton reflection in the torus
→ lead to smaller obscured AGN fraction in the high-L than at low-L
– Anisotropic central XR source
Some questions and suggestions
– Lawrence 1991: Receding torus
– Lawrence & Elvis 2010: No receding torus (“In mid-IR samples, low frequency radio samples and local volume limited samples no evidence for an f_obsc luminosity dependence”)
– IR: torus seems not to be receding (Calderone+12, Roseboom+13, Netzer+16, Stalevski+16, Mateos+15: weak or no dependence of f_obsc on L_AGN)
– XR: torus seems to be receding... BUT WHY?(e.g. Ueda+03; Hasinger08, Beckmann+09; Burlon+11; Ricci+13; Merloni+14; Ueda+14; Buchner+15;...)
– gas torus + dusty torus: decoupled, different dynamics, different CFs ?
– Goodbye for the receding torus ?
ConclusionsConclusions
● Conspiracy of accretion disk and obscuring dust anisotropy messes up Ltorus/LAGN as dust CF proxy
● Type 1s: Low CFs underestimated; high CFs overestimated● Type 2s: CFs always underestimated
● New method to correct the observed Ltorus/LAGN
● Weak or no trend of obscured AGN fraction with luminosity! (f_obsc≈0.65)
● Goodbye receding torus?
Stalevski+2016 MNRAS 458, 2288–2302
https://sites.google.com/site/skirtorus/