Andreas Efstathiou, Frank Heymann, Endrik Kr gel, Nikolai … · 2015-11-04 · Two-phase AGN tours models: SED library Andreas Efstathiou, Frank Heymann, ... RT in homogenous disks

Ralf Siebenmorgen ModGal 2015

v Extinction, emission and polarisation of dust

v Two-phase AGN tours models: SED library

Andreas Efstathiou, Frank Heymann, Endrik Krűgel, Nikolai Voshchinikov, Peter Scicluna (PhD)

AGN Dust Models


Si + aC : 60Å < a < 0.2-0.3µm ~ a-3.5

Graphite : 5Å < a < 80 Å ~ a-3.5

PAH : 30, 200 C

Abundances [X/H in ppm]: 31Si + 150aC + 50gr + 30PAH

Siebenmorgen et al. (2014)

ISM dust Solar neighborhood


PAH absorptioncross section

+ ‘’2200” bump

Malloci et al. (2007)

Verstraete et al. 1992



Nucleus of NGC1808 PAH emissioncross section

Siebenmorgen et al. (2001. 2007)

Starbursts


Linear polarisationSerkowski~Voshchinnikov (2012)



Linear polarisationSerkowski~Voshchinnikov (2012)



Extinction: Prolate / Sphere



Dust model :

- Extinction ✓

- Emission ✓

- Polarisation ✓

ISM dust


Dust model :

- Extinction ✓

- Emission ✓

- Polarisation ✓

ISM dustFitzpatrick (1999)


Reflection nebulae

Dust model :

- Extinction

- Emission

- Polarisation


Albedo +Extinction



Reflection nebulae

Dust model :

- Extinction ✓

- Emission

- Polarisation

8µmPeeters et al. 2012



Emission



Polarisation



Circular polarisationOblate versus Prolate

~maximum of linear polarisation

x

~Voshchinnikov (2002, 2012)


Diffraction limited optical polarimetry of supergiant VYCMa-> Grain sizes (methodology: Krügel 2008)

Scicluna et al, subm.


Diffraction limited optical polarimetry of supergiant VYCMa-> Grains 50 times larger than in ISM



AGN tours models


Clumpy AGN tours models (Elitzur et al. 2001, Nenkova et al. 2008, Hönig & Kishimoto 2010, ….)

Before 2000: RT in homogenous disks (Pier & Krolik 1992, Efstathiou & Rowan-Robinson 1993, …)


Hyrdo-dynamical simulation of AGN torus structure

(Wada 2012)courtesy K.Wada


courtesy M. Schartann

MIR view of the AGN torus (Schartmann et al. 2014)


Dust in polar region of AGN toursV L T I: Burtscher et al. 2013, Hönig et al. 2013, Tristram et al. 2014,

Review by Netzer 2015

VLTI: Circinus


Phenomenological AGN torus structure

Siebenmorgen et al. (2015) ModGal 2015


a) Caveats on approx. treatmentsb) 3D radiative transfer c) ISM dust viz. fluffy grainsd) Caveats on AGN extinction e) 5 parameter SED library:• NIR, 10µm band, intrinsic LAGN

• IRAC colors (Stern’05)• Type I+II ~> pure AGN

Two-phase AGN tours modelSED library



Clumpy AGN tours model

• Clumps in 1,2,3D radiative transfer computations • Total AGN torus emission applying statistical arguments


Caveats on clumpy AGN tours models

• Statistical approach valid for high clump number• Energy balance not strictly hold• No continuous dust distribution, only clumps• No heating of clumps from continuous medium/disk• 9-11 free parameters -> degenerated SED

• Emission of clumps in shadows overestimated, assumed isotropic heating from none shadowed neighboring clumps


Self consistent treatment

3D Monte Carlo radiative transfer


- Arbitrary dust distribution

- Pseudo adaptive mesh important for clumps


1. Geometry:


l Source emits “photon packages” of equal energy


1. Geometry

2. Source


1. Geometry

2. Source

3. Inter-action

4. Dust temperature

l absorption / scattering / no interaction

= - ln(ζ)



l Photons escape model cloud


1. Geometry

2. Source

3. Inter-action

4. Dust temperature

5. Detection

Time as 4thdimension (Light echo’s)


• Multiple photons at a time -> faster !

Challenges:

v Cell locked when hit by photon

v Parallel random number generator

(Mersene Twister)

v Graphical Processing Units (CUDA)

Heymann & Siebenmorgen (2012)

Vectorised 3D Monte Carlo


Dust density distribution



Carbon Silicate

Fluffygrains

ISM dust fluffy grains

diffuse ISMn ~ 1 atom/cm3

Draine 2011, Feltre et al 2012, Jones et al. 2014, Siebenmorgen et al. 2014




AGN dustn ~ 102...6 atom/cm3

Fluffygrains

diffuse ISMn ~ 1 atom/cm3

Draine 2011, Feltre et al 2012, Jones et al. 2014, Siebenmorgen et al. 2014

Krügel & Siebenmorgen 1994


Carbon Silicate



isotropic


ISM dust ✕ scattering medium -> SMC extinction curve

(Krügel 2009)

Caveat on extinction measurements


Caveat on extinction measurements

Scattering in or out-of-the beam

dust clump

Scicluna & Siebenmorgen, 2015


-> No 1:1 link to dust properties !

AGN torus extinction viewing angle

Scicluna & Siebenmorgen, 2015


disk shadows isotropic

AGN imaging

face-on

edge-on

polar dust



SED library of AGN

Library includes ~3600 SEDs


Minumum set of 5 free parameters1) Viewing angle2) Inner radius 3) Cloud filling factor4) Optical depth of clouds5) Optical depth of disk midplane


Impact of AGN parameters on SED


Ralf Siebenmorgen ModGal 2015 Siebenmorgen et al. (2015)

Impact of AGN parameters on SED


NIR flux enhanced by disk

no disk + disk

10 100 10 100

x10



Strength of the 10µm silicate band

Levenson et al. 2008Schartmann et al. 2008Sirocky et al. 2008Thompson et al. 2009Hatziminaoglou et al. 2015

emission absorption



Center wavelength of the 10µm feature



Intrinsic AGN luminosity LAGN

Assuming isotropic AGN emission (Stalevski et al. 2012)



SED Library IRAC colors of AGN


(Stern 2005)


edge-on, high extinction AGNSiebenmorgen et al. (2015)

(Stern 2005)

SED Library IRAC colors of AGN


Seyferts

Ground based MIR:Alonso Herrero et al 2011Gonzales- Martin et al 2013Esquej et al. 2014Ruschel-Dutra et al 2014Ichikawa et al 2015, …


Type I



Type II



Hyper-luminous galaxy


SED fitting methods: MCMC ~ χ2


² ISM dust viz. fluffy grains

² Caveats on AGN extinction

² 5 parameter SED library:• NIR, 10µm band, intrinsic LAGN

• Seyferts ~> AGN + host • Type I+II ~> pure AGN (SB <10%)• www.eso.org/~rsiebenm/agn_models/

Two-phase AGN tours model




Shadows in planet forming disks

v Gaps and ring-like structures:

... are caused by hydrostatic + radiation balance without

the need to postulate a companion/planet

(Siebenmorgen & Heymann, 2012).

v PAH emission from disks:

Low / high detection statistics of PAH in

T Tauri / Herbig Ae stars is consistent with

X-ray destruction of PAH (Siebenmorgen & Krűgel 2010).


Grains are at a few R* large enough, so that outflow might be driven by photon-scattering.

Mechanism known from O-rich AGB stars.

Supergiant VY CMAWhat is the driving mass loss mechanism?



Armitage’07

Lagrange et al, β Pic planet detection, Science’10:

“…validates the use of

disk structures as

fingerprints of embedded

planets.”

Gaps and ring-like structures inhydro-dynamical simulations


Radiative transfer1D slab geometry?


Puffed up inner rimDullemond et al.2001Kama et al. 2010

ShadowTmid - lower


Puffed up second rim

Tmid - warmer

ShadowTmid - lower


Puffed up third rim


0)

II)

Hydrostatic and radiation balance

I) T(x,y,z) by MC


Proto-planetary disk models


T Tauri disk


Gaps and ring-like structures

without planet

extinction layer (photosphere)

τ(zbot) :=1


Gaps and ring-like structures in the

mid-IR emission


Gaps and ring-like structures in

scattered light


v PAH detection statistics

v PAH excitation /

destruction

PAH emission from disks


PAH in a mono-energetic heating bath

if | Uf – Ui – hν | < ½ ΔUf : Afi = Kν Fν / hν

Siebenmorgen & Krűgel (2010) PAH emission from disks


v store PAH absorption events of each cell

v compute PAH emission

v neglect PAH self absorption

Monte Carlo + PAH


Ralf Siebenmorgen Shadows in planet forming disksPAH emission from disks

MC versus benchmark

Ralf Siebenmorgen Shadows in planet forming disks

Eo

PAH destructionUnimoleculardissociation

1) single hard photon : independent of distance2) many soft photons : ~AU

Arrhenius form:tdis ~ exp(Eo/kT) / ν0 « tcool ~ 1s

Tmin = Eo/k ln(ν0) ~2000K; Eo ~ 5eV; ν0 = 1013Hz

ΔE = 3Nc kTmin ~ 0.1 Nc.Eb => Nc < 2 ΔE /[eV]

PAH unstable

Siebenmorgen & Krűgel (2010)

T [K]

time

tcool

tabs ~ 1h


Stationary diskSufficient X-ray photons?

α

ℓ τ = 1

z

I

}

# C in PAH # hard γ absorption/sec

‘PAH removal time’ << T Tauri pahse

top extinction layer Σℓ= α/κ

= hν · 4πr2/Lκ


Vertical mixing

ℓ /v┴ = texp > tdis

Disk lifetime => PAH replenishment

Siebenmorgen & Krűgel (2010)

Ralf Siebenmorgen Shadows in planet forming disksPAH emission from disks

T Tauri



Mid-IR emission from Herbig disks

Siebenmorgen & Heymann (2012)


Shadows in planet forming disks

v Dust model for:

extinction, emission, linear and circular polarisation

vGaps and ring-like structures:

... are caused by hydrostatic + radiation balance without

the need to postulate a companion/planet

(Siebenmorgen&Heymann, 2012).

v PAH emission from disks:

Low / high detection statistics of PAH in T Tauri /

Herbig Ae stars is consistent with X-ray destruction of

PAH (Siebenmorgen & Krűgel 2010).


PAH band ratios:ionisation dehydrogenation


Galiano et al.’08


K06 : Krügel (2006)Dusty : Iveciz et al. (1999)

Dust sphere: AV = 1000mag, heated by star

Comparison of 2 ray tracing codes


SphereT* = 2500Kρ(r) = const.

AV=10

1

100 1000 mag

~5% for0

MC versus benchmark



Method Parallelization AdvantageTime

Benchmarksphere τ~1000)

Lucy YES (but floating) Optical thin >1h

Bjorkman & Wood

Partly(not

independent)No iteration 5min

our YES GPU <1min

MC methods



3Dproto-planetary disk

+ spiral

MHD (Fargo) density

T* = 5800KL * = LsunAv =10mag

8au3au


ELT 42mPAH imaging


D = 50pc50mas

at 11.3µmPSFdual band + coronograph

ELT 42mPAH imaging


D = 50pc50mas

at 11.3µm

MIR imaging

gap

/px


ISMKrügel&Siebenmorgen (1994)

Homogenous versus composite grains

Documents

Andreas Efstathiou, Frank Heymann, Endrik Kr gel, Nikolai … · 2015-11-04 · Two-phase AGN tours models: SED library Andreas Efstathiou, Frank Heymann, ... RT in homogenous disks