Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.eso.org/~rsiebenm/FTP/PPT/Kreta.pdf
Дата изменения: Fri Sep 24 18:50:11 2010
Дата индексирования: Fri Feb 28 11:29:52 2014
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AGN dust model of 3CR sources
Frank Heymann (PhD), Martin Haas, Endrik Krgel, Christian Leipski

MIR imaging & spectroscopy
ISM dust model & PAH SED of a clumpy AGN torus
CenA (ESO)
Crete 2010

vectorized Monte Carlo model

Ralf Siebenmorgen

1) Ground based MIR imaging
Nuclear activity in nearby galaxies
Surface brightness AGN viz. starbursts

Ralf Siebenmorgen

10m telescopes Crete

2010

1) Ground based MIR imaging
Nuclear activity in nearby galaxies
Surface brightness AGN viz. starbursts

unresolved
resolved

Ralf Siebenmorgen Siebenmorgen

et al. (2008)

10m telescopes Crete

2010

ELT 42m
MIR surface brightness diagnostics up to D ~ 500Mpc

Ralf Siebenmorgen

Crete 2010

2) MIR spectroscopy

PAH

No PAH

Silicate emission

Siebenmorgen et al. (2004, 2005) Ralf Siebenmorgen

Crete 2010

3) Spitzer photometr y of 3CR sources
· powerfull AGN: 178MHz flux limited, isotropic sample 23 quasars, 38 radio galaxies (Spitzer GTO: Fazio ) · 1 < z < 2.5 rest frame 1.6-10µm

Ralf Siebenmol. (2008) Haas et a rgen

Crete 2010

3) Spitzer photometr y of 3CR sources
· powerfull AGN: 178MHz flux limited, isotropic sample 23 quasars, 38 radio galaxies (Spitzer GTO: Fazio ) · 1 < z < 2.5 rest frame 1.6-10µm

· SED consistent with unification:

Quasar: ~flat

Haas et al.gen 008) Ralf Siebenmor (2

RG: reddened quasar + host · 24m surveys biased toCtype2010 rete I

4) Spitzer spectroscopy of 3CR sources
mean SED normalised to 178 MHz luminosity

Leipski etrgen (2010) Ralf Siebenmo al.

Quasar (11) ~ flat · no PAH

RG (9): reddened quasar + host similar emission linerete ios C rat 2010

5) Herschel obser vations of 3CR sources at z<1 (proposed by Haas + 19 CoIs)

filling the gap between

Spitzer + SCUBA/MAMBO
Ralf Siebenmorgen Crete 2010

3D Monte Car lo radiative transfer models

1) ISM dust model
2) PAH: SB emission & AGN destruction

4) clumpy AGN torus models

Ralf Siebenmorgen

Crete 2010

CenA (ESO)

3) MC model

1) ISM dust 2010

Abundances [X/H in ppm]:
solar neighborhood

31Si + 150aC + 50gr + 30PAH

extinction

Si + aC : 60е < a <0.2-0.3µm ~ a-3.5 Graphite : 5е < a < 80 е ~a-3.5 PAH : 3 0 C + 200 C
Ralf Siebenmorgen Crete 2010

2) PAH emission Radiative transfer in the nuclei of star bursts
Distribution of stars + "Hot spots" Nucleus of NGC1808

Tutokov & gen gel(1978); Siebenmorgen et al. (2001) Ralf Siebenmor Kr

Crete 2010

2) PAH emission Radiative transfer in the nuclei of star bursts

PAH cross section

Siebenmorgen et al. (2001), Draine & Li (2007); Tielens (2008)
Ralf Siebenmorgen

Crete 2010

SED librar y for SB
www.eso.org/~rsiebenm

· luminosity · size · mass

Siebenmorgen et al. (2007) Ralf Siebenmorgen

Crete 2010

SMG at high z

Efstathiougen Siebenmorgen (2009) Ralf Siebenmor &

Crete 2010

2) PAH destr uction
Eo

Unimolecular dissociation

T [K]

Arrhenius form: tdis ~ exp(Eo/kT) / T
min

0

«t

cool

~ 1s Eo ~ 5eV; 0 = 1013Hz

tcool
time

= Eo/k ln(0) ~2000K;
min

E = 3Nc kT

~ 0.1

Nc.Eb

=>

Nc < 2 E /[eV] (PAH unstable)

t

abs

~ 1h

Tielens Ralf Siebenmorgen

(2005) ; Micelotta et al. (2010) ; Siebenmorgen & Krgel (201Crete 0)

2010

2) PAH destr uction
Eo

Arrhenius form: tdis ~ exp(Eo/kT) / T
min

0

«t

cool

~ 1s Eo ~ 5eV; 0 = 1013Hz

= Eo/k ln(0) ~2000K;
min

E = 3Nc kT

~ 0.1 Nc.E

b

=>

Nc < 2 E /[eV] (PAH unstable)

1) single hard photon : independent of distance 2) many soft photons : ~inner torus
Tielens Ralf Siebenmorgen (2005) ; Micelotta et al. (2010) ; Siebenmorgen & Krgel (201Crete 0)
2010

3) Monte Carlo

Arbitrary dust distribution Pseudo adaptive mesh

1.

geometry

Krgel (2006 Ralf Siebenmorgen )

Crete 2010

Monte Carlo

Source emits "photon packages" of equal energy

1.

geometry source

2.

Ralf Siebenmorgen

Crete 2010

Monte Carlo
= - ln()

absorption / scattering / no interaction

1.

geometry source inter-action dust temperature

2.

3.

4.

Ralf Siebenmorgen

Crete 2010

Monte Carlo

Photons escape model cloud

1.

geometry source inter-action temperature detection
Crete 2010

2.

3.

4.

5.

Ralf Siebenmorgen

MC
parallelization
·

Multiple photons at a time:
Challenges
Cell locked when hit by photon Parallel random number generator (Mersene Twister) Computer games Graphical

Processing Units (CUDA)

Hey iebenmo gen Ralf Smann r(2010, PhD)

Crete 2010

Comparison of 2 ray tracing codes
Dust sphere: AV = 1000mag, heated by star

Benchmark = ,,Dusty code (Iveciz et al. 1999): unphysical at faint flux levels
Ralf Siebenmorgen Crete 2010

1D
MC versus benchmark
1

AV=10

100

1000 mag

Sphere T* = 2500K (r) = const.
~5% for 0

Ralf Siebenmorgen

Crete 2010

MC methods

Method

Parallelization YES (but floating)

Advantage

Time
Benchmark sphere ~1000)

Lucy Bjorkman & Wood our

Optical thin No iteration GPU

>1h 5min <1min

Partly (not independent)
YES

Ralf Siebenmorgen

Crete 2010

2D benchmark

Pascucci et al. (2004)

Disk:
T* = 5800K L * = Lsun (r) : hydro static equilibrium
(Chiang & Goldreich 1997)
Crete 2010

Ralf Siebenmorgen

2D benchmark

1= 10

face-on

edge-on

100

~10% for 0

Ralf Siebenmorgen

Crete 2010

Monte Carlo + PAH

store PAH absorption

events of each cell

compute PAH emission neglect PAH self absorption

Ralf Siebenmorgen

Crete 2010

Monte Carlo + PAH

Ralf Siebenmorgen

Crete 2010

4) clumpy AGN tor us - density structure

face-on

edge-on

3D models:
MIDI: Statistical model:
Ralf Siebenmorgen

Heymann (PhD) Tristram (2007) Nenkova et al.(2002, 2008)

Schartmann et al. (2008)

Crete 2010

Shadows caused by clump str ucture

dark side: cold

bright side: hot

10m emission face-on
Ralf Siebenmorgen Crete 2010

Number of clouds

SED of AGN

Quasar

RG

Ralf Siebenmorgen

Crete 2010

Mean SED of 3CR sources
Data: Haas et al (2008), Leipski et al. (2010)

Ralf Siebenmorgen

Crete 2010

Conclusion
MIR observations consistent with unified scheme. Dust model of the diffuse ISM for extinction and emission. PAH destruction by hard photons.

Monte Carlo dust radiative transfer model including PAH using vectorised computing technology.
Clumpy AGN torus model consistent with SED of 3CR sources.
Ralf Siebenmorgen Crete 2010

PAH in a mono-energetic heating bath

if | Uf Ui h | < Ѕ Uf : Afi = K F / h
Ralf Siebenmorgen Siebenmorgen

& Krgel (2010)

Crete 2010

PAH replenishment
Vertical mixing in torus? /v = t
exp

> NC t

abs

Ralf Siebenmorgen Siebenmorgen

& Krgel (2010)

Crete 2010

AGN and hard photons

(EUV, soft X-ray)

Ralf Siebenmorgen

Crete 2010

4) IRS spectroscopy

of 3CR sources

· Quasar (10) : ~ flat · RG (9): reddened quasar +host · similar emission line ratios

· no PAH

Leipski etrgen (2010) Ralf Siebenmo al.

Crete 2010