Multi-technique observations and modelling of ... fileIntroduction IM Lup Gas & Dust Herschel...

Introduction IM Lup Gas & Dust Herschel Summary

Multi-technique observations and modelling

of protoplanetary disks

Christophe Pinte

University of Exeter

Christophe Pinte Multi-technique modelling 1/12


Collaborators

F. Menard, G. Duchene, J.C. Augereau,J. Olofsson, C. Ceccarelli, G. Duvert (LAOG,Grenoble)

D.L. Padgett, K. Stapelfeldt (IPAC &

JPL/Caltech)

G. Schneider (Steward Observatory)

P. Woitke, W.F. Thi, I. Tilling (ROE,Edinburgh)

I. Kamp (KAI, Groningen)

J. Cernicharo (DAMIR/CSIC, Madrid)

the GASPS teamChristophe Pinte Multi-technique modelling 2/12


Protoplanetary disks

Gas and dust disks are the birthplace of planets

?

Goal : characterizing the first steps of planet formation

Understanding disk structure as well as dust grain and gasproperties to test their evolution processes. For instance:

grain growth and settling

gas dissipation

formation of a large variety of planetary systems



A variety of observations

Each approach probes adifferent part of the disk

Disk modelling mustconsider as manyobservations as possibleat once

Multi-λ modelling

Not so frequent. . . but necessary!

HST/Nicmos HST/WFPC2 HST/WFPC21.6 µm 0.8 µm 0.6 µm

SMA 1.3mmVLTI Spitzer 5-30 µm



A variety of observations

Each approach probes adifferent part of the disk

Disk modelling mustconsider as manyobservations as possibleat once

Multi-λ modelling

Not so frequent. . . but necessary!

CO

OI CII

H2O

rotational lines

The same is true for the gas phase



Multi-λ modelling of IM Lupi Pinte et al, 2008

RT modelling with MCFOST (Pinte et al 2006)

A single model with mild stratification remarkably reproduces allobservations: H(1 mm)≈ 0.5 - 0.75 H(1 µm)

1.0 10.0 100.0 1000.

10−16

10−14

10−12

10.0 20.5.

10−13

2

λ (µm)

λ.F

λ (W

.m−

2 )

⇓

Mdisk, grain growthand settling

1’’N

EWFPC2 0.6 µm

Nicmos 1.6 µmNicmos 1.6 µm

Obs Models

⇓

Rext, i , H0, grain sizes& composition

0.1

0.2

0.05

0 50 100

0.01

0.02

0.005

Fν

(Jy)

Baseline (kλ)

Fν

(Jy)

SMA 1.3mm

ATCA 3.3mm

p=1

p=1

p=2

p=2

p=0

p=0

⇓

Surface densityΣ(r) ∝ r−p



IM Lup : quantitative constraints Pinte et al, 2008

Bayesian probabilities

SED + . . .

≈ 400 000 models

Some parameters fixedfrom data (amax,Mdust, Rout)+ Fitting 6 parameters

Bayesian approach toestimate modelparameters

0.00.51.00.0

0.5

1.0

−2−1 00.0

0.5

1.0

1.0 1.1 1.20.0

0.5

1.0

0.1 1.00.20.05 0.50.0

0.2

0.4

0.6

5 10 150.0

0.5

1.0

0.00 0.05 0.10 0.15 0.200.0

0.2

0.4

0.6

cos(i)cos(i)cos(i)cos(i)cos(i) surface densitysurface densitysurface densitysurface densitysurface density flaringflaringflaringflaringflaring

rin (AU)rin (AU)rin (AU)rin (AU)rin (AU) h0 (AU)h0 (AU)h0 (AU)h0 (AU)h0 (AU) stratificationstratificationstratificationstratificationstratification

Pro

bability

Pro

bability

Pro

bability

Pro

bability

Pro

bability

Pro

bability

Pro

bability

Pro

bability

Pro

bability

Pro

bability





SED + mm visibilities + . . .

≈ 400 000 models



0.00.51.00.0

0.5

1.0

−2−1 00.0

0.5

1.0

1.0 1.1 1.20.0

0.5

1.0

0.1 1.00.20.05 0.50.0

0.2

0.4

0.6

5 10 150.0

0.5

1.0

0.00 0.05 0.10 0.15 0.200.0

0.2

0.4

0.6



Pro

bability

Pro

bability

Pro

bability

Pro

bability

Pro

bability

Pro

bability

Pro

bability

Pro

bability

Pro

bability

Pro

bability





SED + mm visibilities + scattered light images

≈ 400 000 models



0.00.51.00.0

0.5

1.0

−2−1 00.0

0.5

1.0

1.0 1.1 1.20.0

0.5

1.0

0.1 1.00.20.05 0.50.0

0.2

0.4

0.6

5 10 150.0

0.5

1.0

0.00 0.05 0.10 0.15 0.200.0

0.2

0.4

0.6



Pro

bability

Pro

bability

Pro

bability

Pro

bability

Pro

bability

Pro

bability

Pro

bability

Pro

bability

Pro

bability

Pro

bability



Simultaneous modelling of gas & dust

Detailed model of the dust disk ofIRAS 04158+2805Glauser et al, 2008

Radiative transfer + chemistry

1 Temperature structure, UV fluxfrom MCFOST

2 CO abundance from chemistrymodel (coll. with C. Ceccarelli)

3 Level populations and emissionmaps with MCFOST

⇒ central mass (0.3-0.5M⊙) → ageturbulence (0.2-0.3 km.s−1)

Obs Model

−4 −2 0 2 4

0

5

10

−4 −2 0 2 4

v (km.s−1)F

lux

(Jy)

v (km.s−1)

Scattered light (HST) &12CO(3-2) (SMA)



GASPS and the DENT grid of models

Gas in Protoplanetary Systems (GASPS) key program

Systematic survey of gas and dust in disks (PI: W. Dent)

≈ 250 disks, 0.3 to 30 Myrs, spectral types: M4 to B2

PACS: OI, CII, CO and H2O + continuum

The DENT model grid (see poster B47 by P. Woitke)

coupling MCFOST & ProDiMo (Woitke et al 2009)

SEDs + NLTE line fluxes (+physical & chemicalstructure) for ≈ 320 000 disks models

⇒ dependence of continuum & line observation on star, diskand dust properties



Signatures of dust settling

Far-IR

is the regime where signatures ofdust settling are maximum⇒ probed by Herschel

Color-magnitude diagrams

distinction between settledand non settled disks

independent of the geometry,dust properties, . . . if Teff andMdisk known

Spitzer

Herschel

IRAM



Signatures of dust settling

Far-IR

is the regime where signatures ofdust settling are maximum⇒ probed by Herschel

Color-magnitude diagrams

distinction between settledand non settled disks

independent of the geometry,dust properties, . . . if Teff andMdisk known

Spitzer

Herschel

IRAM

31.5 32.0 32.5 33.0 33.5

2

3

4

[24 µm]

[210

µm

]-[2

4µm

]



Constraining the gas disk

Herschel/PACS

should detect lines even for lowluminosity T Tauri stars

First results of the DENT grid

Most lines scale withstellar parameters: Lstar

and UV excess

Line ratios eliminate themain scalings→ information about diskmass and shape

GASPS sensitivity limit



H2O lines with HIFI Cernicharo et al, 2009

Dust settling

dramatically changes theconditions for water vapor indisk⇒ H2O lines powerful tool

But dangerous

strongly depends oncollisional coefficients



Concluding remarks

A variety of datasets = finer disk models

Dust evolution and spatial differentiation are frequent indisks around T Tauri stars

By combining line and continuum data, more detailedinformation about the disks

Testing the physics of dust grains towards planet formation

Grain growth

Separate dust populations

dust and gas evolution?

Simultaneous studies of the gas & dust phases

are promising in the context of Herschel and ALMA


Multi-technique observations and modelling of ... fileIntroduction IM Lup Gas & Dust Herschel...

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