Inga Kamp The role of the central star for the structure of protoplanetary disks

Inga KampInga Kamp

The role of the central star for The role of the central star for the structure of the structure of

protoplanetary disksprotoplanetary disks

Peter Woitke, Wing-Fai Thi, Ian Tilling (all Edinburgh)Peter Woitke, Wing-Fai Thi, Ian Tilling (all Edinburgh)

Protoplanetary Disks and Planet Protoplanetary Disks and Planet FormationFormation

Dust dynamics are controlled by gas, even at late times !• dust substructure• dust coagulation• dust settling

[HR4796: NICMOS 1.6 mSchneider et al. 1999] 8 Myr

Jy/pixel

[Reverse ∂p/∂r at 70 AU Klahr & Lin 2001]

[Barge & Sommeria 1995, Johansen et al. 2006, 2007]

OutlineOutline

• Various planet forming environments (BD - T Tauri - Herbig)

• Second generation disk structure modeling

• How do observations inform us about the star-disk interaction ?

Protoplanetary Disk ModelsProtoplanetary Disk Models

Key astrophysical questions:

• What is the environment in which planets form ? disk structure - boundary conditions for planet formation

• Can planets form around stars different from our Sun ? star-disk interaction - impact on disk structure and dispersal

OutlineOutline




Disk propertiesDisk properties

[2 BDs @ 2 and 10 Myr: Sterzik et al. 2004]

[8m excess @ 5 Myr: Carpenter et al. 2006]

[Pascucci et al. 2003, Allers et al. 2006, Bouy et al. 2008]

Dust in BD disks evolves on same time scale as T Tauri disks

Inner disk clearing occurs much faster in T Tauri disks

Dust models fit BD, T Tauri and Herbig SEDs in the same wayindicating the first steps of planetesimal formation in all cases

some BD SEDs require flaring disks, others flat… low # statistics

Disk propertiesDisk properties

[Pascucci et al. 2009]

[Kessler-Silacci et al. 2007]

lower HCN/H2C2 ratios in the disks around brown dwarfsweaker and more processed silicate features

OutlineOutline




comparisonwith observation

radiativetransfer


physical structure

chemical composition


radiativetransfer


physical structure


surface density = 0 (r/r0)-p

dust temperature T = T0 (r/r0)-q

disk scale height H = H0 (r/r0)-e

[e.g. Menard et al.; Pinte et al. 2006]


radiativetransfer


physical structure


surface density = 0 (r/r0)-p

dust temperature 2D continuum RTdisk scale height H = (cs

2 r3/GM*)0.5

[e.g. D’Alessio et al. 1998, Dullemond et al. 2002]

Gas chemical modeling on top of fixed density structure

[e.g. Aikawa et al. 2002, Semenov et al. 2008]


line radiativetransfer


physical structure


atomic/ionizedrich molecular chemistry

molecule freeze-out

hot flaring surface

cold midplane

[e.g. Aikawa et al. 2002, Kamp & Dullemond 2004][PPV chapters: Dullemond et al. 2007, Bergin et al. 2007]



radiativetransfer

physical structure


[Woitke, Kamp, Thi 2009]

ProDiMo

Similar approaches have been followed by other groups[Nomura & Millar 2005, Gorti & Hollenbach 2004, 2008]

ChemistryChemistry

nnnnknnkdtdn

ijijj

ijkijk

jikkjjk

ijki

stationary solution with modifiedNewton-Raphson algorithm (switch to time-dependant)65 species: H, H+, H-, H2, H2

+, H3+

He, He+

C, C+, CO, CO+, CO2, CO2+, HCO, HCO+, H2CO

CH, CH+, CH2, CH2+, CH3, CH3

+, CH4, CH4+, CH5

+

O, O+, O2, O2+, OH, OH+

H2O, H2O+, H3O+

N, N+, NH, NH+, NH2, NH2+, NH3, NH3

+, N2, HN2+

CN, CN+, HCN, HCN+, NO, NO+ Si, Si+, SiH, SiH+, SiO, SiO+, SiH2

+, SiOH+

S, S+, Mg, Mg+, Fe, Fe+ --> plus CO, H2O, CO2, CH4, NH3 ice

Heating and coolingHeating and cooling

photo-electric heating, PAH heating, viscous (α) heating, cosmic ray, C photo-ionisation, coll. de-excitation of H⋆

2 , H2 on grains, H2 photodissociation, IR background line heatingthermal accomodation on grains, OI, CII, CI fine-structure cooling, CO ro-vibrational (110 levels, 243 lines), o/p H2O rotational (45/45 levels, 258/257 lines), o/p H2 quadrupole (80/80 levels, 803/736 lines), SiII, SII, FeII semi-forbidden (80 levels, 477 lines), Ly α, MgII h&k, OI 6300Å

Heating

Cooling

kk (Tgas,ni) k

k (Tgas,ni)

Heating and coolingHeating and cooling

photo-electric heating, PAH heating, viscous (α) heating, cosmic ray, C photo-ionisation, coll. de-excitation of H⋆

2 , H2 on grains, H2 photodissociation, IR background line heating, (X-ray heating)thermal accomodation on grains, OI, CII, CI fine-structure cooling, CO ro-vibrational (110 levels, 243 lines), o/p H2O rotational (45/45 levels, 258/257 lines), o/p H2 quadrupole (80/80 levels, 803/736 lines), SiII, SII, FeII semi-forbidden (80 levels, 477 lines), Ly α, MgII h&k, OI 6300Å

Heating

Cooling

kk (Tgas,ni) k

k (Tgas,ni)


soft inner and outer edges [Hartmann et al. 1989, Hughes et al. 2008, Woitke, Kamp & Thi 2009]

stellar UV

interstellar UV

stellar X rays

The Thermal BalanceThe Thermal Balance

stellar photonse-

e-e-

e-

small grains: a << (e.g. PAHs)yield ~ ??

large grains: a >> (micron sized)yield ??

Photoelectric heating of the gas


stellar photonse-

e-e-

e-

small grains: a << (e.g. PAHs)yield ~ ??

large grains: a >> (micron sized)yield ??

Photoelectric heating of the gas

[Abbas et al. 2006]

Impact of UV IrradiationImpact of UV Irradiation

FUSE: Apr 2000 STIS: Oct 2001 May 2001 GHRS: Nov 1994

OVI

H2

HD104237

H2, CO photodissociation C ionization


time

UV

exc

ess

5000 K50010 50 80


time

UV

exc

ess

0 log n(OH)/n(tot)-5-14 -10


soft inner and outer edges [Hartmann et al. 1989, Hughes et al. 2008, Woitke, Kamp & Thi 2009]

stellar UV

interstellar UV

stellar X rays


stellar X-rays e-

e-

X-ray heating of the gas

[Glassgold et al. 2004, Meijerink et al. 2008]

TW HyaLX ~ 1030 erg/s

[Kastner et al. 1997][Nomura et al. 2007]

e-

*

Auger electrons

Secondary ionization

Primary ionization

124.0 Å 1.24 Å

*


Flaring disk structure “early Sun”

M* = 1 M

L* = 1 L

Teff = 5800 KMdisk = 10-2 M

0.5-500 AU

dust:

90% Mg2SiO410% Fe0.1-10 m (2.5)

[Woitke, Kamp, Thi 2009]

X-ray source @ 20 R toirradiate disk midplane


Flaring disk structure “Herbig star”

M* = 2.2 M

L* = 32 L

Teff = 8500 KMdisk = 10-2 M

0.5-500 AU

dust:

90% Mg2SiO410% Fe0.1-10 m (2.5)

T Tauri Herbig Ae


Flaring disk structure “Herbig star”

M* = 2.2 M dust: L* = 32 L 90% Mg2SiO4Teff = 8500 K 10% FeMdisk = 10-2, 10-3, 10-4 M 0.05-200 m (3.5)0.5-700 AU

self-similarity

decreasing disk mass

Herbig Ae T Tauri

OutlineOutline




Probes of UV Irradiation: [OI], OHProbes of UV Irradiation: [OI], OH

[Bally et al. 2000, Störzer & Hollenbach 1998, Acke et al. 2005]

WFPC2

OH photodissociation layer: OH + O* + HO* denotes the 1D2 excited level (decay emits a 6300 Å photon)

460 AU

[Mandell et al. 2008, Salyk et al. 2008]

Probes of UV Irradiation: [OI], OHProbes of UV Irradiation: [OI], OH

[Bally et al. 2000, Störzer & Hollenbach 1998, Acke et al. 2005]

OH photodissociation layer: OH + O* + HO* denotes the 1D2 excited level (decay emits a 6300 Å photon)

[Mandell et al. 2008, Salyk et al. 2008]

norm

aliz

ed fl

ux

velocity [km/s]

VLT/UVES: HD97048

Probes of UV, X-ray Irradiation: CO, HProbes of UV, X-ray Irradiation: CO, H22

[Brittain et al. 2007]

Fluorescence excitation vs. thermal emission:CO UV pumping of electronic states => cascade into high v levelsH2 UV (Lyman & Werner bands) or X-rays (collisions with fast e-)

[v=1-0 S(1), S(0), v=2-1 S(1) NIR: Carmona et al. 2008]see talk by Gerrit van der Plas

Probes of UV, X-ray Irradiation: CO, HProbes of UV, X-ray Irradiation: CO, H22

[Brittain et al. 2007]

Fluorescence excitation vs. thermal emission:CO UV pumping of electronic states => cascade into high v levelsH2 UV (Lyman & Werner bands) or X-rays (collisions with fast e-)

[S(1), S(2), S(4) pure rotational MIR lines: Bitner et al. 2008]see talk by Gerrit van der Plas

Probes of X-ray Irradiation: NeIIProbes of X-ray Irradiation: NeII

[Glassgold et a. 2007, Pascucci et al. 2007, Lahuis et al. 2007, Meijerink et al. 2008]

see talk by Richard Alexander

0 50 100 150 200R (AU)

D: 13CO 3-2E: 13CO 1-0

C: 12CO 2-1H: HCO+ 4-5

H

[van Zadelhoff et al. 2001]

Probes of gas-dust decouplingProbes of gas-dust decoupling[Pietu et al. 2007]

temperatures derived from gas lines at the surface are higher than dust temperatures => support for decoupling of gas and dust in the surface layers

C

ED

[Fedele et al. 2008]

Probes of gas-dust decouplingProbes of gas-dust decoupling

dust is flat (self-shadowed) and gas is flaring=> support for decoupling of gas and dust in the surface layers

MIR dust emission

[OI] emission

GASPS: A Herschel Key programGASPS: A Herschel Key programGAS evolution in Protoplanetary Systems (PI: Dent)

~200 disks distributed over spectral type, age, and disk mass

[CII], [OI], CO and H2O lines

Aim: probe the gas mass evolution throughout the planet forming phase

line radiativetransfer

physical structure



GASPS: A Herschel Key programGASPS: A Herschel Key program

Monte Carlo line radiative transfer

understand where the line originatesand then put resolution there !!

Kamp, Tilling, Woitke, Thi, Hogerheijde

[Hogerheijde, van der Tak 2000]

Key points to take homeKey points to take home

• Models predict that stellar UV and X-ray radiation shape the disk structure and chemistry and we actually observe that !

• Individual gas lines DO NOT probe total disk mass ! but we keep trying with multiple tracers …

• Gas lines DO probe the physical and chemical conditions in the region where they arise (interplay between radiative transfer and chemical structure)

and we try hard with GASPS to find the desperately wanted 10-4 M disks…

Thank You !Thank You !

Inga Kamp The role of the central star for the structure of protoplanetary disks

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