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The chemistry and stability of the protoplanetary disk surface. Inga Kamp In collaboration with: Kees Dullemond (MPA) Ewine van Dishoeck (Leiden) Bastiaan Jonkheid (Leiden). David Hardy, NASA. The chemistry and stability of the protoplanetary disk surface. Inga Kamp - PowerPoint PPT Presentation
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The chemistry and stability ofThe chemistry and stability ofthe protoplanetary disk surfacethe protoplanetary disk surface
Inga Kamp
In collaboration with:
Kees Dullemond (MPA)
Ewine van Dishoeck (Leiden)
Bastiaan Jonkheid (Leiden)
David Hardy, NASA
The chemistry and stability ofThe chemistry and stability ofthe protoplanetary disk surfacethe protoplanetary disk surface
Inga Kamp
In collaboration with:
Kees Dullemond (MPA)
Ewine van Dishoeck (Leiden)
Bastiaan Jonkheid (Leiden)
David Hardy, NASA
MotivationMotivation
??
Protoplanetary disk in Orion
Debris disk
The basic modelThe basic model
density distribution
gas temperaturechemical composition
dust temperature
heating/coolingequilibrium
chemistry
- disk masses: 10-4 - 0.01 M Sun
- elemental abundances: molecular cloud abundances
- optical properties of dust grains: single 'mean' grain size
- dust temperature: radiative equilibrium
- gas-to-dust mass ratio: variable
- UV radiation fields: interstellar radiation field, photospheric radiation field, photosphere+chromosphere
Vertical densitystructure in a flaring T Tauri disk
[Dullemond et al. 2002]
CO, H2 photodissociation
UV radiation field of a T Tauri star
scaled solar chromosphere + IUE data + stellar atmosphere model
[Kamp & Sammar 2004]
log
z/r
The chemical structureThe chemical structure
= 1 layer
Interface disk-remnant gas
2000 K
500 K
-4
0
-8
H2 is chemically
destroyed by O inthe hot regions
H2 + O OH + HOH + O + H
The chemical structureThe chemical structure
= 1 layer
Interface disk-remnant gas
- warm H2 present in disk surface
layers (thermally excited, Tex~ few 100 K)
- warm surface contains observable molecules such as e.g. CO, CH, OH
The gas temperatureThe gas temperature
Gas and dust couple well abovethe superheated surface layerof the disk
2000 K
500 K
100 K
50 K
The gas temperatureThe gas temperature
Gas and dust couple well abovethe superheated surface layerof the disk
Evaporation of the surfaceEvaporation of the surface
- Gas densities are high enough to couple H to the remaining species
- Disk surface evaporates inside of ~50 AU verify with fully self-consistent disk models
Structure of the diskfrom the assumption of
hydrostatic equilibrium
Chemistry
Gastemperature
Outlook: Disk structure modelsOutlook: Disk structure models
- self-consistent stationary disk models
- comparison with observations by scanning through the disk with e.g. VISIR, IRAM, ALMA in the NIR to submm feedback for the models
Structure of the diskfrom the assumption of
hydrostatic equilibrium
Chemistry
Gastemperature
Outlook: Disk structure modelsOutlook: Disk structure models
- self-consistent stationary disk models
- comparison with observations by scanning through the disk with e.g. VISIR, IRAM, ALMA in the NIR to submm feedback for the models
Structure of the diskfrom the assumption of
hydrostatic equilibrium
Chemistry
Gastemperature
Outlook: Disk structure modelsOutlook: Disk structure models
- self-consistent stationary disk models
- comparison with observations by scanning through the disk with e.g. VISIR, IRAM, ALMA in the NIR to submm feedback for the models
- evaporation of the inner disk as a function of spectral-type of central star (include X-rays)
- compile heating/cooling tables for hydrodynamical modeling
The EndThe End
