The radiation pressure barrier in massive star formation Rolf Kuiper
The radiation pressure barrier in massive star formation Rolf Kuiper
The radiation pressure barrier in massive star formation Rolf Kuiper
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<strong>The</strong> <strong>radiation</strong> <strong>pressure</strong> <strong>barrier</strong><br />
<strong>in</strong> <strong>massive</strong> <strong>star</strong> <strong>formation</strong><br />
<strong>Rolf</strong> <strong>Kuiper</strong><br />
<strong>Rolf</strong> <strong>Kuiper</strong><br />
H. Klahr, H. Beuther, T. Henn<strong>in</strong>g, C. Dullemond, M. Flock (MPIA),<br />
W. Kley (University of Tüb<strong>in</strong>gen), T. Hosokawa (JPL)<br />
Scientific colloquium - MPIA Fachbeirat, Heidelberg, March, 24 th 2010<br />
Scientific colloquium – MPIA Fachbeirat, Heidelberg March, 24 th 2010
Generalized Edd<strong>in</strong>gton limit:<br />
● M → 20 M º<br />
Dynamic 1D limit:<br />
● M → 40 M º<br />
<strong>Rolf</strong> <strong>Kuiper</strong><br />
<strong>The</strong> <strong>radiation</strong> <strong>pressure</strong> problem<br />
not to scale<br />
Scientific colloquium – MPIA Fachbeirat, Heidelberg March, 24 th 2010
Generalized Edd<strong>in</strong>gton limit:<br />
● M → 20 M º<br />
Dynamic 1D limit:<br />
● M → 40 M º<br />
Yorke & Sonnhalter (2002):<br />
● “Flashlight effect”<br />
● Frequency dependent<br />
<strong>Rolf</strong> <strong>Kuiper</strong><br />
<strong>The</strong> <strong>radiation</strong> <strong>pressure</strong> problem<br />
● But: shorten disk accretion phases<br />
● M → 43 M º<br />
Krumholz et al. (2007, 2009):<br />
● Non-axially symmetric modes required<br />
● M → 41.5 M º (primary) + 29.2 M º (secondary) + 28.3 M º (disk+envelope)<br />
not to scale<br />
Scientific colloquium – MPIA Fachbeirat, Heidelberg March, 24 th 2010
Aim:<br />
● S<strong>in</strong>gle yet versatile code to test<br />
the proposed solutions:<br />
● Splitt<strong>in</strong>g stellar ir<strong>radiation</strong><br />
<strong>Rolf</strong> <strong>Kuiper</strong><br />
and thermal dust emission<br />
● Frequency dependent stellar<br />
lum<strong>in</strong>osity feedback<br />
● 1D, 2D, and 3D<br />
Code:<br />
Code development<br />
● Open source Magneto-Hydrodynamics code Pluto (v3.0)<br />
● plus Frequency dependent <strong>radiation</strong> transport<br />
● plus Poisson-solver<br />
Poisson<br />
PIA cluster at the Garch<strong>in</strong>g comput<strong>in</strong>g center.<br />
● plus Stellar evolution model (tracks by Hosokawa & Omukai 2009)<br />
● plus Dust model (Laor & Dra<strong>in</strong>e 1993)<br />
Scientific colloquium – MPIA Fachbeirat, Heidelberg March, 24 th 2010
●Setup:<br />
<strong>Rolf</strong> <strong>Kuiper</strong><br />
Configuration<br />
● Monolithic collapse <strong>in</strong> spherical coord<strong>in</strong>ates /<br />
Accretion onto a s<strong>in</strong>gle <strong>massive</strong> <strong>star</strong><br />
Initial conditions:<br />
● Outer radius of 0.1 pc<br />
● Density ~ r -2<br />
● Temperature = 20 K<br />
● Rigid rotation = 1.6*10 -5 yr -1 (<strong>in</strong> 2 and 3D)<br />
Numerical configuration:<br />
● 2 nd order accurate <strong>in</strong> space and time<br />
● Semi-permeable <strong>in</strong>ner and outer boundaries<br />
(mass can leave but not enter the doma<strong>in</strong>)<br />
64 x 16 grid:<br />
0.1 pc<br />
100 AU<br />
Scientific colloquium – MPIA Fachbeirat, Heidelberg March, 24 th 2010
<strong>Rolf</strong> <strong>Kuiper</strong><br />
Key features<br />
● Superior frequency dependent ray-trac<strong>in</strong>g step (ir<strong>radiation</strong>)<br />
● Fast and robust flux limited diffusion solver (dust emission)<br />
● Resolution down to 1.27 AU (~10 times higher than before)<br />
● Complete coverage of the accretion phase (10 5 … 10 6 yr) for the first time<br />
● First broad scan of the parameter space (37 simulations analyzed so far)<br />
Scientific colloquium – MPIA Fachbeirat, Heidelberg March, 24 th 2010
● Dimension = 1D, 2D, 3D<br />
● Resolution / Convergence<br />
● S<strong>in</strong>k cell radius = 1 … 160 AU<br />
● Alpha-viscosity (2D) = 0 … 1<br />
● Initial core mass = 60 … 480 M º<br />
<strong>Rolf</strong> <strong>Kuiper</strong><br />
Variations of the 37 simulations<br />
Scientific colloquium – MPIA Fachbeirat, Heidelberg March, 24 th 2010
<strong>Rolf</strong> <strong>Kuiper</strong><br />
Visualization: Global collapse<br />
0.2 pc<br />
Scientific colloquium – MPIA Fachbeirat, Heidelberg March, 24 th 2010
Results:<br />
Larger s<strong>in</strong>k cells lead to ...<br />
● longer free fall phases<br />
<strong>Rolf</strong> <strong>Kuiper</strong><br />
Resolv<strong>in</strong>g the dust condensation front<br />
=> can be elim<strong>in</strong>ated analytically<br />
Scientific colloquium – MPIA Fachbeirat, Heidelberg March, 24 th 2010
<strong>Rolf</strong> <strong>Kuiper</strong><br />
Resolv<strong>in</strong>g the dust condensation front<br />
Scientific colloquium – MPIA Fachbeirat, Heidelberg March, 24 th 2010
Results:<br />
Larger s<strong>in</strong>k cells lead to ...<br />
● longer free fall phases<br />
<strong>Rolf</strong> <strong>Kuiper</strong><br />
Resolv<strong>in</strong>g the dust condensation front<br />
=> can be elim<strong>in</strong>ated analytically<br />
● dim<strong>in</strong>ished shadow<strong>in</strong>g<br />
=> S<strong>in</strong>k cells <strong>in</strong> Yorke & Sonnhalter<br />
(2002) were too large!<br />
Scientific colloquium – MPIA Fachbeirat, Heidelberg March, 24 th 2010
Break<strong>in</strong>g through<br />
the upper mass limit of spherical symmetric accretion<br />
<strong>Rolf</strong> <strong>Kuiper</strong><br />
Scientific colloquium – MPIA Fachbeirat, Heidelberg March, 24 th 2010
<strong>Rolf</strong> <strong>Kuiper</strong><br />
Visualization: Non-axial symmetric outflows<br />
~ 200 AU<br />
Scientific colloquium – MPIA Fachbeirat, Heidelberg March, 24 th 2010
Results:<br />
<strong>Rolf</strong> <strong>Kuiper</strong><br />
<strong>The</strong> 3 rd dimension:<br />
Angular momentum transport via self-gravity<br />
● Gravitational <strong>in</strong>stabilities (Toomre: 1 < Q < 2)<br />
● Mean accretion rate ~ viscous disk evolution<br />
Scientific colloquium – MPIA Fachbeirat, Heidelberg March, 24 th 2010
<strong>Rolf</strong> <strong>Kuiper</strong><br />
Visualization: Angular momentum transport<br />
~ 80 AU<br />
Scientific colloquium – MPIA Fachbeirat, Heidelberg March, 24 th 2010
Ongo<strong>in</strong>g projects:<br />
<strong>Rolf</strong> <strong>Kuiper</strong><br />
What's next?<br />
● Detailed study of the outflow region <strong>in</strong> three dimensions<br />
● Consistent stellar evolution model<strong>in</strong>g (with T. Hosokawa, JPL)<br />
● Broader scan of the parameter space (density profiles, rotation)<br />
Long-term tasks:<br />
● Ionization + <strong>radiation</strong> <strong>pressure</strong> feedback<br />
● Radiation Magneto-Hydrodynamics<br />
Magneto<br />
● S<strong>in</strong>k particles for study of disk fragmentation<br />
Scientific colloquium – MPIA Fachbeirat, Heidelberg March, 24 th 2010
<strong>Rolf</strong> <strong>Kuiper</strong><br />
You shall resolve the<br />
dust condensation front!<br />
No “3D Radiative<br />
Rayleigh-Taylor”<br />
<strong>in</strong>stability.<br />
Summary<br />
Disk accretion produces<br />
the most <strong>massive</strong> <strong>star</strong>s!<br />
Self-gravity drives a sufficient<br />
angular momentum transport!<br />
Scientific colloquium – MPIA Fachbeirat, Heidelberg March, 24 th 2010
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