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The Formation and Early Evolution of Protoplanetary Disks
Division H Meeting
August 10, 2015 IAU General Assembly @Honolulu
Shu-ichiro Inutsuka (Nagoya Univ.)M. Machida
(Kyushu Univ)
Y. Tsukamoto (Riken)
T. Matsumoto(Hosei Univ.)
Ring Separation≈ 10~15AU
100AU
Nov. 5, 2014
Multiple Rings by ALMA
ALMA (arXiv:1503.02649)
Obs: Oct.14-Nov.14, 2014
The Astrophysical Journal, 794:55 (7pp), 2014 October 10 doi:10.1088/0004-637X/794/1/55© 2014. The American Astronomical Society. All rights reserved. Printed in the U.S.A.
TWO-COMPONENT SECULAR GRAVITATIONAL INSTABILITY IN A PROTOPLANETARY DISK:A POSSIBLE MECHANISM FOR CREATING RING-LIKE STRUCTURES
Sanemichi Z. Takahashi1,2 and Shu-ichiro Inutsuka11 Department of Physics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8602,
Japan; [email protected], [email protected] Department of Physics, Kyoto University, Oiwake-cho, Kitashirakawa, Sakyo-ku,
Kyoto 606-8502, Japan; [email protected] 2013 December 25; accepted 2014 July 28; published 2014 September 24
Prediction (Sep. 24, 2014)
Secular Grav. Inst.Origin of Debris
DisksPublished in ApJ prior toALMA press-release (Nov. 5) and even before Observation (Oct.14-Nov.14, 2014)!
No Planet Needed!
Outline• Basic Concepts in Star Formation
First Core & Second Core (=Protostar)Outflows vs. Jets
• Formation of Magnetized PPD• Controversy• All 3 Non-Ideal MHD Effects
Ohmic, Ambipolar, and Hall Diffusion• Fragmentation, Disk Wind by MRI, and Secular GI
Focus on Formation of Single Stars
First Core(Larson 1969)
Second Core = Protostar
γeff = 5/3
Masunaga, Miyama, & SI 1998, ApJ 495, 369; Masunaga & SI 2000, ApJ 531, 350 See also Tomida et al.2011, Commerçon et al. 2011, Vaytet et al. 2012
Second Collapse
First Collapse
Dissociation of H2Ebind = 4.48 eV
dense core:
n=105/cc
γeff = 7/5
Temperature Evolution at Center
Effective Ratio of Specific Heats
γeff =1.1 < γcrit =4/3
mainly H2
Dead Zone
Stage 1: Outflow driven from the first core
360 AU
Grid level L =12 (Side on view) Grid level L =12 (Top on view)
This animation start after the first core is formed at n~1010 cm-3
The evolution of the Outflow around the first core Model for(α, ω)=1, 0.3
Same as in Tomisaka 2002
0.35 AU
Stage 3: Jet driven from the protostar
Grid level L =21 (Side on view)This animation start before the protostar is formed at n~1019 cm-3
The evolution of the Jet around the protostar Model for(α, ω)=1, 0.003
Difference in Driving Mechanism
Outflow
Magnetic Pressure driven Wind
Weak B
Narrow Opening Angle
Magnetocentrifugallydriven Wind
Strong B
Wide Opening Angle
Machida, SI, & Matsumoto (2008) ApJ 676, 1088
jet around protostarBz << Bφ
outflow around first coreBr ≈ Bz ≈ Bφ
only at launching region, not in distant region
Observations:
Velusamy, T. et al. 2007 ApJ 668, L159,
Velusamy, T. et al. 2011 ApJ 741, 60
The first coregradually transforms into a protostellar disk!
Machida et al. (2006-2012), Banerjee & Pudritz (2006), Hennebelle et al. (2008), Duffin & Pudritz (2011), Commerçon et al. (2011), Tomida et al. (2011)
Disks appear only after all of these!
When and Where Disks Form?Outflow jet
first core protostar
v~5 km/s v~50 km/s
360 AU
End of Formation Phase
Machida, SI & Matsumoto (2011) PASJ 63, 555
Disk Growth Correlated with Depletion of Envelope Mass
L
t
L ~ λJRdisk
dead zone
Mdisk < Menv Mdisk > MenvMdisk = M*=0
101AU
102AU
t = t*
Inutsuka (2012) PTEP 2012, 01A307
Formation of Protoplanetary Disk
Formation of First Core
Formation of Second Core
Magnetic Braking and Disk Formation• Ideal MHD No Disk Formation
–“Magnetic Braking Catastrophe” (Mellon & Li 2008) Formation in Dead Zone (SI+2010, Machida+2011)
• Misalignment of Rotation Axis and B Disk Formation?–Hennebelle+2009; Joos+2009 (only a factor of 2 change)–Li+2013 Negative Result Convergence Test Needed
Grid-Scale ReconnectionLarge Numerical Dissipation (Low ReM)
• Turbulence + B Disk Formation?–Turbulent Diffusion of B (Lazarian & Vishniac) –Santos-Lima+11, 12; Seifried+2012 Convergence Test & How to Sustain Turbulence?
Three Different Non-Ideal MHD Effects
re-io
nize
d
ηODead Zone
– Ohmic Dissipation– Hall Current Effect– Ambipolar Diffusione.g., Nakano, Mouchouvias,
Wardle, Tassis, Galli,…
Ohmic + ambipolar diffusion: Tomida+2015, ApJ 801, 117Tsukamoto+2015, MN 452, 278
Tsukamoto+arXiv:1506.07242
ηH
ηA
Hall Current Term “Bimodality in Class 0”
B BOrtho-Disk Para-Disk
Ohm+ambipolar+Hall(parallel case)
Ohm+ambipolar+Hall(anti-parallel case)
Large Disk Formed!B: ⊗B: Only Tiny Disk!
Inherited in Embryo Phase
Tsukamoto+arXiv:1506.07242
Angular Momentum Conservation in Para-Disk Anti-Rotating Envelope with Scale ~ 100AU!
Observational Signature!
Formation of Anti-Rotating Envelope
300 AUB
Para-Disk
Ohm+ambipolar+Hall (anti-parallel case) Tsukamoto+arXiv:1506.07242
Edge-On ViewFace-On View
Summary for Formation Phase• Outflows from First Core & Jets from Protostar
– Ang. Mom. & Mag. Flux Problem• Disk Emerges in Dead Zone and Both Expand Together!• Disk Grows Rapidly after Dispersal of Envelope!• Bimodality in Disk Size Distribution due to Hall Current• The First Core becomes Protoplanetary Disk!
Mdisk > M* in disk formation phaseSuccessive Formation of Planetary-Mass Objects
• Episodic Accretion and Planet Falling Outburst of Protostellar Luminosity
Summarized in Inutsuka (2012) PTEP 2012, 01A307
Slow but Powerful Episodic Disk Winds
Suzuki & SI (2009) ApJ 691, L49Suzuki, Muto, & SI (2010) ApJ 718, 1289Bai & Stone 2013, Fromang+2013, Lesur+2013Distance from Midplane, Z
Observational Signature of Disk Winds
Observational evidence for disk winds•Natta+2014
–Slow (<20km/s) dense outflow of gas from disks around 44 T-Tauri stars•McJunkin+2014
–Extinction by interstellar medium (possibly dust) other than neutral hydrogen toward 31 YSOs•Ellerbroek+2014
–Optical fading and near infrared brightening of a Herbig Ae star probably by dust in disk winds
Miyake+1505.03704v1
Rapid Inner Hole Creation and DispersalDispersal Timescale ~ a few Myr for typical disk models
Suzuki, Muto, & SI (2010) ApJ 718, 1289
Important in Disk DispersalMore Powerful than Photo-Evaporation?
Distance from Central Star
SGI for 2-Component System (α=10−4)
Dispersion Relation
Stabilized!
Ring Formationt~2×106yr @100AU
Origin for α=10−4 (Okuzumi & SI 2015, ApJ 800, 47; Mori & Okuzumi 2015)
10-2,
Takahashi & SI (2014) ApJ 794, 55
Axisymmetric Modes
+ Effects of Turbulent Diffusion and Finite Disk Thickness
100AU
Multiple Rings by ALMA
ALMA (arXiv:1503.02649)
Multiple Rings with Separation ~ 13AU at 100AU Created by SGI if
α < 10-4,Q > 3,
Dust/Gas > 0.1,tstop/Ω ~ 0.1 (mm size)
Possibly we are witnessing the Formation ofSelf-Gravitating Objects!
Integrated Scenario For Planet Formation• Binary Formation
– Planet Formation in Circum-Stellar Disks?– Planet Formation in Circum-Binary Disks?
• Single Star Formation– With Early-Born Gaseous Planets
• Rocky Planet Formation in Outer Region Hybrid Scenario– Without Early-Born Gaseous Planets
• Classical Core-Accretion Scenario• Secular GI Planet Formation in Outer Regions
Origins of Debris Disks?
Planet Formation in Various Environments
September 29 – October 2, 2015Turner, N., Youdin, A., Nelson, R., Baruteau, C., Owen, J., Stamatellos, D., Gressel, O., Wardle,M., Mac Low, M., Nordlund, A., Haghighipour, N.,McNally, C., Keith, S., …
Protoplanetary Disk Dynamics and Planet
Formation
Sept 29-Oct 2 https://sites.google.com/site/ppdisk2015