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; takahashi.sanemichi@a.mbox.nagoya-u.ac.jp, inutsuka@nagoya-u.jp2 Department of Physics, Kyoto University, Oiwake-cho, Kitashirakawa, Sakyo-ku,

Kyoto 606-8502, Japan; sanemichi@tap.scphys.kyoto-u.ac.jpReceived 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!

HL Tauby ALMA

NMA (Nobeyama Millimeter Array)

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

Resistive MHD Calc. from Mole. Cloud Core

SI, Machida, & Matsumoto (2010) ApJ 718, L58

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

SI, Machida, & Matsumoto (2010) ApJ 718, L58

Formation of Protoplanetary Disk

t = t*

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