From Disks to Planets

Thomas Henning Max Planck Institute for Astronomy, Heidelberg

Polarized intensity image of MWC 758 with SPHERE at 1.04 µm with 0.027´´ resolution (26-148 AU) and best-fit model (Benisty et al. 2015) The Diversity of HD 69830 – Neptune´s Trident Planetary Systems

Lovis et al. (2006)

• Close-in giant planets („Hot“ Neptunes and Jupiters) – Super-Earths/-Jupiters

• Planets on eccentric orbits

• Densely packed systems (e.g. Kepler 11 with 6 planets)

• Planets in resonances (e.g. Gliese 876e,b,c: 1:2:4)

• Planets on wide orbits (HR 8799)

• Planets on tilted and retrograde orbits (HAT-P-7b, WASP-17b)

• Planets around binary stars (e.g. Kepler-16b, -34b, -35b) A Closer Look : Protoplanetary Disks

• Masses: 0.01 to 0.1 Msun (most mass in H2, 1% in dust) • Dimensions: A few 100 astronomical units • Structure: Disks with atmospheres, inner rims, gaps, … • Chemistry: Am. & Cryst. Silicates, water ice, molecules

•Dynamics: Special Class of Accretion Disks Transport of mass and angular momentum

TrΦ = ρ <δvr δvΦ > – <δBr δBΦ/4 π> Reynolds stress Maxwell stress Disk mass and planet mass

Mplanet =0.5 Mdisk

Maximal masses] [Jovian mass Planet planet mass increases Log(Mdisk /MMSN) with disk mass . Mordasini et al. (2012) Planet Formation and Disk Properties

Metallicity Disk mass Disk Lifetime

Mordasini, Alibert, Benz, Klahr, Henning (2012) Planet Formation & Evolution: M-R diagram

All synthetic planets and all planets with known Mordasini et al. (2012a, b) M-R outside 0.1 AU

Fraction z of solids (rest H/He) Orange: z ≤ 1% Black: z>90%

Mordasini et al. 2012c Disk Properties

Lifetimes – Masses – Metallicity - Ionization Structure - Viscosity • Total disk mass measurements remain a challenge -2 HD: Mdisk > 5x10 Msun for TW Hya (Bergin et al. 2013) -2 1.0-4.7x10 Msun for DM Tau (McClure et al. 2016)

• Lower gas-to-dust mass ratio from CO study (?) Williams & Best (2014)

1.3-1.9 • Mdust ~ Mstar (Pascucci et al. 2016) Discovery of HD in TW Hya

Bergin et al. (2013, Nature 493, 644), Disk mass > 0.05 Msun 3D Global Stratified MHD Simulation

Radius:1-10 AU

8 pressure scale heights

Blue Gene/P and Pluto code: Flock et al. (2011) PdBI Obs. of DM Tau in CS (3-2) (1“ resolution, 0.126 km/s): Guilloteau et al. (2012) Disk Properties - Turbulence

• Turbulent broadening ≤10-100 m/s ( ≤0.02 – 0.2 cs) for TW Hya and HD 163296 to higher velocities of

≤100-200 m/s ( ≤0.3 – 0.5 cs) for DM Tau, MWC 480, and LkCa15

(Dartois et al. 2003, Pietu et al. 2007, Hughes et al. 2011, Rosenfeld er al. 2012, Guilloteau et al. 2012, Flaherty et al. 2015)

Mostly parameteric models applied

• TW Hya: 130 m/s at 40 au to ~50 m/s in outer disks (Teague et al. 2016) Chemistry and Disk Structure: CO Snowline

+ Dust continuum CO (J=3-2) N 2H (J=4-3) + N2H anti-correlates with CO:

+ N2H + CO →

+ HCO + N 2

+ Modeling of N2H

Observation Model Residuals + N2H is abundant where CO is frozen-out

Qi et al. (2013) TW Hya – 30 AU Search for Snowlines in the Dust Towards Complex Molecules in Disks

• Carbonaceous chondrites contain more than 80 amino acids (e.g. Cronin & Pizzarello 1983, Glovin et al. 2006) • Discovery of glycine (& methylamine and ethylamine) in comets: Stardust mission – Wild 2 (Elsila et al. 2009) ROSINA – 67P/Churyumov-Gerasimenko (Altwegg et al. 2016)

(Sub) Millimetre Interferometry

• HC 3N (cyanopolyyne) in GO Tau & MWC 480 (Chapillon et al. 2012)

• CH 3CN (methylcyanide) in MWC 480 (Öberg et al. 2015)

• CH 3OH (methanol) in TW Hya (Walsh et al. 2016) (3x10 -12 – 4x10 -11 fractional abundance)

Complex organics could be as abundant as CH 3OH in outer disks (Drozdovskaya ea. 16) Evidence for Planet Formation • Radial size seggregation of dust particles (larger particles closer to star): (e.g. Perez et al. 2012, 2015, Menu et al. 2015, Tazzari et al. 2016)

Theoretical picture of pebble accretion (Ormel & Klahr 2010, Lambrechts & Johansen 2014, Kretke & Levison 2014, Levison et al. 2015)

• Massive RV planet in CI Tau (Johns-Krull et al. 2016)

• Protoplanet candidates in

HD 100546 (Quanz et al. 2013, 2015, Currie et al. 2014) HD 169142 (Reggiani et al. 2014, Biller et al. 2014) LkCa 15 (Sallum et al. 2015)

• Gaps and Spiral structures (HL Tau, TW Hya, ….) Evidence for Planet Formation? Lopsided Disks & Rings with ALMA … And Spiral Arms

Perez et al. (2016) Hubble Space Telescope Gallery of Debris Disks

Schneider et al. (2014) Sphere disk image gallery

β Pic MWC 758 SVT

HR4796A HD142527 COMM IFS Y-J Irdis H2 band COMM/GTO Spectral deconv . HD 106906 GTO LkCa 15 SVT AU Mic COMM/GTO Misaligned Disks and Shadows

HD 100453: Benisty et al. (2016); see also 142527 – Marino et al. (2015); HD 135344B - Stolker et al. (2016) No massive planets in outer gap ….

7.5 mag contrast at 70 AU gap (0.5´´): 10-15 Mjup (Testi, Skemer, Henning et al. 2015) Mechanisms for Ring Formation

• Dust Trapping at Local Pressure Maxima

• Secular gravitational instability – dust -gas interaction

• Snow lines of various solid materials – dust opacity Pressure Bumps & Particle Traps

r Whipple (1972), Vortices: Barge & Sommeria (1995), Klahr & Henning (1997)

• Edge of dead zone (Dzyurkevich et al. 2010, Flock et al. 2015, Ruge et al. 2016) • Snowline(s) (Kretke & Lin 2008, Brauer et al. 2008) • MRI instabilities – Zonal flows (e.g. Johansen et al. 2009, Uribe et al. 2011) • Spiral arms in self-gravitating disks (e.g. Dipierro et al. 2015) • Edge of a planet-induced gap (e.g. Pinilla et al. 2012) High-Resolution Study of Streaming Instability

1250x1250 (2D) – dust/gas density=30 (Schreiber et al. 2015) Mechanisms for HL Tau Disk

• Planet-Disk Interactions (Kanagawa et al. 2015, Dipierro et al. 2015, Akiyama et al. 2015, Picogna & Kley 2015)

• Dust Growth close to Condensation Fronts (Zhang et al. 2015) (Enhanced dust growth behind snow lines, leading to dust opacity changes)

• Dust Growth & Radial Drift including Sintering (Okuzumi et al. 2016) (Sintering close to sublimation fronts – Sintering zones appear as bright optically thick rings)

• Secular Gravitational Instabilities (Takahashi & Inutsuka 2016)

• Non-ideal MHD Disks (global simulations) (Flock et al. 2015, Ruge et al. 2016, Bethune et al. 2016) Planet Formation in Inner Ring …

Carrasco-Gonzalez, Henning & Chandler et al. (2016) Grain Size Distribution

Large Small From Gas Disks to Giant Planet Spectra

The Programme • Giant planet formation via core accretion & migration • Calculation of planet evolution & temperature structure • Abundances & chemistry in planet atmospheres • Calculation of emission and Transmission Spectra

A Research Program (with C. Mordasini, R. van Boekel, P. Molliere)

Absorption (methane, (methane, water, water, CO?) CO?)

Swain et al. (2008) Spitzer/IRS HD 209 458b Planetesimal vs. Gas Enrichment

Mordasini , van Boekel, Molliere, Henning & Bennecke (2016) Formation phase – Growth & Migration

Planet internal structure & gas envelope 1D internal structure equations Mass conservation, hydrostatic equilibrium, energy conservation, energy transport

Planetesimal accretion Safronov-type rate equation for dMcore /dt; enrich envelope with refractories and water ice beyond ice-line (water ice/refractories mass ratio 3:1)

Gas disk 1+1D (radial & vertical) α disk including stellar irradiation and photoevaporation; gas is composed of H 2/He

Simple solid disk model Surface density=initial gas surface density x dust-to-gas ratio. Increase at ice-line due to water ice condensation (T=170 K in initial disk model)

Orbital migration Non-isothermal type I and II migration or interaction-dominated motion 30 Resulting Spectra: Emission______Resulting Spectra: Transmission______Search for Gas in Young Debris Disks: HD 21997

•Mstar ~ 1.8 Msun Age: 30 Myrs •ALMA CO and continuum observations (Kospal ea. 2013, Moor ea. 2013) • Ring-like structure of the dust emission

• Dust mass: 0.1-0.2 Mearth • Gas mass in CO: 0.05 Mearth , Total gas mass: 30-60 Mearth AU Mic in Motion – Space & Ground in Concert

Boccaletti + SPHERE GTO + HST Teams (Nature, 2015) Large projected velocities of 4-10 km/s Ring Structures in a Debris Disk

HIP 73145 (HD 131835) – A2IV star in Upper Centaurus Lupus MG (123 pc, 15 Myr) – Feldt et al. (2016) with SPHERE at VLT SPHERE – The Discovery Machine at the VLT

TW Hydrae Ring World – SPHERE/IRDIS @ H band with apodized Lyot coronagraph (93 marcsec) – van Boekel et al. (2016) Final conclusions

• Challenge #1: Determination of fundamental disk parameters

• Challenge #2: Mechanisms for disk structure formation

• Challenge #3: Angular momentum transport (MRI vs. hydro-instabilities)

• Challenge #4: Pebble vs. Planetesimal Accretion Model

• Challenge #5: Connection between disk evolution and planet/atmosphere

• Challenge #6: Discovery of young planets with RV and direct imaging Disks & Planets - The Future is Bright

2018 2024

James Webb Space Telescope European Extremely Large Telescope