Protoplanetary Formation efficiency and time scale

D.N.C. LinUniversity of California, Santa Cruz, KIAA, Peking University, China with

Astronomy Department University of Florida Apr 14th, 2007

K. Kretke, S. Watanabe, Shulin Li, I. Dobbs-Dixon, P.Garaud, Jilin Zhou, M. Nagasawa, H. Klahr, N. Turner, G. Ogilvie, H. Li,C. Agnor, ZX Shen, T. Takeuchi, G. Bryden, C. Beichman, E. Thommes

23 slides

Mass-period distribution

A continuous logarithmic period distributionA pile-up near 3 days and another pile up near 2-3 yearsDoes the mass function depend on the period?Is there a frequency enhancement near the snow line?Is there an edge to the planetary systems?Does the mass function depend on the stellar mass or [Fe/H]?

2/23

Dependence on the stellar [Fe/H]

Santos, Fischer & Valenti

Frequency of Jovian-mass planets increases rapidly with [Fe/H].But, the ESP’s mass and period distribution are insensitive to [Fe/H]!Is there a correlation between [Fe/H] & hot Jupiters ?Do multiple systems tend to associated with stars with high [Fe/H]?

3/23

Disk evolution

4/23

Protostellar disks:Gas/dust = 100

Dabris disks:Gas/dust = 0.01

only external disk but accreting star

Transitional Disks (CG, Garaud)

surface ripples and self shaddows

Watanabe, Kretke, Klahr5/23

Retention of condensable grainsPreferred site: snow line

Local enrichment: abundances fractionation (Stevenson,Takeuchi)

Gas-solid transition

Kyoto minimum mass nebula model

Cuzzi 6/23

Kretke

mxy / dyn cm-2

10 4

10 4

1

1

z

time

1

2Azv 150

years100500

Resistive MHD with Ionization ChemistryResistive MHD with Ionization Chemistry

Ideal MHDIdeal MHD

-4

0

+4

100

Horizontally-Averaged Magnetic Stress Horizontally-Averaged Magnetic Stress Versus Height and TimeVersus Height and Time

Lundquist number unity indicates marginal linear stability.

Turner et al 07

The lively dead zone

7/23

Surface density distribution & ice grain retention

Kretke

8/23

type-II migration

planet’s perturbation

viscous diffusion

type-I migration

disk torque imbalance

MyrAU1

05.023

23

*

g

SNg,Imig,

a

M

M

M

M

op

MM )10010( MM )11.0(

MyrAU1

10

2

12

1

*

o3

J

p

g

SNg,IImig,

a

M

M

M

M

Disk-planet tidal interactions

viscous disk accretion

Goldreich & Tremaine (1979), Ward (1986, 1997), Tanaka et al. (2002)

Lin & Papaloizou (1985),....

9/23

Competition: M growth & a decay

Hyper-solar nebulax30

Metal enhancement does not always help! need to slow down migration

10 Myr 1 Myr0.1 Myr

Limiting isolationMass (Ida)

10/23

Shen

Embryos’ type I migration (10 Mearth)

Cooler and invisic disks

Warmer disks11/23

Giant impacts1) Diversity in core mass2) Spin orientation3) Survival of satellites4) Retention of atmosphere

20/43Late bombardment of planetesimals (Zhou, Li, Agnor)12/23

Flow into the Roche lobe

Bondi radius (Rb=GMp /cs2)

Hill’s radius (Rh=(Mp/3M* )1/3 a)Disk thickness (H=csa/Vk)

Rb/ Rh =31/3(Mp /M*)2/3(a/H)2

decreases with M*

13/23

H/a=0.07

H/a=0.04

Dobbs-Dixon, Li

The period distribution:Type II migration

Disk depletion versus migration14/23

Mean motion resonance capture

Tidal decay out of mean motion resonance(Novak & Lai)

Impact enlargementRejuvenation of gas Giant. HD 209458b(Guillot)

Detection probability of hot Earth Narayan, Cumming

Migration of gas giants can lead To the formation of hot earthImplication for COROT

Zhou

15/23

Effect of type I & II migration

16/23

Habitable planets

M/s accuracy

Stellar mass-metallicity

More data needed for highand low-mass stars 17/23

Dependence on M*

1) J increases with M*

2) Mp and ap increase with M*

Do eccentricity and multiplicity depend on M*? 18/23

ResonantsecularperturbationMdisk ~Mp

(Ward, Ida, Nagasawa)

Transitional disks

19/23

Migration-free sweeping secular resonances

Outer edge of planetary systems

Bryden, Beichman

20/23

Migration, Collisions, & damping

1. Clearing of the asteroid belt2. Earlier formation of Mars3. Sun ward planetesimals

A. Late formation (10-50 Myr)B. Giant-embryo impacts C. Low eccentricities, stable orbitsNagasawa, Thommes 21/23

Sequential accretion scenario summary1) Damping & high leads to rapid growth & large isolation masses at the snow line. Jupiter formed prior to the final assemblage of terrestrial planets within a few Myrs.2) Emergence of the first gas giants after the disk mass was reduced to that of the minimum nebula model. 3) Planetary mobility promotes formation & destruction. Snow line is a good place to halt migration. 4) The first gas giants induce formation of other siblings. 5) Shakeup led to the dynamically porous configuration of the inner solar system & the formation of the Moon.6) Earths are common and detectable within a few yrs!22/23

Outstanding issues:1) Frequency of planets for different stellar masses2) Completeness of the mass-period distribution3) Signs of dynamical evolution4) Mass distribution of close-in planets: efficiency of migration5) Halting mechanisms for close-in planets6) Origin of planetary eccentricity7) Formation and dynamical interaction of multiple planetary systems8) Internal and atmospheric structure and dynamics of gas giants9) Satellite formation10) Low-mass terrestrial planets

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