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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