the evolution of protoplanetary disks and the diversity of giant planets

Physics and AstronomyUniversity of Utah

Extreme Solar Systems II Fall 2011

The Evolution of Protoplanetary Disks and theThe Evolution of Protoplanetary Disks and the

Diversity of Giant PlanetsDiversity of Giant Planets

The Evolution of Protoplanetary Disks and theThe Evolution of Protoplanetary Disks and the

Diversity of Giant PlanetsDiversity of Giant Planets

Extreme Solar Systems II

September 2011

Ben Bromley Physics & Astronomy, University of Utah

Scott Kenyon Smithsonian Astrophysical Observatory

Extreme Solar Systems II

September 2011

Ben Bromley Physics & Astronomy, University of Utah

Scott Kenyon Smithsonian Astrophysical Observatory



Diversity of planets

the Solar System: Is it extreme?



Planet formationtheory and practice

Young stars: gas/dust disk

Coagulation and dynamics; collisional accretion (many, small few, large)

Debris disks are signpostsof planet formation

Massive cores accrete gas (entrained debris helps, tGas ~ Myr)



Dust-to-planetesimals How do planetesimals grow from micron-sized dust?

Migration How do planetary cores survive (fast, <Myr) migration?

Gas giant formationHow do gas giants grow as gas disks vanish?

Evolution of the gas disk is critical!

Planet formation:difficulties



Modeling disk evolution

Timing is everything.

HSolid ~ √α



Simulating planet formation

COAGULATION CODEmergers, fragmentation

growing planetesimalscollisional cascade

FORMATION TIME:

0.1—1 Myr (cores)

1—10 Myr (J,N,SE)

10—100 Myr (Earths)

N-BODY CODEscattering, collisions

photoionization

-viscosity…

gas accretion atmospheres (L,R)migration

PLANETESIMALS:pebbles—plutos

evolve gas, planetesimals, planets in concert


Extreme Solar Systems II Fall 2011log time (yr)

Growth of a planetary system

m /

ME

art

h

sem

imaj

or

axis

(A

U)

150

15

15

3001000

10



Growth of planetary systems: Jupiters++ (> 1 MJupiter)cu

mu

lati

ve f

ract

ion

log semimajor axis (AU)



cum

ula

tive

fra

ctio

n


Growth of planetary systems: Saturns (15 MEarth— 1 MJupiter )



cum

ula

tive

fra

ctio

n


Growth of planetary systems: Earths++ (1—15 MEarth)



cum

ula

tive

fra

ctio

n

log mass (MJupiter)

Growth of planetary systems: planetary masses



cum

ula

tive

fra

ctio

n Growth of planetary systems: Earths+ (1—15 MEarth)Diversity of planets: disk properties

(1—4)

(5—10)

(0—3)

(no gas giants)

(0—3)(2—4)Jupiters

Saturn

s

Super-Earth

s

Earths

log disk viscosity parameter (α)

init

ial

dis

k m

ass

(M)



Results

Diverse systems of gas giants in alpha-disk model

Predictions:

Multiplanet systems, ~MEarth—10’s of Mjupiter

High mass, low viscosity disks: Jupiters

Low mass, high viscosity disks: Neptunes, super-Earths

Next step: Include photoionization, migration….



Simulation summary

photoionization



Simulation summary

migration

photoionization



Diversity of planets

Planetary structure(Radius – Mass, …)

Dynamics(Architecture)

Goal: consistent evolution of full system

the evolution of protoplanetary disks and the diversity of giant planets

Documents