Core accretion in MHD simulations of layered protoplanetary discs - - PowerPoint PPT Presentation

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Core accretion in MHD simulations of layered protoplanetary discs - - PowerPoint PPT Presentation

Nov 08, 2023 28 likes •219 views

Context: planet formation theory Results: embedded planet core Core accretion in MHD simulations of layered protoplanetary discs Oliver Gressel Niels Bohr International Academy (NBIA), Copenhagen Richard P . Nelson (QMUL, London) Neal J.

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SLIDE 1

Context: planet formation theory Results: embedded planet core

Core accretion in MHD simulations

  • f layered protoplanetary discs

Oliver Gressel ⋆

Niels Bohr International Academy (NBIA), Copenhagen

Richard P . Nelson (QMUL, London) Neal J. Turner (JPL-Caltech, Pasadena) Udo Ziegler (AIP

, Potsdam) February 10/11, 2014 Star and Planet Formation for All

⋆ oliver.gressel@nbi.dk

  • O. Gressel

2014-02-10 – SnPFfA Lund 1/13

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SLIDE 2

Context: planet formation theory Results: embedded planet core

gas giant interiors

Image Credit: NASA, Lunar and Planetary Institute

  • O. Gressel

2014-02-10 – SnPFfA Lund 2/13

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SLIDE 3

Context: planet formation theory Results: embedded planet core

motivation

core accretion picture 1D spherical envelopes

I: quasi-static contraction II: runaway growth phase

  • ur goals

identify . . .

accretion time-scales role of circumplanetary disc potential bottle-necks influence of magnetic field

  • O. Gressel

2014-02-10 – SnPFfA Lund 3/13

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SLIDE 4

Context: planet formation theory Results: embedded planet core

schematics of protostellar disc

Armitage (2011)

  • O. Gressel

2014-02-10 – SnPFfA Lund 4/13

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SLIDE 5

Context: planet formation theory Results: embedded planet core global properties / PPD local properties / CPD

spiral arms and gap

isothermal HD non-isoth. HD non-isoth. MHD

  • O. Gressel

2014-02-10 – SnPFfA Lund 5/13

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SLIDE 6

Context: planet formation theory Results: embedded planet core global properties / PPD local properties / CPD

spiral arms and gap

isothermal HD non-isoth. HD non-isoth. MHD

  • O. Gressel

2014-02-10 – SnPFfA Lund 5/13

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SLIDE 7

Context: planet formation theory Results: embedded planet core global properties / PPD local properties / CPD

spiral arms and gap

isothermal HD non-isoth. HD non-isoth. MHD

  • O. Gressel

2014-02-10 – SnPFfA Lund 5/13

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SLIDE 8

Context: planet formation theory Results: embedded planet core global properties / PPD local properties / CPD

gap opening

Saturn-mass planet

rapid growth phase Hill-sphere radius ≃ gas scale height

Gap opening

play

via tidal torques and gas accretion

  • nto planet core

formation not complete gap contrast of 20–30

  • O. Gressel

2014-02-10 – SnPFfA Lund 6/13

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SLIDE 9

Context: planet formation theory Results: embedded planet core global properties / PPD local properties / CPD

embedded sub-disc

isothermal HD non-isoth. HD non-isoth. MHD

  • O. Gressel

2014-02-10 – SnPFfA Lund 7/13

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SLIDE 10

Context: planet formation theory Results: embedded planet core global properties / PPD local properties / CPD

embedded sub-disc

isothermal HD non-isoth. HD non-isoth. MHD

  • O. Gressel

2014-02-10 – SnPFfA Lund 7/13

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SLIDE 11

Context: planet formation theory Results: embedded planet core global properties / PPD local properties / CPD

embedded sub-disc

isothermal HD non-isoth. HD non-isoth. MHD

  • O. Gressel

2014-02-10 – SnPFfA Lund 7/13

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SLIDE 12

Context: planet formation theory Results: embedded planet core global properties / PPD local properties / CPD

disc variability

  • O. Gressel

2014-02-10 – SnPFfA Lund 8/13

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SLIDE 13

Context: planet formation theory Results: embedded planet core global properties / PPD local properties / CPD

the circumplanetary disc

Disc rotation profile

sub-keplerian rotation inner disc hotter → pressure support CPD extends to about half the Hill radius

Disc surface density

non-isoth. case: flat surface density isothermal case: steeper profile m = 2 spiral arms

  • O. Gressel

2014-02-10 – SnPFfA Lund 9/13

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Context: planet formation theory Results: embedded planet core global properties / PPD local properties / CPD

the horseshoe region

isothermal HD non-isoth. HD non-isoth. MHD

  • O. Gressel

2014-02-10 – SnPFfA Lund 10/13

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SLIDE 15

Context: planet formation theory Results: embedded planet core global properties / PPD local properties / CPD

the horseshoe region

isothermal HD non-isoth. HD non-isoth. MHD

  • O. Gressel

2014-02-10 – SnPFfA Lund 10/13

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SLIDE 16

Context: planet formation theory Results: embedded planet core global properties / PPD local properties / CPD

the horseshoe region

isothermal HD non-isoth. HD non-isoth. MHD

  • O. Gressel

2014-02-10 – SnPFfA Lund 10/13

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SLIDE 17

Context: planet formation theory Results: embedded planet core global properties / PPD local properties / CPD

accretion flow properties

play

  • O. Gressel

2014-02-10 – SnPFfA Lund 11/13

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SLIDE 18

Context: planet formation theory Results: embedded planet core global properties / PPD local properties / CPD

circum-jovian jet

predicted theoretically by Quillen & Trilling (1998) and Fendt (2003)

  • O. Gressel

2014-02-10 – SnPFfA Lund 12/13

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SLIDE 19

summary of results

Gap opening process

incomplete, but contrasts of 20–30 reached in the MHD model: enlivening of the dead zone

Core accretion

spin-out circumplanetary disc mainly vertical inflow of low-metallicity gas → efficient cooling of contracting envelope (!?) high accretion rate (∼ 8 × 10−3M⊕ yr−1) → Jupiter size after ∼ 30, 000 yr

Launching of a planetary jet

tornado-like flow drags down azimuthal field swirling → helical field → magneto-centrifugal jet disc wind important for CPD accretion (!?)

  • O. Gressel

2014-02-10 – SnPFfA Lund 13/13