Oligarchic growth of giant planets

By E. Thommes, M. Duncan, Harold Levison. 2003

182 citations recorded by the source corpus.

Runaway growth ends when the largest protoplanets dominate the dynamics of the planetesimal disk; the subsequent self-limiting accretion mode is referred to as “oligarchic growth.” Here, we begin by expanding on the existing analytic model of the oligarchic growth regime. From this, we derive global estimates of the planet formation rate throughout a protoplanetary disk. We find that a relatively high-mass protoplanetary disk (∼10 × minimum-mass) is required to produce giant planet core-sized bodies (∼10 M⊕) within the lifetime of the nebular gas (≲10 million years). However, an implausibly massive disk is needed to produce even an Earth mass at the orbit of Uranus by 10 Myrs. Subsequent accretion without the dissipational effect of gas is even slower and less efficient. In the limit of noninteracting planetesimals, a reasonable-mass disk is unable to produce bodies the size of the Solar System’s two outer giant planets at their current locations on any timescale; if collisional damping of planetesimal random velocities is sufficiently effective, though, it may be possible for a Uranus/Neptune to form in situ in less than the age of the Solar System. We perform numerical simulations of oligarchic growth with gas and find that protoplanet growth rates agree reasonably well with the analytic model as long as protoplanet masses are well below their estimated final masses. However, accretion stalls earlier than predicted, so that the largest final protoplanet masses are smaller than those given by the model. Thus the oligarchic growth model, in the form developed here, appears to provide an upper limit for the efficiency of giant planet formation.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/727fa1fd14c59a72903da92d4f4813afca716965

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Citations in the corpus

Gravoturbulent Formation of Planetesimals (2005, background): “Similar assumptions are common in simulations of giant planet core formation from colliding planetesimals (Kokubo & Ida 2002; Thommes et al. 2003) as well as in cosmological N -body simulations (Sommer-Larsen et al. 2003).”
Models of Jupiter's growth incorporating thermal and hydrodynamic constraints (2008, methodology): “As pointed out by Fortier et al. (2007), using a more physically sophisticated model to compute the eccentricities and inclinations of planetesimals (Kokubo and Ida 1998; Kokubo et al. 2000; Thommes et al. 2003 ) gives a lower value of _”
Planetary accretion in the inner Solar System (2004, background): “1–1 Myr from the time when planetesimals first appear in large numbers [58,60].”
Dynamics of pebbles in the vicinity of a growing planetary embryo: hydro-dynamical simulations (2012, background): “…∼10 Earth masses (ME) form beyond the so-called snowline (the orbital radius beyond which temperature is cold enough that water condenses into ice; Podolak & Zucker 2004), as required in the core-accretion model for giant planet formation (Thommes et al. 2003; Goldreich et al. 2004; Chambers 2006).”
Asteroids Were Born Big (2009, background): “In the outer Solar System, beyond the so-called snowline (Podolak and Zucker, 2004), it is generally expected that the end result is the formation of a few super-Earth cores (Thommes et al., 2003; Goldreich et al., 2004; Chambers, 2006) that, by accretion of a massive gaseous atmosphere from the dis”
Models of giant planet formation with migration and disc evolution (2004, background): “We also neglect, apart for ejection and accretion onto the planet, the perturbations created by the growing planet in the planetesimal disc such as heating, gap formation and shepherding (Tanaka & Ida 1997, Tanaka & Ida 1999, Thommes et al. 2003).”
On the ionisation fraction in protoplanetary disks. I. Comparing different reaction networks (2005, background): “The growth of planetesimals is controlled by the velocity dispersion (e.g. Wetherill & Stewart 1993), as is the growth of protoplanetary cores (Kokubo & Ida 2000; Thommes et al. 2003).”
The great dichotomy of the Solar System: Small terrestrial embryos and massive giant planet cores (2015, methodology): “7 of Thommes et al. (2003), if one remembers that Σm/em in that paper is the same as rρp here and one plugs in the radial dependences of ρp and e given above.”
Terrestrial planet formation with strong dynamical friction (2006, background): “The fact that Jupiter’s ∼10 Earth-mass core was able to accrete in our Solar System beyond the asteroid belt suggests that embryos were likely able to accrete in the asteroid belt, even accounting for the roughly 3–4× decrease in the mass density of solid material inside the snow line (Thommes et al”
Three-dimensional simulations of multiple protoplanets embedded in a protostellar disc (2008, methodology): “Numerical simulations of the oligarchic growth phase Article published by EDP Sciences have been used to examine the interactions of planetary embryos (Kokubo & Ida 2000; Thommes et al. 2003).”
Collisional processes and size distribution in spatially extended debris discs (2007, background): “Within the frame of the “standard” planet formation scenario, it is like y that these regions are beyond the limit where accretion of large planetesimals/embryos is possible (e.g Thommes et al. 2003), so that the presence of collisional cascades starting from large parent bodies is questionable.”
Origin of water in the inner Solar System: Planetesimals scattered inward during Jupiter and Saturn's rapid gas accretion (2017, background): “If the giant planets formed from a swarm of planetesimals (Thommes et al., 2003; Levison et al., 2010), it stands to reason that there would be an abundant population of planetesimals in the cores’ vicinity when they undergo runaway gas accretion (albeit with orbits sculpted by the growing cores).”
Planetary migration in a planetesimal disk: why did Neptune stop at 30 AU? (2004, background): “Levison and Stewart (2001 showed that the in situ formation of Uranus and Neptun unlikely, suggesting that these planets formed much cl to Jupiter and Saturn, where the growth timescales were matically shorter(Thommes et al., 2003).”
Origin of the structure of the Kuiper belt during a dynamical instability in the orbits of Uranus and Neptune (2007, result): “In addition, since Uranus and Neptune are often started on crossing orbits and we want to avoid chaotic evolution due to close encounters, we soften the gravitational forces (fUN) between these two planets so that fUN = GmNmU (x2UN + ǫ 2) 3/2 xUN , (1) where xUN is the relative position vector of Ur”