Oort cloud and Scattered Disc formation during a late dynamical instability in the Solar System

By R. Brasser, A. Morbidelli. 2012

174 citations recorded by the source corpus.

Abstract One of the outstanding problems of the dynamical evolution of the outer Solar System concerns the observed population ratio between the Oort cloud (OC) and the Scattered Disc (SD): observations suggest that this ratio lies between 100 and 1000 but simulations that produce these two reservoirs simultaneously consistently yield a value of the order of 10. Here we stress that the populations in the OC and SD are inferred from the observed fluxes of new long period comets (LPCs) and Jupiter-family comets (JFCs), brighter than some reference total magnitude. However, the population ratio estimated in the simulations of formation of the SD and OC refers to objects bigger than a given size. There are multiple indications that LPCs are intrinsically brighter than JFCs, i.e. an LPC is smaller than a JFC with the same total absolute magnitude. When taking this into account we revise the SD/JFC population ratio from our simulations relative to Duncan and Levison (1997) , and then deduce from the observations that the size-limited population ratio between the OC and the SD is 44 - 34 + 54 . This is roughly a factor of four higher than the value 12 ± 1 that we obtain in simulations where the OC and the SD form simultaneously while the planets evolve according to the so-called ‘Nice model’. Thus, we still have a discrepancy between model and ‘observations’, but the agreement cannot be rejected by the null hypothesis.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/f5be37f9903fa8aa9a4682c0448eb79fd6d4f8bc

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Citations in the corpus

The timeline of the lunar bombardment: Revisited (2018, background): “ataclysm. While the evidence for a giant planet instability strengthened over the years with the detailed analysis of the Solar System structure (Nesvorny et al., 2007; Nesvorny and Morbidelli, 2012; Brasser and Morbidelli, 2013; Nesvorny et al. 2013; Nesvorny, 2015a,b), the dynamical models remaine”
The primordial nucleus of comet 67P/Churyumov-Gerasimenko (2015, methodology): “The number of comets in the primordial disk with H < 17.3 (D > 2.3 km if pV = 0.04) was predicted as 5 × 1011 by Morbidelli et al. (2009) and as 1.9×1011 by Brasser & Morbidelli (2013).”
Elemental and molecular abundances in comet 67P/Churyumov-Gerasimenko (2019, background): “…[cf. Altwegg et al. (2017a) and references therein] in the water of a suite of OCCs and JFCs support the theory that the comets in both families may have formed over a wide range of overlapping heliocentric distances before being scattered to where they are found today (Brasser & Morbidelli 2013).”