RAYMOND, Sean N.; ARMITAGE, Philip J.; VERAS, Dimitri; QUINTANA, Elisa V.; BARCLAY, Thomas

doi:10.1093/mnras/sty468

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RAYMOND, Sean N.
ECLIPSE 2018

ARMITAGE, Philip J.

VERAS, Dimitri

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Ce document a été publié dans

Monthly Notices of the Royal Astronomical Society. 2018, vol. 476, n° 3, p. 3031-3038

Oxford University Press (OUP): Policy P - Oxford Open Option A

Résumé en anglais

'Oumuamua, the first bona-fide interstellar planetesimal, was discovered passing through our Solar System on a hyperbolic orbit. This object was likely dynamically ejected from an extrasolar planetary system after a series of close encounters with gas giant planets. To account for 'Oumuamua's detection, simple arguments suggest that ~1 Earth-mass of planetesimals are ejected per Solar mass of Galactic stars. However, that value assumes mono-sized planetesimals. If the planetesimal mass distribution is instead top-heavy the inferred mass in interstellar planetesimals increases to an implausibly high value. The tension between theoretical expectations for the planetesimal mass function and the observation of 'Oumuamua can be relieved if a small fraction (~1%) of planetesimals are tidally disrupted on the pathway to ejection into 'Oumuamua-sized fragments. Using a large suite of simulations of giant planet dynamics including planetesimals, we confirm that roughly 1% of planetesimals pass within the tidal disruption radius of a gas giant on their pathway to ejection. 'Oumuamua may thus represent a surviving fragment of a disrupted planetesimal. Finally, we argue that an asteroidal composition is dynamically disfavoured for 'Oumuamua, as asteroidal planetesimals are both less abundant and ejected at a lower efficiency than cometary planetesimals.< Réduire

Mots clés en anglais

Astrophysics - Earth and Planetary Astrophysics

Astrophysics - Solar and Stellar Astrophysics

DOI

http://dx.doi.org/10.1093/mnras/sty468

Project ANR

Modélisation du processus de croissance des planètes Joviennes/ - ANR-13-BS05-0003

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Importé de hal

Unités de recherche

Laboratoire d'Astrophysique de Bordeaux (LAB) - UMR 5804