Embryo impacts and gas giant mergers I: Dichotomy of Jupiter and Saturn's core mass - Astrophysics > Earth and Planetary AstrophysicsReportar como inadecuado




Embryo impacts and gas giant mergers I: Dichotomy of Jupiter and Saturn's core mass - Astrophysics > Earth and Planetary Astrophysics - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Abstract: Interior to the gaseous envelopes of Saturn, Uranus, and Neptune, there arehigh-density cores with masses larger than 10 Earth masses. According to theconventional sequential accretion hypothesis, such massive cores are needed forthe onset of efficient accretion of their gaseous envelopes. However, Jupiter-sgaseous envelope is more massive and core may be less massive than those ofSaturn. In order to account for this structural diversity and the super-solarmetallicity in the envelope of Jupiter and Saturn, we investigate thepossibility that they may have either merged with other gas giants or consumedseveral Earth-mass proto-planetary embryos during or after the rapid accretionof their envelope. In general, impinging sub-Earth-mass planetesimalsdisintegrate in gas giants- envelopes deposit heavy elements well outside thecores and locally suppress the convection. Consequently, their fragmentssediment to promote the growth of cores. Through a series of numericalsimulations, we show that it is possible for colliding super-Earth-mass embryosto reach the cores of gas giants. Direct parabolic collisions also lead to thecoalescence of gas giants and merging of their cores. In these cases, theenergy released from the impact leads to vigorous convective motion throughoutthe envelope and the erosion of the cores. This dichotomy contributes to theobserved dispersion in the internal structure and atmospheric compositionbetween Jupiter and Saturn and other gas giant planets and elsewhere.



Autor: Shu Lin Li, C. B. Agnor, D. N. C. Lin

Fuente: https://arxiv.org/







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