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Tidal downsizing model – I. Numerical methods: saving giant planets from tidal disruptions

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journal contribution
posted on 24.01.2017, 09:58 by Sergei Nayakshin
Tidal downsizing (TD) is a recently developed planet formation theory that supplements the classical gravitational instability (GI) disc model with planet migration inward and tidal disruptions of GI fragments in the inner regions of the disc. Numerical methods for a detailed population synthesis of TD planets are presented here. As an example application, the conditions under which GI fragments collapse faster than they migrate into the inner a ∼ a few AU are considered. It is found that most gas fragments are tidally or thermally disrupted unless (a) their opacity is ∼3 orders of magnitude less than the interstellar dust opacity at metallicities typical of the observed giant planets, or (b) the opacity is high but the fragments accrete large dust grains (pebbles) from the disc. Case (a) models produce very low mass solid cores (Mcore ≲ 0.1 M⊕) and follow a negative correlation of giant planet frequency with host star metallicity. In contrast, case (b) models produce massive solid cores, correlate positively with host metallicity and explain naturally while giant gas planets are overabundant in metals. Present paper does not address survival of giant planets against rapid migration into the host star, a question which is addressed in two follow-up papers.

Funding

Theoretical astrophysics research in Leicester is supported by an STFC grant. This paper used the DiRAC Complexity system, operated by the University of Leicester, which forms part of the STFC DiRAC HPC Facility (www.dirac.ac.uk). This equipment is funded by a BIS National E-Infrastructure capital grant ST/K000373/1 and DiRAC Operations grant ST/K0003259/1. DiRAC is part of the UK National E-Infrastructure.

History

Citation

Monthly Notices of the Royal Astronomical Society, 2015, 454 (1), pp. 64-82 (19)

Author affiliation

/Organisation/COLLEGE OF SCIENCE AND ENGINEERING/Department of Physics and Astronomy

Version

VoR (Version of Record)

Published in

Monthly Notices of the Royal Astronomical Society

Publisher

Oxford University Press (OUP), Royal Astronomical Society

issn

0035-8711

eissn

1365-2966

Acceptance date

18/08/2015

Available date

24/01/2017

Publisher version

https://academic.oup.com/mnras/article-lookup/doi/10.1093/mnras/stv1915

Language

en