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Breaking the chains : Hot super-Earth systems from migration and disruption of compact resonant chains

Izidoro, Andre; Ogihara, Masahiro; Raymond, Sean N.; Morbidelli, Alessandro; Pierens, Arnaud; Bitsch, Bertram LU ; Cossou, Christophe and Hersant, Franck (2017) In Monthly Notices of the Royal Astronomical Society 470(2). p.1750-1770
Abstract

'Hot super-Earths' (or 'mini-Neptunes') between one and four times Earth's size with period shorter than 100 d orbit 30-50 per cent of Sun-like stars. Their orbital configuration - measured as the period ratio distribution of adjacent planets in multiplanet systems - is a strong constraint for formation models. Here, we use N-body simulations with synthetic forces from an underlying evolving gaseous disc to model the formation and long-term dynamical evolution of super-Earth systems. While the gas disc is present, planetary embryos grow and migrate inward to form a resonant chain anchored at the inner edge of the disc. These resonant chains are far more compact than the observed super-Earth systems. Once the gas dissipates, resonant... (More)

'Hot super-Earths' (or 'mini-Neptunes') between one and four times Earth's size with period shorter than 100 d orbit 30-50 per cent of Sun-like stars. Their orbital configuration - measured as the period ratio distribution of adjacent planets in multiplanet systems - is a strong constraint for formation models. Here, we use N-body simulations with synthetic forces from an underlying evolving gaseous disc to model the formation and long-term dynamical evolution of super-Earth systems. While the gas disc is present, planetary embryos grow and migrate inward to form a resonant chain anchored at the inner edge of the disc. These resonant chains are far more compact than the observed super-Earth systems. Once the gas dissipates, resonant chains may become dynamically unstable. They undergo a phase of giant impacts that spreads the systems out. Disc turbulence has no measurable effect on the outcome. Our simulations match observations if a small fraction of resonant chains remain stable, while most super- Earths undergo a late dynamical instability. Our statistical analysis restricts the contribution of stable systems to less than 25 per cent. Our results also suggest that the large fraction of observed single-planet systems does not necessarily imply any dichotomy in the architecture of planetary systems. Finally, we use the low abundance of resonances in Kepler data to argue that, in reality, the survival of resonant chains happens likely only in ~5 per cent of the cases. This leads to a mystery: in our simulations only 50-60 per cent of resonant chains became unstable, whereas at least 75 per cent (and probably 90-95 per cent) must be unstable to match observations.

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Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Disc interactions, Methods: Numerical, Planet, Planets and satellites: Dynamical evolution and stability, Planets and satellites: Formation, Protoplanetary discs
in
Monthly Notices of the Royal Astronomical Society
volume
470
issue
2
pages
21 pages
publisher
Wiley-Blackwell
external identifiers
  • scopus:85023780823
  • wos:000406839900035
ISSN
0035-8711
DOI
10.1093/mnras/stx1232
language
English
LU publication?
yes
id
12bf8721-9a84-4064-9780-873885e7f09a
date added to LUP
2017-07-27 09:33:23
date last changed
2017-09-18 11:39:58
@article{12bf8721-9a84-4064-9780-873885e7f09a,
  abstract     = {<p>'Hot super-Earths' (or 'mini-Neptunes') between one and four times Earth's size with period shorter than 100 d orbit 30-50 per cent of Sun-like stars. Their orbital configuration - measured as the period ratio distribution of adjacent planets in multiplanet systems - is a strong constraint for formation models. Here, we use N-body simulations with synthetic forces from an underlying evolving gaseous disc to model the formation and long-term dynamical evolution of super-Earth systems. While the gas disc is present, planetary embryos grow and migrate inward to form a resonant chain anchored at the inner edge of the disc. These resonant chains are far more compact than the observed super-Earth systems. Once the gas dissipates, resonant chains may become dynamically unstable. They undergo a phase of giant impacts that spreads the systems out. Disc turbulence has no measurable effect on the outcome. Our simulations match observations if a small fraction of resonant chains remain stable, while most super- Earths undergo a late dynamical instability. Our statistical analysis restricts the contribution of stable systems to less than 25 per cent. Our results also suggest that the large fraction of observed single-planet systems does not necessarily imply any dichotomy in the architecture of planetary systems. Finally, we use the low abundance of resonances in Kepler data to argue that, in reality, the survival of resonant chains happens likely only in ~5 per cent of the cases. This leads to a mystery: in our simulations only 50-60 per cent of resonant chains became unstable, whereas at least 75 per cent (and probably 90-95 per cent) must be unstable to match observations.</p>},
  articleno    = {stx1232},
  author       = {Izidoro, Andre and Ogihara, Masahiro and Raymond, Sean N. and Morbidelli, Alessandro and Pierens, Arnaud and Bitsch, Bertram and Cossou, Christophe and Hersant, Franck},
  issn         = {0035-8711},
  keyword      = {Disc interactions,Methods: Numerical,Planet,Planets and satellites: Dynamical evolution and stability,Planets and satellites: Formation,Protoplanetary discs},
  language     = {eng},
  month        = {09},
  number       = {2},
  pages        = {1750--1770},
  publisher    = {Wiley-Blackwell},
  series       = {Monthly Notices of the Royal Astronomical Society},
  title        = {Breaking the chains : Hot super-Earth systems from migration and disruption of compact resonant chains},
  url          = {http://dx.doi.org/10.1093/mnras/stx1232},
  volume       = {470},
  year         = {2017},
}