| Full text | |
| Author(s): |
Izidoro, Andre
[1]
;
Bitsch, Bertram
[2]
;
Raymond, Sean N.
[3]
;
Johansen, Anders
[4]
;
Morbidelli, Alessandro
[5]
;
Lambrechts, Michiel
[4]
;
Jacobson, Seth A.
[6]
Total Authors: 7
|
| Affiliation: | [1] Univ Estadual Paulista, UNESP, Grp Dinam Orbital & Planetol, BR-12516410 Sao Paulo - Brazil
[2] Max Planck Inst Astron, Konigstuhl 17, D-69117 Heidelberg - Germany
[3] Univ Bordeaux, CNRS, Lab Astrophys Bordeaux, B18N, Allee Geoffroy St Hilaire, F-33615 Pessac - France
[4] Lund Univ, Dept Astron & Theoret Phys, Lund Observ, Box 43, S-22100 Lund - Sweden
[5] Univ Cote Azur, CNRS, Observ Cote Azur, Lab Lagrange, UMR7293, Blvd Observ, F-06304 Nice 4 - France
[6] Michigan State Univ, Dept Earth & Environm Sci, E Lansing, MI 48824 - USA
Total Affiliations: 6
|
| Document type: | Journal article |
| Source: | Astronomy & Astrophysics; v. 650, JUN 22 2021. |
| Web of Science Citations: | 8 |
| Abstract | |
At least 30% of main sequence stars host planets with sizes of between 1 and 4 Earth radii and orbital periods of less than 100 days. We use N-body simulations including a model for gas-assisted pebble accretion and disk-planet tidal interaction to study the formation of super-Earth systems. We show that the integrated pebble mass reservoir creates a bifurcation between hot super-Earths or hot-Neptunes (less than or similar to 15 M-circle plus) and super-massive planetary cores potentially able to become gas giant planets (greater than or similar to 15 M-circle plus). Simulations with moderate pebble fluxes grow multiple super-Earth-mass planets that migrate inwards and pile up at the inner edge of the disk forming long resonant chains. We follow the long-term dynamical evolution of these systems and use the period ratio distribution of observed planet-pairs to constrain our model. Up to similar to 95% of resonant chains become dynamically unstable after the gas disk dispersal, leading to a phase of late collisions that breaks the original resonant configurations. Our simulations naturally match observations when they produce a dominant fraction (greater than or similar to 95%) of unstable systems with a sprinkling (less than or similar to 5%) of stable resonant chains (the Trappist-1 system represents one such example). Our results demonstrate that super-Earth systems are inherently multiple (N >= 2) and that the observed excess of single-planet transits is a consequence of the mutual inclinations excited by the planet-planet instability. In simulations in which planetary seeds are initially distributed in the inner and outer disk, close-in super-Earths are systematically ice rich. This contrasts with the interpretation that most super-Earths are rocky based on bulk-density measurements of super-Earths and photo-evaporation modeling of their bimodal radius distribution. We investigate the conditions needed to form rocky super-Earths. The formation of rocky super-Earths requires special circumstances, such as far more efficient planetesimal formation well inside the snow line, or much faster planetary growth by pebble accretion in the inner disk. Intriguingly, the necessary conditions to match the bulk of hot super-Earths are at odds with the conditions needed to match the Solar System. (AU) | |
| FAPESP's process: | 16/19556-7 - Planetary Formation and Dynamics: from the Solar System to Exoplanets |
| Grantee: | André Izidoro Ferreira da Costa |
| Support Opportunities: | Scholarships in Brazil - Young Researchers |
| FAPESP's process: | 16/12686-2 - Planetary formation and dynamics: from the Solar System to exoplanets |
| Grantee: | André Izidoro Ferreira da Costa |
| Support Opportunities: | Research Grants - Young Investigators Grants |