Formation and Early Evolution of Planetary Systems

Research output: ThesisDoctoral Thesis (compilation)


Over the past 20 years we have discovered that exoplanets are common in the Galaxy, and are far more diverse than anyone expected. Half of all Sun-like stars are accompanied by at least one super-Earth (a planet with a size between Earth and Neptune), many planets have very high eccentricities indicative of a dynamical origin, and a small fraction of stars are accompanied by hot Jupiters, whose origin is poorly understood. In this thesis I investigate the formation and dynamical evolution of planetary systems. In half of this thesis I develop constraints for the formation of planetesimals by the runaway convergence of radial migration known as the streaming instability, and apply the result to a computer model of a photo-evaporating protoplanetary disk. In the rest of this thesis I study the dynamical stability of planetary systems with multiple giant planets in order to learn about the past history of exoplanet systems.
All of my work relies heavily on computer modelling. I used hydrodynamic simulations of a shearing box inside a protoplanetary disk to determine the dust-to-gas ratio needed to trigger the streaming instability as a function of particle size. Similarly, the protoplanetary disk model is a one-dimensional hydrodynamic model that includes sink terms for photoevaporative outflows. The dynamical evolution of planetary systems occurs after planet formation is complete and the disk has fully dissipated. Dynamical simulations were performed with an N-body code designed for long-term modelling of planetary orbits.
My work has shown that the streaming instability is active for smaller particles than previously thought possible. I also found that in a protoplanetary disk, planetesimals begin to form early in the outer disk, where photoevaporation can more easily remove the gas component. As the disk evolves, planetesimal formation moves inward. From my dynamical simulations I am able to use present-day observations to estimate the probability that a habitable planet would have survived in a given planetary system, and I can estimate the masses of the planets that suffered ejections or collisions in that system.


  • Daniel Carrera
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Astronomy, Astrophysics and Cosmology


  • planet formation, planets and satellites: dynamical evolution and stability -- planets and satellites: gaseous planets -- planets and satellites: terrestrial planets, planets and satellites: terrestrial planets
Original languageEnglish
Awarding Institution
Supervisors/Assistant supervisor
Award date2016 Nov 24
Place of PublicationLund
  • Lund University, Faculty of Science, Department of Astronomy and Theoretical Physics
Print ISBNs978-91-7623-978-0
Electronic ISBNs978-91-7623-979-7
StatePublished - 2016 Oct
Publication categoryResearch

Bibliographic note

Defence details Date: 2016-11-24 Time: 09:00 Place: Lund Observatory, Lundmark lecture hall, Sölvegatan 27, Lund External reviewer(s) Name: Raymond, Sean Title: Dr. Affiliation: Laboratoire d’Astrophysique de Bordeaux, France ---

Related research output

Carrera, D., Melvyn B Davies & Anders Johansen, 2016, In : Monthly Notices of the Royal Astronomical Society. p. 3226-3238

Research output: Contribution to journalArticle

Carrera, D., Anders Johansen & Melvyn B Davies, 2015, In : Astronomy & Astrophysics. 579, A43

Research output: Contribution to journalArticle

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Related projects

Daniel Carrera, Anders Johansen & Melvyn B Davies


Project: Dissertation

Anders Johansen, Chao-Chin Yang, Bertram Bitsch, Katrin Ros, Karl Wahlberg Jansson & Daniel Carrera

European Commission - FP7


Project: ResearchIndividual research project

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