Anders Johansen
Professor
The Formation of Giant Planets
Author
Summary, in English
In paper I, II, III we describe a novel theory that explains how embryos, planetesimals larger than ~1000 km, grow efficiently by sweeping up the surrounding pebbles. The accretion radius of the embryo is large because gas drag aids the settling of passing pebbles to the core. In this way, the formation of large cores of 10 Earth masses is possible even in wide orbits (beyond the current Jupiter orbit), which previously could not be achieved when only considering the accretion of building blocks with sizes larger than km in size. Such high core masses are necessary for the attraction of massive gaseous envelopes, like the ones around the giant planets Jupiter and Saturn.
The above model relies on large planetesimal seeds to form and particles to settle to the midplane.
In paper IV, we study the previously unexplored sedimentation of particles in fluids with high dust-to-gas ratio and detect spontaneous clumping which could aid the sedimentation and formation of a midplane of pebbles in the outer disc.
Department/s
- Lund Observatory - Undergoing reorganization
Publishing year
2015
Language
English
Document type
Dissertation
Publisher
Department of Astronomy and Theoretical Physics, Lund University
Topic
- Astronomy, Astrophysics and Cosmology
Keywords
- Planet formation
- Solar System
- Exoplanets
- Giant planets
- Hydrodynamics
Status
Published
Supervisor
- Anders Johansen
ISBN/ISSN/Other
- ISBN: 978-91-7623-269-9
Defence date
9 March 2015
Defence time
09:00
Defence place
Lundmarksalen (Department of Astronomy and Theoretical Physics)
Opponent
- Roman Rafikov (Dr.)