Movie: Talk "Planetary Population Synthesis" at Kavli Institute of Theoretical Physics

Talk at the KITP, 26.3.2010, Santa Barbara, within the workshop Exoplanets Rising: Astronomy and Planetary Science at the Crossroads. ( Coordinators: Adam Burrows, Kristen Menou ) Talk KITP flash format movie Talk KITP mp4 format movie

Animation: Simulation of the diversity of extrasolar planets (updated from Mordasini et al. 2009, A&A 501, 1139 with non-isothermal migration)

This animation shows how the mass-semimajor axis distribution gets populated in planetary population synthesis calculations. The underlying theoretical formation model follows the core accretion paradigm and builds on observational knowledge about protoplanetary disks (e.g. distributions of disk masses and lifetimes), as well as standard theories about important physical mechanism governing planet formation (e.g. accretion of gas and solids, orbital migration, disk evolution).

Formation tracks
For each simulation of the formation of a synthetic planet, a small protoplanet is initially placed at some randomly chose initial distance from the young star inside a disk with some randomly chosen properties. Each simulation run is represented by a solid, multicolored line, i.e. a formation track in the mass-distance plane which shows how the protoplanet grows and migrates. Masses are measured in units of the Earth's mass and distances are in astronomical units. The randomly chosen disk properties are drawn from probability distributions that are derived from actual observed properties of protoplanetary disks. The planetary seeds start to grow at the lower boundary of the diagram by accreting first planetesimals and later also gas. Due to this growth in mass they move upwards along vertical tracks. Then they start to migrate inwards at a rate set by the mass of the planet and the local properties of the gas disk. Depending on the particular type of the migration process, the formation tracks are plotted in different colors (locally isothermal, adiabatic unsaturated, adiabatic saturated, type II). At the moment when the protoplanetary disk disappears, the planets reach their final position, indicated by a black symbol. As the mechanism halting planetary migration close to the star is currently poorly understood, simulations are arbitrarily stopped once a planet migrates to about 0.1 AU from the host star.

Diversity in the population synthesis
The final positions show that in the model planets of large diversity form, despite the fact that always exactly the same formation model is used: There are super-Jupiters with masses higher than ten times the mass of Jupiter, there are Neptunian planets and there is foremost a large number of small planets with masses similar to the Earth.

Parameters: Stellar mass: 1 Msun. Disk alpha: 7x10^-3. Non-isothermal migration without any artificial reduction. 1 seed per disk. No reduction of gas accretion in runaway due to gap formation.

Animation of planetary formation tracks