Structural and thermal models of rocky planets and solid exoplanets

• Applicant: Dr. Frank Sohl
• Subject Area: Geophysics ; Mineralogy, Petrology and Geochemistry
• Term: from 2017 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 280637173

The project is aimed at the construction of models of the interior structure and thermal budget of generic terrestrial-type planets of given mass and radius in the super-Earth regime and of rock/metal cores of Neptune-like planets. Structural models of solid bodies are chemically layered and composed of volatile constituents, rock-forming elements, and metals such as iron, the latter concentrated in central cores. In the first funding period, the parameterization of these models will be based on thermal and transport properties such as thermal conductivity and expansivity, equation-of-state and phase diagram data that will be iteratively improved within other subprojects of this Research Unit through ab initio calculations (SP1, SP2) and laboratory experiments (SP7, SP8) of solid and liquid matter at high compression ratios. Since the convective energy transport in the silicate mantles of massive super-Earths could be inefficient owing to pressure effects on viscosity, the interplay between internal heat production, secular cooling and intrinsic luminosity or surface heat flow will be studied in detail. To partly overcome model ambiguities, the calculated density profiles will be used to determine in close collaboration with subprojects SP5 and SP6 the secular or fluid Love number k_{2,f}. The latter is an important measure for the concentration of mass toward the center and related to key observational parameters affected by planetary rotation and tides (SP6). In this way, we expect to derive novel, improved relationships between mass, radius, degree of internal differentiation, bulk composition and thermal budget of close-in solid exoplanets transiting their host stars.

• DFG Programme: Research Units
• Subproject of: FOR 2440: Matter Under Planetary Interior Conditions - High-Pressure, Planetary and Plasma Physics
• Cooperation Partner: Professor Dr. Tilman Spohn
• Co-Investigator: Professorin Dr. Doris Breuer