The role of giant collisions in extrasolar systems

• Applicant: Dr. Christoph Schäfer
• Subject Area: Astrophysics and Astronomy
• Term: from 2018 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 398488521

The present project is focussed to investigate the effect of giant collisions in extrasolar planetary systems. Giant impacts refer to collisions between two objects each of which is massive enough to be considered at least a planetary embryo. These close encounters (such as the giant impact that led to the formation of the Moon) are not atypical occurrences, but rather common incidents in the late phase of planet formation. We will study these incidents by the use of numerical modelling and high-performance computing simulations. Following effects will be considered: (i) the change of the mean bulk density and material composition of impactor and target, (ii) the formation of exomoons, (iii) the production of debris and the formation of a debris disk. Within the scope of the project, we will in particular investigate the formation process of super-Earths with a low envelope-to-core mass ratio and a high bulk density by studying the fate of the He/H envelope around a silicate mantle and iron core of a super-Earth during a giant collision.The main goal of the project is to explain the diversity of bulk densities of extrasolar planets especially in the super-Earth mass range and to provide predictions to observable constraints.

• DFG Programme: Research Grants