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Research Grants: Self-consistent Modeling of Planet Formation-II

Motivation

This project is a continuation of the OMAA-90öu25 project, in which we focused on a new GPU implementation of disk self-gravity. This implementation was of vital importance for the self-consistent modelling of massive protostellar and protoplanetary disks. We successfully implemented the GPU-based self-gravity solver in both codes used by the project partners. Our results have been published in two articles in the peer-reviewed journal „Astronomy & Astrophysics“. We plan to continue our collaboration aiming at the very early phase of planet formation, when the dust dynamics plays a major role.

Proposal Objectives

According to the most widely accepted theory of planet formation -- the core-accretion scenario -- planet formation begins with the coagulation of micron-sized dust particles. The coagulation process is sensitive to the distribution of gas in a circumstellar disk, because dust particles are accumulated in the local gas enhancements. Such enhancements can be created by various mechanisms in circumstellar disks, such as vortices (see e.g. Regály et al. 2012). Later, dust accumulation in these gas enhancements can serve as a seed for the formation of protoplanetary solid cores.

In recent investigations, the project members have successfully applied the FEoSaD code to model the star and disk formation and the GFARGO code to model the planet-disk interactions. In the proposed project, we will develop a module to both hydrodynamical codes, which allows us to model the dust accumulation. The physical model for dust dynamics is based on the calculation of the drag force exerted on the dust particles by the gas disk. Dust can be handled as individual massless particles (particle-based N-body approach) or as a low-pressure fluid (fluid-based, Boltzmann moment equation approach). By comparing models calculated with both methods we will be able to select the most effective approach for the long-term simulations of the formation of planetary seeds.

During the project, both codes will be modified and improved. First, the GFARGO code (Hungarian partners) will be modified to include the particle-based dust module. Since GFARGO is a fully GPU-based code, which enables high-performance computing using graphical processor units (GPUs), our N-body dust solver will be also GPU-enabled. As a next step the Austrian partner will develop a fluid-based dust module to the FEoSaD code. As a final step of the project, we will model dust accumulation in protoplanetary disk vortices (Hungarian partners) and in gaseous clumps formed via gravitational instability (Austrian partners).

According the current state of the art in the planet formation numerical models, our improved GFARGO code will be the first that self-consistently model the disk self-gravity and dust dynamics in protoplanetary disks. At the same time, the FEoSaD numerical codewill, for the first time, employ the Boltzmann moment equation approach (rather than the classical fluid dynamics approach with zero kinetic temperature) for modeling the dust dynamics in protostellar disks.

Project Details

The research plan of our project entitled Selbstkonsistente Modellierung der Entstehung und Evolution von Planeten-II: OMAA_95öu13_ResearchPlan.pdf. Members of the research group are E. Vorobyov and Zs. Regály. The research project was jointly funded by the Bundesministerium für Wissenschaft und Forschung and Magyar Művelődési és Közoktatási Minisztérium in 2017. The total budget of this four year project is EUR 6 000.

Publications

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