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Reference : UMR5274-CLADUP-012
Workplace : GRENOBLE
Date of publication : Thursday, June 3, 2021
Scientific Responsible name : Geoffroy LESUR
Type of Contract : PhD Student contract / Thesis offer
Contract Period : 36 months
Start date of the thesis : 1 October 2021
Proportion of work : Full time
Remuneration : 2 135,00 € gross monthly
Description of the thesis topic
During this thesis, we will focus on the initial stage of protoplanetary disks in which the disk is still surrounded by a gas cocoon, known as a class 0 object. The objective of the thesis will be to understand and model the interaction between this gas cocoon and the winds generated at the surface of the disc by magnetic processes. The aim will be to understand under which conditions (mass, temperature of the cocoon, magnetic field strength) the wind manages to be ejected from the system, but also to study the dynamics of the interface that forms between the material falling on the outer disk and the wind ejected from the inner regions. This will be done using a new magnetohydrodynamics code developed in the laboratory to be run on European exascale supercomputers. The PhD student will have to learn how to use these numerical tools, create physical initial conditions corresponding to the class 0 phase, run the simulations on supercomputers and interpret the results. In a second phase, we will seek to identify the observational signatures of the interaction between the cocoon and the disk wind. The calculation of these signatures will be based on the simulations carried out in the first part of the thesis and on the work done during the M2 internship (if carried out in our team). In particular, the millimetre line profiles (e.g. CO) will be computed using a ray-tracing code for comparison with the ALMA data at our disposal.
The candidate should have knowledge of programming (especially c++) and an interest in magnetised fluid dynamics and numerical simulation.
IPAG is a Mixed Research Unit of 150 people under the supervision of CNRS and Grenoble Alpes University. IPAG will provide all the necessary resources (office, workstation, scientific environment) to carry out this work within the dynamic MHDISCS team.
Accretion disks are ubiquitous objects in the universe. They are found around young stars but also in the vicinity of galactic black holes. It is known that these disks are often associated with winds, emitted from the surface of the disk. These winds are observed in several astrophysical systems and are thought to be partly responsible for the accretion of matter towards the central object (black hole, young star), via magnetohydrodynamic processes.
This PhD project is an integral part of the MHDiscs project funded by the European Research Council (ERC), so the funding of this thesis as well as the associated mission costs (conference, collaboration) is already secured.
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