|
European Astronomical Society
|
|
|
|
|
|
|
EAS Job Directory
Find Jobs
| PhD Fellowship in Disequilibrium Dynamics of Galactic Dark Matter Halos and its Impact on the Milky Way | Closing date: 2023-01-25
Contact: La Caixa Fellowships |
| This PhD will focus on presenting an in-depth study of DM halo wakes harnessing the power of basis function expansions (BFE) to study them in idealised and full cosmological context. In this PhD, the student will use state-of-the-art codes (EXP, Arepo), develop code (integrating a BFE module to Arepo) and design numerical experiments tailored to answer the above questions with applications from stellar halo dynamics to that of the disc to interpret the latest observations (e.g. Gaia, WEAVE, SDSS-V). This will involve use of HPC facilities at the national and European level. | | ▸ more | Research Project:
The stars in our Milky Way (MW) only constitute about 6% of the total mass in the Galaxy. The rest of this mass is invisible to us, the so-called dark matter (DM) and distributed in a halo that surrounds the Galaxy. In the current LCDM model galaxies grow hierarchically through mergers of smaller units into large ones. The recent Gaia satellite has revealed that our Galaxy underwent a massive merger event 10 Gyr ago with the Gaia-Sausage-Enceladus (GSE) galaxy and that the disc is currently reacting to recent perturbations whose origins are still highly debated. When satellite galaxies merge into bigger ones, they generate gravitational density wakes as they orbit within the DM haloes of their hosts, causing their orbits to decay over time.
Wakes have been noted to be important to understand the interaction of both the Large Magellanic Cloud (LMC) and Sgr with the MW (and likely the GSE). However, little is known about the dynamics of wakes: How long do these last (in the stellar halo, in the MW disc)? How do they affect large/small scale dynamics of Galactic discs? What is their role in setting the structure of the Galaxy versus that of the self-gravity in discs? This non-linear problem can only be tracked with numerical tools.
This project will be carried out with the Near Field Cosmology group led by Dr. Laporte (currently 2 postdocs and a PI) with funding from an ERC grant who develop numerical simulations to understand the accretion history of the MW and its impact on its formation, and with the Gaia group of the ICCUB. The GaiaUB team (4 staff, 8 postdocs, 4 PhD, and 8 engineers) has a leading role in Gaia at the highest technological, scientific and management levels, as well as in the scientific and technical building of WEAVE, and performs research in Galactic fields including dynamics, open clusters and the LMCs. We have weekly science group meetings and a weekly journal club.
Job position description
How long do DM wakes persist in the Galaxy? How do they affect the dynamics of Galactic discs or stellar halos? What is their role in setting the structure of the Galaxy versus that of the self-gravity in discs?
This PhD will focus on presenting an in-depth study of DM halo wakes harnessing the power of basis function expansions (BFE) to study them in idealised and full cosmological context. In this PhD, the student will use state-of-the-art codes (EXP, Arepo), develop code (integrating a BFE module to Arepo) and design numerical experiments tailored to answer the above questions with applications from stellar halo dynamics to that of the disc to interpret the latest observations (e.g. Gaia, WEAVE, SDSS-V). This will involve use of HPC facilities at the national and European level. The student will interact with Drs. Laporte and Antoja informally practically on a daily basis (weekly formal) and will be expected to participate in the group meetings.
The student will also analyse catalogues from the Gaia mission (ESA) from the releases DR3 and DR4 (2025-2026) and data from large spectroscopic surveys from the ground (WEAVE @ WHT, SDSS-V) that will soon provide kinematic and chemical data for a large amount of stars but also use/test results from their numerical experiments to interpret some of these data.
The PhD candidate will create strong collaborations by being integrated in the international network of the joint teams (e.g., Beyond BFE Collaboration, VIRGO Consortium, SDSS-V, DPAC consortium with 450 scientists and engineers, WEAVE science team, MW-Gaia COST and REG networks). The candidate will also benefit from the interaction with the software engineering group at the ICCUB Technological Unit.
More information:
Group leader
Dr. Chervin Laporte and Teresa Antoja ?chervin.laporte @ icc.ub.edu
Research product / Research group
Website of the ?VIA LACTEA? ERC Project led at the ICCUB
https://cordis.europa.eu/project/id/852839
Gaia group site
https://gaia.ub.edu/
Relevant paper
https://www.nature.com/articles/s41586-018-0510-7
Relevant paper
https://ui.adsabs.harvard.edu/abs/2019MNRAS.485.3134L/abstract
https://icc.ub.edu/node/21461
|
More resources
Links to other job lists
|
