Thesis

Cosmic tidal fields in galaxy formation: impact on the weak lensing measurements of Euclid

• Call:

  IDPASC Portugal - PHD Programme 2015

• Academic Year:

  2015 / 2016

• Domains:

  Cosmology | Astrophysics

• Supervisor:

  Antonio da Silva

• Co-Supervisor:

  Ismael Tereno

• Institution:

  Faculdade de Ciências - Universidade de Lisboa

• Host Institution:

  FCUL / Institute of Astrophysics and Space Sciences - U. Lisbon

• Abstract:

  Cosmological weak lensing is a powerful probe of gravity, geometry and mass in the Universe, and is in the core of the forthcoming Euclid space mission by the European Space Agency (ESA). Weak lensing cosmological measurements are however contaminated by astrophysical effects originated by mechanisms that operate during the galaxy formation process. In order to achieve highly precise constraints in the parameters of the dark universe, the contamination must be mitigated. For this, the effects need to be studied and modelled and their impact on the cosmological signal understood. This project aims to investigate the process of angular momentum acquisition of galaxies using dedicated state-of-the-art N-body simulations of large-scale structure. With this investigation we will be able to design effective models for intrinsic alignments and to estimate their effects in weak lensing data. Finally, we will define estimators to efficiently combine the modelled effects with forecasted Euclid cosmic shear data, in order to mitigate the impact of intrinsic alignments of galaxies in cosmological parameters constraints. The project will allow the candidate to acquire a solid preparation in the fields of Cosmology, the physics of weak gravitational lensing and numerical simulations of large-scale structure. It will also allow him/her to become familiar with fundamental aspects of the scientific preparation of the Euclid mission and to engage (if the candidate demonstrates the interest and the competences to do so) in the Science Working Groups of Euclid. Numerical analysis interest and coding competences on programming languages, such as C/Fortran/Python/IDL/Matlab, are not mandatory but would be highly recommended for the prospective candidates.