Constraining the Galactic potential with frequency analysis of the Gaia survey data

• Grant number: 17/01421-0
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• Start date: April 10, 2017
• End date: April 09, 2018
• Field of knowledge: Physical Sciences and Mathematics - Astronomy - Extragalactic Astrophysics
• Principal Investigator: Laerte Sodré Junior
• Grantee: Leandro José Beraldo e Silva
• Supervisor: Monica Valluri
• Host Institution: Instituto de Astronomia, Geofísica e Ciências Atmosféricas (IAG). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Institution abroad: University of Michigan, United States
• Associated to the scholarship: 14/23751-4 - Dynamics and Statistical Mechanics of dark matter halos, BP.PD

Abstract

The main objective of this project is to constrain the Galactic (especially the dark matter halo) potential making use of accurate 3 dimensional positions and velocities (phase space coordinates) of millions of stars in the stellar halo provided by the Gaia survey and a ground based spectroscopic survey (DESI). The availability of accurate phase space coordinates can yield orbits for these stars which will be analyzed using frequency analysis, which allows the identification of the classes of orbits (e.g. if they are regular or chaotic). Since all these orbits are expected to be approximately in equilibrium in the Galactic potential, by putting constraints on the fractions of chaotic orbits we can recover the true gravitational potential of the Galaxy. The theoretical basis for this technique was previously illustrated using numerical simulations, by Valluri et al (2012), with whom this project will be carried out. The main goal of this project is to further develop this method and to apply it to both real and mock Gaia and DESI data. A secondary goal is to investigate whether the frequency analysis methods can be applied to time dependent self-gravitating systems. The mastery of the frequency analysis technique will allow us to make future investigations (possibly during this project) in order to understand whether chaotic mixing plays a role in violent relaxation