The origin of moving groups and the dynamical stability of the sun in the galaxy

• Grant number: 16/18886-3
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: December 01, 2016
• End date: March 31, 2017
• Field of knowledge: Physical Sciences and Mathematics - Astronomy
• Principal Investigator: Tatiana Alexandrovna Michtchenko
• Grantee: Douglas Augusto de Barros
• Host Institution: Instituto de Astronomia, Geofísica e Ciências Atmosféricas (IAG). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The post-doctoral project is part of a new line of research which is being developed at the Department of Astronomy of IAG. The main goal of this proposal is the study of the orbital characteristics of the sun and of the stars of the solar neighbourhood, with the investigation of the possible dynamical origins of the kinematic structures known as moving groups. Such structures, which were known for decades but were not explained, appear as regions of higher density in the velocity plane of the solar neighbourhood; these structures were also known as "stellar streams". Some of the assumptions for explaining the presence of moving groups is that of a common dynamical origin for the stars that are members of a specific group. In particular, resonant orbits in the galactic potential perturbed by non-axisymmetric structures are some of the possible explanations. We will analyse the structure of the phase space in the solar neighbourhood for several galactic potential models and its main non-axisymmetric components (central bar and spiral arms). In particular, the co-rotation resonance will be an object of intense examination, so its effects on the local distribution of velocities, as well as its influence on the orbital stability of the sun in the galaxy. Numerical methods for the analysis of the structure of the phase space and statistical methods for the analysis of the velocity space resulting from simulations of orbits of test-particles will be employed. The present study is expected to produce galactic models that will serve as a basis for dynamical models that reproduce the kinematic structures observed in the solar neighbourhood. This is a very appropriate theme, given the current era of large spectroscopic and astrometric surveys of the milky way, such as the GAIA mission and its forthcoming data. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

LEPINE, JACQUES R. D.; MICHTCHENKO, TATIANA A.; BARROS, DOUGLAS A.; VIEIRA, RONALDO S. S.. The Dynamical Origin of the Local Arm and the Sun's Trapped Orbit. ASTROPHYSICAL JOURNAL, v. 843, n. 1, JUL 1 2017. (15/10577-9, 09/54006-4, 16/18886-3)