Chaos in galaxies: bridging the time-dependent analytical models and N-body simulations

• Grant number: 13/11219-3
• Support Opportunities: Research Grants - Visiting Researcher Grant - International
• Duration: October 05, 2013 - October 19, 2013
• Field of knowledge: Physical Sciences and Mathematics - Astronomy - Extragalactic Astrophysics
• Principal Investigator: Rubens Eduardo Garcia Machado
• Grantee: Rubens Eduardo Garcia Machado
• Visiting researcher: Athanasios Manos
• Visiting researcher institution: University of Maribor (UM), Slovenia
• Host Institution: Instituto de Astronomia, Geofísica e Ciências Atmosféricas (IAG). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The distinction between the chaotic and regular behavior of orbits in galactic models constitutes an important issue in understanding the dynamical evolution of barred galaxies. The exploration of the nature of their orbits has attracted the interest of many researchers over the last years. Two methods have been generally employed: (i) analytical time-independent potentials and (ii) self-consistent (time-dependent) N-body simulations. The common goal in both approaches, regarding orbital study, is not only the astronomical interest in classifying the types of orbits that exist in such systems, but also of finding the appropriate orbits needed for constructing self-consistent models of galaxies. A relatively new method, the Generalized ALingment Index (GALI), has been employed successfully and broadly over the last years for the distinction between chaotic and regular motion in several Hamiltonian (mainly time-independent) systems and only very recently in one case of a time-dependent (analytical) galaxy model. With this proposal we intend to: (a) build improved new time-dependent models of barred galaxies using the detailed information as provided by N-body simulations, for the study of chaotic and regular orbits including now more realistic evolutionary scenarios and (b) measure and quantify regular and chaotic motion in N-body simulations in a similar manner, seeking for suitable initial conditions and parameters that generate stable galaxy structures comparable with real observations. To help advance this project, we request funding for a visiting researcher, Dr. Manos, to participate in a two-week collaboration at IAG/USP. (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)

MANOS, T.; MACHADO, RUBENS E. G.. Chaos and dynamical trends in barred galaxies: bridging the gap between N-body simulations and time-dependent analytical models. Monthly Notices of the Royal Astronomical Society, v. 438, n. 3, p. 2201-2217, MAR 2014. (09/54006-4, 13/11219-3, 10/12277-9)