Chaotic motion and the evolution of morphological components in a time-dependent model of a barred galaxy within a dark matter halo

Autor(es)

Machado, R. E. G. ^{[1, 2]} ; Manos, T. ^{[3, 4, 5]}

Afiliação do(s) autor(es)

^[1] Univ Andres Bello, Dept Ciencias Fis, Av Republ 220, Santiago - Chile

^[2] Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, R do Matao 1226, BR-05508090 Sao Paulo - Brazil

^[3] Univ Maribor, CAMTP, Krekova 2, SI-2000 Maribor - Slovenia

^[4] Univ Nova Gor, Sch Appl Sci, Vipavska 11c, SI-5270 Ajdovscina - Slovenia

^[5] Res Ctr Julich, Inst Neurosci & Med, Neuromodulat INM 7, Julich - Germany

• Tipo de documento: Artigo Científico
• Fonte: Monthly Notices of the Royal Astronomical Society; v. 458, n. 4, p. 3578-3591, JUN 1 2016.
• Citações Web of Science: 5

Resumo

Studies of dynamical stability (chaotic versus regular motion) in galactic dynamics often rely on static analytical models of the total gravitational potential. Potentials based upon self-consistent N-body simulations offer more realistic models, fully incorporating the time-dependent nature of the systems. Here we aim at analysing the fractions of chaotic motion within different morphological components of the galaxy. We wish to investigate how the presence of chaotic orbits evolves with time, and how their spatial distribution is associated with morphological features of the galaxy. We employ a time-dependent analytical potential model that was derived from an N-body simulation of a strongly barred galaxy. With this analytical potential, we may follow the dynamical evolution of ensembles of orbits. Using the Generalized Alignment Index (GALI) chaos detection method, we study the fraction of chaotic orbits, sampling the dynamics of both the stellar disc and of the dark matter halo. Within the stellar disc, the global trend is for chaotic motion to decrease in time, specially in the region of the bar. We scrutinized the different changes of regime during the evolution (orbits that are permanently chaotic, permanently regular, those that begin regular and end chaotic, and those that begin chaotic and end regular), tracing the types of orbits back to their common origins. Within the dark matter halo, chaotic motion also decreases globally in time. The inner halo (r < 5 kpc) is where most chaotic orbits are found and it is the only region where chaotic orbits outnumber regular orbits, in the early evolution. (AU)

• Processo FAPESP: 09/54006-4 - Um cluster de computadores para o Departamento de Astronomia do IAG-USP e para o Núcleo de Astrofísica da UNICSUL
• Beneficiário: Elisabete Maria de Gouveia Dal Pino
• Modalidade de apoio: Auxílio à Pesquisa - Programa Equipamentos Multiusuários