Velocity-space substructures and bar resonances in an N-body Milky Way. Issue Volume 16:Issue S362(2020) (June 2020)

• Record Type: Journal Article
• Authors: Asano, Tetsuro; Fujii, Michiko S.; Baba, Junich; Bédorf, Jeroen; Sellentin, Elena; Portegies Zwart, Simon
• Editors: Bisikalo, Dmitry; Wiebe, Dmitri; Boily, Christian
• Is Part Of: Proceedings of the International Astronomical Union. Volume 16:Issue S362(2020)
• Page Start: 116
• Page End: 121
• Publication Date: 2020-06
• Subjects: Galaxy: disk -- Galaxy: kinematics and dynamics -- (Galaxy:) solar neighborhood -- Galaxy: structure -- methods: numerical; Astronomy -- Congresses; Astronomy -- Periodicals; 520
• DOI: 10.1017/S1743921322001521
• Languages: English
• ISSNs: 1743-9213

Abstract

Abstract: The velocity-space distribution of the solar neighborhood stars shows complex substructures (moving groups) including the well-known Hercules stream. Recently, the Gaia observation revealed their detailed structures, but their origins are still in debate. We analyzed a high-resolution N -body simulation of a Milky Way (MW)-like galaxy. To find velocity-space distributions similar to that of the solar neighborhood stars, we used Kullback-Leibler divergence (KLD), which is a metric to measure similarities between probability distributions. The KLD analysis shows the time evolution and the spatial variation of the velocity-space distribution. Velocity-space distributions with small KLDs (i.e. high similarities) are frequently but not always detected around in the simulated MW. In the velocity-map with smallest KLD, the velocity-space substructures are made from bar resonances.