Milky Way's Thick and Thin disk: Is there distinct thick disk?

Abstract

This article is based on our discussion session on Milky Way models at the 592 WE-Heraeus Seminar, Reconstructing the Milky Way's History: Spectroscopic Surveys, Asteroseismology and Chemodynamical models. The discussion focused on the following question: "Are there distinct thick and thin disks?". The answer to this question depends on the definition one adopts for thin and thick disks. The participants of this discussion converged to the idea that there are at least two different types of disks in the Milky Way. However, there are still important open questions on how to best define these two types of disks (chemically, kinematically, geometrically or by age?). The question of what is the origin of the distinct disks remains open. The future Galactic surveys which are highlighted in this conference should help us answering these questions. The almost one-hour debate involving researchers in the field representing different modelling approaches (Galactic models such as TRILEGAL, Besancon and Galaxia, chemical evolution models, extended distribution functions method, chemodynamics in the cosmological context, and self-consistent cosmological simulations) illustrated how important is to have all these parallel approaches. All approaches have their advantages and shortcomings (also discussed), and different approaches are useful to address specific points that might help us answering the more general question above.

7 pages, no figure. To appear in Astronomische Nachrichten, special issue "Reconstruction the Milky Way's History: Spectroscopic surveys, Asteroseismology and Chemo-dynamical models", Guest Editors C. Chiappini, J. Montalban, and M. Steffen

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Cited by in corpus (6)

• Bright Metal-Poor Stars from the Hamburg/ESO Survey. II. A Chemodynamical Analysis
• The AMBRE project: a study of Li evolution in the Galactic thin and thick discs
• Explaining the decrease in ISM lithium at super-solar metallicities in the solar vicinity
• Deciphering the evolution of the Milky Way discs: Gaia APOGEE Kepler giant stars and the Besançon Galaxy Model
• Metallicity Gradient of the Thick Disc Progenitor at High Redshift
• Asteroseismology of red giants & galactic archaeology