Galaxy simulations in the Gaia era

TL;DR

This paper discusses how upcoming large-scale astronomical data from Gaia and other surveys will enhance our understanding of the Milky Way's formation and evolution, emphasizing the role of advanced simulations.

Contribution

It highlights the necessity of cosmological simulations to interpret complex Milky Way data and explores specific topics like the thick disk and radial migration.

Findings

Upcoming data will provide detailed 6D kinematics and chemistry for millions of stars.

Simulations are essential for understanding the formation of the Milky Way's structures.

Radial migration significantly influences the galaxy's chemodynamical evolution.

Abstract

We live in an age where an enormous amount of astrometric, photometric, asteroseismic, and spectroscopic data of Milky Way stars are being acquired, many orders of magnitude larger than about a decade ago. Thanks to the Gaia astrometric mission and followup ground-based spectroscopic surveys in the next 5-10 years about 10-20 Million stars will have accurate 6D kinematics and chemical composition measurements. KEPLER-2, PLATO, and TESS will provide asteroseismic ages for a good fraction of those. In this article we outline some outstanding problems concerning the formation and evolution of the Milky Way and argue that, due to the complexity of physical processes involved in the formation of disk galaxies, numerical simulations in the cosmological context are needed for the interpretation of Milky Way observations. We also discuss in some detail the formation of the Milky Way thick disk, chemodynamical models, and the effects of radial migration.