Gaia: unraveling the chemical and dinamical history of our Galaxy

TL;DR

Gaia is a space mission designed to map the Milky Way in 6D with unprecedented precision, using multiple instruments to collect comprehensive astrometric, photometric, and spectroscopic data for about a billion objects.

Contribution

This paper details the Gaia mission's instruments, capabilities, and scientific goals, highlighting its potential to revolutionize our understanding of galactic and extragalactic phenomena.

Findings

Complete 6D mapping of the Milky Way will be achieved.

Data will enable studies of solar system, stellar, and extragalactic objects.

Unprecedented precision in astrometry and spectroscopy will be obtained.

Abstract

The Gaia astrometric mission - the Hipparcos successor - is described in some detail, with its three instruments: the two (spectro)photometers (BP and RP) covering the range 330-1050 nm, the white light (G-band) imager dedicated to astrometry, and the radial velocity spectrometer (RVS) covering the range 847-874 nm at a resolution R \simeq 11500. The whole sky will be scanned repeatedly providing data for ~10^9 point-like objects, down to a magnitude of V \simeq 20, aiming to the full 6D reconstruction of the Milky Way kinematical and dinamical structure with unprecendented precision. The horizon of scientific questions that can find an answer with such a set of data is vast, including besides the Galaxy: Solar system studies, stellar astrophysics, exoplanets, supernovae, Local group physics, unresolved galaxies, Quasars, and fundamental physics. The Italian involvement in the mission preparation is briefly outlined.