Gaia Data Release 3

Autor(en)

, Gaia Collaboration, A. Recio-Blanco, G. Kordopatis, P. de Laverny, P. A. Palicio, A. Spagna, L. Spina, D. Katz, P. Re Fiorentin, E. Poggio, P. J. McMillan, A. Vallenari, M. G. Lattanzi, G. M. Seabroke, L. Casamiquela, A. Bragaglia, T. Antoja, C. A. L. Bailer-Jones, R. Andrae, M. Fouesneau, M. Cropper, T. Cantat-Gaudin, U. Heiter, A. Bijaoui, T. Prusti, J. H. J. de Bruijne, F. Arenou, P. Ábrahám, J. Alves, T. Lebzelter

Abstrakt

Context. The motion of stars has been used to reveal details

of the complex history of the Milky Way, in constant interaction with

its environment. Nevertheless, to reconstruct the Galactic history

puzzle in its entirety, the chemo-physical characterisation of stars is

essential. Previous Gaia data releases were supported by a

smaller, heterogeneous, and spatially biased mixture of chemical data

from ground-based observations.

Aims. Gaia Data Release 3 opens a new era of all-sky

spectral analysis of stellar populations thanks to the nearly 5.6

million stars observed by the Radial Velocity Spectrometer (RVS) and

parametrised by the GSP-Spec module. In this work, we aim to demonstrate

the scientific quality of Gaia’s Milky Way chemical cartography through a chemo-dynamical analysis of disc and halo populations.

Methods. Stellar atmospheric parameters and chemical abundances provided by Gaia

DR3 spectroscopy are combined with DR3 radial velocities and EDR3

astrometry to analyse the relationships between chemistry and Milky Way

structure, stellar kinematics, and orbital parameters.

Results. The all-sky Gaia chemical cartography allows a

powerful and precise chemo-dynamical view of the Milky Way with

unprecedented spatial coverage and statistical robustness. First, it

reveals the strong vertical symmetry of the Galaxy and the flared

structure of the disc. Second, the observed kinematic disturbances of

the disc – seen as phase space correlations – and kinematic or orbital

substructures are associated with chemical patterns that favour stars

with enhanced metallicities and lower [α/Fe] abundance ratios

compared to the median values in the radial distributions. This is

detected both for young objects that trace the spiral arms and older

populations. Several α, iron-peak elements and at least one heavy

element trace the thin and thick disc properties in the solar cylinder.

Third, young disc stars show a recent chemical impoverishment in

several elements. Fourth, the largest chemo-dynamical sample of open

clusters analysed so far shows a steepening of the radial metallicity

gradient with age, which is also observed in the young field population.

Finally, the Gaia chemical data have the required coverage and

precision to unveil galaxy accretion debris and heated disc stars on

halo orbits through their [α/Fe] ratio, and to allow the study of the chemo-dynamical properties of globular clusters.

Conclusions. Gaia DR3 chemo-dynamical diagnostics open

new horizons before the era of ground-based wide-field spectroscopic

surveys. They unveil a complex Milky Way that is the outcome of an

eventful evolution, shaping it to the present day.

Organisation(en)

Institut für Astrophysik

Journal

Astronomy & Astrophysics

Band

674

Anzahl der Seiten

50

ISSN

0004-6361

DOI

https://doi.org/10.1051/0004-6361/202243511

Publikationsdatum

06-2023

Peer-reviewed

Ja

ÖFOS 2012

103004 Astrophysik

Schlagwörter

ASJC Scopus Sachgebiete

Astronomy and Astrophysics, Space and Planetary Science

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/c73d6370-5aa2-4af5-a962-94a9f26e3207