Gaia Data Release 3: Mapping the asymmetric disc of the Milky Way

Publikation: Beitrag in FachzeitschriftForschungsartikelBeigetragenBegutachtung

Beitragende

  • Gaia Collaboration - (Autor:in)
  • Arbeitsgruppe Astronomie
  • National Institute for Astrophysics
  • Universitat de Barcelona
  • Universidad de Antofagasta
  • Université de Strasbourg
  • Observatoire de la Cote d'Azur
  • Osservatorio Astronomico di Capodimonte
  • Max Planck Institute for Astronomy
  • Royal Observatory of Belgium
  • Leiden University
  • Istituto di Astrofisica Spaziale e Fisica Cosmica di Bologna
  • Radagast Solutions
  • University of Groningen
  • Université de Toulouse
  • Astronomical Observatory of Padua
  • ESTEC - European Space Research and Technology Centre
  • Institut de Mecanique Celeste et de Calcul des Ephemerides
  • IPAG - Institut de planétologie et d'astrophysique de Grenoble
  • Universität Heidelberg
  • Université de Bordeaux
  • University of Cambridge
  • Universität Genf
  • European Space Astronomy Centre
  • European Space Agency - ESA
  • Technische Universität Dresden
  • Lund University
  • Centre national d'études spatiales
  • Université libre de Bruxelles (ULB)
  • Fonds de la Recherche Scientifique Belgique
  • Osservatorio Astrofisico Di Arcetri, Florence

Abstract

Context. With the most recent Gaia data release, the number of sources with complete 6D phase space information (position and velocity) has increased to well over 33 million stars, while stellar astrophysical parameters are provided for more than 470 million sources, and more than 11 million variable stars are identified. Aims. Using the astrophysical parameters and variability classifications provided in Gaia DR3, we selected various stellar populations to explore and identify non-axisymmetric features in the disc of the Milky Way in configuration and velocity space. Methods. Using more about 580 000 sources identified as hot OB stars, together with 988 known open clusters younger than 100 Myr, we mapped the spiral structure associated with star formation 4'5 kpc from the Sun. We selected over 2800 Classical Cepheids younger than 200 Myr that show spiral features extending as far as 10 kpc from the Sun in the outer disc. We also identified more than 8.7 million sources on the red giant branch (RGB), of which 5.7 million have line-of-sight velocities. This later sample allows the velocity field of the Milky Way to be mapped as far as 8 kpc from the Sun, including the inner disc. Results. The spiral structure revealed by the young populations is consistent with recent results using Gaia EDR3 astrometry and source lists based on near-infrared photometry, showing the Local (Orion) Arm to be at least 8 kpc long, and an outer arm consistent with what is seen in HI surveys, which seems to be a continuation of the Perseus arm into the third quadrant. The subset of RGB stars with velocities clearly reveals the large-scale kinematic signature of the bar in the inner disc, as well as evidence of streaming motions in the outer disc that might be associated with spiral arms or bar resonances. A local comparison of the velocity field of the OB stars reveals similarities and differences with the RGB sample. Conclusions. This cursory study of Gaia DR3 data shows there is a rich bounty of kinematic information to be explored more deeply, which will undoubtedly lead us to a clearer understanding of the dynamical nature of the non-axisymmetric structures of the Milky Way.

Details

OriginalspracheEnglisch
AufsatznummerA37
Seiten (von - bis)1-35
Seitenumfang35
FachzeitschriftAstronomy and Astrophysics
Jahrgang674
PublikationsstatusVeröffentlicht - 1 Juni 2023
Peer-Review-StatusJa

Externe IDs

ORCID /0000-0002-9533-2168/work/168205406
ORCID /0000-0003-4682-7831/work/168206664
ORCID /0000-0001-6967-8707/work/168207053

Schlagworte

Schlagwörter

  • Catalogs, Galaxy: bulge, Galaxy: disk, Galaxy: kinematics and dynamics, Galaxy: structure