RT journal article
T1 Gaia Data Release 3: Mapping the asymmetric disc of the Milky Way
A1 Drimmel, R.
A1 Romero Gómez, M.
A1 Chemin, L.
A1 Ramos, P.
A1 Poggio, E.
A1 Berihuete Macías, Ángel
A2 Estadística e Investigación Operativa
K1 galaxy
K1 kinematics and dynamics – Galaxy
K1 structure – Galaxy
K1 catalogs
K1 disk – Galaxy
K1 bulge – catalogs
AB Context. With the most recent Gaia data release, the number of sources with complete 6D phase space information (position and velocity) hasincreased to well over 33 million stars, while stellar astrophysical parameters are provided for more than 470 million sources, and more than 11million variable stars are identified.Aims. Using the astrophysical parameters and variability classifications provided in Gaia DR3, we selected various stellar populations to exploreand 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 mappedthe spiral structure associated with star formation 4−5 kpc from the Sun. We selected over 2800 Classical Cepheids younger than 200 Myr thatshow 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 giantbranch (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 faras 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 listsbased 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 HIsurveys, which seems to be a continuation of the Perseus arm into the third quadrant. The subset of RGB stars with velocities clearly reveals thelarge-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 withspiral 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 willundoubtedly lead us to a clearer understanding of the dynamical nature of the non-axisymmetric structures of the Milky Way.
PB EDP Sciences
SN 1432-0746
YR 2022
FD 2022-06-06
LK http://hdl.handle.net/10498/32136
UL http://hdl.handle.net/10498/32136
LA eng
DS Repositorio Institucional de la Universidad de Cádiz
RD 11-nov-2026