TY - JOUR
T1 - Characterizing the spiral Lin–Shu-type density-wave structure of the Milky Way in the 3-kpc-scale solar neighborhood
T2 - Astrophysical conclusions
AU - Griv, Evgeny
AU - Gedalin, Michael
AU - Martinez-Medina, Luis
AU - Pérez-Villegas, Angeles
AU - Jiang, Ing Guey
N1 - Publisher Copyright:
© 2024
PY - 2025/5/1
Y1 - 2025/5/1
N2 - In the concluding work of a series of studies, the disk's spiral structure of the Milky Way is anew considered as a Lin–Shu-type density-wave pattern. As a step forward, a sample of ∼500000 stars from a total of 656161 sources within 3 kpc from the Sun and ±250 pc from the disk's mean plane identified in the Gaia EDR3 is examined. The parameters of Galactic rotation and solar peculiar motion corrected for the effects of 3D density waves, and the radial, azimuthal, and vertical components of the streaming motion of stars due to the spiral arms are derived from the measured velocities of objects. The parameters of the waves are also estimated. Two almost equal scales of periodic compression/rarefaction irregularity of the streaming velocity field with the radial and vertical wavelengths of ≲2 kpc in the form of a spiral density wave propagating in the disk at the Sun are revealed, which are reasonably related to the global spiral pattern. The Sun is located between the central part and the inner edge of the Orion (Local) wave arm. The spiral pattern in the kinematics of stars is consistent with the spatial distribution of the nearby arm segments traced by young populations. In agreement with the original Lin and Shu proposal, the gravitational field associated with the arms is a small deviation from the total gravitational field of the Galaxy that is axisymmetric in the mean. The very existence of the spiral arrangement in the velocity field suggests that the localized disk is gravitationally unstable.
AB - In the concluding work of a series of studies, the disk's spiral structure of the Milky Way is anew considered as a Lin–Shu-type density-wave pattern. As a step forward, a sample of ∼500000 stars from a total of 656161 sources within 3 kpc from the Sun and ±250 pc from the disk's mean plane identified in the Gaia EDR3 is examined. The parameters of Galactic rotation and solar peculiar motion corrected for the effects of 3D density waves, and the radial, azimuthal, and vertical components of the streaming motion of stars due to the spiral arms are derived from the measured velocities of objects. The parameters of the waves are also estimated. Two almost equal scales of periodic compression/rarefaction irregularity of the streaming velocity field with the radial and vertical wavelengths of ≲2 kpc in the form of a spiral density wave propagating in the disk at the Sun are revealed, which are reasonably related to the global spiral pattern. The Sun is located between the central part and the inner edge of the Orion (Local) wave arm. The spiral pattern in the kinematics of stars is consistent with the spatial distribution of the nearby arm segments traced by young populations. In agreement with the original Lin and Shu proposal, the gravitational field associated with the arms is a small deviation from the total gravitational field of the Galaxy that is axisymmetric in the mean. The very existence of the spiral arrangement in the velocity field suggests that the localized disk is gravitationally unstable.
KW - Fundamental parameters – galaxy
KW - Galaxy
KW - Kinematics and dynamics – galaxy
KW - Spiral
KW - Structure – galaxies
UR - http://www.scopus.com/inward/record.url?scp=85211999386&partnerID=8YFLogxK
U2 - 10.1016/j.newast.2024.102340
DO - 10.1016/j.newast.2024.102340
M3 - Article
AN - SCOPUS:85211999386
SN - 1384-1076
VL - 116
JO - New Astronomy
JF - New Astronomy
M1 - 102340
ER -