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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

On the Stellar Velocity Distribution in the Solar Neighborhood in Light of Gaia DR2

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Michtchenko, Tatiana A. [1] ; Lepine, Jacques R. D. [1] ; Perez-Villegas, Angeles [1] ; Vieira, Ronaldo S. S. [1] ; Barros, Douglas A. [2]
Total Authors: 5
[1] Univ Sao Paulo, IAG, Rua Matao, 1226 Cidade Univ, BR-05508090 Sao Paulo - Brazil
[2] Rua Sessenta Tres 125, BR-53090393 Olinda, Pernambuco - Brazil
Total Affiliations: 2
Document type: Journal article
Source: Astrophysical Journal Letters; v. 863, n. 2 AUG 20 2018.
Web of Science Citations: 4

The aim of this Letter is to contribute to the understanding of the stellar velocity distribution in the solar neighborhood (SN). We propose that the structures on the U-V planes, known as the moving groups, can be mainly explained by the spiral arms perturbations. The applied model of the Galactic disk and spiral arms, with the parameters defined by observational data and with pattern speed Omega(p) = 28.0 km s(-1) kpc(-1), is the same that allowed us to explain the origin of the Local Arm and the Sun's orbit trapped inside the corotation resonance (CR). We show that the U-V picture of the SN consists of the main component, associated with the CR, and the inner and outer structures, which we could associate with the Hercules and Sirius streams, respectively. The Coma-Berenices and Hyades-Pleiades groups, and the Sun itself, belong to the main part. The substructures of Hercules are formed mainly by the nearby 8/1, 12/1, and even 6/1 inner Lindblad resonances, while Sirius is shaped by the bulk of overlapping outer Lindblad resonances, -8/1, -12/1, -16/1, which are stuck to the CR. This richness in resonances only exists near corotation, which should be of the spiral arms, not of the Galactic bar, whose stable corotation zone is far away from the Sun. The model's predictions of the velocity distribution match qualitatively and quantitatively the distribution provided by Gaia data release 2. (AU)

FAPESP's process: 09/54006-4 - A computer cluster for the Astronomy Department of the University of São Paulo Institute of Astronomy, Geophysics and Atmospheric Sciences and for the Cruzeiro do Sul University Astrophysics Center
Grantee:Elisabete Maria de Gouveia Dal Pino
Support type: Multi-user Equipment Program
FAPESP's process: 17/15893-1 - Globular cluster orbits of bulge: the formation and evolution of the Milky Way
Grantee:Maria de Los Angeles Perez Villegas
Support type: Scholarships in Brazil - Post-Doctorate
FAPESP's process: 15/10577-9 - Chaos and integrability in galactic disks
Grantee:Ronaldo Savioli Sumé Vieira
Support type: Scholarships in Brazil - Post-Doctorate