Issue |
A&A
Volume 634, February 2020
|
|
---|---|---|
Article Number | A90 | |
Number of page(s) | 11 | |
Section | Galactic structure, stellar clusters and populations | |
DOI | https://doi.org/10.1051/0004-6361/201834042 | |
Published online | 12 February 2020 |
Signatures of the Galactic bar in high-order moments of proper motions measured by Gaia
1
Instituto de Astrofísica de Canarias, 38205 La Laguna, Tenerife, Spain
e-mail: pedroap@iac.es
2
Universidad de La Laguna, Dpto. Astrofísica, 38206 La Laguna, Tenerife, Spain
3
Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Laboratoire Lagrange, Nice, France
Received:
8
August
2018
Accepted:
10
December
2019
Our location in the Milky Way provides an exceptional opportunity to gain insight on the galactic evolution processes, and complement the information inferred from observations of external galaxies. Since the Milky Way is a barred galaxy, the study of motions of individual stars in the bulge and disc is useful to understand the role of the bar. The Gaia mission enables such study by providing the most precise parallaxes and proper motions to date. In this theoretical work, we explore the effects of the bar on the distribution of higher-order moments – the skewness and kurtosis – of the proper motions by confronting two simulated galaxies, one with a bar and one nearly axisymmetric, with observations from the latest Gaia data release (Gaia DR2). We introduce the code ASGAIA to account for observational errors of Gaia in the kinematical structures predicted by the numerical models. As a result, we find clear imprints of the bar in the skewness distribution of the longitudinal proper motion μℓ in Gaia DR2, as well as other features predicted for the next Gaia data releases.
Key words: Galaxy: structure / Galaxy: evolution / Galaxy: kinematics and dynamics / methods: numerical
© ESO 2020
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.