Dynamical heating across the Milky Way disc using APOGEE and Gaia

Mackereth, J. Ted; Bovy, Jo; Leung, Henry W.; Schiavon, Ricardo P.; H. Trick, Wilma; Chaplin, William J.; Cunha, Katia; Feuillet, Diane K.; Majewski, Steven R.; Martig, Marie; Miglio, Andrea; Nidever, David; Pinsonneault, Marc H.; Aguirre, Victor Silva; Sobeck, Jennifer; Tayar, Jamie; Zasowski, Gail

doi:10.1093/mnras/stz1521

アイテム詳細

登録内容を編集ファイル形式で保存

一時保存へ追加

タグ情報を表示リリース履歴を表示詳細要約

公開

学術論文

Dynamical heating across the Milky Way disc using APOGEE and Gaia

MPS-Authors

/persons/resource/persons231821

H. Trick, Wilma
Computational Structure Formation, MPI for Astrophysics, Max Planck Society;

External Resource

There are no locators available

Fulltext (restricted access)

There are currently no full texts shared for your IP range.

フルテキスト (公開)

公開されているフルテキストはありません

付随資料 (公開)

There is no public supplementary material available

引用

Mackereth, J. T., Bovy, J., Leung, H. W., Schiavon, R. P., H. Trick, W., Chaplin, W. J., Cunha, K., Feuillet, D. K., Majewski, S. R., Martig, M., Miglio, A., Nidever, D., Pinsonneault, M. H., Aguirre, V. S., Sobeck, J., Tayar, J., & Zasowski, G. (2019). Dynamical heating across the Milky Way disc using APOGEE and Gaia. Monthly Notices of the Royal Astronomical Society, 489(1), 176-195. doi:10.1093/mnras/stz1521.

引用: https://hdl.handle.net/21.11116/0000-0005-55C1-1

要旨

The kinematics of the Milky Way disc as a function of age are well measured at the solar radius, but have not been studied over a wider range of Galactocentric radii. Here, we measure the kinematics of mono-age, mono-[Fe/H] populations in the low and high [α/Fe] discs between 4 ≲ R ≲ 13 kpc and |z| ≲ 2 kpc using 65 719 stars in common between APOGEE DR14 and Gaia DR2 for which we estimate ages using a Bayesian neural network model trained on asteroseismic ages. We determine the vertical and radial velocity dispersions, finding that the low and high [α/Fe] discs display markedly different age–velocity dispersion relations (AVRs) and shapes σ_z/σ_R. The high [α/Fe] disc has roughly flat AVRs and constant σ_z/σ_R= 0.64 ± 0.04, whereas the low [α/Fe] disc has large variations in this ratio that positively correlate with the mean orbital radius of the population at fixed age. The high [α/Fe] disc component’s flat AVRs and constant σ_z/σ_Rclearly indicate an entirely different heating history. Outer disc populations also have flatter radial AVRs than those in the inner disc, likely due to the waning effect of spiral arms. Our detailed measurements of AVRs and σ_z/σ_Racross the disc indicate that low [α/Fe], inner disc (⁠R≲10kpc⁠) stellar populations are likely dynamically heated by both giant molecular clouds and spiral arms, while the observed trends for outer disc populations require a significant contribution from another heating mechanism such as satellite perturbations. We also find that outer disc populations have slightly positive mean vertical and radial velocities likely because they are part of the warped disc.