McMillan, Paul J;
Petersson, Jonathan;
Tepper-Garcia, Thor;
Bland-Hawthorn, Joss;
Antoja, Teresa;
Chemin, Laurent;
Figueras, Francesca;
... Seabroke, George; + view all
(2022)
The disturbed outer Milky Way disc.
Monthly Notices of the Royal Astronomical Society
, 516
(4)
pp. 4988-5002.
10.1093/mnras/stac2571.
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Abstract
The outer parts of the Milky Way’s disc are significantly out of equilibrium. Using only distances and proper motions of stars from Gaia’s Early Data Release 3, in the range |b| < 10○, 130○ < ℓ < 230○, we show that for stars in the disc between around 10 and 14 kpc from the Galactic centre, vertical velocity is strongly dependent on the angular momentum, azimuth, and position above or below the Galactic plane. We further show how this behaviour translates into a bimodality in the velocity distribution of stars in the outer Milky Way disc. We use an N-body model of an impulse-like interaction of the Milky Way disc with a perturber similar to the Sagittarius dwarf to demonstrate that this mechanism can generate a similar disturbance. It has already been shown that this interaction can produce a phase spiral similar to that seen in the Solar neighbourhood. We argue that the details of this substructure in the outer galaxy will be highly sensitive to the timing of the perturbation or the gravitational potential of the Galaxy, and therefore may be key to disentangling the history and structure of the Milky Way.
| Type: | Article |
|---|---|
| Title: | The disturbed outer Milky Way disc |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1093/mnras/stac2571 |
| Publisher version: | http://dx.doi.org/10.1093/mnras/stac2571 |
| Language: | English |
| Additional information: | This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. © The Author(s) 2022. Published by Oxford University Press on behalf of Royal Astronomical Society. |
| Keywords: | methods: numerical, Galaxy: evolution, Galaxy: kinematics and dynamics, Galaxy: structure |
| UCL classification: | UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Space and Climate Physics UCL > Provost and Vice Provost Offices > UCL BEAMS UCL |
| URI: | https://discovery-pp.ucl.ac.uk/id/eprint/10156438 |
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