Carrillo, I;
Minchev, I;
Kordopatis, G;
Steinmetz, M;
Binney, J;
Anders, F;
Bienayme, O;
... Zwitter, T; + view all
(2018)
Is the Milky Way still breathing? RAVE-Gaia streaming motions.
Monthly Notices of the Royal Astronomical Society
, 475
(2)
pp. 2679-2696.
10.1093/mnras/stx3342.
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Abstract
We use data from the Radial Velocity Experiment (RAVE) and the Tycho-Gaia astrometric solution (TGAS) catalogue to compute the velocity fields yielded by the radial (VR), azimuthal (Vϕ),and vertical (Vz) components of associated Galactocentric velocity. We search in particular for variation in all three velocity components with distance above and below the disc mid-plane, as well as how each component of Vz (line-of-sight and tangential velocity projections) modifies the obtained vertical structure. To study the dependence of velocity on proper motion and distance, we use two main samples: a RAVE sample including proper motions from the Tycho-2, PPMXL, and UCAC4 catalogues, and a RAVE–TGAS sample with inferred distances and proper motions from the TGAS and UCAC5 catalogues. In both samples, we identify asymmetries in VR and Vz. Below the plane, we find the largest radial gradient to be ∂VR/∂R = −7.01 ± 0.61 km s−1 kpc−1, in agreement with recent studies. Above the plane, we find a similar gradient with ∂VR/∂R = −9.42 ± 1.77 km s−1 kpc−1. By comparing our results with previous studies, we find that the structure in Vz is strongly dependent on the adopted proper motions. Using the Galaxia Milky Way model, we demonstrate that distance uncertainties can create artificial wave-like patterns. In contrast to previous suggestions of a breathing mode seen in RAVE data, our results support a combination of bending and breathing modes, likely generated by a combination of external or internal and external mechanisms.
| Type: | Article |
|---|---|
| Title: | Is the Milky Way still breathing? RAVE-Gaia streaming motions |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1093/mnras/stx3342 |
| Publisher version: | http://dx.doi.org/10.1093/mnras/stx3342 |
| Language: | English |
| Additional information: | This version is the version of record. For information on re-use, please refer to the publisher’s terms and conditions. |
| Keywords: | Science & Technology, Physical Sciences, Astronomy & Astrophysics, Galaxy: disc, Galaxy: kinematics and dynamics, Galaxy: structure, STELLAR VELOCITY DISTRIBUTION, GALACTIC BAR, MOVING GROUPS, SPIRAL ARMS, SOLAR NEIGHBORHOOD, LOCAL KINEMATICS, MINOR MERGERS, NEARBY STARS, DISC, GALAXY |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS 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 |
| URI: | https://discovery-pp.ucl.ac.uk/id/eprint/10027073 |
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