Williams, MEK;
Steinmetz, M;
Binney, J;
Siebert, A;
Enke, H;
Famaey, B;
Minchev, I;
... Zwitter, T; + view all
(2013)
The wobbly Galaxy: kinematics north and south with RAVE red-clump giants.
Monthly Notices of the Royal Astronomical Society
, 436
(1)
pp. 101-121.
10.1093/mnras/stt1522.
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Abstract
The RAdial Velocity Experiment survey, combined with proper motions and distance estimates, can be used to study in detail stellar kinematics in the extended solar neighbourhood (solar suburb). Using 72 365 red-clump stars, we examine the mean velocity components in 3D between 6 < R < 10 kpc and −2 < Z < 2 kpc, concentrating on north–south differences. Simple parametric fits to the (R, Z) trends for Vϕ and the velocity dispersions are presented. We confirm the recently discovered gradient in mean Galactocentric radial velocity, VR, finding that the gradient is marked below the plane (δ〈VR〉/δR = −8 km s−1 kpc−1 for Z < 0, vanishing to zero above the plane), with a Z gradient thus also present. The vertical velocity, VZ, also shows clear, large-amplitude (|VZ| = 17 km s−1) structure, with indications of a rarefaction–compression pattern, suggestive of wave-like behaviour. We perform a rigorous error analysis, tracing sources of both systematic and random errors. We confirm the north–south differences in VR and VZ along the line of sight, with the VR estimated independent of the proper motions. The complex three-dimensional structure of velocity space presents challenges for future modelling of the Galactic disc, with the Galactic bar, spiral arms and excitation of wave-like structures all probably playing a role.
| Type: | Article |
|---|---|
| Title: | The wobbly Galaxy: kinematics north and south with RAVE red-clump giants |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1093/mnras/stt1522 |
| Publisher version: | https://doi.org/10.1093/mnras/stt1522 |
| 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: | Galaxy: kinematics and dynamics, solar neighbourhood, Galaxy: structure |
| 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.ucl.ac.uk/id/eprint/10090603 |
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