Kordopatis, G;
Gilmore, G;
Wyse, RFG;
Steinmetz, M;
Siebert, A;
Bienayme, O;
McMillan, PJ;
... Siviero, A; + view all
(2013)
In the thick of it: metal-poor disc stars in RAVE.
Monthly Notices of the Royal Astronomical Society
, 436
(4)
pp. 3231-3246.
10.1093/mnras/stt1804.
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Abstract
By selecting in the Radial Velocity Experiment-fourth data release (RAVE-DR4) survey the stars located between 1 and 2 kpc above the Galactic plane, we question the consistency of the simplest three-component model (thin disc, thick disc and halo) for the Milky Way. We confirm that the metallicity and azimuthal velocity distribution functions of the thick disc are not Gaussian. In particular, we find that the thick disc has an extended metallicity tail going at least down to [M/H] = ‒2 dex, contributing roughly 3 per cent of the entire thick disc population and having a shorter scalelength compared to the canonical thick disc. The mean azimuthal velocity of these metal-poor stars allows us to estimate the correlation between the metallicity ([M/H]) and the orbital velocity (Vϕ), which is an important constraint on the formation mechanisms of the Galactic thick disc. Given our simple approach, we find ∂Vϕ/∂[M/H]≈ 50 km s−1 dex−1, which is in very good agreement with previous literature values. We complete the study with a brief discussion on the implications of the formation scenarios for the thick disc and suggest that given the above-mentioned characteristics, a thick disc mainly formed by radial migration mechanisms seems unlikely.
| Type: | Article |
|---|---|
| Title: | In the thick of it: metal-poor disc stars in RAVE |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1093/mnras/stt1804 |
| Publisher version: | https://doi.org/10.1093/mnras/stt1804 |
| 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: abundances, Galaxy: disc, Galaxy: kinematics and dynamics, Galaxy: stellar content, 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-pp.ucl.ac.uk/id/eprint/10090579 |
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