Chemical separation of disc components using RAVE

Wojno, Jennifer Leigh; Kordopatis, Georges, 1985-; Steinmetz, Matthias, 1966-; McMillan, Paul J.; Matijevič, Gal; Binney, James, 1950-; Wyse, Rosemary F. G.; Boeche, Corrado; Just, Andreas; Grebel, Eva K.; Siebert, Arnaud, 1974-; Bienaymé, Olivier; Gibson, Brad K.; Zwitter, Tomaž; Bland-Hawthorn, J. (Joss); Navarro, Julio F. (Julio Fernando); Parker, Quentin A.; Reid, Warren A. (Warren Alfred); Seabroke, George; Watson, F. (Fred)

EA Milne Centre for Astrophysics
Galaxy : kinematics and dynamics; Galaxy : disc; Galaxy : abundances; Galaxy : structure; Galaxy : evolution
2016

Journal article


Rights
© 2016 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society
Abstract

We present evidence from the RAdial Velocity Experiment (RAVE) survey of chemically separated, kinematically distinct disc components in the solar neighbourhood. We apply probabilistic chemical selection criteria to separate our sample into α-low (‘thin disc’) and α-high (‘thick disc’) sequences. Using newly derived distances, which will be utilized in the upcoming RAVE DR5, we explore the kinematic trends as a function of metallicity for each of the disc components. For our α-low disc, we find a negative trend in the mean rotational velocity (Vϕ) as a function of iron abundance ([Fe/H]). We measure a positive gradient ∂Vϕ/∂[Fe/H] for the α-high disc, consistent with results from high-resolution surveys. We also find differences between the α-low and α-high discs in all three components of velocity dispersion. We discuss the implications of an α-low, metal-rich population originating from the inner Galaxy, where the orbits of these stars have been significantly altered by radial mixing mechanisms in order to bring them into the solar neighbourhood. The probabilistic separation we propose can be extended to other data sets for which the accuracy in [α/Fe] is not sufficient to disentangle the chemical disc components a priori. For such datasets which will also have significant overlap with Gaia DR1, we can therefore make full use of the improved parallax and proper motion data as it becomes available to investigate kinematic trends in these chemical disc components.

Publisher
The University of Hull
Peer reviewed
Yes
Language
English
Extent
1 MB
Identifier
hull:13538

Journal

Journal title
Monthly notices of the Royal Astronomical Society
Publication date
2016
Publisher
Oxford University Press
DOI
10.1093/mnras/stw1633
ISSN (Print)
0035-8711
ISSN (Electronic)
1365-2966
Volume
461
Issue
4
Start page
4246
End page
4255
Notes

This is a copy of an article published in Monthly notices of the Royal Astronomical Society following peer review. The version of record, Jennifer Wojno, Georges Kordopatis, Matthias Steinmetz, Paul McMillan, Gal Matijevič, James Binney, Rosemary F. G. Wyse, Corrado Boeche, Andreas Just, Eva K. Grebel, Arnaud Siebert, Olivier Bienaymé, Brad K. Gibson, Tomaž Zwitter, Joss Bland-Hawthorn, Julio F. Navarro, Quentin A. Parker, Warren Reid, George Seabroke, and Fred Watson (2016) Chemical separation of disc components using RAVE in MNRAS, is available online at: http://mnras.oxfordjournals.org/content/early/2016/07/07/mnras.stw1633.abstract

Link
Published article
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