Climbing the cosmic ladder with stellar twins in RAVE with Gaia

Jofré, Paula; Traven, Gregor; Hawkins, Keith (Astrophysicist); Gilmore, Gerry, 1951-; Sanders, Jason, 1989-; Mädler, Thomas; Steinmetz, Matthias, 1966-; Kunder, A. (Andrea); Kordopatis, Georges, 1985-; McMillan, Paul J.; Bienaymé, Olivier; Bland-Hawthorn, J. (Joss); Gibson, Brad K.; Grebel, Eva K.; Munari, Ulisse; Navarro, Julio F. (Julio Fernando); Parker, Quentin A.; Reid, Warren A. (Warren Alfred); Seabroke, George; Zwitter, Tomaž

EA Milne Centre for Astrophysics
Stars : distances; Techniques : spectroscopic; Methods : statistical
2017

Journal article


Rights
© 2017 The Authors
Abstract

We apply the twin method to determine parallaxes to 232,545 stars of the RAVE survey using the parallaxes of Gaia DR1 as a reference. To search for twins in this large dataset, we apply the t-stochastic neighbour embedding t-SNE projection which distributes the data according to their spectral morphology on a two dimensional map. From this map we choose the twin candidates for which we calculate a chi^2 to select the best sets of twins. Our results show a competitive performance when compared to other model-dependent methods relying on stellar parameters and isochrones. The power of the method is shown by finding that the accuracy of our results is not significantly affected if the stars are normal or peculiar since the method is model free. We find twins for 60% of the RAVE sample which is not contained in TGAS or that have TGAS uncertainties which are larger than 20%. We could determine parallaxes with typical errors of 28%. We provide a complementary dataset for the RAVE stars not covered by TGAS, or that have TGAS uncertainties which are larger than 20%, with model-free parallaxes scaled to the Gaia measurements.

Publisher
The University of Hull
Peer reviewed
Yes
Language
English
Extent
5 MB
Identifier
hull:15342

Journal

Journal title
Monthly notices of the Royal Astronomical Society
Publication date
2017
Publisher
Oxford University Press
DOI
10.1093/mnras/stx1877
ISSN (Print)
0035-8711
ISSN (Electronic)
1365-2966
Volume
472
Issue
3
Start page
2517
End page
2533
Notes

This article has been accepted for publication in Monthly notices of the Royal Astronomical Society ©: 2017 The authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.

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