The GALAH survey: lithium-strong KM dwarfs
Article
Article Title | The GALAH survey: lithium-strong KM dwarfs |
---|---|
ERA Journal ID | 1074 |
Article Category | Article |
Authors | Zerjal, M. (Author), Ireland, M. J. (Author), Nordlander, T. (Author), Lin, J. (Author), Buder, S. (Author), Casagrande, L. (Author), Cotar, K. (Author), de Silva, G. (Author), Horner, J. (Author), Martell, S. (Author), Traven, G. (Author) and Zwitter, T. (Author) |
Journal Title | Monthly Notices of the Royal Astronomical Society |
Journal Citation | 484 (4), pp. 4591-4600 |
Number of Pages | 10 |
Year | 2019 |
Publisher | Oxford University Press |
Place of Publication | United Kingdom |
ISSN | 0035-8711 |
1365-2966 | |
Digital Object Identifier (DOI) | https://doi.org/10.1093/mnras/stz296 |
Web Address (URL) | https://academic.oup.com/mnras/article/484/4/4591/5304632 |
Abstract | Identifying and characterizing young stars in the Solar neighbourhood is essential to find and describe planets in the early stages of their evolution. This work seeks to identify nearby young stars showing a lithium 6708 Å absorption line in the GALAH survey. A robust, data- driven approach is used to search for corresponding templates in the pool of 434 215 measured dwarf spectra in the survey. It enables a model-free search for best-matching spectral templates for all stars, including M dwarfs with strong molecular absorption bands. 3147 stars have been found to have measurable lithium: 1408 G and 892 K0-K5 dwarfs (EW(Li) > 0.1 Å), 335 K5-K9 (>0.07 Å) and 512 M0-M4 dwarfs (>0.05 Å). Stars with such lithium features are used to investigate the possibility of searching for young stars above the main sequence based merely on their parallaxes and broad-band photometry. The selection of young stars above the main sequence is highly effective for M dwarfs, moderately effective for K dwarfs and ineffective for G dwarfs. Using a combination of the lithium information and the complete 6D kinematics from Gaia and GALAH, 305 new candidate moving group members have been found, 123 of which belong to the Scorpius-Centaurus association, 36 to the Pleiades and 25 to the Hyades clusters. |
Keywords | stars; abundances; late-type; pre-main-sequence; astrophysics; solar and stellar astrophysics |
ANZSRC Field of Research 2020 | 510109. Stellar astronomy and planetary systems |
Public Notes | This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2019 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved. |
Institution of Origin | University of Southern Queensland |
Byline Affiliations | Australian National University |
Max Planck Society, Germany | |
University of Ljubljana, Slovenia | |
Australian Astronomical Observatory, Australia | |
Centre for Astrophysics | |
University of New South Wales | |
Lund Observatory, Sweden |
https://research.usq.edu.au/item/q5434/the-galah-survey-lithium-strong-km-dwarfs
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