Advanced

The GALAH Survey : Lithium-strong KM dwarfs

, ; Zerjal, M.; Ireland, M. J.; Nordlander, T.; Lin, J.; Buder, S.; Casagrande, L.; Åotar, K.; De Silva, G. and Horner, J., et al. (2019) In Monthly Notices of the Royal Astronomical Society 484(4). p.4591-4600
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... (More)

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.

(Less)
Please use this url to cite or link to this publication:
author
, et al. (More)
(Less)
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
stars: abundances, stars: late-type, stars: pre-main-sequence
in
Monthly Notices of the Royal Astronomical Society
volume
484
issue
4
pages
10 pages
publisher
Oxford University Press (OUP)
external identifiers
  • scopus:85062273834
ISSN
0035-8711
DOI
10.1093/mnras/stz296
language
English
LU publication?
yes
id
a4e944b1-3fa3-47ea-a58a-ffcb128b28d6
date added to LUP
2019-03-12 12:23:16
date last changed
2019-11-05 05:14:28
@article{a4e944b1-3fa3-47ea-a58a-ffcb128b28d6,
  abstract     = {<p>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) &gt; 0.1 Å), 335 K5-K9 (&gt;0.07 Å) and 512 M0-M4 dwarfs (&gt;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.</p>},
  author       = {,  and Zerjal, M. and Ireland, M. J. and Nordlander, T. and Lin, J. and Buder, S. and Casagrande, L. and Åotar, K. and De Silva, G. and Horner, J. and Martell, S. and Traven, G. and Zwitter, T.},
  issn         = {0035-8711},
  keyword      = {stars: abundances,stars: late-type,stars: pre-main-sequence},
  language     = {eng},
  number       = {4},
  pages        = {4591--4600},
  publisher    = {Oxford University Press (OUP)},
  series       = {Monthly Notices of the Royal Astronomical Society},
  title        = {The GALAH Survey : Lithium-strong KM dwarfs},
  url          = {http://dx.doi.org/10.1093/mnras/stz296},
  volume       = {484},
  year         = {2019},
}