Volume 654, October 2021
|Number of page(s)||11|
|Section||Atomic, molecular, and nuclear data|
|Published online||21 October 2021|
GSP-spec line list for the parametrisation of Gaia-RVS stellar spectra★
Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Laboratoire Lagrange, Bd de l’Observatoire, CS 34229,
Nice Cedex 4, France
Accepted: 29 June 2021
Context. The Gaia mission is a magnitude-limited whole-sky survey that collects an impressive quantity of astrometric, spectro-photometric and spectroscopic data. Among all the on-board instruments, the Radial Velocity Spectrometer (RVS) produces millions of spectra up to a magnitude of GRVS ~ 16. For the brightest RVS targets, stellar atmospheric parameters and individual chemical abundances are automatically estimated by the Generalized Stellar Parametriser – spectroscopy group (GSP-Spec). These data will be published with the third Gaia Data Release.
Aims. Some major ingredients of the determination of these stellar parameters include the atomic and molecular line lists that are adopted to compute reference synthetic spectra, on which the parametrisation methods rely. We aim to build such a specific line list optimised for the analysis of RVS late-type star spectra.
Methods. Starting from the Gaia-ESO line lists, we first compared the observed and synthetic spectra of six well-known reference late-type stars in the wavelength range covered by the RVS instrument. We then improved the quality of the atomic data for the transitions presenting the largest mismatches.
Results. The new line list is found to produce very high-quality synthetic spectra for the tested reference stars and has thus been adopted within GSP-Spec. We note, however, that a couple of atomic line profiles, in particular the calcium infrared triplet lines, still show some deviations compared to the reference spectra, probably because of the adopted line-transfer assumptions (local thermodynamical equilibrium, hydrostatic, and no chromosphere). Future works should focus on such lines and should extend the present work towards OBA and M-type stellar spectra.
Key words: stars: abundances / atomic data / line: identification / surveys / stars: fundamental parameters
Full Table 4 is only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (22.214.171.124) or via http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/654/A130
© G. Contursi et al. 2021
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.