Estimating the atmospheric properties of 44 M dwarfs from SPIRou spectra. Issue 3 (29th August 2022)

• Record Type: Journal Article
• Authors: Cristofari, P I; Donati, J-F; Masseron, T; Fouqué, P; Moutou, C; Carmona, A; Artigau, E; Martioli, E; Hébrard, G; Gaidos, E; Delfosse, X
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 516:Issue 3(2022)
• Page Start: 3802
• Page End: 3820
• Publication Date: 2022-08-29
• Subjects: techniques: spectroscopic -- stars: fundamental parameters -- stars: low-mass -- infrared: stars; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stac2364
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: We describe advances on a method designed to derive accurate parameters of M dwarfs. Our analysis consists in comparing high-resolution infrared spectra acquired with the near-infrared spectro-polarimeter SPIRou to synthetic spectra computed from MARCS model atmospheres, in order to derive the effective temperature ( T eff ), surface gravity (log g ), metallicity ($\rm {[M/H]}$ ), and alpha-enhancement ($\rm {[\alpha /Fe]}$ ) of 44 M dwarfs monitored within the SPIRou Legacy Survey (SLS). Relying on 12 of these stars, we calibrated our method by refining our selection of well-modelled stellar lines, and adjusted the line list parameters to improve the fit when necessary. Our retrieved T eff, log g, and $\rm {[M/H]}$ are in good agreement with literature values, with dispersions of the order of 50 K in T eff and 0.1 dex in log g and $\rm {[M/H]}$ . We report that fitting $\rm {[\alpha /Fe]}$ has an impact on the derivation of the other stellar parameters, motivating us to extend our fitting procedure to this additional parameter. We find that our retrieved $\rm {[\alpha /Fe]}$ are compatible with those expected from empirical relations derived in other studies.