TY - JOUR
T1 - ZASpE
T2 - A code to measure stellar atmospheric parameters and their covariance from spectra
AU - Brahm, Rafael
AU - Jordán, Andrés
AU - Hartman, Joel
AU - Bakos, Gáspár
N1 - Funding Information:
RB is supported by CONICYT-PCHA/Doctorado Nacional. RB acknowledges additional support from project IC120009 ‘Millennium Institute of Astrophysics (MAS)’ of the Millennium Science Initiative, Chilean Ministry of Economy. AJ acknowledges support from FONDECYT project 1130857, BASAL CATA PFB-06 and project IC120009 ‘Millennium Institute of Astrophysics (MAS)’ of the Millennium Science Initiative, Chilean Ministry of Economy.
Publisher Copyright:
© 2016 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society
PY - 2017/5/1
Y1 - 2017/5/1
N2 - We describe the Zonal Atmospheric Stellar Parameters Estimator (ZASPE), a new algorithm, and its associated code, for determining precise stellar atmospheric parameters and their uncertainties from high-resolution echelle spectra of FGK-type stars. ZASPE estimates stellar atmospheric parameters by comparing the observed spectrum against a grid of synthetic spectra only in the most sensitive spectral zones to changes in the atmospheric parameters. Realistic uncertainties in the parameters are computed from the data itself, by taking into account the systematic mismatches between the observed spectrum and the best-fitting synthetic one. The covariances between the parameters are also estimated in the process. ZASPE can in principle use any pre-calculated grid of synthetic spectra, but unbiased grids are required to obtain accurate parameters. We tested the performance of two existing libraries, and we concluded that neither is suitable for computing precise atmospheric parameters. We describe a process to synthesize a new library of synthetic spectra that was found to generate consistent results when compared with parameters obtained with different methods (interferometry, asteroseismology, equivalent widths).
AB - We describe the Zonal Atmospheric Stellar Parameters Estimator (ZASPE), a new algorithm, and its associated code, for determining precise stellar atmospheric parameters and their uncertainties from high-resolution echelle spectra of FGK-type stars. ZASPE estimates stellar atmospheric parameters by comparing the observed spectrum against a grid of synthetic spectra only in the most sensitive spectral zones to changes in the atmospheric parameters. Realistic uncertainties in the parameters are computed from the data itself, by taking into account the systematic mismatches between the observed spectrum and the best-fitting synthetic one. The covariances between the parameters are also estimated in the process. ZASPE can in principle use any pre-calculated grid of synthetic spectra, but unbiased grids are required to obtain accurate parameters. We tested the performance of two existing libraries, and we concluded that neither is suitable for computing precise atmospheric parameters. We describe a process to synthesize a new library of synthetic spectra that was found to generate consistent results when compared with parameters obtained with different methods (interferometry, asteroseismology, equivalent widths).
KW - Methods: data analysis
KW - Planetary systems
KW - Stars: fundamental parameters
KW - Techniques: spectroscopic
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U2 - 10.1093/mnras/stx144
DO - 10.1093/mnras/stx144
M3 - Article
AN - SCOPUS:85017227903
VL - 467
SP - 971
EP - 984
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
SN - 0035-8711
IS - 1
ER -