Astrophys. J., 836, 77-77 (2017/February-2)
Precision stellar characterization of FGKM stars using an empirical spectral library.
YEE S.W., PETIGURA E.A. and VON BRAUN K.
Abstract (from CDS):
Classification of stars, by comparing their optical spectra to a few dozen spectral standards, has been a workhorse of observational astronomy for more than a century. Here, we extend this technique by compiling a library of optical spectra of 404 touchstone stars observed with Keck/HIRES by the California Planet Search. The spectra have high resolution (R ≃ 60,000), high signal-to-noise ratio (S/N ≃ 150/pixel), and are registered onto a common wavelength scale. The library stars have properties derived from interferometry, asteroseismology, LTE spectral synthesis, and spectrophotometry. To address a lack of well-characterized late-K dwarfs in the literature, we measure stellar radii and temperatures for 23 nearby K dwarfs, using modeling of the spectral energy distribution and Gaia parallaxes. This library represents a uniform data set spanning the spectral types ∼M5-F1 (Teff ≃ 3000-7000 K, R* ≃ 0.1-16 R☉). We also present "Empirical SpecMatch" (SpecMatch-Emp), a tool for parameterizing unknown spectra by comparing them against our spectral library. For FGKM stars, SpecMatch-Emp achieves accuracies of 100 K in effective temperature (Teff), 15% in stellar radius (R*), and 0.09 dex in metallicity ([Fe/H]). Because the code relies on empirical spectra it performs particularly well for stars ∼K4 and later, which are challenging to model with existing spectral synthesizers, reaching accuracies of 70 K in Teff, 10% in R*, and 0.12 dex in [Fe/H]. We also validate the performance of SpecMatch-Emp, finding it to be robust at lower spectral resolution and S/N, enabling the characterization of faint late-type stars. Both the library and stellar characterization code are publicly available.
© 2017. The American Astronomical Society. All rights reserved.
techniques: spectroscopic - techniques: spectroscopic
VizieR on-line data:
<Available at CDS (J/ApJ/836/77): table1.dat table6.dat>
View the reference in ADS
To bookmark this query, right click on this link: simbad:2017ApJ...836...77Y and select 'bookmark this link' or equivalent in the popup menu