J/ApJ/836/77 A library of high-S/N optical spectra of FGKM stars (Yee+, 2017)
Precision stellar characterization of FGKM stars using an empirical spectral
library.
Yee S.W., Petigura E.A., von Braun K.
<Astrophys. J., 836, 77-77 (2017)>
=2017ApJ...836...77Y 2017ApJ...836...77Y (SIMBAD/NED BibCode)
ADC_Keywords: Spectroscopy ; Abundances, [Fe/H] ; Effective temperatures ;
Stars, masses ; Stars, ages ; Parallaxes, trigonometric
Keywords: techniques: spectroscopic
Abstract:
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∼60000), 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∼3000-7000K, R*∼0.1-16R☉). 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 100K in
effective temperature (Teff), 15% in stellar radius (R*), and
0.09dex 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 70K in Teff, 10% in R*, and 0.12dex 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.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 88 23 Properties of 23 K-dwarfs
table6.dat 91 404 Empirical SpecMatch library
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See also:
I/311 : Hipparcos, the New Reduction (van Leeuwen, 2007)
I/337 : Gaia DR1 (Gaia Collaboration, 2016)
J/PASP/110/863 : Stellar Spectral Flux Library: 1150-25000Å (Pickles 1998)
J/ApJS/159/141 : Spectroscopic properties of cool stars. I. (Valenti+, 2005)
J/ApJ/680/728 : Diameters of exoplanet host stars (Baines+, 2008)
J/ApJ/694/1085 : Radii of exoplanet host stars (van Belle+, 2009)
J/other/A+ARV/18.67 : Accurate masses and radii of normal stars (Torres+, 2010)
J/MNRAS/423/122 : Abundances of 93 solar-type Kepler targets (Bruntt+, 2012)
J/ApJ/771/40 : Main-sequence A, F, G & K stars photometry (Boyajian+, 2013)
J/ApJ/768/155 : RVs and photometry of HD 38529 system (Henry+, 2013)
J/ApJ/767/127 : Asteroseismic solutions for 77 Kepler stars (Huber+, 2013)
J/AJ/145/52 : Abundances of late K & M dwarfs in bin. systems (Mann+, 2013)
J/ApJ/804/64 : Empirical and model parameters of 183 M dwarfs (Mann+, 2015)
J/ApJS/225/32 : Extended abundance analysis of cool stars (Brewer+, 2016)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Name Object identifier
11- 16 I6 --- HIP Hipparcos identifier
18- 22 F5.2 mag Vmag [7.9/10.1] V band magnitude
24- 27 F4.2 mag e_Vmag [0.02/0.05] Uncertainty in Vmag
29- 32 F4.2 mag Kmag [5.2/6.9] K band magnitude
34- 37 F4.2 mag e_Kmag [0.03/0.06] Uncertainty in Kmag
39- 42 I4 K Teff [3904/4615] Effective temperature
44- 46 I3 K e_Teff [177/301] Uncertainty in Teff
48- 51 F4.2 10-11W/m2 Fbol [0.5/2.8] Bolometric flux; 1e-8erg/cm2/s
53- 56 F4.2 10-11W/m2 e_Fbol [0.01/0.02] Uncertainty in Fbol
58- 61 F4.1 mas plx [38.5/68.5] Parallax
63- 65 F3.1 mas e_plx [0.2/1.6] Uncertainty in plx
67- 70 F4.2 Rsun R* [0.5/0.8] Stellar radius
72- 75 F4.2 Rsun e_R* [0.04/0.1] Uncertainty in R*
77- 81 F5.2 [Sun] [Fe/H] [-0.9/0.2] Metallicity
83- 86 F4.2 [Sun] e_[Fe/H] [0.1] Uncertainty in [Fe/H]
88 I1 --- r_plx [1/2] Reference code for plx (1)
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Note (1): Reference as follows:
1 = Parallax from the Tycho-Gaia Astrometric Solution (TGAS;
Gaia Collaboration+ 2016, I/337; Lindegren+ 2016A&A...595A...4L 2016A&A...595A...4L;
Michalik+ 2015A&A...574A.115M 2015A&A...574A.115M).
2 = Parallax from Hipparcos (I/311).
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Name Object identifier
14- 17 I4 K Teff [3056/6738] Effective temperature
19- 21 I3 K e_Teff [9/301] Uncertainty in Teff
23- 28 F6.3 Rsun R* [0.1/15.8] Stellar radius
30- 34 F5.3 Rsun e_R* [0.001/1.2] Uncertainty in R*
36- 39 F4.2 [cm/s2] log(g) [2.1/5.2] Log stellar surface gravity
41- 44 F4.2 [cm/s2] e_log(g) [0.01/0.2] Uncertainty in log(g)
46- 50 F5.2 [Sun] [Fe/H] [-0.6/0.6] Metallicity
52- 55 F4.2 [Sun] e_[Fe/H] [0.03/0.1] Uncertainty in [Fe/H]
57- 60 F4.2 Msun M* [0.1/1.7] Stellar mass
62- 65 F4.2 Msun e_M* [0/0.3] Uncertainty in M*
67- 71 F5.2 [yr] logAge [9/10.2] Log stellar age
73- 76 F4.2 [yr] e_logAge [0.03/0.6] Uncertainty in logAge
78- 82 F5.1 mas plx [1.8/549]? Parallax
84- 87 F4.1 mag Vmag [3.2/12.3]? V band magnitude
89- 91 A3 --- Notes Additional note code(s) (1)
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Note (1): Code as follows:
A = Brewer et al. (2016, J/ApJS/225/32) sample (Section 2.1.3).
Teff, log(g), [Fe/H] from single line fits to stellar models; M*, R*,
age from isochrones.
B = Asteroseismic sample from Bruntt+ (2012, J/MNRAS/423/122)
(Section 2.1.4). log(g) from asteroseismic analysis; Teff and [Fe/H]
from individual spectral line fits; M*, R* and age from isochrones.
C = New K-dwarf sample (Section 2.2). Teff from empirical V-K
color-temperature relationship; R* from combining Teff with parallax
and Fbol calculated from SED fitting; [Fe/H] from SME fitting in
Gaidos et al. (2013ApJ...771...18G 2013ApJ...771...18G); M*, log(g), age from isochrones.
D = Mann et al. (2015, J/ApJ/804/64) sample (Section 2.1.2). Teff
from stellar atmosphere models; R* from combining Teff with Fbol
obtained from flux-calibrated spectra; [Fe/H] and M* from empirical
relationships; logg calculated directly from R* and M*; age from
isochrones.
E = Interferometric sample, as compiled in von Braun+ (2014MNRAS.438.2413V 2014MNRAS.438.2413V)
(Section 2.1.1). R* from optical and infrared interferometry;
Teff and [Fe/H] by a variety of methods;
M*, logg and age from isochrones.
1 = Parallaxes from Gaia DR1 (Gaia Collaboration+ 2016, I/337).
2 = Parallaxes from Hipparcos (van Leeuwen 2007, I/311).
3 = No parallaxes found.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 15-Sep-2017