J/AJ/145/52 Abundances of late K and M dwarfs in binary systems (Mann+, 2013) ================================================================================ Prospecting in late-type dwarfs: a calibration of infrared and visible spectroscopic metallicities of late K and M dwarfs spanning 1.5 dex. Mann A.W., Brewer J.M., Gaidos E., Lepine S., Hilton E.J. =2013AJ....145...52M ================================================================================ ADC_Keywords: Stars, F-type ; Stars, G-type ; Stars, K-type ; Stars, M-type ; Spectral types ; Effective temperatures ; Abundances Keywords: binaries: visual - stars: abundances - stars: fundamental parameters - stars: late-type - techniques: spectroscopic Abstract: Knowledge of late K and M dwarf metallicities can be used to guide planet searches and constrain planet formation models. However, the determination of metallicities of late-type stars is difficult because visible wavelength spectra of their cool atmospheres contain many overlapping absorption lines, preventing the measurement of equivalent widths. We present new methods, and improved calibrations of existing methods, to determine metallicities of late K and M dwarfs from moderate resolution (1300-0.5, but are less useful for more metal-poor stars. Description: Between 2011 January and 2012 April, 60 F-, G- and early K-type stars were observed using the ESPaDOnS (Echelle SpectroPolarimetric Device for the Observation of Stars) spectrograph attached to the Canada-France-Hawaii Telescope (CFHT) on Mauna Kea. Observations were taken in the star+sky mode, which gave a resolution of R~65000 and a wavelength range from 0.37{mu}m to 1.05{mu}m. All observations were designed to achieve a signal-to-noise ratio (S/N) of >100 at 0.67{mu}m, and typical S/N was >150 (per resolving element). We obtained near-infrared spectra of our sample of companions using the SpeX spectrograph attached to the NASA Infrared Telescope Facility (IRTF) on Mauna Kea. SpeX observations were taken in the short cross-dispersed (SXD) mode using the 0.3"*15" slit, yielding simultaneous coverage from 0.8 to 2.4{mu}m and a resolution of R~2000. We obtained a visible spectrum of each companion with the SuperNova Integral Field Spectrograph (SNIFS) on the University of Hawaii 2.2m telescope atop Mauna Kea. SNIFS has R~1300 and splits the signal with a dichroic mirror into blue (0.32-0.52{mu}m) and red (0.52-0.95{mu}m) channels. File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table1.dat 88 112 Wide binary sample table2.dat 113 50 Parameters of primary stars observed at Canada-France-Hawaii Telescope (CFHT) table5.dat 43 111 Metal-sensitive features in the near-IR spectrum -------------------------------------------------------------------------------- See also: B/pastel : The PASTEL catalogue (Soubiran+, 2010-) I/317 : The PPMXL Catalog (Roeser+ 2010) I/311 : Hipparcos, the New Reduction (van Leeuwen, 2007) I/298 : LSPM-North Catalog (Lepine+ 2005) I/239 : The Hipparcos and Tycho Catalogues (ESA 1997) J/AJ/144/102 : Cat. of wide companions to Hipparcos stars (Tokovinin+, 2012) J/AJ/143/67 : SLoWPoKES. II. Properties of wide, low-mass binaries (Dhital+, 2012) J/ApJ/753/90 : Stellar paramet. of K5 & later type Kepler stars (Mann+, 2012) J/ApJ/748/93 : K-band spectra for 133 nearby M dwarfs (Rojas-Ayala+, 2012) J/AJ/142/138 : All-sky catalog of bright M dwarfs (Lepine+, 2011) J/A+A/526/A71 : C abundances in G and K nearby stars (Da Silva+, 2011) J/A+A/533/A141 : Stellar parameters for 582 HARPS FGK stars (Sousa+, 2011) J/AJ/139/2566 : SLoWPoKES catalog (Dhital+, 2010) J/PASP/121/117 : Fe & Ti abundance of 12 low-metallicity M stars (Woolf+, 2009) J/AJ/133/889 : Faint companions of Hipparcos stars (Lepine+, 2007) J/ApJS/169/430 : Atmospheric parame. of 1907 metal-rich stars (Robinson+, 2007) J/ApJS/159/141 : Spectroscopic properties of cool stars. I. (Valenti+, 2005) J/PASJ/57/27 : Atmospheric parameters of nearby F-K stars (Takeda+, 2005) J/ApJS/150/455 : New HIP-based parallaxes for 424 faint stars (Gould+, 2004) Byte-by-byte Description of file: table1.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 14 A14 --- Name Name of the companion star (late K or M dwarf) 16- 23 F8.4 deg RAdeg Right Ascension in decimal degrees (J2000) 25- 32 F8.4 deg DEdeg Declination in decimal degrees (J2000) 34- 37 A4 --- SpT Spectral type of the companion star (1) 39- 41 A3 --- --- [HIP] 43- 56 A14 --- HIP Identifier of the primary (F, G, or K star) (G1) 58- 62 F5.2 [Sun] [Fe/H] The [Fe/H] metallicity of the primary (2) 64- 67 F4.2 [Sun] e_[Fe/H] Uncertainty in [Fe/H] 69- 72 A4 --- r_[Fe/H] Reference for [Fe/H] (3) 74- 78 F5.2 [Sun] [M/H] ? Metallicity of the primary (2) 80- 83 F4.2 [Sun] e_[M/H] ? Uncertainty in [M/H] 85- 88 A4 --- r_[M/H] Reference for [M/H] (3) -------------------------------------------------------------------------------- Note (1): Derived from TiO and CaH indices (Lepine et al., 2013AJ....145..102L). Continuous spectral types (to 0.1) are used for plotting/binning/calculations, even though spectral types are only accurate to +/-0.2 (and by convention should be rounded to the nearest 0.5). Note (2): Includes our applied corrections (see Section 4.1). Note (3): Note that all metallicities sources are from high-resolution spectra, with the exception of Ro07, which uses moderate-resolution spectra, and C11, which uses Stromgren photometry. References as follows: C01 = Cayrel de Strobel et al. (2001, cat. III/221; obsoleted by B/pastel); M04 = Mishenina et al. (2004, cat. J/A+A/418/551); LH05 = Luck & Heiter (2005, cat. J/AJ/129/1063); VF05 = Valenti & Fischer (2005, cat. J/ApJS/159/141); T05 = Takeda et al. (2005, cat. J/PASJ/57/27); B06 = Bean et al. (2006ApJ...652.1604B); Ra07 = Ramirez et al. (2007, cat. J/A+A/465/271); Ro07 = Robinson et al. (2007, cat. J/ApJS/169/430); F08 = Fuhrmann (2008MNRAS.384..173F); S11 = da Silva et al. (2011, cat. J/A+A/526/A71); C11 = Casagrande et al. (2011, cat. J/A+A/530/A138); N12 = Neves et al. (2012A&A...538A..25N); TW = This work: analysis of the spectra from the ESPaDOnS (Echelle SpectroPolarimetric Device for the Observation of Stars) spectrograph attached to the Canada-France-Hawaii Telescope (CFHT) on Mauna Kea. -------------------------------------------------------------------------------- Byte-by-byte Description of file: table2.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 3 A3 --- --- [HIP] 5- 18 A14 --- HIP Identifier of primary (F, G, or K star) (G1) 20- 23 I4 K Teff Effective temperature 25- 26 I2 K e_Teff Error in Teff 28- 31 F4.2 [cm/s2] logg Surface gravity 33- 36 F4.2 [cm/s2] e_logg Error in logg 38- 42 F5.2 [Sun] [Fe/H] The [Fe/H] metallicity 44- 47 F4.2 [Sun] e_[Fe/H] Error in [Fe/H] 49- 53 F5.2 [Sun] [M/H] Metallicity 55- 58 F4.2 [Sun] e_[M/H] Error in [M/H] 60- 64 F5.2 [Sun] [Na/H] Abundance of Na 66- 69 F4.2 [Sun] e_[Na/H] Error in [Na/H] 71- 75 F5.2 [Sun] [Ti/H] Abundance of Ti 77- 80 F4.2 [Sun] e_[Ti/H] Error in [Ti/H] 82- 86 F5.2 [Sun] [Si/H] Abundance of Si 88- 91 F4.2 [Sun] e_[Si/H] Error in [Si/H] 93- 97 F5.2 [Sun] [Ni/H] Abundance of Ni 99-102 F4.2 [Sun] e_[Ni/H] Error in [Ni/H] 104-107 F4.1 --- chi2 Reduced {chi}^2^ (1) 109-113 A5 --- Run Run type (ITER or VESTA) (2) -------------------------------------------------------------------------------- Note (1): Our final model parameters are {chi}^2^-weighted averages of 3 runs. Note (2): Run type as follows: ITER = parameters determined using Hipparcos parallaxes and Yonsei-Yale (Y^2^) isochrones (Demarque et al., 2004ApJS..155..667D). VESTA = parameters determined using classical SME (Spectroscopy Made Easy) fitting (no parallax information included) with a correction using Vesta as described in Valenti & Fischer (2005, cat. J/ApJS/159/141). -------------------------------------------------------------------------------- Byte-by-byte Description of file: table5.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1 A1 --- --- [F] 2- 3 I2 --- F [1/22]? Feature number (1) 5- 10 F6.4 um lambda [0.398/2.3844] Center wavelength (2) 12- 13 I2 0.1nm W [20/98] Feature width; in {AA} (3) 15- 18 F4.2 --- r1 [0.1/0.86]? Correlation coefficient for all dwarfs (K5.5-M6.0), [Fe/H] (4) 20- 23 F4.2 --- r2 [0.19/0.89]? Correlation coefficient for early-type dwarfs (K5.5-M2.0), [Fe/H] (4) 25- 28 F4.2 --- r3 [0.18/0.83]? Correlation coefficient for late-type dwarfs (M2.0-M6.0), [Fe/H] (4) 30- 33 F4.2 --- r4 [0.1/0.78]? Correlation coefficient for all dwarfs (K5.5-M6.0), [M/H] (4) 35- 38 F4.2 --- r5 [0.2/0.86]? Correlation coefficient for early-type dwarfs (K5.5-M2.0), [M/H] (4) 40- 43 F4.2 --- r6 [0.18/0.68]? Correlation coefficient for late-type dwarfs (M2.0-M6.0), [M/H] (4) -------------------------------------------------------------------------------- Note (1): In total we find ~120 features in K and M dwarf (companion star) spectra that are statistically significant predictors of primary star metallicity, although only ~20 of these features are used in our final calibrations. Some features may not correspond to any one specific element or molecule, but simply to a region of the spectrum that undergoes overall changes as a function of the metallicity of the star (see Section 6 for further details). Note (2): A center wavelength is selected, starting at the blue end of the spectrum (~0.33{mu}m) and ending at the red end (~2.4{mu}m). See Section 5 for more details. Note (3): For each feature center, we select a feature width starting at 20{AA}. We use an upper limit of 100{AA} (see Section 5 for more details). Note (4): The adjusted square of the multiple correlation coefficient (R_ap_^2^) as defined in Equation (6). A blank denotes that the feature did not have an R_ap_^2^ value above the R_rand_^2^ value (the 99.9% highest R_ap_^2^ value from the randomly assigned metallicities), and thus is not considered a statistically significant metal-sensitive feature. -------------------------------------------------------------------------------- Global notes: Note (G1): HIP number (with the exception of three NLTT and two PM designation). History: From electronic version of the journal ================================================================================ (End) Greg Schwarz [AAS], Sylvain Guehenneux [CDS] 25-Mar-2014