J/ApJ/851/26 Teff, metallicity and Ti abundance of M dwarfs (Veyette+, 2017)
A physically motivated and empirically calibrated method to measure the
effective temperature, metallicity, and Ti abundance of M dwarfs.
Veyette M.J., Muirhead P.S., Mann A.W., Brewer J.M., Allard F., Homeier D.
<Astrophys. J., 851, 26 (2017)>
=2017ApJ...851...26V 2017ApJ...851...26V
ADC_Keywords: Abundances; Stars, M-type; Effective temperatures;
Spectra, infrared; Models
Keywords: stars: abundances; stars: atmospheres; stars: fundamental parameters;
stars : late-type; stars: low-mass
Abstract:
The ability to perform detailed chemical analysis of Sun-like F-, G-,
and K-type stars is a powerful tool with many applications, including
studying the chemical evolution of the Galaxy and constraining planet
formation theories. Unfortunately, complications in modeling cooler
stellar atmospheres hinders similar analyses of M dwarf stars.
Empirically calibrated methods to measure M dwarf metallicity from
moderate-resolution spectra are currently limited to measuring overall
metallicity and rely on astrophysical abundance correlations in
stellar populations. We present a new, empirical calibration of
synthetic M dwarf spectra that can be used to infer effective
temperature, Fe abundance, and Ti abundance. We obtained
high-resolution (R∼25000), Y-band (∼1µm) spectra of 29 M dwarfs
with NIRSPEC on Keck II. Using the PHOENIX stellar atmosphere modeling
code (version 15.5), we generated a grid of synthetic spectra covering
a range of temperatures, metallicities, and alpha-enhancements. From
our observed and synthetic spectra, we measured the equivalent widths
of multiple Fe I and Ti I lines and a temperature-sensitive index
based on the FeH band head. We used abundances measured from widely
separated solar-type companions to empirically calibrate
transformations to the observed indices and equivalent widths that
force agreement with the models. Our calibration achieves precisions
in Teff, [Fe/H], and [Ti/Fe] of 60K, 0.1dex, and 0.05dex,
respectively, and is calibrated for 3200K<Teff<4100K,
-0.7<[Fe/H]<+0.3, and -0.05<[Ti/Fe]<+0.3. This work is a step toward
detailed chemical analysis of M dwarfs at a precision similar to what
has been achieved for FGK stars.
Description:
On the nights of 2016 May 24 and 2017 February 2, we used the NIRSPEC
instrument on Keck II on Maunakea to observe a total of 44 M dwarfs
from the Mann+ (2013, J/AJ/145/52) catalog of FGK+M systems. We
observed with the NIRSPEC-1 filter covering 0.947-1.121um (Y-band);
with R∼25000.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 52 33 Calibration sample
table4.dat 124 29 Measured indices and EWs of calibration sample
table5.dat 124 546 Measured indices and EWs of model grid
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See also:
J/ApJ/622/1102 : The planet-metallicity correlation. (Fischer+, 2005)
J/MNRAS/389/585 : Fundamental parameters of M dwarfs (Casagrande+, 2008)
J/ApJ/725/2349 : C/O vs Mg/Si of planetary systems (Delgado Mena+, 2010)
J/ApJ/735/41 : Carbon and oxygen abundances in FGK stars (Petigura+, 2011)
J/A+A/533/A141 : Stellar parameters for 582 HARPS FGK stars (Sousa+, 2011)
J/A+A/545/A32 : Chemical abundances of 1111 FGK stars (Adibekyan+, 2012)
J/ApJ/757/112 : Stellar diameters. II. K and M-stars (Boyajian+, 2012)
J/other/Nat/486.375 : Stellar parameters of KOI stars (Buchhave+, 2012)
J/A+A/542/A33 : 3 M dwarfs near-infrared spectra (Onehag+, 2012)
J/ApJ/748/93 : K-band spectra for 133 nearby M dwarfs (Rojas-Ayala+, 2012)
J/ApJ/771/107 : Spectroscopy of faint KOI stars (Everett+, 2013)
J/ApJ/765/12 : Carbon stars and DQ WDs from SDSS-DR7+DR8 (Green, 2013)
J/AJ/145/52 : Late K & M dwarfs abundances in binary systems (Mann+, 2013)
J/ApJ/779/188 : Spectra of nearby late K and M Kepler stars (Mann+, 2013)
J/ApJ/770/43 : Spectroscopic [Fe/H] of Kepler stars (Mann+, 2013)
J/A+A/556/A15 : Effective temperature scale of M dwarfs (Rajpurohit+, 2013)
J/A+A/562/A71 : Abundances of solar neighbourhood dwarfs (Bensby+, 2014)
J/AJ/147/20 : Spectroscopy of 447 nearby M dwarfs (Newton+, 2014)
J/A+A/568/A25 : C and O abundances in stellar populations (Nissen+, 2014)
J/ApJ/788/39 : Hot Jupiter exoplanets host stars abundances (Teske+, 2014)
J/ApJ/808/187 : Metallicities of KIC stars without planets (Buchhave+, 2015)
J/A+A/577/A132 : Stellar parameters of early M dwarfs (Maldonado+, 2015)
J/ApJ/804/64 : Empirical and model parameters of 183 M dwarfs (Mann+, 2015)
J/ApJS/220/16 : SpeX NIR survey of 886 nearby M dwarfs (Terrien+, 2015)
J/AJ/152/141 : Solar neighborhood. XXXVII. M dwarfs (Benedict+, 2016)
J/ApJ/831/20 : C/O and Mg/Si for solar neighborhood's stars (Brewer+, 2016)
J/ApJS/225/32 : Extended abundance analysis of cool stars (Brewer+, 2016)
J/ApJ/818/153 : MEarth photom.: nearby M-dwarf magnitudes (Dittmann+, 2016)
J/ApJ/817/40 : NIR spectra of local giants (Feuillet+, 2016)
J/ApJ/821/93 : Rotation & Galactic kinematics of M dwarfs (Newton+, 2016)
J/A+A/602/A88 : 5 M dwarfs radial velocity curves (Astudillo-Defru+, 2017)
J/ApJS/228/15 : MARVEL analysis of TiO energy levels (McKemmish+, 2017)
J/ApJ/834/85 : Hα emission in nearby M dwarfs (Newton+, 2017)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 16 A16 --- NameM M dwarf name
18- 33 A16 --- NameFGK FGK name
35- 38 I4 K Teff [3167/4106] M dwarf effective temperature
40- 45 F6.3 [Sun] [Fe/H] [-0.8/0.4] FGK [Fe/H]
47- 52 F6.3 [Sun] [Ti/Fe] [-0.07/0.4] FGK [Ti/Fe]
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 16 A16 --- NameM M dwarf name
18- 22 F5.3 0.1nm FeH [1/1.1] FeH index
24- 28 F5.3 0.1nm FeI1.014 [0.1/0.3] Fe I line between 1.01475-1.01506um
30- 34 F5.3 0.1nm FeI1.021 [0.05/0.3] Fe I line between 1.02183-1.02200um
36- 40 F5.3 0.1nm FeI1.039 [0.05/0.2] Fe I line between 1.03980-1.03990um
42- 46 F5.3 0.1nm FeI1.042 [0.04/0.2] Fe I line between 1.04253-1.04273um
48- 52 F5.3 0.1nm FeI1.047 [0.05/0.2] Fe I line between 1.04719-1.04733um
54- 58 F5.3 0.1nm FeI1.053 [0.04/0.1] Fe I line between 1.05343-1.05360um
60- 64 F5.3 0.1nm FeI1.078 [0.03/0.09] Fe I line between 1.07854-1.07867um
66- 70 F5.3 0.1nm TiI1.000 [0.07/0.2] Ti I line between 1.00001-1.00013um
72- 76 F5.3 0.1nm TiI1.003 [0.07/0.2] Ti I line between 1.00367-1.00378um
78- 82 F5.3 0.1nm TiI1.005 [0.06/0.3] Ti I line between 1.00597-1.00609um
84- 88 F5.3 0.1nm TiI1.039 [0.2/0.4] Ti I line between 1.03990-1.04009um
90- 94 F5.3 0.1nm TiI1.049 [0.2/0.4] Ti I line between 1.04979-1.05000um
96-100 F5.3 0.1nm TiI1.058 [0.2/0.5] Ti I line between 1.05866-1.05886um
102-106 F5.3 0.1nm TiI1.061 [0.05/0.2] Ti I line between 1.06100-1.06111um
108-112 F5.3 0.1nm TiI1.067 [0.09/0.2] Ti I line between 1.06793-1.06806um
114-118 F5.3 0.1nm TiI1.072 [0.1/0.3] Ti I line between 1.07285-1.07300um
120-124 F5.3 0.1nm TiI1.077 [0.09/0.2] Ti I line between 1.07768-1.07787um
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 4 I4 K Teff [3000/4200] Model effective temperature
6- 10 F5.2 [Sun] [M/H] [-1.0/0.5] Model [M/H]
12- 16 F5.2 [Sun] [a/M] [-0.1/0.4] Model [α/M]
18- 22 F5.3 --- FeH [1/1.2] FeH index
24- 28 F5.3 0.1nm FeI1.014 [0.02/0.5] Fe I line between 1.01475-1.01506um
30- 34 F5.3 0.1nm FeI1.021 [0.01/0.2] Fe I line between 1.02183-1.02200um
36- 40 F5.3 0.1nm FeI1.039 [0.04/0.2] Fe I line between 1.03980-1.03990um
42- 46 F5.3 0.1nm FeI1.042 [0.02/0.3] Fe I line between 1.04253-1.04273um
48- 52 F5.3 0.1nm FeI1.047 [0.02/0.2] Fe I line between 1.04719-1.04733um
54- 58 F5.3 0.1nm FeI1.053 [0.01/0.2] Fe I line between 1.05343-1.05360um
60- 64 F5.3 0.1nm FeI1.078 [0/0.2] Fe I line between 1.07854-1.07867um
66- 70 F5.3 0.1nm TiI1.000 [0.01/0.3] Ti I line between 1.00001-1.00013um
72- 76 F5.3 0.1nm TiI1.003 [0.01/0.3] Ti I line between 1.00367-1.00378um
78- 82 F5.3 0.1nm TiI1.005 [0.01/0.2] Ti I line between 1.00597-1.00609um
84- 88 F5.3 0.1nm TiI1.039 [0.1/0.6] Ti I line between 1.03990-1.04009um
90- 94 F5.3 0.1nm TiI1.049 [0.07/0.6] Ti I line between 1.04979-1.05000um
96-100 F5.3 0.1nm TiI1.058 [0.1/0.5] Ti I line between 1.05866-1.05886um
102-106 F5.3 0.1nm TiI1.061 [0.009/0.2] Ti I line between 1.06100-1.06111um
108-112 F5.3 0.1nm TiI1.067 [0.02/0.3] Ti I line between 1.06793-1.06806um
114-118 F5.3 0.1nm TiI1.072 [0.05/0.4] Ti I line between 1.07285-1.07300um
120-124 F5.3 0.1nm TiI1.077 [0.02/0.3] Ti I line between 1.07768-1.07787um
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 05-Jul-2018