J/ApJ/949/86 Effective temperatures from IGRINS high-res. sp. (Afsar+, 2023)
Effective temperature estimations from line depth ratios in the H- and K-band
spectra of IGRINS.
Afsar M., Bozkurt Z., Topcu G.B., Ozdemir S., Sneden C., Mace G.N.,
Jaffe D.T., Lopez-Valdivia R.
<Astrophys. J., 949, 86 (2023)>
=2023ApJ...949...86A 2023ApJ...949...86A
ADC_Keywords: Abundances; Effective temperatures; Spectra, infrared;
Stars, horizontal branch
Keywords: Stellar effective temperatures ; Stellar properties ;
Stellar spectral lines ; Infrared spectroscopy
Abstract:
Determining accurate effective temperatures of stars buried in the
dust-obscured Galactic regions is extremely difficult from photometry.
Fortunately, high-resolution infrared spectroscopy is a powerful tool
for determining the temperatures of stars with no dependence on
interstellar extinction. It has long been known that the depth ratios
of temperature-sensitive and relatively insensitive spectral lines are
excellent temperature indices. In this work, we provide the first
extensive line depth ratio (LDR) method application in the infrared
region that encompasses both the H and K bands (1.48µm-2.48µm).
We applied the LDR method to high-resolution (R∼45000) H- and K-band
spectra of 110 stars obtained with the Immersion Grating Infrared
Spectrograph. Our sample contained stars with 3200<Teff(K)<5500,
0.20≤logg<4.6, and -1.5<[M/H]<0.5. The application of this method in
the K band yielded 21 new LDR-Teff relations. We also report five new
LDR-Teff relations found in the H-band region, augmenting the
relations already published by other groups. The temperatures found
from our calibrations provide reliable temperatures within ∼70K
accuracy compared to spectral Teff values from the literature.
Description:
High-resolution (R∼45000), high signal-to-noise ratio (S/N>100)
spectral data of 110 stars were obtained with the Immersion Grating
Infrared Spectrograph (IGRINS) on the 2.7m Harlan J. Smith Telescope
(McDonald Observatory, Texas) and the 4.3m Lowell Discovery Telescope
(Lowell Observatory, Arizona) between the years of 2014 and 2018.
IGRINS covers the H and K bands (1.48-2.48um) simultaneously, with a
small gap of about 100Å between bands.
About 70% of our sample (Table 1) consists of red horizontal-branch
stars (also known as secondary red clump stars) listed in
Afsar+ (2018, J/AJ/155/240). The rest of the sample was selected from
the IGRINS Spectral Library (Park+ 2018, J/ApJS/238/29).
See Section 2.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 33 110 Atmospheric parameters of stellar sample
table4.dat 29 109 *Teff values of our sample from various sources:
spectral Teff values from Table 1,
TLDR (this study), Teff from Gaia, and Teff(J-K)
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Note on table4.dat: In Table 4, we list the mean line depth ratio (LDR)
temperatures (TLDR) for the entire sample, except for HIP 79248,
where we could not measure the LDRs from any of the line pairs listed
in Table 3.
See Section 4.1.
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See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
III/286 : APOGEE-2 DR17 final allStar catalog (Abdurro'uf+, 2022)
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
J/A+AS/117/227 : Dwarf effective temperatures (Alonso+ 1996)
J/A+A/333/231 : O-M stars model atmospheres (Bessell+ 1998)
J/ApJS/124/527 : Oscillator strengths for lines in J & H (Melendez+, 1999)
J/AN/321/277 : Effective temperatures of K-M giants (Strassmeier+, 2000)
J/A+A/411/559 : Effective temperature for 181 F-K dwarfs (Kovtyukh+, 2003)
J/PASJ/57/27 : Atmospheric parameters of nearby F-K stars (Takeda+, 2005)
J/MNRAS/371/879 : Effective temperatures of 215 FGK giants (Kovtyukh+, 2006)
J/A+A/450/735 : Effective temperatures and radii of stars (Masana+, 2006)
J/AN/328/938 : Teff/line-depth ratio for ELODIE spectra (Biazzo+, 2007)
J/A+A/475/1003 : Stellar parameters of G and K giant stars (Hekker+, 2007)
J/A+A/497/497 : Physical param. from JHK flux (Gonzalez-Hernandez+, 2009)
J/A+A/536/A71 : Atmospheric parameters of nearby giant stars (Jones+, 2011)
J/A+A/531/A165 : MILES atmospheric parameters (Prugniel+, 2011)
J/A+A/538/A143 : Atmospheric param. of stars for UV models (Koleva+, 2012)
J/A+A/547/A13 : Homogeneous sample of F6-K4 Hyades stars (Tabernero+, 2012)
J/A+A/554/A84 : Abundances of evolved stars (Maldonado+, 2013)
J/ApJ/764/78 : Oxygen abundances in nearby FGK stars (Ramirez+, 2013)
J/A+A/564/A133 : Gaia FGK benchmark stars: metallicity (Jofre+, 2014)
J/AJ/147/137 : Atmospheric parameters in luminous stars (Luck, 2014)
J/MNRAS/446/3562 : Abundances of red giants in NGC752 (Bocek Topcu+, 2015)
J/A+A/580/A24 : Abundances in dwarfs, subgiants & giants (da Silva+, 2015)
J/A+A/574/A50 : Chemical abundances of giants and subgiants (Jofre+, 2015)
J/ApJS/221/24 : SDSS-III APOGEE H-band spectral line lists (Shetrone+, 2015)
J/ApJ/819/103 : Abundances of two very metal-poor stars (Afsar+, 2016)
J/MNRAS/463/580 : Abundances of red giants in NGC6940 (Bocek+, 2016)
J/ApJ/817/40 : High-res. NIR spectra of local giants (Feuillet+, 2016)
J/A+A/606/A94 : Chemical abundances of 1059 FGK stars (Delgado Mena+, 2017)
J/A+A/598/A100 : Abundances of disk giants: O, Mg, Ca and Ti (Jonsson+, 2017)
J/AJ/153/21 : The local region abund. II. F, G & K dwarfs (Luck+, 2017)
J/AJ/155/240 : A spectroscopic survey of field RHB stars (Afsar+, 2018)
J/ApJS/238/29 : IGRINS spectral library (Park+, 2018)
J/ApJ/879/105 : Effective temp. of low-mass stars (Lopez-Valdivia+, 2019)
J/MNRAS/491/544 : NGC752 abundances from IR spectra (Bocek Topcu+, 2020)
J/MNRAS/494/1724 : Effect of surface gravity on line-depth ratios (Jian+, 2020)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 A9 --- ID Star identifier
11- 14 I4 K Teff [3250/5464] Effective temperature
16- 19 F4.2 [cm/s2] log(g) [0.2/4.59] log surface gravity
21- 25 F5.2 [Sun] [M/H] [-1.48/0.44] Metallicity
27- 30 F4.2 km/s VTurb [0.19/3.49] Turbulent velocity
32- 33 I2 --- Ref [1/26] Reference (1)
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Note (1): References as follows:
1 = Smith & Lambert (1985ApJ...294..326S 1985ApJ...294..326S);
2 = Koleva & Vazdekis (2012, J/A+A/538/A143);
3 = Prugniel et al. (2011, J/A+A/531/A165);
4 = Mallik (1998A&A...338..623M 1998A&A...338..623M);
5 = Smith & Lambert (1990ApJS...72..387S 1990ApJS...72..387S);
6 = Afsar et al. (2018, J/AJ/155/240);
7 = Pakhomov (2013, J/PAZh/39/58);
8 = McWilliam (1990ApJS...74.1075M 1990ApJS...74.1075M);
9 = Luck & Challener (1995AJ....110.2968L 1995AJ....110.2968L);
10 = Luck (2014, J/AJ/147/137);
11 = Jonsson et al. (2017, J/A+A/598/A100);
12 = Lyubimkov et al. (2010MNRAS.402.1369L 2010MNRAS.402.1369L);
13 = Feuillet et al. (2016, J/ApJ/817/40);
14 = Delgado Mena et al. (2017, J/A+A/606/A94);
15 = Hekker & Melendez (2007, J/A+A/475/1003);
16 = Ramirez et al. (2013, J/ApJ/764/78);
17 = Maldonado et al. (2013, J/A+A/554/A84);
18 = da Silva et al. (2015, J/A+A/580/A24);
19 = Jones et al. (2011, J/A+A/536/A71);
20 = Jofre et al. (2014, J/A+A/564/A133);
21 = Takeda et al. (2008PASJ...60..781T 2008PASJ...60..781T);
22 = Luck (2017, J/AJ/153/21);
23 = Jofre et al. (2015, J/A+A/574/A50);
24 = Tabernero et al. (2012, J/A+A/547/A13);
25 = Takeda et al. (2005, J/PASJ/57/27);
26 = This study.
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 A9 --- ID Star identifier
11- 14 I4 K Teff [3250/5464] Effective temperature from Table 1
16- 19 I4 K TLDR [3279/5360] Effective temperature from line
depth ratio
21- 24 I4 K TGaia [3851/5613]? Effective temperature from Gaia
26- 29 I4 K T(J-K) [3451/6449]? Effective temperature from (J-K)
color
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 16-Jul-2025