J/A+A/684/A85 Red giants, spectroscopy and asteroseismology (Vernekar+, 2024)
Stellar population astrophysics with the TNG.
Abundance analysis of nearby red giants and red clump stars:
Combining high-resolution spectroscopy and asteroseismology.
Vernekar N., Lucatello S., Bragaglia A., Miglio A., Sanna N., Andreuzzi G.,
Frasca A.
<Astron. Astrophys. 684, A85 (2024)>
=2024A&A...684A..85V 2024A&A...684A..85V (SIMBAD/NED BibCode)
ADC_Keywords: Stars, giant ; Abundances ; Equivalent widths ; Spectroscopy ;
Optical ; Infrared
Keywords: techniques: spectroscopic - stars: abundances - stars: evolution
Abstract:
Asteroseismology, a powerful approach for obtaining internal structure
and stellar properties, requires surface temperature and chemical
composition information to determine mass and age. High-resolution
spectroscopy is a valuable technique for precise stellar parameters
(including surface temperature) and for an analysis of the chemical
composition. We combine spectroscopic parameters with asteroseismology
to test stellar models. Using high-resolution optical and near-IR
spectra from GIARPS at the Telescopio Nazionale Galileo, we conducted
a detailed spectroscopic analysis of 16 stars that were
photometrically selected to be on the red giant and red clump branch.
Stellar parameters and chemical abundances for light elements (Li, C,
N, and F), Fe peak, α and n-capture elements were derived using
a combination of equivalent widths and spectral synthesis techniques
based on atomic and molecular features. Ages were determined through
asteroseismic scaling relations and were compared with ages based on
chemical clocks, Y/Mg and C/N.The spectroscopic parameters confirmed
that the stars are part of the red giant branch and red clump. Two
objects, HD 22045 and HD 24680, exhibit relatively high Li abundances,
and HD 24680 might be a Li-rich giant resulting from mass transfer
with an intermediate-mass companion that already underwent its
asymptotic giant branch phase. The stellar parameters derived from
scaling different sets of relations were consistent with each other.
The values based on asteroseismology for the ages agree excellently
with those derived from theoretical evolutionary tracks, but they
disagree with ages derived from the chemical clocks Y/Mg and C/N.
Description:
We used optical and infrared high resolution spectra from HARPS-N and
GIANO, respectively, to derive the stellar parameters and chemical
abundances of 16 stars. A total of 16 spectra, one per star were
analysed with a wavelength range of 3800-6900Å in the optical and
9700-24000Å in the infrared. stars.dat contains the list of stars
with the derived stellar parameters as well as the abundances of
different elements. tablei1.dat gives the equivalent widths of
different lines in each star that were used to derive the elemental
abundances.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
stars.dat 313 17 Stellar parameters and abundances
table.dat 45 1109 Equivalent widths of lines used to derive
abundances
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Byte-by-byte Description of file: stars.dat
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Bytes Format Units Label Explanations
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1- 28 A28 --- GaiaDR3 Gaia DR3 ID
30- 38 A9 --- Star Star identifier
40- 56 F17.13 deg RAdeg Right ascension (J2000)
58- 75 F18.15 deg DEdeg Declination (J2000)
77- 80 I4 K Teff Effective temperature
82- 85 F4.2 [cm/s2] logg Surface gravity
87- 91 F5.2 [-] [Fe/H] Metallicity
93- 96 F4.2 km/s Vmic Microturbulent velocity
98-103 F6.2 km/s RV ? Radial velocity
105-108 F4.2 km/s e_RV ? Error in radial velocity
110-114 F5.2 --- [C/Fe]opt Carbon abundance in optical [C/Fe]
116-119 F4.2 --- [N/Fe]opt Nitrogen abundance in optical [N/Fe]
121-125 F5.2 --- [O/Fe]opt Oxygen abundance in optical [O/Fe]
127-131 F5.2 --- [C/Fe]IR ? Carbon abundance in infrared [C/Fe]
133-136 F4.2 --- [N/Fe]IR ? Nitrogen abundance in infrared [N/Fe]
138-141 A4 --- [O/Fe]IR Oxygen abundance in infrared [O/Fe]
143 A1 --- l_C12/C13 [~> ] Limit flag on C12/C13
144-145 I2 --- C12/C13 ? Carbon isotopic ratio C12/C13
147-150 F4.2 --- [Mg/Fe] Magnesium abundance
152-155 F4.2 --- e_[Mg/Fe] Error in magnesium abundance
157-161 F5.2 --- [Si/Fe] Silicon abundance
163-166 F4.2 --- e_[Si/Fe] Error in silicon abundance
168-172 F5.2 --- [Ca/Fe] Calcium abundance
174-177 F4.2 --- e_[Ca/Fe] Error in Calcium abundance
179-183 F5.2 --- [Ti1/Fe] Neutral titanium abundance
185-188 F4.2 --- e_[Ti1/Fe] Error in neutral titanium abundance
190-194 F5.2 --- [Ti2/Fe] Ionised titanium abundance
196-199 F4.2 --- e_[Ti2/Fe] Error in ionised titanium abundance
201-205 F5.2 --- [Cr/Fe] Chromium abundance
207-210 F4.2 --- e_[Cr/Fe] Error in chromium abundance
212-216 F5.2 --- [Ni/Fe] Nickel abundance
218-221 F4.2 --- e_[Ni/Fe] Error in nickel abundance
223-229 A7 --- A(Li) Lithium abundance
231-234 F4.2 --- NLTE-Li ? NLTE correction in lithium abundance
236-239 F4.2 --- [F/Fe] ? Flourine abundance
241-244 F4.2 --- e_[F/Fe] ? Error in flourine abundance
246-250 F5.2 --- [Y/Fe] ? Yttrium abundance
252-255 F4.2 --- e_[Y/Fe] ? Error in yttrium abundance
257-260 F4.2 --- [Na/Fe] ? Sodium abundance
262-265 F4.2 --- e_[Na/Fe] ? Error in sodium abundance
267-270 F4.2 --- [Al/Fe] ? Aluminium abundance
272-275 F4.2 --- e_[Al/Fe] ? Error in aluminium abundance
277-280 F4.2 --- [Sr/Fe] ? Strontium abundance
282-285 F4.2 --- e_[Sr/Fe] ? Error in strontium abundance
287-289 F3.1 --- [Zr/Fe] ? Zirconium abundance
291-293 F3.1 --- e_[Zr/Fe] ? Error in zirconium abundance
295-298 F4.2 --- [La/Fe] ? Lanthanum abundance
300-303 F4.2 --- e_[La/Fe] ? Error in lanthanum abundance
305-308 F4.2 --- [Eu/Fe] ? Europium abundance
310-313 F4.2 --- e_[Eu/Fe] ? Error in europium abundance
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Byte-by-byte Description of file: table.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Star Star identifier
11- 18 F8.5 --- Ion Atomic number of the element
20- 27 F8.3 --- lambda Wavelength of the line in Angstroms
29- 32 F4.2 --- EP Excitation potential of the line
34- 39 F6.3 [-] loggf Log of oscillator strength of the line
41- 45 F5.1 --- EW Equivalent width of the line
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Acknowledgements:
Nagaraj Vernekar, nagarajvernekar30(at)gmail.com
(End) Patricia Vannier [CDS] 29-Jan-2024