J/A+A/664/A78 Kepler targets class based on LAMOST spectra (Frasca+, 2022)
Characterization of Kepler targets based on medium-resolution LAMOST spectra
analyzed with ROTFIT.
Frasca A., Molenda-Zakowicz J., Alonso-Santiago J., Catanzaro G., De Cat P.,
Fu J.N., Zong W., Wang J.X., Cang T., Wang J.T.
<Astron. Astrophys. 664, A78 (2022)>
=2022A&A...664A..78F 2022A&A...664A..78F (SIMBAD/NED BibCode)
ADC_Keywords: Surveys; Equivalent widths ; Abundances ; Effective temperatures ;
Radial velocities ; Rotational velocities ; Optical
Keywords: surveys - techniques: spectroscopic - stars: activity -
binaries: spectroscopic - stars: fundamental parameters -
stars: abundances
Abstract:
In this work we present the results of our analysis of 16300
medium-resolution LAMOST spectra of late-type stars in the Kepler
field aimed at the determination of the stellar parameters, activity
level, lithium atmospheric content and binarity.
We have used a purposely developed version of the code ROTFIT for the
determination of the stellar parameters by adopting a grid of spectra
of real stars. We provide a catalog with the atmospheric parameters
(Teff, logg, and [Fe/H]), radial velocity (RV), and projected rotation
velocity (vsini).
For cool stars (Teff<6500K), we also calculated the H-alpha and
LiI-6708 equivalent width, which are important indicators of
chromospheric activity and evolutionary stage, respectively.
We have derived the RV and atmospheric parameters for 14300 spectra
of 7443 stars. Literature data (mainly from high- or medium-resolution
spectra) were used for a quality control of the results and to assess
the accuracy of the derived parameters. The Teff and logg values are
in good agreement with the literature, although their distribution
displays some clustering effect, which can be the result of the
non-uniform distribution of the templates in the parameter space. The
most relevant differences are found for [Fe/H], which appears to be
overestimated for metal poor stars; this is also likely caused by the
template grid. We propose a relation to correct the [Fe/H] values
derived with ROTFIT.
We were able to identify interesting objects, such as double-lined
binaries, stars with variable RV, lithium-rich giants, and
emission-line objects. Based on the H-halpha flux, we found 327 active
stars. We could detect the LiI-6708 line and measure its equivalent
width for 1657 stars both giants and on the main sequence. Regarding
the latter, we performed a discrete age classification based on their
atmospheric lithium abundance and the upper envelopes of a few open
clusters. Among the giants we found 195 Li-rich stars, 161 are
reported here for the first time. No relationship is found between
stellar rotation and lithium abundance, which allows us to rule out
merger scenarios as the predominant ones to explain the enrichment of
Li in our sample. The fraction of Li-rich giants, about 4%, is higher
than expected.
Description:
Spectral type, average atmospheric parameters (Teff, logg, and
[Fe/H]), radial velocity (RV) and projected rotational velocity
(vsini) are quoted in Table 2 for 7443 stars.
Table 3 reports the H-alpha equivalent width and flux at the stellar
surface for 327 targets.
Table 4 reports the LiI-6708 equivalent width and lithium abundance
for 1657 targets.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 161 7443 Final stellar parameters
table3.dat 165 327 Activity indicators
table4.dat 140 1657 Lithium equivalent width and abundance
tablec2.dat 240 16286 Stellar parameters for individual red-arm spectra
tablec3.dat 240 16301 Stellar parameters for individual blue-arm spectra
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See also:
V/133 : Kepler Input Catalog (Kepler Mission Team, 2009)
V/156 : LAMOST DR7 catalogs (Luo+, 2019)
J/A+A/594/A39 : LAMOST-Kepler parameters & activity indicators (Frasca+, 2016)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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2- 11 F10.6 deg RAdeg Right ascension (J2000)
15- 23 F9.6 deg DEdeg Declination (J2000)
26- 36 A11 --- KIC Kepler Input Catalog designation
(KICNNNNNNNN) (1)
38- 56 A19 --- Target LAMOST designation (JHHMMSS.ss+DDMMSS.s) (1)
58- 59 I2 --- Nsp Number of spectra
62- 66 I5 K Teff Effective temperature
69- 72 I4 K e_Teff Effective temperature error
76- 80 F5.2 [cm/s2] logg Logarithm of surface gravity
84- 88 F5.2 [cm/s2] e_logg Error on logarithm of surface gravity
91- 96 F6.2 [Sun] [Fe/H] Iron abundance relative to the Sun
100-104 F5.2 [Sun] e_[Fe/H] Error on iron abundance relative to the Sun
107 A1 --- l_vsini Limit flag on vsini
109-113 F5.1 km/s vsini Projected rotational velocity
117-121 F5.1 km/s e_vsini ?=-9.9 Projected rotational velocity error
125-137 A13 --- SpType Spectral type in MK or HD
140-143 I4 --- S/N Signal-to-noise ratio
145-146 A2 --- Arm Spectral arm used (2)
150-161 A12 --- Remarks Remarks (3)
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Note (1): Designation is KIC or LAMOST.
Note (2): Spectral arm used as follows:
b = Blue-arm spectrum only
r = Red-arm spectrum only
br = Blue-arm + red-arm spectrum
Note (3): Remarks as follows:
Li = Lithium 6708Å line detected
Haf = H-alpha line filled in
Hae = H-alpha line in emission
RVvar = Variable Radial Velocity
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
2- 20 A19 --- Target Target designation (JHHMMSS.ss+DDMMSS.s)
28- 38 A11 --- KIC Kepler Input Catalog number, KICNNNNNNN
42- 52 F11.6 deg RAdeg Right Ascention (J2000)
57- 66 F10.6 deg DEdeg Declination (J2000)
70- 74 I5 K Teff Effective temperature
79- 82 I4 K e_Teff Effective temperature error
87- 91 F5.2 [cm/s2] logg Logarithm of surface gravity
95- 99 F5.2 [cm/s2] e_logg Error on logarithm of surface gravity
102-108 F7.3 0.1nm EWHa Hα equivalent width
111-117 F7.3 0.1nm e_EWHa Hα equivalent width error
120-129 E10.2 mW/m2 FHa Hα flux
132-141 E10.2 mW/m2 e_FHa Hα flux error
143-149 F7.3 --- R'Ha Luminosity ratio LHα/Lbol
151-157 F7.3 --- b_R'Ha Lower value of R'Ha considering the errors
159-165 F7.3 --- B_R'Ha Upper value of R'Ha considering the errors
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Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
2- 20 A19 --- Target Target designation (JHHMMSS.ss+DDMMSS.s)
28- 38 A11 --- KIC Kepler Input Catalog number (KICNNNNNNN)
40- 50 F11.6 deg RAdeg Right Ascention (J2000)
53- 62 F10.6 deg DEdeg Declination (J2000)
66- 70 I5 K Teff Effective temperature
75- 78 I4 K e_Teff Effective temperature error
82- 86 F5.2 [cm/s2] logg Logarithm of surface gravity
90- 94 F5.2 [cm/s2] e_logg Error on logarithm of surface gravity
98 A1 --- l_A(Li) Limit flag on A(Li)
101-105 F5.2 [-] A(Li) ?=-9.99 Lithium abundance
109-113 F5.2 [-] e_A(Li) Lower error on A(Li)
117-121 F5.2 [-] E_A(Li) Upper error on A(Li)
125 A1 --- l_EW(Li) Limit flag on EW(Li)
126-129 I4 0.1pm EW(Li) Lithium equivalent width
132-134 I3 0.1pm e_EW(Li) rms uncertainty on EW(Li)
137-140 A4 --- Class Age class (1)
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Note (1): Notes as follows:
Hya = Hyades-like
UMa = UMa-like
Ple = Pleiades-like
PMS = PMS-like
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Byte-by-byte Description of file: tablec2.dat tablec3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
2- 20 A19 --- Target Target designation (JHHMMSS.ss+DDMMSS.s)
23- 34 A12 --- KIC Kepler Input Catalog number (KICNNNNNNN)
37- 47 F11.6 deg RAdeg Right Ascention (J2000)
51- 60 F10.6 deg DEdeg Declination (J2000)
64- 74 F11.5 d HJD Reduced Heliocentric Julian day
(HJD-2400000)
76-115 A40 --- Sp LAMOST Spectrum name
119-124 F6.1 --- S/N ?=- Signal-to-noise ratio in the red arm
128-132 I5 K Teff ?=- Effective temperature
137-140 I4 K e_Teff ?=- Effective temperature error
144-148 F5.2 [cm/s2] logg ?=- Logarithm of surface gravity
152-156 F5.2 [cm/s2] e_logg ?=- Error on logarithm of surface gravity
159-164 F6.2 [Sun] [Fe/H] ?=- Iron abundance relative to the Sun
168-172 F5.2 [Sun] e_[Fe/H] ?=- Error on iron abundance relative
to the Sun
175-180 F6.1 km/s vsini ?=- Projected rotational velocity
184-188 F5.1 km/s e_vsini ?=- Projected rotational velocity error
190-197 F8.2 km/s HRV ?=- Heliocentric Radial Velocity
201-206 F6.2 km/s e_HRV ?=- Heliocentric Radial Velocity error
208-215 F8.2 km/s HRVcorr ?=- Corrected Heliocentric Radial Velocity
217-226 A10 --- SpType Spectral type in MK or HD
228-240 A13 --- Remarks Remarks (1)
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Note (1): Notes as follows:
SB2 = Double-lined spectroscopic binary
SB3 = Spectroscopic triple system
Bad_spe = Spectrum with flaws
Noisy = Noisy spectrum
Ha_em = H-alpha emission
EB = Eclipsing binary
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Acknowledgements:
Antonio Frasca, antonio.frasca(at)inaf.it
(End) Antonio Frasca [INAF-OACt, Italy], Patricia Vannier [CDS] 02-May-2022