J/ApJS/266/14 Am stars selected in LAMOST DR8-DR10 (Tian+, 2023)
A new catalog of Am-type chemically peculiar stars based on LAMOST.
Tian X.-M., Wang Z.-H., Zhu L.-Y., Yang X.-L.
<Astrophys. J. Suppl. Ser., 266, 14 (2023)>
=2023ApJS..266...14T 2023ApJS..266...14T
ADC_Keywords: Abundances, peculiar; Stars, Am; Spectra, optical; Spectral types;
Stars, masses; Stars, distances; Binaries, eclipsing
Keywords: Chemically peculiar stars ; Am stars ; Multiple stars ;
Astrometric binary stars ; Eclipsing binary stars
Abstract:
A total of about 21,600 Am candidates were detected with the MKCLASS
code based on the low-resolution spectra of the Large Sky Area
Multi-Object Fiber Spectroscopic Telescope Data Releases 8 (v1.0),
9 (v0), and 10 (v0), which greatly expands the database of Am-type
stars. By crossmatching the known catalogs of Am stars and our Am
candidates with the AAVSO International Variable Star Index catalog, a
catalog of the largest eclipsing Am binaries was obtained, which
includes 754 binaries and provides a substantial sample with which to
study Am stars. Fundamental information, including atmospheric
parameters of the two kinds of candidates, are collected and listed in
the catalogs, such as temperature, log g, and metallicity. We further
carried out statistical analysis of the types of parameters. In our
new catalog, there are some Am candidates with a temperature lower
than 7000 K and some eclipsing Am binary candidates with a period of
less than 1 day, which poses challenges to the slow rotation of stars
classified as type Am observed in previous research. These candidates
are significant and provide a great opportunity to explore the real
relationship between Am-type stars' peculiarity and slow stellar
rotation. The Hertzsprung-Russell diagram of Am stars and the primary
stars of eclipsing Am binary candidates indicate that a majority of
the Am stars and almost all primary stars of binaries are in or around
the main- sequence evolution stage.
Description:
The MKCLASS code (Gray & Corbally 2014AJ....147...80G 2014AJ....147...80G) was used to
search for Am stars through all the low-resolution early F-type
(including F0, F1 and F2) and A-type spectra (with a S/N of the g
filter larger than 50) of LAMOST DR8 v1.0, DR9 v0, and DR10 v0.
See Section 4.2.
LAMOST is a Chinese national scientific research facility operated by
the National Astronomical Observatories, Chinese Academy of Sciences.
It is a special reflecting Schmidt telescope with 4000 fibers in a
field of view of 20 deg2 in the sky. The Low-Resolution Spectroscopic
Survey of Data Release 8 (DR8, v1.0) contains all the observation data
from 2011 October 24 to 2020 May 27. These spectra cover a wavelength
range of 3700-9100Å with a resolution of 1800 at 5500Å. The data
products of this release are available from the LAMOST website. The
following Data Release 9 (DR9, v0) published new observation results
from 2020 September 1 to 2021 June 30, and Data Release 10 (DR10, v0)
published new observation results from 2021 Sept 1 to 2021 Dec 31.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 321 21635 The new catalog of the Am candidates based on LAMOST
table2.dat 392 523 The new catalog of eclipsing Am binary candidates
based on LAMOST
table3.dat 341 239 The catalog of the eclipsing Am binary candidates
based on the known Am catalogs and cross-match
results
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See also:
B/vsx : AAVSO International Variable Star Index VSX (Watson+, 2006-)
III/162 : General Catalogue of Ap and Am stars (Renson+ 1991)
III/260 : General Catalogue of Ap and Am stars (Renson+ 2009)
V/146 : LAMOST DR1 catalogs (Luo+, 2015)
I/347 : Distances to 1.33 billion stars in Gaia DR2 (Bailer-Jones+, 2018)
IV/38 : TESS Input Catalog - v8.0 (TIC-8) (Stassun+, 2019)
V/156 : LAMOST DR7 catalogs (Luo+, 2019)
IV/39 : TESS Input Catalog version 8.2 (TIC v8.2) (Paegert+, 2021)
J/A+A/463/671 : Rotational velocities of A-type stars. III. (Royer+, 2007)
J/MNRAS/449/1401 : Am stars candidates from LAMOST DR1 (Hou+, 2015)
J/AJ/151/13 : LAMOST-Kepler MKCLASS spectral classification (Gray+, 2016)
J/MNRAS/466/546 : Parameters for the 172 λ Boo stars (Murphy+, 2017)
J/MNRAS/480/2953 : Catalogue of CP stars (HgMn, ApBp, AmFm) (Ghazaryan+, 2018)
J/ApJS/235/5 : EA-type eclipsing binaries observed by LAMOST (Qian+, 2018)
J/ApJS/242/13 : Am stars from LAMOST DR5 (Qin+, 2019)
J/MNRAS/485/1067 : Composition of eclipsing close binary syst. (Takeda+, 2019)
J/ApJS/244/43 : Binary stars param. from LAMOST & Kepler obs. (Zhang+, 2019)
J/A+A/640/A40 : 1002 mCP stars from LAMOST DR4 (Hummerich+, 2020)
http://www.lamost.org/ : LAMOST home page
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 14 A14 --- Version LAMOST Data release version
16- 59 A44 --- FileName vsstring giving the name of the FITS file
61- 66 A6 --- --- [LAMOST]
68- 86 A19 --- LAMOST Designation of LAMOST target
(JHHMMSS.ss+DDMMSS.s) (1)
88- 97 F10.6 deg RAdeg Right ascension during observing (J2000) (1)
99- 107 F9.6 deg DEdeg [-9.1/79] Declination during observing
(J2000) (1)
109- 127 A19 "datime" Date The observation date; median UTC (1)
129- 134 F6.2 --- SNg [50/999] SNR of g filter (1)
136- 139 A4 --- Class Object type (always "STAR") (1)
141- 144 A4 --- subCl Subclass of object (1)
146- 154 A9 --- SpT MK spectral type (2)
156- 159 I4 K Teff1 [6000/9979]? Effective temperature obtained
by the LASP (1)
161- 163 I3 K e_Teff1 [7/851]? Uncertainty in Teff1 (1)
165- 169 F5.3 [cm/s2] logg1 [1/4.8]? Surface gravity obtained by the
LASP (1)
171- 175 F5.3 [cm/s2] e_logg1 [0.009/1.11]? Uncertainty in logg1 (1)
177- 182 F6.3 [Sun] FeH1 [-1/0.99]? Metallicity obtained by the LASP
(1)
184- 188 F5.3 [Sun] e_FeH1 [0.004/0.9]? Uncertainty in FeH1 (1)
190- 197 F8.6 arcsec SepTESS [0/2]? Angle distance between the Am star
and the target of the input catalog of TESS
199- 204 F6.3 mag Vmag [7.9/20.24]? TIC-v8 Johnson V magnitude (G1)
206- 210 F5.3 mag e_Vmag [0.002/1.5]? Uncertainty in mag
212- 216 A5 --- Flag TIC-v8 Stellar Properties Flag (SPFlag) (G4)
218- 221 I4 K Teff2 [1001/9998]? TIC-v8 Effective Temperature
223- 225 I3 K s_Teff2 [9/987]? Dispersion in Teff2
227- 232 F6.4 [cm/s2] logg2 [3.12/5]? TIC-v8 surface gravity
234- 239 F6.4 [cm/s2] s_logg2 [0.01/0.5]? Dispersion in logg2
241- 247 F7.4 [Sun] FeH2 [-1/0.81]? TIC-v8 Metallicity (M/H)
249- 254 F6.4 [Sun] e_FeH2 [0.003/0.5]? Uncertainty in FeH2 (e_M/H)
256- 261 F6.3 Rsun Rad [0.5/53.7]? TIC-v8 radius
263- 267 F5.3 Rsun s_Rad [0.017/2.6]? Dispersion in Rad
269- 273 F5.3 Msun Mass [0.5/3.2]? TIC-v8 mass
275- 279 F5.3 Msun s_Mass [0.02/0.6]? Dispersion in Mass
281- 289 F9.5 Lsun Lum [0.049/256]? Stellar luminosity
291- 299 F9.5 Lsun s_Lum [0.01/228.1]? Dispersion in Lum
301- 310 F10.4 pc Dist [94/10070]? TIC-v8 distance("d") from
Bailer-Jones+ (2018, I/347)
312- 321 F10.4 pc s_Dist [1/3527]? Dispersion in distance (e_d)
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Note (1): From the LAMOST LRS Stellar Parameter Catalog of A, F, G
and K Stars.
Note (2): MK spectral type were obtained by us through the MKCLASS
program based on the LAMOST spectra.
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Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 --- Version LAMOST Data release version
12- 55 A44 --- FileName The vsstring giving the name of this FITS
file
57- 62 A6 --- --- [LAMOST]
64- 82 A19 --- LAMOST Designation of LAMOST target
(JHHMMSS.ss+DDMMSS.s) (1)
84- 93 F10.6 deg RAdeg Right ascension during observing (J2000) (1)
95- 103 F9.6 deg DEdeg [-8.1/67] Declination during observing
(J2000) (1)
105- 123 A19 "datime" Date The observation date; median UTC (1)
125- 130 F6.2 --- SNg [50/772] SNR of g filter (1)
132- 135 A4 --- Class Object type (always "STAR") (1)
137- 141 A5 --- subCl Subclass of object (1)
143- 146 I4 K Teff1 [6061/8484]? Effective temperature obtained
by the LASP (1)
148- 150 I3 K e_Teff1 [9/243]? Uncertainty in Teff1 (1)
152- 156 F5.3 [cm/s2] logg1 [2.4/4.6]? Surface gravity obtained by the
LASP (1)
158- 162 F5.3 [cm/s2] e_logg1 [0.01/0.5]? Uncertainty in logg1 (1)
164- 169 F6.3 [Sun] FeH1 [-0.9/0.5]? Metallicity obtained by the
LASP (1)
171- 175 F5.3 [Sun] e_FeH1 [0.007/0.3]? Uncertainty in FeH (1)
177- 185 A9 --- SpT MK spectral type (2)
187- 194 F8.6 arcsec SepVSX [0/2] Angle distance between the Am star
and the target of AAVSO International
Variable Star Index VSX
196- 202 I7 --- OID [46/2345176] VSX internal identifier
204 A1 --- f_OID VSX flag on ID (B: bibliography;
V: an additional VSX name)
206- 233 A28 --- Name Variable star identifier from VSX
235 I1 --- Vflag [0/3] VSX variability flag (0: variable) (G2)
237- 248 A12 --- Type VSX variability type, as in GCVS catalog
250- 255 F6.3 mag maxmag [6.7/17.1]? VSX magnitude at maximum, or
amplitude
257- 261 A5 --- n_maxmag VSX passband on max magnitude (G3)
263- 268 F6.3 mag minmag [0.001/19.6]? VSX magnitude at minimum, or
amplitude
270- 274 A5 --- n_minmag VSX passband on min magnitude (G3)
276- 288 F13.9 d Per [0.15/110.4]? VSX period of the variable
290- 298 F9.5 deg RA2deg Right ascension, AAVSO VSX (J2000)
300- 307 F8.5 deg DE2deg [-8.1/67] Declination, AAVSO VSX (J2000)
309- 317 F9.7 arcsec SepTESS [0.0009/2] Angle distance between the Am
star and the target of the input catalog
of TESS
319- 324 F6.3 mag Vmag [9.2/17.5]? TIC-8 Johnson V magnitude (G1)
326- 330 F5.3 mag e_Vmag [0.004/1.2]? Uncertainty in Vmag
332- 336 A5 --- Flag TIC-8 Stellar Properties Flag (SPFlag) (G4)
338- 342 I5 K Teff2 [5316/12052]? TIC-8 Effective Temperature
344- 346 I3 K s_Teff2 [12/728]? Dispersion in Teff
348- 354 F7.4 [Sun] FeH2 [-0.85/0.5]? TIC-8 Metallicity (M/H)
356- 361 F6.4 [Sun] e_FeH2 [0.0046/0.3]? Uncertainty in FeH2
363- 367 F5.3 Msun Mass [1/2.4]? TIC-8 Mass
369- 373 F5.3 Msun s_Mass [0.16/0.4]? Dispersion in Mass
375- 383 F9.5 Lsun Lum [1.7/114]? Stellar luminosity
385- 392 F8.5 Lsun s_Lum [0.28/22]? Dispersion in Lum
--------------------------------------------------------------------------------
Note (1): From the LAMOST LRS Stellar Parameter Catalog of A, F, G and K Stars
Note (2): MK spectral type were obtained by us through the MKCLASS
program based on the LAMOST spectra.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 F8.6 --- SepVSX [0/2] Angle distance between the Am star
and the target of AAVSO International
Variable Star Index (VSX)
10- 19 A10 --- OriCat The original referenced catalog of Am stars
(1)
21- 31 F11.7 deg RAdeg Right ascension (J2000)
33- 43 F11.7 deg DEdeg [-77.1/77.7] Declination (J2000)
45 A1 --- n_OriCat [/?* ] Peculiarity probability note (2)
47- 56 F10.8 --- Conf [0.3/0.7]? Confidence for Am type from
Cat. J/MNRAS/449/1401/table4m (3)
58- 66 A9 --- SpT1 Spectral type or CP type (4)
68- 76 A9 --- SpT2 Other spectral type or CP type
78- 87 A10 --- r_SpT2 Ref for the Other spectral type or CP type
89- 95 I7 --- OID [67/2213681] VSX internal identifier
97 A1 --- n_OID VSX OID flag (B: bibliography;
V: an additional VSX name)
99- 126 A28 --- Name Variable star identifier from VSX
128 I1 --- Vflag [0/3] VSX variability flag (0:variable) (G2)
130- 141 A12 --- Type VSX variability type, as in GCVS catalog
143- 148 F6.3 mag maxmag [1.89/14.81]? VSX magnitude at maximum, or
amplitude
150- 152 A3 --- n_maxmag VSX passband on max magnitude (G3)
154- 159 F6.3 mag minmag [0.001/15.3]? VSX magnitude at minimum, or
amplitude
161- 164 A4 --- n_minmag VSX passband on min magnitude (G3)
166- 178 F13.9 d Per [0.09/136]? VSX period of the variable
180- 190 F11.9 arcsec SepLRS [0/0.91]? Angle distance between the Am
star and the target of LAMOST LRS Stellar
Parameter Catalog of A, F, G and K Stars
192- 210 A19 --- LAMOST Designation of LAMOST target
(JHHMMSS.ss+DDMMSS.s) (5)
212- 217 F6.2 --- SNg [24.13/718.34]? SNR of g filter (5)
219- 222 A4 --- Class Object type (always "STAR") (5)
224- 225 A2 --- subCl Stellar spectral type (5)
227- 230 I4 K Teff1 [6708/8690]? Effective temperature obtained
by the LASP (5)
232- 233 I2 K e_Teff1 [12/56]? Effective temperature uncertainty
obtained by the LASP (5)
235- 239 F5.3 [cm/s2] logg1 [3.7/4.42]? Surface gravity obtained by the
LASP (5)
241- 245 F5.3 [cm/s2] e_logg1 [0.015/0.1]? Surface gravity uncertainty
obtained by the LASP (5)
247- 252 F6.3 [Sun] FeH1 [-0.27/0.8]? Metallicity obtained by the
LASP (5)
254- 258 F5.3 [Sun] e_FeH1 [0.007/0.06]? Metallicity uncertainty
obtained by the LASP (5)
260- 267 F8.6 arcsec SepTESS [0.0002/0.91] Angle distance between the Am
star and the target of the input catalog
of TESS
269- 274 F6.3 mag Vmag [1.8/15.6] TIC-v8 Johnson V magnitude (G1)
276- 280 F5.3 mag e_Vmag [0.002/0.3] Uncertainty in Vmag
282- 286 A5 --- Flag TIC-v8 Stellar Properties Flag (SPFlag) (G4)
288- 291 I4 K Teff2 [1035/9962]? TIC-v8 Effective Temperature
293- 295 I3 K s_Teff2 [17/479]? Dispersion in Teff2
297- 303 F7.4 [Sun] FeH2 [-0.24/0.77]? TIC-v8 Metallicity (M/H)
305- 310 F6.4 [Sun] e_FeH2 [0.008/0.31]? Uncertainty in FeH2
312- 316 F5.3 Msun Mass [1.18/2.8]? TIC-v8 Mass
318- 322 F5.3 Msun s_Mass [0.2/0.4]? Dispersion in Mass
324- 332 F9.5 Lsun Lum [3.5/134]? TIC-v8 Stellar luminosity
334- 341 F8.5 Lsun s_Lum [0.28/19.2]? Dispersion in Lum
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Note (1): References as follows:
Renson+ = 2009A&A...498..961R 2009A&A...498..961R, Cat. II/260/catalog;
Qin+ = 2019ApJS..242...13Q 2019ApJS..242...13Q, table 8;
Hou+ = 2015MNRAS.449.1401H 2015MNRAS.449.1401H, Cat. J/MNRAS/449/1401/table4m;
Ghazaryan+ = 2018MNRAS.480.2953G 2018MNRAS.480.2953G, Cat. J/MNRAS/480/2953/cpstars;
Gray+ = 2016AJ....151...13G 2016AJ....151...13G, Cat. J/AJ/151/13/table1.
Note (2): Note for objects also contained in the catalogue of Renson
& Manfroid (2009A&A...498..961R 2009A&A...498..961R, Cat. III/260)
Note (3): The possibility of one star being an Am star is low when
the value is near 0, and high for a value near 1.
Note (4): The spectra type were obtained form the referenced catalog
of Am stars that shown in front.
Note (5): From the LAMOST LRS Stellar Parameter Catalog of A, F, G
and K Stars
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Global notes:
Note (G1): Observed V magnitudes are preferred when they are converted
from Tycho Vt, Hipparcos or UCAC. Otherwise, a Johnson V
magnitude is calculated from the Gaia colors (G, Bp, Rp) for
stars that do not have a reliable observed Johnson V magnitude.
If a star does not have a reliable Gaia color, the V magnitude is
calculated following the relations implemented for TICv7
described in Stassun+ (2018, J/AJ/156/102).
Note (G2): Code as follows:
0 = Variable;
1 = Suspected variable;
2 = Constant or non-existing;
3 = Possible duplicate.
Note (G3): Passbands include the following:
U B V R I = Johnson broad-band;
J H K L M = Johnson infra-red (1.2, 1.6, 2.2, 3.5, 5µm);
Rc Ic = Cousins' red and infra-red;
u v b y = Stroemgren intermediate-band;
u'g'r'i'z' = Sloan (SDSS);
pg pv bj rf = photographic blue (pg, bj) visual (pv), red (rf);
w C CR CV = white (clear); R or V used for comparison star.;
R1 = ROTSE-I (450-1000nm);
Hp T = Hipparcos and Tycho (Cat. I/239);
NUV = near-UV (Galex);
H1A H1B = STEREO mission filter (essentially 600-800nm).
Note (G4): Stellar Properties Flag (SPFlag) as follows:
gaia2 = from Gaia DR2 (I/345);
cdwrf = from the cool dwarf catalog (TICv7,
see Stassun+ 2018, J/AJ/156/102);
splin = characteristics imported from TICv7, spline relation
tic7 = TICv7;
spect = from a spectroscopic catalog;
spec = from a spectroscopic catalog;
spec7 = characteristics computed using the spectroscopic
Torres+ (2010A&ARv..18...67T 2010A&ARv..18...67T) relations
tplx = parallax from Tycho2 (I/259) - Gaia Astrometric Solution
hplx = parallax from Hipparcos (see I/239 and I/311)
See the appendix of the full documentation for a more comprehensive
description of each source (Stassun+, 2019AJ....158..138S 2019AJ....158..138S ; Cat. IV/38).
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 31-Jul-2023