J/ApJS/249/22 Radial velocity variable stars from LAMOST DR4 (Tian+, 2020)
A catalog of RV variable star candidates from LAMOST.
Tian Z., Liu X., Yuan H., Fang X., Chen B., Xiang M., Huang Y., Bi S.,
Yang W., Wu Y., Wang C., Zhang H., Huo Z., Yang Y., Liu G., Guo J., Zhang M.
<Astrophys. J. Suppl. Ser., 249, 22 (2020)>
=2020ApJS..249...22T 2020ApJS..249...22T
ADC_Keywords: Stars, variable; Radial velocities; Spectra, optical; Surveys;
Cross identifications
Keywords: Variable stars; Catalogs; Radial velocity; Extrinsic variable stars;
Intrinsic variable stars; Binary stars; Pulsating variable stars;
Star counts; Stellar astronomy; Astrostatistics; Spectroscopy;
Surveys
Abstract:
Radial velocity (RV) variable stars are important in astrophysics. The
Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST)
spectroscopic survey has provided ∼6.5 million stellar spectra in its
Data Release 4 (DR4). During the survey ∼4.7 million unique sources
were targeted and ∼1 million stars observed repeatedly. The
probabilities of stars being RV variables are estimated by comparing
the observed RV variations with simulated ones. We build a catalog of
80702 RV variable candidates with probability greater than 0.60 by
analyzing the multi-epoch sources covered by LAMOST DR4. Simulations
and cross-identifications show that the purity of the catalog is
higher than 80%. The catalog consists of 77% binary systems and 7%
pulsating stars as well as 16% pollution by single stars. 3138 RV
variables are classified through cross-identifications with published
results in literatures. By using the 3138 sources common in both
LAMOST and a collection of published RV variable catalogs, we are able
to analyze LAMOST's RV variable detection rate. The efficiency of the
method adopted in this work relies not only on the sampling frequency
of observations but also periods and amplitudes of RV variables. With
the progress of LAMOST, Gaia, and other surveys, more and more RV
variables will be confirmed and classified.
Description:
The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST)
spectroscopic survey provides the largest database of low-resolution
(R∼2000) spectra to measure stellar atmospheric parameters and radial
velocities (RVs) for millions of stars.
We build a catalog of 80702 RV variable candidates with probability
greater than 0.60 by analyzing the multi-epoch sources covered by
LAMOST DR4 (V/153).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
catalog.dat 317 80702 Catalog of radial velocity (RV) variable
star candidates
epochs.dat 134 304473 Measurements per epoch (extracted
from catalog.dat by CDS)
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Description of file:
catalogrvvariables_new.fits also available on the FTP is the original FITS
file for Table 2.
See also:
B/vsx : AAVSO International Variable Star Index VSX (Watson+, 2006-2014)
B/gcvs : General Catalogue of Variable Stars (Samus+, 2007-2017)
III/218 : ELODIE archive (Prugniel+, 2001)
V/133 : Kepler Input Catalog (Kepler Mission Team, 2009)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
V/153 : LAMOST DR4 catalogs (Luo+, 2018)
II/366 : ASAS-SN catalog of variable stars (Jayasinghe+, 2018-2020)
J/MNRAS/371/703 : MILES library of empirical spectra (Sanchez-Blazquez+, 2006)
J/ApJS/190/1 : A survey of stellar families (Raghavan+, 2010)
J/ApJS/213/9 : Catalina Surveys periodic variable stars (Drake+, 2014)
J/ApJ/788/48 : X-ray through NIR photometry of NGC 2617 (Shappee+, 2014)
J/ApJS/220/19 : LAMOST obs. in the Kepler field. I. (De Cat+, 2015)
J/MNRAS/448/822 : LAMOST candidate members of star clusters (Xiang+, 2015)
J/ApJS/232/16 : Mira stars discovered in LAMOST DR4 (Yao+, 2017)
J/AJ/154/94 : APOGEE-2 data from DR16 (Majewski+, 2017)
J/AJ/156/90 : New cat. of APOGEE RV standard stars (Huang+, 2018)
J/AJ/156/18 : APOGEE DR14: evolved star companions (Price-Whelan+, 2018)
J/A+A/616/A7 : Gaia DR2 RV standard stars catalog (Soubiran+, 2018)
J/A+A/622/A60 : Gaia DR2 misclassified RR Lyrae list (Clementini+, 2019)
J/other/RAA/19.64 : LAMOST spectrosc. binaries & variable stars (Qian+, 2019)
Byte-by-byte Description of file: catalog.dat
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Bytes Format Units Label Explanations
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1- 11 F11.7 deg RAdeg Right ascension (J2000) (RA)
13- 22 F10.7 deg DEdeg [-9.5/87] Declination (J2000) (DEC)
24- 34 F11.7 deg GLON Galactic longitude (L)
36- 46 F11.7 deg GLAT Galactic latitude (B)
48- 49 I2 --- Nep [2/47] Number of epochs of the object (EPOCH)
51- 60 F10.5 d Dur [0.0075/1611] Time span of observation
for the object (DURATION)
62- 72 F11.5 d DeltaT [-1603/1611] Δt between epochs
with max and min RV (DT)
74- 82 F9.5 km/s dRV [9.8/415] Maximum RV difference
between any two epochs (DRV_MAX)
84- 91 F8.5 [cm/s2] dlogg [-5.15/4.82] logg between epochs
with max and min RV (DLOGG)
93-104 F12.5 K dTeff [-18681/16743] ΔTeff
between epochs with max and min RV (DTEFF)
106-113 F8.5 [-] dFeH [-3.3/3.8] Δ[Fe/H] between
epochs with max and min RV (DFEH)
115-124 F10.5 --- Chi2 [0.16/1095] Chi square of RVs calculated
with equation 4 (CHIS) (1)
126-131 F6.1 km/s RV [-939/777] Weighted radial velocity
via equation 1 (WMRV) (2)
133-138 F6.3 km/s e_RV [3/17.1] Weighted RV error
via equation 3 (WMRVERR) (3)
140-175 A36 --- SpecId LAMOST unique spectral ID for epoch
of target (SPEC_ID)
177-178 I2 --- RVmax [0/40] Index of RV_EPOCH
responding for max RV (INDMM1)
180-181 I2 --- RVmin [0/39] Index of RV_EPOCH responding
for min RV (INDMM2)
183-187 F5.3 --- PV [0.6/0.95] Probability of being
a RV variable star
189-220 A32 --- Type Variability types
222-230 I9 --- KIC ?=-1 Kepler identifier (see V/133)
232-250 I19 --- Gaia ?=-1 GAIA identifier for 203 sources
(see I/345) (GAIASOURCEID)
252-281 A30 --- OName VSX name (see B/vsx) for 3044 sources
(VSX_NAME)
283-288 A6 --- GCVS GCVS Constellation numeric code (bytes 1-2),
Star Number within constellation (bytes 3-6)
(see B/gcvs) (GCVSCONNUM)
290-297 A8 --- --- [ASASSNV-]
299-317 A19 --- ASASSN-V ASAS-SN name for 2011 sources (see II/366)
(ASASSN_NAME)
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Note (1): The variance of the RV is (Equation 4):
S2=(1/n)Σni=1(RVi-RV)2/σ2RVi
See Section 2.2.
Note (2): The weighted RV is expressed as (Equation 1):
RV=(Σni=1RVi/σ2RVi)/(Σni=11/σ2RVi)
Note (3): the weighted error is (Equation 3):
σRV=(Σni=1σRVi/σ2RVi)/
(Σni=11/σ2RVi)
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Byte-by-byte Description of file: epochs.dat
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Bytes Format Units Label Explanations
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1- 11 F11.7 deg RAdeg Right ascension (J2000) (RA)
13- 22 F10.7 deg DEdeg Declination (J2000) (DEC)
24- 34 F11.3 d JD Julian Day of exposure
of the SpecId (JULS_EPOCH)
36- 43 F8.3 --- SNR [10/2329]?=0 S/N(4650A) per pixel
in blue arm of epochs (SNRB_EPOCH)
45- 50 F6.1 km/s RV [-968/785]?=0 Radial Velocity (RV_EPOCH)
52- 57 F6.3 km/s e_RV [3/21]?=0 RV uncertainty (ERRRVEPOCH)
59- 66 F8.5 [cm/s2] logg [-1.1/6.42]?=0 log of surface gravity
(LOGG_EPOCH)
68- 75 F8.6 [cm/s2] e_logg [0.05/0.42]?=0 logg uncertainty (ERRLOGGEPOCH)
77- 87 F11.5 K Teff [3402/23942]?=0 Effective
temperature (TEFF_EPOCH)
89- 98 F10.6 K e_Teff [58/660]?=0 Teff uncertainty (ERRTEFFEPOCH)
100-107 F8.5 [-] [Fe/H] [-3.7/1.7]? Metallicity (FEH_EPOCH)
109-116 F8.6 [-] e_[Fe/H] [0.05/0.6]? Error of [Fe/H] (ERRFEHEPOCH)
118-125 F8.5 [-] [a/Fe] [-0.4/0.8]? Abundance [alpha/Fe] (AFE_EPOCH)
127-134 F8.6 [-] e_[a/Fe] [0.026/0.3]? Error of [alpha/Fe] (ERRAFEEPOCH)
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History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 22-Oct-2020