J/ApJS/244/27 Radial velocity measurements in LAMOST-II (Wang+, 2019)
Properties of radial velocities measurement based on LAMOST-II medium-resolution
spectroscopic observations.
Wang R., Luo A.-L., Chen J.-J., Bai Z.-R., Chen L., Chen X.-F., Dong S.-B.,
Du B., Fu J.-N., Han Z.-W., Hou J.-L., Hou Y.-H., Hou W., Jiang D.-K.,
Kong X., Li L.-F., Liu C., Liu J.-M., Qin L., Shi J.-R., Tian H., Wu H.,
Wu C.-J., Xie J.-W., Zhang H.-T., Zhang S., Zhao G., Zhao Y.-H., Zhong J.,
Zong W.-K., Zuo F.
<Astrophys. J. Suppl. Ser., 244, 27-27 (2019)>
=2019ApJS..244...27W 2019ApJS..244...27W (SIMBAD/NED BibCode)
ADC_Keywords: Radial velocities; Abundances, [Fe/H]; Spectra, optical;
Photometry, G band
Keywords: binaries: spectroscopic; methods: data analysis
techniques: spectroscopic
Abstract:
The radial velocity (RV) is a basic physical quantity that can be
determined through the Doppler shift of the spectrum of a star. The
precision of the RV measurement depends on the resolution of the
spectrum we used and the accuracy of wavelength calibration. In this
work, radial velocities of the Large Sky Area Multi-Object Fibre
Spectroscopic Telescope-II (LAMOST-II) medium-resolution (R∼7500)
spectra are measured for 1,594,956 spectra (each spectrum has two
wavebands) through matching with templates. A set of RV standard stars
are used to recalibrate the zero point of the measurement, and some
reference sets with RVs derived from medium-/high-resolution
observations are used to evaluate the accuracy of the measurement. By
comparing with reference sets, the accuracy of our measurement can get
0.0277km/s with respect to radial velocities of standard stars. The
intrinsic precision is estimated with the multiple observations of
single stars, which can be achieved to 1.36km/s, 1.08km/s, and
0.91km/s for the spectra at signal-to-noise levels of 10, 20, and 50,
respectively.
Description:
The test observation for the LAMOST medium-resolution mode (MRS;
R=7500) began on 2017 September 1, and a total of 1,594,956 spectra
(each has two bands) of stars with S/Ns higher than 10 was collected
until 2017 December 31 (in LAMOST phase two; LAMOST-II).
LAMOST is a telescope possessing an effective aperture of 4m and
5° fields of view, which is located at the Xinglong Observatory,
Hebei Province, China.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
lamostMRS.dat 541 1594956 The LAMOST medium-resolution radial
velocities catalog (LAMOST MRS RV)
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Description of file:
LAMOSTMRSRV.csv in the FTP section is the original file as downloaded from:
http://registry.china-vo.org/resource/101009
See also:
III/279 : RAVE 5th data release (Kunder+, 2017)
I/345 : Gaia DR2 (Gaia, 2018)
V/164 : LAMOST DR5 catalogs (Luo+, 2019)
J/AJ/137/4377 : List of SEGUE plate pairs (Yanny+, 2009)
J/A+A/524/A10 : Radial Velocity standard stars (Crifo+, 2010)
J/other/RAA/11.924 : Atmospheric parameters for 771 stars (Wu+, 2011)
J/A+A/552/A64 : Gaia-RVS standards (Soubiran+, 2013)
J/AJ/150/97 : Radial velocities in M67. I. Candidate members (Geller+, 2015)
J/A+A/616/A7 : Gaia DR2 radial velocity standard stars cat. (Soubiran+, 2018)
J/AJ/156/90 : New cat. of APOGEE RVel standard stars (Huang+, 2018)
J/A+A/622/A114 : Detached eclipsing binaries MITSuME photom. (Helminiak+, 2019)
J/A+A/624/A68 : 47 single-line eclipsing binaries BEBOP veloc. (Martin+, 2019)
Byte-by-byte Description of file: lamostMRS.dat
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Bytes Format Units Label Explanations
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1- 22 E22.17 --- Gaia ? Gaia DR2 identifier when available
24- 29 A6 --- --- [LAMOST]
31- 49 A19 --- LAMOST LAMOST identifier (JHHMMSS.ss+DDMMSS.s)
51- 97 A47 --- medID LAMOST spectral ID (Date-PlateID-
SpectrographID-FiberID-MJM_PiplineVersion)
99-145 A47 --- medIDb LAMOST spectral ID for the blue part
147-193 A47 --- medIDr LAMOST spectral ID for the red part
195-204 A10 "Y-M-D" Date Date of the observation
206-207 I2 --- spId [1/16] Spectrograph ID
209-218 A10 --- Lamp Lamp used for wavelength calibration
220-243 F24.20 deg RAdeg Right ascension (J2000)
245-266 E22.19 deg DEdeg [-10/79.1] Declination (J2000)
268-273 F6.2 --- SNRb [10/618] Signal-to-noise ratio of the blue part
275-280 F6.2 --- SNRr [10/667] Signal-to-noise ratio of the red part
282-303 F22.17 km/s RVb [-572/577] RV measured from the blue part
without zero-point correction
305-325 F21.16 km/s e_RVb [-121/391] RVb uncertainty
327-348 F22.17 km/s RVr [-546/591] RV measured from the red part
without zero-point correction
350-371 F22.17 km/s e_RVr [-10/318] RVr uncertainty
373-394 E22.19 km/s RVbc [-571/583] RV with zero-point corrected
for the blue part (see Section 4.1)
396-420 F25.20 km/s RVrc [-546/592] RV with zero-point corrected
for the red part (see Section 4.1)
422-439 F18.16 --- bcorr [0.924/1] Correlation coefficient between
the blue part and the best-fit template
441-458 F18.16 --- rcorr [0.919/1] Correlation coefficient between
the red part and the best-fit template
460-466 F7.1 K Teffb [3500/10000] Effective temperature of the
best-fit template of the blue part
468-470 F3.1 [cm/s2] loggb [0/5] Surface gravity of the best-fit template
of the blue part
472-475 F4.1 [-] [Fe/H]b [-4/0.5] [Fe/H] of the best-fit template
of the blue part
477-483 F7.1 K Teffr [3500/10000] Effective temperature
of the best-fit template of the red part
485-487 F3.1 [cm/s2] loggr [0/5] Surface gravity of the best-fit template
of the red part
489-492 F4.1 [-] [Fe/H]r [-4/0.5] [Fe/H] of the best-fit template
of the red part
494 I1 --- Flb [0] Quality flag for accessing RV derived from
the blue part, 0 for good (always "0")
496 I1 --- Flr [0/1] Quality flag for accessing RV derived
from the blue part (0=good, 1=bad)
498-517 F20.16 mag Gmag [4.5/21.2]? G magnitude from Gaia DR2
519-541 F23.20 mag bp-rp [-0.6/6]? bp-rp color index from Gaia DR2
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History:
Downloaded from http://registry.china-vo.org/resource/101009 =
doi:10.12149/101008
(End) Emmanuelle Perret [CDS] 19-Feb-2020