J/other/RAA/19.88 DB white dwarfs from the LAMOST DR5 (Kong+, 2019)
A catalog of DB white dwarfs from the LAMOST DR5 and construction of templates.
Kong X., Luo A.-L., Li X.-R.
<Res. Astron. Astrophys., 19, 88 (2019)>
=2019RAA....19...88K 2019RAA....19...88K (SIMBAD/NED BibCode)
ADC_Keywords: Stars, white dwarf ; Effective temperatures ;
Photometry, ultraviolet ; Radial velocities
Abstract:
In this study, we employ machine learning to build a catalog of DB
white dwarfs (DBWDs) from the LAMOST Data Release (DR) 5. Using known
DBs from SDSS DR14, we selected samples of high-quality DB spectra
from the LAMOST database and applied them to train the machine
learning process. Following the recognition procedure, we chose 351 DB
spectra of 287 objects, 53 of which were new identifications. We then
utilized all the DBWD spectra from both SDSS DR14 and LAMOST DR5 to
construct DB templates for LAMOST 1D pipeline reductions. Finally, by
applying DB parameter models provided by D. Koester and the distance
from Gaia DR2, we calculated the effective temperatures, surface
gravities and distributions of the 3D locations and velocities of all
DBWDs.
Description:
We spectroscopically identified 287 DBWDs from 351 spectra in the
LAMOST DR5, including 53 new objects, using ML, i.e., LASSO and an
SVM.
The table contains 356 spectra of 292 objects, 54 stars of them are
reported for the first time.
There are 16 DB plus M double star that have radial velocity of two
components.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
dbwd.dat 194 356 Newly identified DB white dwarfs (DBWDs)
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See also:
V/164 : LAMOST DR5 catalogs (Luo+, 2019)
J/AJ/146/34 : Infrared photometry of DA white dwarfs from LAMOST (Zhang+, 2013)
Byte-by-byte Description of file: dbwd.dat
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Bytes Format Units Label Explanations
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1- 19 A19 --- LAMOST LAMOST designations of the objects,
JHHMMSS.ss+DDMMSS.s
21- 53 A33 --- M-P-S-F LAMOST
Modified Julian date-Planid_SPid-Fiberid
55- 61 A7 --- Type Classification of objects derived
from ML method
63- 66 I4 km/s RVDB Radial velocity of each spectrum
68- 71 I4 km/s e_RVDB ? Uncertainty of radial velocity of
each spectrum
74- 77 I4 km/s RVM ? Radial velocity of M companions
80- 83 I4 km/s e_RVM ? Uncertainty of radial velocity of
M companions
86- 90 I5 K Teff Effective temperature
92- 96 I5 K e_Teff Uncertainty of Effective temperature
98-101 F4.2 [cm/s2] logg Surface gravity
103-106 F4.2 [cm/s2] e_logg Uncertainty of Surface gravity
108-111 F4.1 mag FUV ? Magnitude of FUV from GALEX
114-116 F3.1 mag e_FUV ? Uncertainty of Magnitude of FUV from GALEX
120-123 F4.1 mag NUV ? Magnitude of NUV from GALEX
126-128 F3.1 mag e_NUV ? Uncertainty of Magnitude of NUV from GALEX
132-136 F5.1 --- S/N Median S/N from catalog of LAMOST DR5
138-145 F8.3 mas/yr pmRA ? Proper motion at J2015.5 in the direction
of RA, pmRA*cosDE
147-151 F5.3 mas/yr e_pmRA ? Uncertainty of pmRA
153-160 F8.3 mas/yr pmDE ? Proper motion at J2015.5 in the direction
of DEC
162-166 F5.3 mas/yr e_pmDE ? Uncertainty of pmDE
168-174 F7.4 mas Plx ? Absolute stellar parallax of the source at
the reference epoch J2015.5
176-181 F6.4 mas e_Plx ? Uncertainty of parallax
183-186 F4.2 Msun Mass ? Mass obtained from literature
189-194 F6.1 Myr Age ? Age obtained from literature
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History:
From electronic version of the journal
Acknowledgements:
A-Li Luo, lal(at)nao.cas.cn
(End) Xiao Kong [NAOC], Patricia Vannier [CDS] 16-Nov-2020