J/MNRAS/454/2787 LAMOST DR2 white dwarfs (Guo+, 2015)
White dwarfs identified in LAMOST DR 2.
Guo J., Zhao J., Tziamtzis A., Liu J., Li L., Zhang Y., Hou Y., Wang Y.
<Mon. Not. R. Astron. Soc., 454, 2787-2797 (2015)>
=2015MNRAS.454.2787G 2015MNRAS.454.2787G (SIMBAD/NED BibCode)
ADC_Keywords: Surveys ; Stars, white dwarf
Keywords: white dwarfs
Abstract:
Here we present a catalogue of 1056 spectroscopically identified
hydrogen-dominated white dwarfs (DAWDs), 34 helium-dominated white
dwarfs (DBWDs) and 276 white dwarf main sequence (WDMS) binaries from
the Large sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST)
survey data release 2 (DR2). 383 DAWDs, 4 DBWDs and 138 WDMSs are new
identifications after cross-match with literature. There are ∼4100k
spectra in total from DR 2. The low ratio of white dwarfs found in
LAMOST is attributed to biased selection of LAMOST input catalogue and
much brighter targets relative to stars observed in Sloan Digital Sky
Survey. In this paper, a new DAWD selection method is adopted as a new
attempt and supplement to the traditional methods. The effective
temperature, surface gravity, mass, cooling age and distance of high
signal-to-noise DAWDs are estimated. The peak of the mass distribution
is found to be ∼0.6M☉, which is consistent with previous work.
The parameters of WDMS binaries are also provided in this paper. As
the foundation of our future work, which is to identify more WDs with
debris disc, WDs found in LAMOST showed a lot of potential.
Interesting infrared-excess WDs will be reported in our forthcoming
paper.
Description:
LAMOST DR1 released 2204860 spectra, which included 717660 objects
from the pilot survey, observed from 2011 October to 2012 June and
1487200 objects from the regular survey from 2012 September to 2013
June. DR2, which included DR1, released 1588 746 new spectra during
the second year in 2014.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 177 1664 White dwarfs identified in LAMOST DR2
table4.dat 139 190 WDMS catalogue from LAMOST DR2
table4b.dat 63 92 *WDMS candidates
table6.dat 241 1664 Information of white dwarfs identified in
LAMOST DR2
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Note on table4b.dat: Classifications are not very certain due to some reasons.
(i.e. flux calibration problem, low S/N).
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See also:
V/146 : LAMOST DR1 catalogs (Luo+, 2015)
J/AJ/146/34 : LAMOST DA white dwarfs infrared photometry (Zhang+, 2013)
J/A+A/570/A107 : WDMS from LAMOST DR1 (Ren+, 2014)
J/MNRAS/452/765 : LAMOST DR3 white dwarf candidates (Gentile Fusillo+, 2016)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- GID Group ID (i.e. 1_2 means group 1 has 2
spectra observations)
10- 18 F9.5 deg RAdeg Right ascension (J2000)
20- 28 F9.5 deg DEdeg Declination (J2000)
30- 48 A19 --- LAMOST Designation: assigned name for a source by
LAMOST (JHHMMSS.ss+DDMMSS.s) (1)
50- 84 A35 --- specId Mjd-Planid_spid-Fiberid (G1)
86- 91 F6.2 --- snrg Signal to Noise ratio in g band
93- 97 I5 K Teff ?=-9999 Effective temperature
99-103 I5 K e_Teff ?=-9999 rms uncertainty on Teff
105-109 F5.2 [cm/s2] logg ?=-9.0 Surface gravity
111-115 F5.2 [cm/s2] e_logg ?=-9.0 rms uncertainty on logg
117-121 F5.2 Msun Mass ?=-9.0 Estimated mass
123-127 F5.2 Msun e_Mass ?=-9.0 rms uncertainty on Mass
129-132 I4 Myr Age ?=-999 White dwarf cooling age
134-137 I4 Myr e_Age ?=-999 rms uncertainty on Age
139-143 F5.2 mag E(B-V) ?=-9.0 Extinction
145-148 I4 pc Dist ?=-999 Estimated distance
150-168 A19 --- Type Classification of spectral type (2)
171-177 A7 --- New new means new identification,
not_new means already identified
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Note (1): Could be slight different for the same source.
Note (2): Question mark (?) means uncertain about the classification.
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 35 A35 --- specId Mjd-Planid_spid-Fiberid (G1)
37- 41 I5 K TeffWD ?=-9999 Effective temperature of WD
43- 47 F5.2 [cm/s2] loggWD ?=-9.0 Surface gravity of WD
48- 52 F5.2 Msun MassWD ?=-9.0 Mass of WD
54- 58 F5.2 [yr] logAge ?=-9.0 log of cooling age
60- 65 F6.3 Rsun RadWD ?=-9.0 Radius of WD
67- 74 F8.2 pc DistWD ?=-9999 Distance of WD
76- 80 I5 K TeffM ?=-9999 Effective temperature of M star
82- 86 F5.2 [cm/s2] loggM ?=-9.0 Surface gravity of M star
88- 92 F5.2 Msun MassM ?=-9.0 Mass of M star
94- 99 F6.3 Rsun RadM ?=-9.0 Radius of M star
101-106 F6.2 [-] [Fe/H] ?=-99.0 [Fe/H] of M star
108-113 F6.2 --- SpTypeM ?=-99.0 Spectral type of M star.
(-1 means K type star secondary)
115-122 F8.2 --- a ?=-9999.0 Scaling factor a
124-131 F8.2 --- b ?=-9999.0 Scaling factor b
133-139 F7.2 --- Chi2 ?=-999.0 chi-square of best-fit
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Byte-by-byte Description of file: table4b.dat
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Bytes Format Units Label Explanations
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1- 33 A33 --- specId Mjd-Planid_spid-Fiberid (G1)
35- 63 A29 --- Notes Notes
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 11 F11.7 deg RAdeg Right ascension (J2000)
13- 23 F11.7 deg DEdeg Declination (J2000)
26- 60 A35 --- specId Mjd-Planid_spid-Fiberid (G1)
62- 80 A19 --- LAMOST Assigned name for a source by LAMOST. Could be
slight different for the same source
82- 91 A10 "date" Obs.Date Spectra observed date
93- 97 I5 d MJD modified Julian Day
98-118 A21 --- PlanId Plate identifier
120-121 I2 --- spId Spectrograph identifier
123-125 I3 --- FiberId Fiber identifier
127-133 F7.2 --- snru ?=-999.0 Signal to noise ratio in u band
135-140 F6.2 --- snrg Signal to noise ratio in g band
142-146 F5.2 --- snrr Signal to noise ratio in r band
148-154 F7.2 --- snri ?=-999.0 Signal to noise ratio in i band
156-162 F7.2 --- snrz ?=-999.0 Signal to noise ratio in z band
164-170 A7 --- Class Class assigned by LAMOST pipeline
(STAR, GALAXY, QSO or UNKNOWN)
172-181 A10 --- SubClass Spectral class assigned by LAMOST pipeline
183-192 A10 --- magType Magnitude band of object
194-199 F6.2 mag mag1 ?=-99.0 Magnitude in band 1 of magType (1)
201-206 F6.2 mag mag2 ?=-99.0 Magnitude in band 2 of magType (1)
208-213 F6.2 mag mag3 ?=-99.0 Magnitude in band 3 of magType (1)
215-220 F6.2 mag mag4 ?=-99.0 Magnitude in band 4 of magType (1)
222-227 F6.2 mag mag5 ?=-99.0 Magnitude in band 5 of magType (1)
229-234 F6.2 mag mag6 ?=-99.0 Magnitude in band 6 of magType (1)
236-241 F6.2 mag mag7 ?=-99.0 Magnitude in band 7 of magType (1)
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Note (1): i.e. if the magType is "ugrizjh", the mag1, mag2, mag3, mag4, mag5,
mag6 and mag7 provide the magnitudes of u, g, r, i, z, j and h filter
respectively.
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Global notes:
Note (G1): Unique ID for each LAMOST spectrum.
Complete spectrum name is spec-specId.fits.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 25-Jul-2016