J/MNRAS/509/2674 White dwarfs in LAMOST DR5 (Guo+, 2022)
White dwarfs identified in LAMOST Data Release 5.
Guo J., Zhao J., Zhang H., Zhang J., Bai Y., Walters N., Yang Y., Liu J.
<Mon. Not. R. Astron. Soc. 509, 2674-2688>
=2022MNRAS.509.2674G 2022MNRAS.509.2674G (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Stars, white dwarf ; MK spectral classification ;
Photometry, classification ; Spectroscopy ; Photometry ;
Ultraviolet ; Radio sources ; Infrared ; Optical ;
Positional data ; Effective temperatures ; Stars, masses ;
Parallaxes, trigonometric ; Proper motions ; Stars, ages
Keywords: astronomical data bases: surveys - catalogues -
stars: fundamental parameters - stars: white dwarfs
Abstract:
In this paper, we report white dwarfs (WD) identified in the 5th Data
Release of the Large Area Multi-Object fibre Spectroscopic Telescope
(LAMOST), including spectral types of DA, DB, DC, DZ, and so on. There
are 2625 DA spectra of 2281 DA stars, 182 DB spectra of 166 DB stars,
62 DC spectra of 58 DC stars, 36 DZ spectra of 33 DZ stars, and many
other types identified, in addition to our previous paper (Data
Release 2). Amongst those sources, 393 DA stars and 46 DB stars are
new identifications after cross-matching with the literature. In order
to select DA candidates, we use the classification result from the
LAMOST pipeline, colour-colour cut method and a random forest (RF)
machine learning method. For DBs, since there is no template for DB in
the pipeline model, a RF machine learning method is chosen to select
candidates. All the WD candidates have been visually checked
individually. The parameters of effective temperature, surface
gravity, mass, and cooling age have been estimated for relatively high
signal-to-noise ratio DAs and DBs. The peaks of the DA and DB mass
distributions are found to be around 0.62 and 0.65 M☉,
respectively. Finally, the data and method we used to select WD
candidates for the second phase of LAMOST survey are also addressed in
this paper.
Description:
In this work, we present a catalogue of WDs discovered in LAMOST DR5,1
as well as their physical parameter estimation. LAMOST is a 4-m
reflecting Schmidt telescope, equipped with a multiobject spectrograph
that has a 20 deg2 field of view and 4000 fibres. The LAMOST
project began its 1 yr pilot study in 2012, followed by a 5 yr first
phase survey. The first part is the LAMOST Experiment for Galactic
Understanding and Exploration (LEGUE) survey, focused on understanding
the structure and evolution of the Milky Way (Deng et al.
2012RAA....12..735D 2012RAA....12..735D). The targets are mainly chosen from the Galactic
disc, spheroid, and anticentre. Although LAMOST is a spectroscopic
survey only, there are also photometric data provided by different
astronomers from various photometric catalogues 2MASS, SDSS, Kepler,
NVSS, etc. More than 50 per cent of the input catalogue entries at
least have g, r, and i magnitudes, mainly from XSTPS-GAC and SDSS. In
LAMOST DR5, there are almost 10 million spectra. Whilst the second
phase of LAMOST is ongoing, this work is based on the completed first
phase of LAMOST, in particular DR 3, 4, and 5.
In the section 2, we describe candidate selection of white dwarfs as
DA, DB, WDMagnetic, DoubleStar, and CarbonWD and other WD spectral
types with LAMOST pipeline, random forest algorithm, colour-colour cut
selection method and visual inspection of spectra. In the section 3 we
give details on astrometric parameters determination such Teff,
logg, M* and tcool. Results are presented in table3.dat and
table4.dat with magnitude from other catalogues like 2MASS and SDSS.
More, proper motions, magnitude, and parallax of Gaia DR2 are also
provided in our catalogue.
Hereafter, these new catalogue cross-matchs and LAMOST pipeline
version allow us to provide an update classification of WDs identified
in LAMOST DR1&2, results are avaiable in the table5.dat. Especially,
we update astrometric parameters for DA White dwarfs identified in
LAMOST DR1&2 as the table6.dat shows.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table3.dat 314 3517 Basic parameters of WDs from LAMOST DR 3, 4, 5
table4.dat 234 3517 Determined WD parameters and Gaia DR2 parameters
table5.dat 299 87 Updated types for White dwarfs identified in
LAMOST DR1&2
table6.dat 374 892 Updated parameters for DA White dwarfs
identified in LAMOST DR1&2
--------------------------------------------------------------------------------
See also:
V/149 : LAMOST DR2 catalogs (Luo+, 2016)
V/153 : LAMOST DR4 catalogs (Luo+, 2018)
V/164 : LAMOST DR5 catalogs (Luo+, 2019)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/MNRAS/482/715 : WD luminosity functions from the PS1 3pi Survey (Lam+, 2019)
J/MNRAS/486/2169 : White dwarf and subdwarf stars in SDSS DR14 (Kepler+, 2019)
J/MNRAS/455/3413 : New white dwarf and subdwarf stars in SDSS DR12
(Kepler+, 2016)
J/AJ/146/34 : Infrared photometry of DA white dwarfs from LAMOST
(Zhang+, 2013)
J/MNRAS/454/2787 : LAMOST DR2 white dwarfs (Guo+, 2015)
J/MNRAS/452/765 : White dwarf candidates using LAMOST DR3
(Gentile Fusillo+, 2015)
J/MNRAS/477/4641 : LAMOST DR5 White dwarf-main sequence binaries (Ren+, 2018)
J/MNRAS/480/3942 : The Gaia 20 pc white dwarf sample (Hollands+, 2018)
J/MNRAS/497/130 : Gaia white dwarfs within 40pc. I (Tremblay+, 2020)
J/MNRAS/480/4505 : A white dwarf catalogue from Gaia-DR2
(Jimenez-Esteban+, 2018)
J/MNRAS/482/4570 : Gaia DR2 white dwarf candidates (Gentile Fusillo+, 2019)
J/MNRAS/485/5573 : Gaia-DR2 100pc white dwarf population (Torres+, 2019)
http://dr5.lamost.org/ : LAMOST DR5 spectra home page
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- GroupID Group identifier number (GroupID)
6 I1 --- Size Number of available spectra (GroupSize)
8- 16 I9 --- ObsID Observation ID unique for each
spectrum (obsid)
18- 36 A19 --- Name Object name designation as
JHHMMSS.SS±DDMMSS.S (designation) (G1)
38- 48 F11.7 deg RAdeg Right ascension (ra_obs) (J2000)
50- 59 F10.7 deg DEdeg Declination (dec_obs) (J2000)
61- 70 A10 "Y:M:D" Date Target observation date (obsdate)
72- 76 I5 d LMJD Local modified Julian Day (lmjd)
78- 95 A18 --- PlanID Plan ID (planid)
97- 98 I2 --- SpID Spectrograph ID (spid)
100-102 I3 --- FiberID Fiber ID (fiberid)
104-146 A43 --- FileName Unique ID for each LAMOST spectrum
fits name (fits)
148-159 A12 --- SpType Classification of spectral types (type)
161-166 F6.2 --- S/Nu Signal to Noise ratio in u band (snru)
168-173 F6.2 --- S/Ng Signal to Noise ratio in g band (snrg)
175-180 F6.2 --- S/Nr Signal to Noise ratio in r band (snrr)
182-187 F6.2 --- S/Ni Signal to Noise ratio in i band (snri)
189-194 F6.2 --- S/Nz Signal to Noise ratio in z band (snrz)
196-204 A9 --- Type Object type by Pipeline (objtype)
206-212 A7 --- Class Spectra type by Pipeline (class)
214-223 A10 --- SubClass Stellar sub-class by Pipeline (subclass)
225-236 E12.8 --- z ?=-9999.0 Spectroscopic redshift (z)
238-249 E12.9 --- e_z []?=-9999.0 Mean error on z (z_err)
251-253 A3 --- MagType1 Target Magnitude type 1 available
(magtype) (G2)
255-256 A2 --- MagType2 Target Magnitude type 2 available
(magtype) (G2)
258-259 A2 --- MagType3 Target Magnitude type 3 available
(magtype) (G2)
261-263 A3 --- MagType4 Target Magnitude type 4 available
(magtype) (G2)
265 A1 --- MagType5 Target Magnitude type 5 available
(magtype) (G2)
267-269 A3 --- MagType6 Target Magnitude type 6 available
(magtype) (G2)
271-272 A2 --- MagType7 Target Magnitude type 7 available
(magtype) (G2)
274-278 F5.2 mag mag1 ?=99.0 Apparent magnitude in the
band 1 (mag1)
280-284 F5.2 mag mag2 ?=99.0 Apparent magnitude in the
band 2 (mag2)
286-290 F5.2 mag mag3 ?=99.0 Apparent magnitude in the
band 3 (mag3)
292-296 F5.2 mag mag4 ?=99.0 Apparent magnitude in the
band 4 (mag4)
298-302 F5.2 mag mag5 ?=99.0 Apparent magnitude in the
band 5 (mag5)
304-308 F5.2 mag mag6 ?=99.0 Apparent magnitude in the
band 6 (mag6)
310-314 F5.2 mag mag7 ?=99.0 Apparent magnitude in the
band 7 (mag7)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- GroupID Group identifier number (GroupID)
6 I1 --- Size Number of available spectra (GroupSize)
8- 16 I9 --- ObsID Observation ID unique for each spectrum
(obsid)
18- 23 F6.2 --- S/Ng Signal to Noise ratio in g band (snrg)
25- 33 F9.2 K Teff ?=- Effective temperature (teff)
35- 42 F8.2 K e_Teff ?=- Mean uncertainty of Teff (e_teff)
44- 48 F5.2 [cm/s2] logg ?=- Surface gravity (logg)
50- 53 F4.2 [cm/s2] e_logg ?=- Mean uncertainty of logg (e_logg)
55- 62 F8.6 Msun M* ?=- Estimated mass (mass)
64- 73 F10.8 Msun e_M* ?=- Mean uncertainty of M* (e_mass)
75- 86 E12.8 yr tcool ?=- White dwarf cooling age (age)
88- 99 E12.8 yr e_tcool ?=- Mean uncertainty of tcool (e_age)
101-107 F7.4 mas Plx ?=- Absolute stellar parallax from Gaia DR2
(parallax)
109-114 F6.4 mas e_Plx ?=- Mean uncertainty of Plx from Gaia DR2
(parallax_error)
116-123 F8.3 mas/yr pmRA ?=- Proper motion in right ascension
direction pmRA*cosDE from Gaia DR2 (pmra)
125-129 F5.3 mas/yr e_pmRA ?=- Mean uncertainty of pmRA (pmra_error)
131-138 F8.3 mas/yr pmDE ?=- Proper motion in declination direction
pmdec from Gaia DR2 (pmdec)
140-144 F5.3 mas/yr e_pmDE ?=- Mean uncertainty of pmDE (pmdec_error)
146-154 F9.6 mag Gmag ?=- G-band mean magnitude (Vega)
(photgmean_mag)
156-167 A12 --- SpType Classification of spectral types
from this work (type)
169-179 F11.7 deg RAdeg Fiber pointing right ascension
(ra_obs) (J2000)
181-190 F10.7 deg DEdeg Fiber pointing declination
(dec_obs) (J2000)
192-234 A43 --- FileName Unique ID for each LAMOST spectrum
fits name (fits)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 I9 --- ObsID Observation ID unique for each spectrum
(obsid)
11- 29 A19 --- Name Object name designation as
JHHMMSS.SS±DDMMSS.S (designation) (G1)
31- 40 A10 "Y:M:D" Date Target observation date (obsdate)
42- 46 I5 d LMJD Local modified Julian Day (lmjd)
48- 52 I5 d MJD Modified Julian date (mjd)
54- 71 A18 --- PlanID Plan ID (planid)
73- 74 I2 --- SpID Spectrograph ID (spid)
76- 78 I3 --- FiberID Fiber ID (fiberid)
80- 90 F11.7 deg RAdeg Fiber pointing right ascension
(ra_obs) (J2000)
92-101 F10.7 deg DEdeg Fiber pointing declination (dec_obs) (J2000)
103-107 F5.2 --- S/Nu Signal to Noise ratio in u band (snru)
109-114 F6.2 --- S/Ng Signal to Noise ratio in g band (snrg)
116-121 F6.2 --- S/Nr Signal to Noise ratio in r band (snrr)
123-128 F6.2 --- S/Ni Signal to Noise ratio in i band (snri)
130-135 F6.2 --- S/Nz Signal to Noise ratio in z band (snrz)
137-144 A8 --- Type Object type by Pipeline (objtype)
146-152 A7 --- Class Spectra type by Pipeline (class)
154-163 A10 --- SubClass Stellar sub-class by Pipeline (subclass)
165-176 E12.8 --- z ?=-9999.0 Spectroscopic redshift (z)
178-188 E11.7 --- e_z ?=-9999.0 Mean error on z (z_err)
190-191 A2 --- MagType1 Target Magnitude type 1 available
(magtype) (G2)
193 A1 --- MagType2 Target Magnitude type 2 available
(magtype) (G2)
195 A1 --- MagType3 Target Magnitude type 3 available
(magtype) (G2)
197 A1 --- MagType4 Target Magnitude type 4 available
(magtype) (G2)
199 A1 --- MagType5 Target Magnitude type 5 available
(magtype) (G2)
201-203 A3 --- MagType6 Target Magnitude type 6 available
(magtype) (G2)
205-206 A2 --- MagType7 Target Magnitude type 7 available
(magtype) (G2)
208-212 F5.2 mag mag1 ?=99.0 Apparent magnitude in the band 1
(mag1)
214-218 F5.2 mag mag2 ?=99.0 Apparent magnitude in the band 2
(mag2)
220-224 F5.2 mag mag3 ?=99.0 Apparent magnitude in the band 3
(mag3)
226-230 F5.2 mag mag4 ?=99.0 Apparent magnitude in the band 4
(mag4)
232-236 F5.2 mag mag5 ?=99.0 Apparent magnitude in the band 5
(mag5)
238-242 F5.2 mag mag6 ?=99.0 Apparent magnitude in the band 6
(mag6)
244-248 F5.2 mag mag7 ?=99.0 Apparent magnitude in the band 7
(mag7)
250-292 A43 --- FileName Unique ID for each LAMOST spectrum fits name
(fits)
294-299 A6 --- NType New updated types (type)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 I9 --- ObsID Observation ID unique for each spectrum
(obsid)
11- 29 A19 --- Name Object name designation as
JHHMMSS.SS±DDMMSS.S (designation) (G1)
31- 40 A10 "Y:M:D" Date Target observation date (obsdate)
42- 46 I5 d LMJD Local modified Julian Day (lmjd)
48- 52 I5 d MJD Modified Julian date (mjd)
54- 73 A20 --- PlanID Plan ID (planid)
75- 76 I2 --- SpID Spectrograph ID (spid)
78- 80 I3 --- FiberID Fiber ID (fiberid)
82- 92 F11.7 deg RAdeg Fiber pointing right ascension
(ra_obs) (J2000)
94-103 F10.7 deg DEdeg Fiber pointing declination (dec_obs) (J2000)
105-109 F5.2 --- S/Nu Signal to Noise ratio in u band (snru)
111-116 F6.2 --- S/Ng Signal to Noise ratio in g band (snrg)
118-123 F6.2 --- S/Nr Signal to Noise ratio in r band (snrr)
125-130 F6.2 --- S/Ni Signal to Noise ratio in i band (snri)
132-137 F6.2 --- S/Nz Signal to Noise ratio in z band (snrz)
139-147 A9 --- Type Object type by Pipeline (objtype)
149-155 A7 --- Class Spectra type by Pipeline (class)
157-166 A10 --- SubClass Stellar sub-class by Pipeline (subclass)
168-178 E11.8 --- z ?=-9999.0 Spectroscopic redshift (z)
180-189 E10.8 --- e_z ?=-9999.0 Mean error on z (z_err)
191-195 A5 --- MagType1 Target Magnitude type 1 available
(magtype) (G2)
197-198 A2 --- MagType2 Target Magnitude type 2 available
(magtype) (G2)
200-201 A2 --- MagType3 Target Magnitude type 3 available
(magtype) (G2)
203 A1 --- MagType4 Target Magnitude type 4 available
(magtype) (G2)
205 A1 --- MagType5 Target Magnitude type 5 available
(magtype) (G2)
207-209 A3 --- MagType6 Target Magnitude type 6 available
(magtype) (G2)
211-212 A2 --- MagType7 Target Magnitude type 7 available
(magtype) (G2)
214-218 F5.2 mag mag1 ?=99.0 Apparent magnitude in the band 1
(mag1)
220-224 F5.2 mag mag2 ?=99.0 Apparent magnitude in the band 2
(mag2)
226-230 F5.2 mag mag3 ?=99.0 Apparent magnitude in the band 3
(mag3)
232-236 F5.2 mag mag4 ?=99.0 Apparent magnitude in the band 4
(mag4)
238-242 F5.2 mag mag5 ?=99.0 Apparent magnitude in the band 5
(mag5)
244-248 F5.2 mag mag6 ?=99.0 Apparent magnitude in the band 6
(mag6)
250-254 F5.2 mag mag7 ?=99.0 Apparent magnitude in the band 7
(mag7)
256-300 A45 --- FileName Unique ID for each LAMOST spectrum fits name
(fits)
302-309 F8.5 --- BP-RP Colour BPmag-RPmag from Gaia DR2
(photBpMeanMag-photRMeanMag) (bp_rp)
311-318 F8.2 K Teff ?=- Effective temperature (teff)
320-324 F5.2 [cm/s2] logg ?=- Surface gravity (logg)
326-333 F8.2 K e_Teff ?=- Mean uncertainty of Teff (e_teff)
335-338 F4.2 [cm/s2] e_logg ?=- Mean uncertainty of logg (e_logg)
340-344 F5.3 Msun M* ?=- Estimated mass (mass)
346-350 F5.3 Msun e_M* ?=- Mean uncertainty of M* (e_mass)
352-362 E11.8 yr tcool ?=- White dwarf cooling age (age)
364-374 E11.8 yr e_tcool ?=- Mean uncertainty of tcool (e_age)
--------------------------------------------------------------------------------
Global notes:
Note (G1): Assigned name for a source by LAMOST, could be slight different for
the same source.
Note (G2): We denote spectral bands as follows:
u = SDSS u band
g = SDSS g band
r = SDSS r band
i = SDSS i band
z = SDSS z band
h = h band infrared
ha = H-alpha band
j = j band infrared
v = v band optical
V = V band optical
w = w band microwave
w12 = w12 band infrared
Kp = Kp band infrared
Fuv = Far ultraviolet band
Uv = Ultraviolet band
B = B band optical
R = R band optical
R1 = R1 band
R2 = R2 band
I = I band infrared
J = J band infrared
F = F band radio
N = N band infrared
MOD = Modulus of distance magnitude
psf_u = SDSS u band magnitude computed with the point spread function
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History:
From electronic version of the journal
(End) Luc Trabelsi [CDS] 19-Sep-2024