J/MNRAS/482/4570 Gaia DR2 white dwarf candidates (Gentile Fusillo+, 2019)
A Gaia Data Release 2 catalogue of white dwarfs and a comparison with SDSS.
Gentile Fusillo N.P., Tremblay P-E, Gaensicke B.T., Manser C.J.,
Cunningham T., Cukanovaite E., Hollands M., Marsh T., Raddi R.,
Jordan S., Toonen S., Geier S., Barstow M., Cummings J.D.
<Mon. Not. R. Astron. Soc. 482, 4570-4591 (2019)>
=2019MNRAS.482.4570G 2019MNRAS.482.4570G (SIMBAD/NED BibCode)
ADC_Keywords: Surveys ; Stars, white dwarf ; Parallaxes, trigonometric;
Photometry
Keywords: catalogues - surveys - white dwarfs
Abstract:
We present a catalogue of white dwarf candidates selected from the
second data release of Gaia (DR2). We used a sample of
spectroscopically confirmed white dwarfs from the Sloan Digital Sky
Survey (SDSS) to map the entire space spanned by these objects in the
Gaia Hertzsprung-Russell diagram.
We then defined a set of cuts in absolute magnitude, colour, and a
number of Gaia quality flags to remove the majority of contaminating
objects. Finally, we adopt a method analogous to the one presented in
our earlier SDSS photometric catalogues to calculate a probability of
being a white dwarf (PWD) for all Gaia sources which passed the
initial selection. The final catalogue is composed of 486641 stars
with calculated PWD from which it is possible to select a sample
of∼260000 high-confidence white dwarf candidates in the magnitude
range 8<G<21. By comparing this catalogue with a sample of SDSS white
dwarf candidates we estimate an upper limit in completeness of 85 per
cent for white dwarfs with G≤20mag and Teff>7000K, at high
Galactic latitudes (|b|>20deg). However, the completeness drops at
low Galactic latitudes, and the magnitude limit of the catalogue
varies significantly across the sky as a function of Gaia's scanning
law. We also provide the list of objects within our sample with
available SDSS spectroscopy.
Description:
The main catalogue provides 486,641 stars selected from Gaia DR2 with
calculated probabilities of being a white dwarf (PWD). The PWD values
can used to reliably select high-confidence white dwarf candidates
with a flexible compromise between completeness and level of potential
contamination. As a generic guideline selecting objects with PWD>0.75
recovers 96 per cent of the spectroscopically confirmed white dwarfs
from SDSS and only 1 per cent of the contaminant (non white dwarfs)
objects.
All Gaia sources in the catalogue have also been cross matched with
SDSS DR14 taking into account the difference in epoch of observation
and proper motions. Whether available we include SDSS ugriz
photometry. In a separate table we provide informations on all the
available SDSS spectra for the Gaia sources in the main catalogue.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
gaia2wd.dat 1008 486641 DR2 white dwarf candidates, corrected version
(gaiadr2whitedwarfcandidates.dat)
gaiasdss.dat 344 37259 Available SDSS spectra of candidates, corrected
version (gaia-sdsswhitedwarf_catalogue.dat)
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See also:
B/wd : Spectroscopically identified white dwarfs (McCook+, 2014)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
V/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)
J/MNRAS/465/2849 : Gaia DR1 mass-radius relation of WD (Tremblay+ 2017)
Byte-by-byte Description of file: gaia2wd.dat
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Bytes Format Units Label Explanations
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1- 23 A23 --- WD WD name (WDJHHMMSS.ss+DDMMSS.ss, J2000)
(whitedwarfname)
25- 52 A28 --- DR2Name Unique Gaia source designation (designation)
54- 72 I19 --- Source Unique Gaia source identifier (source_id)
74- 96 F23.19 deg RAdeg Gaia DR2 barycentric right ascension (ICRS)
at epoch J2015.5 (ra)
98- 117 F20.18 mas e_RAdeg Standard error of right ascension (ra_error)
119- 140 E22.18 deg DEdeg Gaia DR2 barycentric declination (ICRS)
at epoch J2015.5 (dec)
142- 161 F20.18 mas e_DEdeg Standard error of declination (dec_error)
163- 183 F21.17 mas Plx Absolute stellar parallax of the source
at J2015.5 (parallax)
185- 204 F20.18 mas e_Plx Standard error of parallax (parallax_error)
206- 227 E22.19 mas/yr pmRA Proper motion in right ascension
(pmRAxcosDE) (pmra)
229- 248 F20.18 mas/yr e_pmRA Standard error of proper motion in
right ascension (pmra_error)
250- 271 E22.19 mas/yr pmDE Proper motion in declination (pmdec)
273- 292 F20.18 mas/yr e_pmDE Standard error of proper motion
in declination (pmdec_error)
294- 315 F22.19 mas epsi Measure of the residuals in the astrometric
solution for the source
(astrometricexcessnoise)
317- 327 F11.9 mas amax Five-dimensional equivalent to the
semi-major axis of the Gaia position error
ellipse (astrometricsigma5dmax)
329- 350 F22.14 e-/s FG Gaia G-band mean flux (photgmean_flux)
352- 374 F23.17 e-/s e_FG Error on G-band mean flux
(photgmeanfluxerror)
376- 385 F10.7 mag Gmag Gaia G-band mean magnitude (Vega scale)
(photgmean_mag)
387- 409 F23.15 e-/s FBP Integrated GBP mean flux (photbpmean_flux)
411- 435 F25.18 e-/s e_FBP Error on GBP-band mean flux
(photbpmeanfluxerror)
437- 446 F10.7 mag BPmag Gaia GBP-band mean magnitude (Vega scale)
(photbpmean_mag)
448- 470 F23.15 e-/s FRP Integrated GRP mean flux (photrpmean_flux)
472- 497 F26.19 e-/s e_FRP Error on GRP-band mean flux
(photrpmeanfluxerror)
499- 508 F10.7 mag RPmag Gaia GRP-band mean magnitude (Vega scale)
(photrpmean_mag)
510- 520 F11.9 --- E(BR/RP) GBP/GRP excess factor estimated from the
comparison of the sum of integrated GBP and
GRP fluxes with respect to the flux in the
G-band (photbprpexcessfactor)
522- 542 E21.19 deg GLON Galactic longitude (l)
544- 565 E22.19 deg GLAT Galactic latitude (b)
567- 578 F12.4 --- Density The number of Gaia sources per square degree
around this object (density)
580- 602 F23.19 mag AG Extinction in the Gaia G-band band derived
from E(B-V) values from Schlafly and
Finkbeiner (2011ApJ...737..103S 2011ApJ...737..103S) (AG)
604- 622 A19 --- SDSS SDSS object name if available
(JHHMMSS,.ss+DDMMSS.s, J2000) (SDSS_name)
624- 641 F18.15 mag umag ? SDSS u band magnitude (umag)
643- 664 F22.18 mag e_umag ? SDSS u band magnitude uncertainty (e_umag)
666- 683 F18.15 mag gmag ? SDSS g band magnitude (gmag)
685- 706 F22.19 mag e_gmag ? SDSS g band magnitude uncertainty (e_gmag)
708- 725 F18.15 mag rmag ? SDSS r band magnitude (rmag)
727- 747 F21.18 mag e_rmag ? SDSS r band magnitude uncertainty (e_rmag)
749- 766 F18.15 mag imag ? SDSS i band magnitude (imag)
768- 789 F22.19 mag e_imag ? SDSS i band magnitude uncertainty (e_imag)
791- 808 F18.15 mag zmag ? SDSS z band magnitude (zmag)
810- 830 F21.18 mag e_zmag ? SDSS z band magnitude uncertainty (e_zmag)
832- 852 E21.19 --- Pwd [0/1]? The probability of being a white
dwarf (Pwd)
854 I1 --- f_Pwd [0/1] If 1 it indicates the PWD value
could be unreliable (Pwd_flag)
856- 868 F13.6 K TeffH ? Effective temperature from fitting the
dereddened G,GBP, and GRP absolute fluxes
with pure-H model atmospheres (Teff_H)
870- 882 F13.6 K e_TeffH ? Uncertainty on Teff_H (eTeff_H)
884- 891 F8.6 --- loggH ? Surface gravity from fitting the
dereddened G,GBP,and GRP absolute fluxes
with pure-H model atmospheres (loggH)
893- 900 E8.6 --- e_loggH ? Uncertainty on loggH (eloggH)
902- 909 F8.6 Msun MassH ? Stellar mass resulting from the adopted
mass-radius relation (mass_H)
911- 919 E9.6 Msun e_MassH ? Uncertainty on the mass (emass_H)
921- 931 E11.6 --- chi2H ? chi2 value of the fit (pure-H) (chi2_H)
933- 944 F12.6 K TeffHe ? Effective temperature from fitting the
dereddened G,GBP, and GRP absolute fluxes
with pure-He model atmospheres (Teff_He)
946- 959 F14.6 K e_TeffHe ? Uncertainty on Teff_He (eTeff_He)
961- 968 F8.6 --- loggHe ? Surface gravity from fitting the
dereddened G,GBP,and GRP absolute fluxes
with pure-He model atmospheres (loggHe)
970- 977 E8.6 --- e_loggHe ? Uncertainty on loggHe (eloggHe)
979- 986 F8.6 Msun MassHe ? Stellar mass resulting from the adopted
mass-radius relation (mass_He)
988- 996 E9.6 Msun e_MassHe ? Uncertainty on the mass (emass_He)
998-1008 E11.6 --- chisqHe ? chi2 value of the fit (pure-H) (chisq_He)
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Byte-by-byte Description of file: gaiasdss.dat
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Bytes Format Units Label Explanations
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1- 22 A22 --- WD WD name (WDJHHMMSS.ss+DDMMSS.ss, J2000)
(whitedwarfname)
23 A1 --- n_WD [a] Multiplicity index on WD
24- 42 I19 --- Source Unique Gaia source identifier (source_id)
44- 62 A19 --- SDSS SDSS object name (JHHMMSS,.ss+DDMMSS.s, J2000)
(SDSS_name)
64- 83 F20.16 deg RAdeg Right ascension (J2000) of the spectrum source
from SDSS DR14 (SDSS_ra)
85- 98 E14.10 deg DEdeg Declination (J2000) of the spectrum source
from SDSS DR14 (SDSS_dec)
100-117 F18.15 mag umag ? SDSS u band magnitude (umag)
119-139 F21.18 mag e_umag ? SDSS u band magnitude uncertainty (e_umag)
141-158 F18.15 mag gmag ? SDSS g band magnitude (gmag)
160-179 F20.18 mag e_gmag ? SDSS g band magnitude uncertainty (e_gmag)
181-198 F18.15 mag rmag ? SDSS r band magnitude (rmag)
200-219 F20.18 mag e_rmag ? SDSS r band magnitude uncertainty (e_rmag)
221-238 F18.15 mag imag ? SDSS i band magnitude (imag)
240-260 F21.18 mag e_imag ? SDSS i band magnitude uncertainty (e_imag)
262-279 F18.15 mag zmag ? SDSS z band magnitude (zmag)
281-301 F21.18 mag e_zmag ? SDSS z band magnitude uncertainty (e_zmag)
303-306 I4 --- Plate Identifier of the plate used in the
observation of the spectrum (Plate)
308-312 I5 --- MJD Modified Julian date of the observation of
the spectrum (mjd)
314-317 I4 --- Fiber Identifier of the fiber used in the
observation of the spectrum (fiberID)
319-333 F15.11 --- S/N Signal-to-noise ratio of the spectrum
calculated in the range 4500-5500 A (S/N)
335-344 A10 --- SpClass Classification of the object based on a visual
inspection of the SDSS spectrum
(spectral_class) (1)
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Note (1): spectral classes are as follows:
CV = Cataclysmic Variable star
DA = white dwarfs with H lines only
DAB/DAB = white dwarfs with H lines and neutral He lines
DABZ/DBAZ/DZAB/DZBA = white dwarfs with H lines, neutral He lines and
Ca H & K lines
DAO/DO = white dwarfs with H lines and He II lines
DAZ/DZA = white dwarfs with H lines and Ca H & K lines
DB = white dwarfs with neutral He lines only
DBZ/DZB = white dwarfs with neutral He lines and Ca H & K lines
DC = white dwarfs with feature-less spectra
DQ = white dwarfs with molecular C absorptions
hotDQ = white dwarfs with atomic C absorption
DQpec = Peculiar white dwarfs with molecular C absorptions
DZ = white dwarfs with Ca H & K lines
DAH = white dwarfs with Zeeman split H lines
DBH = white dwarfs with Zeeman split He lines
DZH = white dwarfs with Zeeman split Ca H & K lines
MWD = Magnetic white dwarfs with unidentified absorption lines
WDPec = Peculiar magnetic white dwarf
PG1159 = Pre-white dwarf star
DB+MS/DA+MS/DC+M = White Dwarf - Main Sequence binary
STAR = non white dwarf stellar object
QSO = Quasar
UNK = Spectra which we were unable to classify
Unreliable = Unreliable spectra
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Acknowledgements:
Nicola Gentile Fusillo, n.gentile-fusillo(at)warwick.ac.uk
History:
* 01-Feb-2019: on-line version
* 01-Apr-2019: corrected version (from author)
(End) Patricia Vannier [CDS] 31-Jan-2019