J/MNRAS/480/3942 The Gaia 20 pc white dwarf sample (Hollands+, 2018)
The Gaia 20 pc white dwarf sample.
Hollands M.A., Tremblay P.-E., Gansicke B.T., Gentile-Fusillo N.P.,
Toonen S.
<Mon. Not. R. Astron. Soc., 480, 3942-3961 (2018)>
=2018MNRAS.480.3942H 2018MNRAS.480.3942H (SIMBAD/NED BibCode)
ADC_Keywords: HR diagrams ; Magnitudes ; Stars, white dwarf
Keywords: Hertzsprung-Russell and colour-magnitude diagrams -
stars: statistics, white dwarfs
Abstract:
Using Gaia DR2 data, we present an up-to-date sample of white dwarfs
within 20pc of the Sun. In total we identified 139 systems in Gaia
DR2, nine of which are new detections, with the closest of these
located at a distance of 13.05pc. We estimated atmospheric parameters
for all stellar remnants based on the Gaia parallaxes and photometry.
The high precision and completeness of the Gaia astrometry allowed us
to search for wide binary companions. We re-identified all known
binaries where both components have accurate DR2 astrometry, and
established the binarity of one of the nine newly identified white
dwarfs. No new companions were found to previously known 20pc white
dwarfs. Finally, we estimated the local white dwarf space-density to
be (4.49±0.38)x10-3pc-3, having given careful consideration to
the distance-dependent Gaia completeness, which misses known objects
at short distances, but is close to complete for white dwarfs near
20pc.
Description:
With the goal to inspect, and define the local white dwarf cooling
sequence in the Hertzsprung-Russell diagram (HRD), we began by
searching the Gaia DR2 source catalogue for all objects with
parallaxes greater than 40mas, (i.e. D=<25pc), resulting in 9284
objects. We then cross-matched an up-to-date list of 193 confirmed
white dwarfs, based on Toonen et al. (2017A&A...602A..16T 2017A&A...602A..16T) with
revisions from the recent literature, with published distance
estimates that placed them, within uncertainties, within 20pc.
Applying a Gaia parallax cut, plx+3σplx>50, i.e. including
white dwarfs that are within their uncertainties at D<20pc, we
recovered 125 previously known 20pc white dwarfs, indicated by their
WD numbers in Table 1. Additionally, 57 white dwarfs of the 193 were
found to have distances beyond 20pc (Table 2) and 11 stellar remnants
were either absent in Gaia DR2, or did not have full five-parameter
astrometry (Table 4).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 179 139 Astrometric and photometric data for our Gaia
20pc white dwarf sample, as well as the results
from our model atmosphere fits
table2.dat 108 57 White dwarfs previously thought to reside within
20pc that are now confirmed to be outside the
20pc sample
table3.dat 81 6 Rejected white dwarf candidates from our
selection of 20pc sources
table4.dat 80 11 Known white dwarfs within 20pc and potential
20pc members without reliable five-parameter
astrometric solutions
table5.dat 140 46 Wide binaries identified in our 20pc white dwarf
sample
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 h RAh Barycentric right ascension (ICRS) at
Ep=2015.5
4- 5 I2 min RAm Barycentric right ascension (ICRS) at
Ep=2015.5
7- 11 F5.2 s RAs Barycentric right ascension (ICRS) at
Ep=2015.5
13 A1 --- DE- Barycentric declination sign (ICRS) at
Ep=2015.5
14- 15 I2 deg DEd Barycentric declination (ICRS) at Ep=2015.5
17- 18 I2 arcmin DEm Barycentric declination (ICRS) at Ep=2015.5
20- 23 F4.1 arcsec DEs Barycentric declination (ICRS) at Ep=2015.5
25- 37 A13 --- WDName ?=- White Dwarf Name (WD HHMM+DDd.N)
39- 57 I19 --- GaiaDR2 Gaia DR2 ID
59- 64 F6.2 mas plx Parallax (1)
66- 69 F4.2 mas e_plx Error on plx (1)
71- 78 F8.2 mas/yr pmRA Proper motion in Right Ascension (pmRA*cosDE)
80- 83 F4.2 mas/yr e_pmRA Error on pmRA
85- 92 F8.2 mas/yr pmDE Proper motion in Declination
94- 97 F4.2 mas/yr e_pmDE Error on pmDE
99-105 F7.4 mag Gmag Gaia G-band mean magnitude
107-112 F6.4 mag e_Gmag Error on Gmag
114-120 F7.4 mag BPmag Gaia Integrated BP mean magnitude
122-127 F6.4 mag e_BPmag Error on BPmag
129-135 F7.4 mag RPmag Gaia Integrated RP mean magnitude
137-142 F6.4 mag e_RPmag Error on RPmag
144-149 A6 --- SpType ?=- Spectral type
151-154 A4 --- comp ?=- Adopted atmospheric composition used for
our fits to the Gaia photometry and
parallaxes
156-160 I5 K Teff ?=- Effective temperature
162-165 I4 K e_Teff ?=- Error on Teff
167-170 F4.2 [cm/s2] logg ? Surface gravity
172-175 F4.2 [cm/s2] e_logg ? Error on logg
177-179 A3 --- Note ? Note (2)
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Note (1): The parallaxes are given without the 0.03mas offset suggested by
Lindegren et al. (2018A&A...616A...2L 2018A&A...616A...2L, Cat. I/345)
Note (2): Comments as follows:
1 = For our model atmosphere fits, log[H/He]=-1 and -3 were assumed
for WD 0038-226 and WD 2008-600, respectively
2 = Newly identified white dwarf
3 = The photbprpexcessfactor value of 1.661 indicates that the
modelling of the background flux is not good enough to fit the
Gaia fluxes
4 = Known white dwarf, but not previously considered a potential
20pc member
5 = White dwarf candidate recently identified by Smith et al.
(2018MNRAS.474.1826S 2018MNRAS.474.1826S, Cat. II/364) via its proper motion
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 h RAh Barycentric right ascension (ICRS) at Ep=2015.5
4- 5 I2 min RAm Barycentric right ascension (ICRS) at Ep=2015.5
7- 11 F5.2 s RAs Barycentric right ascension (ICRS) at Ep=2015.5
13 A1 --- DE- Barycentric declination sign (ICRS) at
Ep=2015.5
14- 15 I2 deg DEd Barycentric declination (ICRS) at Ep=2015.5
17- 18 I2 arcmin DEm Barycentric declination (ICRS) at Ep=2015.5
20- 23 F4.1 arcsec DEs Barycentric declination (ICRS) at Ep=2015.5
25- 36 A12 --- WDName White Dwarf Name (WD HHMM+DDd.N)
38- 56 I19 --- GaiaDR2 Gaia DR2 ID
58- 63 F6.3 mas plx Parallax (1)
65- 69 F5.3 mas e_plx Error on plx (1)
71- 76 F6.3 pc Dist Distance to the source (1)
78- 82 F5.3 pc e_Dist Error on Dist
84- 88 F5.2 mas plxold ? Previous parallax estimate
90- 94 F5.2 mas e_plxold ? Error on plxold
96-100 F5.2 pc Distold Previous distance estimate
102-105 F4.2 pc e_Distold ? Error on plxold
107-108 I2 --- r_Distold Source of the previous parallax/distance
estimate (2)
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Note (1): The 0.03mas offset (Lindegren et al. 2018A&A...616A...2L 2018A&A...616A...2L) is not
included in the parallax, but is folded into the calculation of
the distance.
Note (2): References as follows:
1 = Limoges et al. (2015ApJS..219...19L 2015ApJS..219...19L, Cat. J/ApJS/219/19)
2 = Gliese & Jahreiss (1991adc..rept.....G, Cat. V/70)
3 = Gianninas et al. (2011ApJ...743..138G 2011ApJ...743..138G, Cat. J/ApJ/743/138)
4 = van Altena, Lee & Hoffleit (1995gcts.book.....V 1995gcts.book.....V, Cat I/238)
5 = Subasavage et al. (2017AJ....154...32S 2017AJ....154...32S, Cat. J/AJ/154/32)
6 = Finch et al. (2018AJ....155..176F 2018AJ....155..176F, Cat. I/344)
7 = Holberg et al. (2016MNRAS.462.2295H 2016MNRAS.462.2295H, Cat. J/MNRAS/462/2295)
8 = Subasavage et al. (2009AJ....137.4547S 2009AJ....137.4547S)
9 = Subasavage et al. (2008AJ....136..899S 2008AJ....136..899S)
10 = van Leeuwen (2007A&A...474..653V 2007A&A...474..653V, Cat. I/311)
11 = Lepine et al. (2009AJ....137.4109L 2009AJ....137.4109L)
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 19 I19 --- GaiaDR2 Gaia DR2 ID
21- 25 F5.2 mas plx Parallax
27- 30 F4.2 mas e_plx Error on plx
32- 37 F6.2 mas/yr pmRA Proper motion in Right Ascension (pmRA*cosDE)
39- 42 F4.2 mas/yr e_pmRA Error on pmRA
44- 50 F7.2 mas/yr pmDE Proper motion in Declination
52- 55 F4.2 mas/yr e_pmDE Error on pmDE
57- 60 F4.2 mas AEM Astrometric excess noise
62- 65 I4 K Teff Effective temperature (1)
67- 69 I3 K e_Teff Error on Teff (1)
71- 74 F4.2 [cm/s2] logg Surface gravity (1)
76- 79 F4.2 [cm/s2] e_logg Error on logg (1)
81 I1 --- n_GaiaDR2 Note on the rejected white dwarf
candidates (2)
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Note (1): The Teff and logg are from our fits to the absolute photometry of
Gaia and where available Pan-STARRS and 2MASS, assuming a white dwarf
with a hydrogen-dominated atmosphere
Note (2): Notes as follows:
1 = Atypically large astrometric noise, low proper motion, and
infrared photometry that is inconsistent with the optical fit
2 = Extremely small proper motion and moderate astrometric noise
3 = Infrared 2MASS photometry suggests a cool main-sequence object.
Furthermore, the low PPMXL proper motion value of
(pmRA, pmDE)=(-5.2, +3.9)±3.8mas/yr is inconsistent
with Gaia DR2
4 = Low proper motion, moderate astrometric noise and low measured
logg assuming a white dwarf. The even lower PPMXL proper motion of
(+3.4, -10.3)±4.0mas/yr is discrepant with Gaia DR2
5 = The proper motion is inconsistent with data from elsewhere calling
into question the accuracy of the parallax. Furthermore, this star
appears very close to a much brighter B-type star
6 = Low proper motion and low logg required to fit the photometry and
parallax. The very low PPMXL proper motion of
(+4.9, -1.6)±7.3mas/yr is inconsistent with Gaia DR2
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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- 12 A12 --- WDName White Dwarf Name (WD HHMM+DDd.N)
14- 27 A14 --- AltName Alternative name
29- 47 I19 --- GaiaDR2 ? Gaia DR2 ID
49- 55 F7.3 mas plx ? Parallax
57- 61 F5.3 mas e_plx ? Error on plx
63- 68 F6.3 pc Dist Distance to the source
70- 74 F5.3 pc e_Dist Error on Dist
76 I1 --- r_Dist Reference of the quoted distance or parallax (1)
78- 80 A3 --- n_GaiaDR2 ? Notes on the reliability of the five-parameter
astrometric solution (2)
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Note (1): References as follows:
1 = Gaia DR2 (companion)
2 = Limoges et al. (2015ApJS..219...19L 2015ApJS..219...19L, Cat. J/ApJS/219/19)
3 = van Altena et al. (1995gcts.book.....V 1995gcts.book.....V, Cat. I/238)
4 = van Leeuwen (2007A&A...474..653V 2007A&A...474..653V, Cat. I/311)
Note (2): Notes as follows:
a = White dwarf does not have DR2 five-parameter astrometry, but
known companion does
b = A full Gaia astrometric solution is listed, but with a parallax
of 11.36±0.23mas and ASTROMETRICEXCESSNOISE>1mas. We do not
rule out that it corresponds to this DA+dM system.
c = Three sources of similar magnitude and no Gaia astrometry at this
position
d = No Gaia detection due to saturation of Procyon A
e = No Gaia detection, noting that the white dwarf has an ∼4arcsec/yr
proper motion
f = Detected with the established proper motion, but with a parallax
of 1.44±0.55mas
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 2 I2 h RAh Barycentric right ascension (ICRS) at Ep=2015.5
4- 5 I2 min RAm Barycentric right ascension (ICRS) at Ep=2015.5
7- 11 F5.2 s RAs Barycentric right ascension (ICRS) at Ep=2015.5
13 A1 --- DE- Barycentric declination sign (ICRS) at
Ep=2015.5
14- 15 I2 deg DEd Barycentric declination (ICRS) at Ep=2015.5
17- 18 I2 arcmin DEm Barycentric declination (ICRS) at Ep=2015.5
20- 23 F4.1 arcsec DEs Barycentric declination (ICRS) at Ep=2015.5
25- 43 I19 --- GaiaDR2 Gaia DR2 ID
45- 50 F6.2 mas plx Parallax
52- 55 F4.2 mas e_plx Error on plx
57- 64 F8.2 mas/yr pmRA Proper motion in Right Ascension (pmRA*cosDE)
66- 69 F4.2 mas/yr e_pmRA Error on pmRA
71- 78 F8.2 mas/yr pmDE Proper motion in Declination
80- 83 F4.2 mas/yr e_pmDE Error on pmDE
85- 91 F7.4 mag GMAG G-band absolute magnitude
93- 98 F6.4 mag e_GMAG Error on GMAG
100-105 F6.3 mag BP-RP Gaia BP-RP colour index
107-111 F5.3 mag e_BP-RP Error on BP-RP
113-120 F8.2 AU Dt ? Projected separation
122-126 F5.2 AU e_Dt ? Error on Dt
128-132 F5.3 km/s Deltavt ? Tangential velocity difference (1)
134-138 F5.3 km/s e_Deltavt ? Error on Deltavt
140 I1 --- n_GaiaDR2 ?=- Notes on the source (2)
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Note (1): The tangential velocity difference is defined by
Δvt=4.7405sqrt(ΔpmRA2+ΔpmDE2)/plx
Note (2): Notes as follows:
1 = Both the white dwarf and companionship are newly identified in
this work
2 = Companion astrometry adversely affected by astrometric noise
3 = Wide double-degenerate system
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History:
From electronic version of the journal
(End) Ana Fiallos [CDS] 25-May-2022