J/ApJ/882/106 DB white dwarfs with SDSS and Gaia data (Genest-Beaulieu+, 2019)
A photometric and spectroscopic investigation of the DB white dwarf population
using SDSS and Gaia data.
Genest-Beaulieu C., Bergeron P.
<Astrophys. J., 882, 106 (2019)>
=2019ApJ...882..106G 2019ApJ...882..106G
ADC_Keywords: Stars, white dwarf; Effective temperatures; Stars, masses;
Abundances; Photometry, SDSS; Spectroscopy; Surveys;
Models, atmosphere
Keywords: stars: evolution ; stars: fundamental parameters ;
techniques: photometric ; techniques: spectroscopic ; white dwarfs
Abstract:
We present a comprehensive analysis of DB white dwarfs drawn from the
Sloan Digital Sky Survey, based on model fits to ugriz photometry and
medium-resolution spectroscopy from the Sloan Digital Sky Survey. We
also take advantage of the exquisite trigonometric parallax
measurements recently obtained by the Gaia mission. Using the
so-called photometric and spectroscopic techniques, we measure the
atmospheric and physical parameters of each object in our sample
(Teff, logg, H/He, Ca/He, R, M), and compare the values obtained from
both techniques in order to assess the precision and accuracy of each
method. We then explore in great detail the surface gravity, stellar
mass, and hydrogen abundance distributions of DB white dwarfs as a
function of effective temperature. We present some clear evidence for
a large population of unresolved double-degenerate binaries composed
of DB+DB and even DB+DA white dwarfs. In the light of our results, we
finally discuss the spectral evolution of DB white dwarfs, in
particular the evolution of the DB-to-DA ratio as a function of Teff,
and we revisit the question of the origin of hydrogen in DBA white
dwarfs.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 85 1915 List of photometric/spectroscopic
atmospheric/physical parameter
table2.dat 63 10 List of DA+DB double degenerate candidates
table3.dat 50 55 List of DB+DB double degenerate candidates
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See also:
B/wd : Spectroscopically identified white dwarfs (McCook+, 2014)
III/210 : Spectroscopically Identified White Dwarfs (McCook+, 1999)
III/235 : Spectroscopically Identified White Dwarfs (McCook+, 2008)
V/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/A+A/363/1040 : DB white dwarfs from the Hamburg/ESO survey (Friedrich+, 2000)
J/ApJS/156/47 : DA WDs from the Palomar Green Survey (Liebert+, 2005)
J/ApJS/167/40 : SDSS4 confirmed white dwarfs catalog (Eisenstein+, 2006)
J/AJ/132/676 : SDSS hot DB white dwarfs (Eisenstein+, 2006)
J/A+A/470/1079 : UVES/VLT spectra of white dwarfs (Voss+, 2007)
J/A+A/505/441 : UVES/VLT spectra of white dwarfs (Koester+, 2009)
J/ApJ/714/1037 : White dwarfs from the Kiso survey (Limoges+, 2010)
J/ApJ/743/138 : Spectroscopic survey of bright WDs (Gianninas+, 2011)
J/ApJ/730/128 : Spectroscopy of DA WD from the SDSS-DR4 (Tremblay+, 2011)
J/ApJS/204/5 : SDSS DR7 white dwarf catalog (Kleinman+, 2013)
J/MNRAS/446/4078 : New white dwarf stars in SDSS DR10 (Kepler+, 2015)
J/A+A/583/A86 : DB white dwarfs in SDSS DR10 and DR12 (Koester+, 2015)
J/MNRAS/455/3413 : White dwarf and subdwarf stars in SDSS DR12 (Kepler+, 2016)
J/ApJ/848/11 : Spectroscopic & photometric analysis of WDs (Bedard+, 2017)
J/PASP/130/H4203 : Spectroscopically confirmed DB white dwarfs (Kong+, 2018)
J/other/RAA/19.88 : DB white dwarfs from the LAMOST DR5 (Kong+, 2019)
J/MNRAS/482/4570 : Gaia DR2 white dwarf candidates (Gentile Fusillo+, 2019)
J/A+A/634/A93 : Limb-darkening coeff. for compact stars (Claret+, 2020)
J/A+A/641/A157 : Limb-darkening coefficients for white dwarfs (Claret+, 2020)
http://www.sdss.org/ : SDSS home page
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 19 A19 --- Name SDSS identifier (HHMMSS.ss+DDMMSS.ss; J2000)
21- 25 I5 K pTeff [8837/52475]? Photometric surface effective
temperature
27- 30 F4.2 [cm/s2] plogg [5.3/9.6]? Log of photometric surface gravity
32- 36 F5.3 Msun pMstar [0.04/1.4]? Photometric stellar mass
38- 42 F5.3 --- sig/pi [0.003/5.4]? σπ/π
44- 48 I5 K sTeff [9727/54438] Spectroscopic surface effective
temperature
50- 54 F5.2 [cm/s2] slogg [6/10.5] Log of spectroscopic surface gravity
56- 61 F6.3 Msun sMstar [-0.2/6.7] Spectroscopic stellar mass
63- 63 A1 --- l_logH Limit flag on logH
66- 71 F6.3 [-] logH [-7.81/-2] log(H/He)
73- 77 F5.2 [-] logCa [-7.5/-6]? log(Ca/He)
79- 83 F5.2 --- SN [1.9/97] Spectroscopic signal-to-noise
85- 85 A1 --- Notes Notes (1)
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Note (1): Note as follows:
1 = Marginal helium lines;
2 = DB+DB unresolved double degenerate candidate (see Table 3);
3 = DA+DB unresolved double degenerate system (see Table 2);
4 = Objects excluded from the analysis.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 19 A19 --- Name SDSS identifier (HHMMSS.ss+DDMMSS.ss; J2000)
21- 21 A1 --- Flag Source flag (1)
23- 27 I5 K pTeff [12620/38700] Photometric surface effective
temperature
29- 32 F4.2 Msun pMstar [0.2/0.7] Photometric stellar mass
35- 39 I5 K sTeff [14110/18870] Spectroscopic surface effective
temperature
41- 44 F4.2 Msun sMstar [0.39/0.91] Spectroscopic stellar mass
46- 51 F6.3 [-] logH [-6.1/-4.5] log(H/He)
53- 57 I5 K TDA [9580/14120] Deconvoluted effective temperature,
component DA
59- 63 I5 K TDB [15260/48810] Deconvoluted effective temperature,
component DB
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Note (1): Source flags as follows:
a = Photometric solution obtained by assuming logg=8.0;
b = The DB and the DA components are both magnetic.
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Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 A19 --- Name SDSS identifier (HHMMSS.ss+DDMMSS.ss; J2000)
21- 21 A1 --- Flag a = based on photometry only
23- 27 I5 K pTeff [12181/31289] Photometric surface
effective temperature
29- 32 F4.2 Msun pMstar [0.2/0.6] Photometric stellar mass
34- 38 I5 K sTeff [12771/35428] Spectroscopic surface
effective temperature
40- 43 F4.2 Msun sMstar [0.3/0.9] Spectroscopic stellar mass
45- 50 F6.3 [-] logH [-6.4/-3.1] log(H/He)
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmnanuelle Perret [CDS] 10-Feb-2021