J/A+A/496/191 Spectral analysis of 636 SDSS WD-M binaries (Heller+, 2009)
Spectral analysis of 636 white dwarf - M star binaries from the
Sloan Digital Sky Survey.
Heller R., Homeier D., Dreizler S., Oestensen R.
<Astron. Astrophys. 496, 191 (2009)>
=2009A&A...496..191H 2009A&A...496..191H
ADC_Keywords: Binaries, spectroscopic ; Stars, white dwarf ; Stars, M-type
Keywords: binaries: spectroscopic - white dwarfs - stars: late-type -
stars: fundamental parameters - methods: data analysis -
binaries: visual
Abstract:
We present a catalog of 857 WD-M star binaries from the Sloan Digital
Sky Survey (SDSS), most of which were previously identified by other
authors, and the results of our spectral analysis for a subsample of
636 WD-M composite spectra. Our automatic fitting procedure bases on
a chi2 minimization technique, yielding a decomposition of each
combined spectrum and a derivation of independent parameter estimates
for both components. On the respective photometric data from the SDSS,
we also find 41 optically resolved binaries. We also investigated the
spectra for hydrogen and helium emission.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 68 41 Orbital and physical parameters of optically
resolved binaries
table2.dat 127 636 Physical parameters for spectral fits on 636
WD-M binaries
table3.dat 186 857 Coordinates and references to the whole catalog
of 857 objects
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See also:
J/ApJ/607/426 : Catalog of white dwarfs in SDSS-DR1 (Kleinman+, 2004)
J/AJ/131/1674 : Close binary systems from SDSS DR4 (Silvestri+, 2006)
J/ApJS/167/40 : SDSS4 confirmed white dwarfs catalog (Eisenstein+, 2006)
J/MNRAS/382/1377 : SDSS WD main-sequence binaries (Rebassa-Mansergas+, 2007)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- SDSSs Short SDSS name (JHHMM+DDMM)
11 A1 --- n_SDSSs [+] very-low-mass-object candidate (G1)
13- 15 F3.1 arcsec dproj Projected separation of WD and M
17- 20 I4 pc dmean Mean distance of WD and M
22- 25 I4 AU d Projected orbital separation
27- 30 I4 AU dcorr Statistically corrected separation d
32- 35 F4.2 solMass MM Mass of the M component from spectral fit
37- 41 I5 yr P Lower limit for orbital period
43- 48 I6 yr Pcorr Statistically corrected P
50- 68 A19 --- SDSS SDSS long name (JHHMMSS.ss+DDMMSS.s)
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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- 2 A2 --- n_SDSSs [p +*] Note on the binary (G1)
3- 12 A10 --- SDSSs Short SDSS name (JHHMM+DDMM)
13 A1 --- m_SDSSs [AC] Multiplicity index on SDSSs
15 A1 --- u_dWD [?] fit to a fixed Teff=40kK (2)
16 A1 --- l_dWD Limit flag on dWD
17- 22 F6.1 pc dWD Distance of the WD to Earth
25 A1 --- l_dM Limit flag on dM
26- 31 F6.1 pc dM ?=- Distance of the M dwarf to Earth
33 A1 --- u_C [?] fit to a fixed Teff=40kK (2)
34 A1 --- l_C Limit flag on C
35- 40 F6.3 --- C ?=- Distance evaluation coefficient (3)
42 A1 --- u_TeffWD [?] fit to a fixed Teff=40kK (2)
43 A1 --- l_TeffWD Limit flag on TeffWD
44- 50 F7.1 K TeffWD Effective temperature of the WD
52- 57 F6.1 K TeffM Effective temperature of the M dwarf
59- 63 F5.3 solRad radWD Radius of the WD
65 A1 --- l_radM Limit flag on radM
66- 70 F5.3 solRad radM Radius of the M dwarf
72- 74 F3.1 [cm/s2] loggWD Surface gravity of the WD
76- 78 F3.1 [cm/s2] loggM Surface gravity of the M dwarf
80- 82 F3.1 solMass MWD Mass of the WD
84 A1 --- l_MWD Limit flag on MWD
85- 88 F4.2 solMass MM Mass of the M dwarf
90- 93 F4.1 [-] [Fe/H] Metallicity of the M dwarf
95-106 A12 --- Emiss Emission features (4)
108-109 A2 --- WD WD type, DA or DO (5)
111 A1 --- Res [oO*?] Optically resolved (6)
113-116 I4 --- m Nb of data points used from spectrum
118-121 I4 --- DOF Nb of degrees of freedom from the fit
123-127 F5.2 --- Chi2 Chi2 of the fit
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Note (3): As defined in Eq. (16) in the paper:
C = sqrt(2)[(dWD-dM)/(dWD+dM)]
Note (2): For most of the helium-rich white dwarfs (DO) that we fitted to
have an effective temperature of 40000K. Since this temperature is the
lowest of our grid of DO template spectra, it could also be that the
real Teff of that object is smaller than 40kK. Since the WD distances
are derived from the stars' temperatures, we can also only give an
upper limit for dWD for those (?<40000K) objects because lower
temperature would mean that they would have to closer to Earth.
Note (4): Emission features code as follows:
H = Halpha and possibly other Balmer emission
HeI = Helium I emission
HeII = Helium II emission
rm* = WD parameters taken from Rebassa-Mansergas et al. (2007,
Cat. J/MNRAS/382/1377)
Note (5): WD types are:
DA = DA white dwarf (hydrogen-rich),
DO = DO white dwarf (helium-rich)
Note (6): Optically resolved code as follows:
o = Clearly resolved binary with projected angular distance <1.5"
O = Binary components with slight angular separation and without
further treatment
* = Objects separated by >1.5", likely to be not those
represented in the spectrum
? = Photometric data corresponding to the object id not available
in the SDSS database
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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- 10 A10 --- SDSSs Short name (JHHMM+DDMM)
12- 30 A19 --- SDSS SDSS long name (JHHMMSS.ss+DDMMSS.s)
32- 38 A7 --- --- [spSpec-]
39- 52 A14 --- SDSS-sp Spectral plate (SDSS) (1)
53- 56 A4 --- --- [.fit]
58- 71 A14 --- Ref References (2)
73- 81 A9 --- Name ?=- Alternative name (dash when none found)
83-106 A24 --- SName1 Simbad Name (4)
108-111 F4.1 arcsec Off1 ? Offset from target for SName1
113-137 A25 --- SName2 Simbad Name (4)
139-142 F4.1 arcsec Off2 ? Offset from target for SName2
144-168 A25 --- SName3 Simbad Name (4)
170-173 F4.1 arcsec Off3 ? Offset from target for SName3
175-181 A7 --- SName4 Simbad Name (4)
183-186 F4.1 arcsec Off4 ? Offset from target for SName4
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Note (1): Spectral plate on which the object was taken, coded as
mmmmm-pppp-fff, where mmmmm is the Modified Julian Date,
pppp is the plate ID number and fff is the fiber ID number
Note (2): References as follows:
g = Greenstein et al. (1986AJ.....92..867G 1986AJ.....92..867G)
l99b = Luyten (1999, Cat. III/70)
r = Raymond et al. (2003AJ....125.2621R 2003AJ....125.2621R)
kl = Kleinmann et al. (2004, Cat. J/ApJ/607/426)
e = Eisenstein et al. (2006, Cat. J/ApJS/167/40)
h = Huegelmeyer et al. (2006A&A...454..617H 2006A&A...454..617H)
s6 = Silvestri et al. (2006, Cat. J/AJ/131/1674)
s7 = Silvestri et al. (2007AJ....134..741S 2007AJ....134..741S)
rm = Rebassa-Mansergas et al. (2007, Cat. J/MNRAS/382/1377) (non-PCEB)
rm* = Rebassa-Mansergas et al. (2007, Cat. J/MNRAS/382/1377) (PCEB)
Note (4): We have searched SIMBAD for objects closer than 30 arcmin to the
target. Most of the found objects have a distance of order 1arcmin.
Those with much larger distances, which were found in more recent
catalogs, might not be the same objects as the SDSS targets.
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Global Notes:
Note (G1): Notes as follows:
p = Objects mentioned as post-common envelope binary (PCEB) or
PCEB candidates in Rebassa-Mansergas et al. (2007, Cat.
J/MNRAS/382/1377)
+ = M component very-low-mass-object candidate
* = M component probably giant due to the low surface gravity of 3dex
Acknowledgements:
Rene Heller, rheller(at)hs.uni-hamburg.de
History:
* 13-Mar-2009: Original files
* 13-Jul-2010: In table3, 39 long SDSS names corrected
* 14-Jul-2010: In table3, 2 positions and SDSS-sp numbers corrected
(End) Rene Heller [Hamburger Sternwart], Patricia Vannier [CDS] 13-Mar-2009