J/MNRAS/467/1414 Radial velocity changes for 439 white dwarfs (Maoz+, 2017)
The binary fraction, separation distribution and merger rate of white dwarfs
from SPY.
Maoz D., Hallakoun N.
<Mon. Not. R. Astron. Soc. 467, 1414 (2017)>
=2017MNRAS.467.1414M 2017MNRAS.467.1414M (SIMBAD/NED BibCode)
ADC_Keywords: Stars, white dwarf ; Stars, double and multiple ;
Radial velocities
Keywords: binaries: close - binaries: spectroscopic - supernovae: general -
white dwarfs
Abstract:
From a sample of spectra of 439 white dwarfs (WDs) from the ESO-VLT
Supernova-Ia Progenitor Survey (SPY), we measure the maximal changes
in radial velocity (ΔRVmax) between epochs (generally two
epochs, separated by up to 470d), and model the observed ΔRVmax
statistics via Monte Carlo simulations, to constrain the population
characteristics of double WDs (DWDs). The DWD fraction among WDs is
fbin=0.10±0.02 (1σ, random) +0.02 (systematic), in the
separation range ≲4au within which the data are sensitive to
binarity. Assuming the distribution of binary separation, a, is a
power law, dN/da∝aalpha, at the end of the last
common-envelope phase and the start of solely
gravitational-wave-driven binary evolution, the constraint by the data
is alpha=-1.3±0.2(1σ) ±0.2 (systematic). If these parameters
extend to small separations, the implied Galactic WD merger rate per
unit stellar mass is Rmerge=(1-80)x10-13yr-1M[sun-1
(2σ), with a likelihood-weighted mean of
Rmerge=(7±2)x10-13yr-1M☉-1 (1σ). The Milky Way's
specific Type Ia supernova (SN Ia) rate is likely
RIa~=1.1x10-13yr-1M☉-1 and therefore, in terms of
rates, a possibly small fraction of all merging DWDs (e.g. those with
massive-enough primary WDs) could suffice to produce most or all SNe
Ia.
Description:
Table A1 contains parameters for 439 WDs obtained from 926 spectra.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 71 439 Full final WD sample
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Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1 A1 --- Note [*] Note (1)
3- 15 A13 --- Name WD name
17- 18 I2 h RAh Right ascension (J2000)
20- 21 I2 min RAm Right ascension (J2000)
23- 27 F5.2 s RAs Right ascension (J2000)
29 A1 --- DE- Declination sign (J2000)
30- 31 I2 deg DEd Declination (J2000)
33- 34 I2 arcmin DEm Declination (J2000)
36- 39 F4.1 arcsec DEs Declination (J2000)
41- 45 F5.1 d Deltat Epoch separation
47- 51 F5.1 km/s DeltaRVmax Maximum velocity difference between epochs
53- 55 F3.1 km/s sigma Root of the summed squares of the RV errors
of the two individual RV measurements
forming each difference
57- 61 F5.1 --- Nsigma DeltaRVmax/sigma ratio
63- 66 F4.2 Msun M1 Derived mass for the photometric-primary WD
68- 71 A4 --- Com Comments (2)
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Note (1): * for DWD candidates with ΔRVmax>10km/s.
Note (2): Comments as follows:
1 = Double-lined DWD
2 = HE1414-0848: P=0.5178d, M1=0.55M☉, M2=0.71M☉
(Napiwotzki et al., 2002A&A...386...57N 2002A&A...386...57N)
3 = WD0326-273: P=1.8754d, M1=0.51M☉, M2,min=0.59M☉
(Nelemans et al. 2005A&A...440.1087N 2005A&A...440.1087N)
4 = WD1210+140: P=0.64194d, M1=0.23M☉, M2,min=0.38M☉
(Nelemans et al. 2005A&A...440.1087N 2005A&A...440.1087N)
5 = WD0135-052: P=1.553d, M1=0.47M☉, M2=0.52M☉
(Saffer et al. 1988ApJ...334..947S 1988ApJ...334..947S; Bergeron et al. 1989ApJ...345L..91B 1989ApJ...345L..91B)
6 = HE2209-1444: P=0.2769d, M1=0.58M☉, M2=0.58M☉
(Karl et al. 2003A&A...410..663K 2003A&A...410..663K)
7 = WD1824+040: P=6.26600d, M1=0.428M☉, M2,min=0.515M☉
(Morales-Rueda et al. 2005MNRAS.359..648M 2005MNRAS.359..648M)
8 = WD1349+144: P=2.2094d, M1=0.44M☉, M2=0.44M☉
(Karl et al. 2003, NATO ASIB Proc. 105, 43)
9 = HS1102+0934: P=0.55319d, M1=0.46M☉, M2,min=0.55M☉
(Brown et al. 2013ApJ...769...66B 2013ApJ...769...66B)
10 = HE0320-1917: P=0.86492d, M1=0.29M☉, M2,min=0.35M☉
(Nelemans et al. 2005A&A...440.1087N 2005A&A...440.1087N)
11 = WD0032-317: possible 1500 K BD companion, based on weak N=R excess.
12 = WD1013-010: P=0.43653d, M1=0.44M☉, M2,min=0.38M☉
(Nelemans et al. 2005A&A...440.1087N 2005A&A...440.1087N)
13 = HE0516-1804: possible NIR excess indicating a Teff∼3000K companion with
radius ∼0.2R☉
14 = WD1241-010: P=3.34741d, M1=0.31M☉, M2,min=0.373M☉
(Marsh et al. 1995MNRAS.275..828M 1995MNRAS.275..828M)
15 = WD2032+188: P=5.0846d, M1=0.406M☉, M2,min=0.469M☉
(Morales-Rueda et al. 2005MNRAS.359..648M 2005MNRAS.359..648M)
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 15-Nov-2019