J/MNRAS/484/5362 White dwarf+M dwarf binaries radial velocities (Ashley+, 2019)
Evidence for bimodal orbital separations of white dwarf-red dwarf binary stars.
Ashley R.P., Farihi J., Marsh T.R., Wilson D.J., Gansicke B.T.
<Mon. Not. R. Astron. Soc. 484, 5362 (2019)>
=2019MNRAS.484.5362A 2019MNRAS.484.5362A (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Stars, white dwarf ; Stars, M-type ;
Radial velocities
Keywords: binaries: general - stars: evolution - stars: formation -
stars: low-mass - stars: luminosity function, mass function -
white dwarfs
Abstract:
We present the results of a radial velocity survey of 20 white dwarf
plus M dwarf binaries selected as a follow up to a Hubble Space
Telescope study that aimed to spatially resolve suspected binaries.
Our candidates are taken from the list of targets that were spatially
unresolved with Hubble. We have determined the orbital periods for 16
of these compact binary candidates. The period distribution ranges
from 0.14 to 9.16d and peaks near 0.6d. The original sample therefore
contains two sets of binaries, wide orbits (∼100-1000au) and close
orbits (∼1-10au), with no systems found in the ∼10-100au. This
observational evidence confirms the bimodal distribution predicted by
population models and is also similar to results obtained in previous
studies. We find no binary periods in the months to years range,
supporting the post common envelope evolution scenario. One of our
targets, WD 1504+546, was discovered to be an eclipsing binary with a
period of 0.93d.
Description:
Isaac Newton Telescope, Intermediate Dispersion Spectrograph, Grating
R831R.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 35 20 The targets observed during the campaign.
tableb1.dat 45 416 Measured radial velocities of our targets from a
fit of a double-Gaussian to the NaI doublet
at 8190Å
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See also:
J/AJ/125/2621 : SDSS WD-M binary parameters (Raymond+, 2003)
J/AJ/129/2428 : M dwarf-white dwarf binary systems (Silvestri+, 2005)
J/AJ/131/1674 : Close binary systems from SDSS DR4 (Silvestri+, 2006)
J/AJ/134/741 : New close binary systems from the SDSS DR5 (Silvestri+, 2007)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- WD WD name (HHMM+DDd)
10- 11 I2 h RAh Right ascension (J2000)
13- 14 I2 min RAm Right ascension (J2000)
16- 19 F4.1 s RAs Right ascension (J2000)
21 A1 --- DE- DEclination sign (J2000)
22- 23 I2 deg DEd Declination (J2000)
25- 26 I2 arcmin DEm Declination (J2000)
28- 29 I2 arcsec DEs Declination (J2000)
31- 32 I2 --- Nsp Number of spectra taken (1)
34- 35 I2 --- Nspu Number of usable spectra (2)
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Note (1): For all targets the NaI doublet at 8190Å was observed, with the
exception of WD 2257+162, where we observed the Hα emission from
the secondary.
Note (2): Spectra were deemed unusable if we were unable to fit a profile to
the NaI or Hα feature.
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Byte-by-byte Description of file: tableb1.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- WD WD name
10- 23 F14.6 d HJD Heliocentric Julian date
25- 35 F11.6 km/s RV Radial velocity
37- 45 F9.6 km/s e_RV Radial velocity error
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Acknowledgements:
Richard Ashley, rashley(at)gmail.com
(End) Patricia Vannier [CDS] 26-Nov-2018