Two new Double-lined Spectroscopic Binary White Dwarfs

Abstract

We present radial velocity observations of four binary white dwarf candidates identified through their over-luminosity. We identify two new double-lined spectroscopic binary systems, WD 0311-649 and WD 1606+422, and constrain their orbital parameters. WD 0311-649 is a 17.7 h period system with a mass ratio of $1.44\pm 0.06$ and WD 1606+422 is a 20.1 h period system with a mass ratio of $1.33\pm 0.03$. An additional object, WD 1447-190, is a 43 h period single-lined white dwarf binary, whereas WD 1418-088 does not show any significant velocity variations over timescales ranging from minutes to decades. We present an overview of the 14 over-luminous white dwarfs that were identified by Bedard et al., and find the fraction of double- and single-lined systems to be both 31%. However, an additional 31% of these over-luminous white dwarfs do not show any significant radial velocity variations. We demonstrate that these must be in long-period binaries that may be resolved by Gaia astrometry. We also discuss the over-abundance of single low-mass white dwarfs identified in the SPY survey, and suggest that some of those systems are also likely long period binary systems of more massive white dwarfs.

MNRAS, in press

References in corpus (36)

• Gaia Data Release 2. Summary of the contents and survey properties
• The Pan-STARRS1 Surveys
• Population synthesis for double white dwarfs I.Close detached systems
• Spectroscopic Analysis of DA White Dwarfs: Stark Broadening of Hydrogen Lines Including Non-Ideal Effects
• A Spectroscopic Survey & Analysis of Bright, Hydrogen-Rich White Dwarfs
• Spectroscopic analysis of DA white dwarfs with 3D model atmospheres
• On the Measurement of Fundamental Parameters of White Dwarfs in the Gaia Era
• A 12 minute Orbital Period Detached White Dwarf Eclipsing Binary
• General relativistic orbital decay in a seven-minute-orbital-period eclipsing binary system
• Search for progenitors of supnernovae type Ia with SPY
• The ELM Survey. VII. Orbital Properties of Low Mass White Dwarf Binaries
• Measurements of Physical Parameters of White Dwarfs: A Test of the Mass-Radius Relation
• Binaries discovered by the SPY project. IV. Five single-lined DA double white dwarfs
• Formation of Extremely Low-mass White Dwarfs in Double Degenerates
• The ESO supernovae type Ia progenitor survey (SPY)
• A New Generation of Cool White Dwarf Atmosphere Models. IV. Revisiting the Spectral Evolution of Cool White Dwarfs
• Discovery of the Eclipsing Detached Double White Dwarf Binary NLTT 11748
• The Discovery of a Short Period Double-Degenerate Binary Star
• A detached double degenerate with a 1.4 hr orbital period
• Six detached white-dwarf close binaries
• Weighing the Darkness: Astrometric Mass Measurement of Hidden Stellar Companions using Gaia
• The Solar Neighborhood. XXXIX. Parallax Results from the CTIOPI and NOFS Programs: 50 New Members of the 25 Parsec White Dwarf Sample
• WD1953-011 - a magnetic white dwarf with peculiar field structure
• Precise parameters for both white dwarfs in the eclipsing binary CSS 41177
• Binaries discovered by the SPY project. II. HE 1414-0848: a double degenerate with a mass close to the Chandrasekhar limit
• The mass ratio distribution of short period double degenerate stars
• SDSS J1152+0248: An eclipsing double white dwarf from the Kepler K2 campaign
• Binaries discovered by the SPY project. III. HE2209-1444: a massive, short period double degenerate
• Discovery of a Detached, Eclipsing 40 min Period Double White Dwarf Binary and a Friend: Implications for He+CO White Dwarf Mergers
• Orbital periods and component masses of three double white dwarfs
• Very Low Mass Stellar and Substellar Companions to Solar-Like Stars From MARVELS V: A Low Eccentricity Brown Dwarf from the Driest Part of the Desert, MARVELS-6b
• The Mass Distribution of Companions to Low-Mass White Dwarfs
• A New Merging Double Degenerate Binary in the Solar Neighborhood
• Mass-ratio distribution of extremely low-mass white dwarf binaries
• The Binary White Dwarf LHS 3236
• Searching for new white dwarf pulsators for TESS observations at Konkoly Observatory

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• The 100 pc White Dwarf Sample in the SDSS Footprint
• The 40 pc sample of white dwarfs from Gaia
• $\text{Gaia}$ white dwarfs within 40 pc III: spectroscopic observations of new candidates in the southern hemisphere
• The ELM Survey South. II. Two dozen new low mass white dwarf binaries
• wdwarfdate: A Python Package to Derive Bayesian Ages of White Dwarfs
• A 1201 s Orbital Period Detached Binary: the First Double Helium Core White Dwarf LISA Verification Binary
• Hidden in Plain Sight: A Double-lined White Dwarf Binary 26 pc Away and a Distant Cousin
• The Discovery of Two LISA Sources within 0.5 kpc
• A 99-minute Double-lined White Dwarf Binary from SDSS-V
• The first phase of mass transfer in low-mass binaries: neither stable nor a common envelope
• Precise Parameters for Two LISA Sources
• Studying the black widow pulsars PSR J0312$-$0921 and PSR J1627$+$3219 in the optical and X-rays
• A new code for low-resolution spectral identification of white dwarf binary candidates