The Binary Fraction of Low-Mass White Dwarfs

Brown, Justin M.; Kilic, Mukremin; Brown, Warren R.; Kenyon, Scott J.

doi:10.1088/0004-637x/730/2/67

Cited by 62 publications

(55 citation statements)

References 35 publications

(51 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The only estimate of the fraction of single low-mass WDs derived from observations are the < ∼ 20 − 30 per cent of single WDs among low-mass WDs from Brown et al (2011). If combined with the finding from Kepler et al (2007) that low-mass WDs make up 10 per cent of all WDs in the solar neighbourhood, we find good agreement with the model predictions.…”

Section: Resultssupporting

confidence: 72%

“…As a third possibility strong mass loss or spontaneous ejection of the envelope close to the tip of the first giant branch for metal-rich stars has been proposed as an explanation for the existence of single low-mass WDs (Kilic, Stanek & Pinsonneault 2007;Brown et al 2011;Han, Podsiadlowski & Eggleton 1994;Meng, Chen & Han 2008). This scenario is consistent with the colour-magnitude diagram for the metal-rich cluster NGC 6791, which can be explained by a WD population dominated by low-mass WDs (Hansen 2005;Kalirai et al 2007).…”

Section: L2 Zorotovic and Schreibermentioning

confidence: 99%

“…However, while the binary fraction is 100 per cent for extremely lowmass WDs (M WD < 0.25M ⊙ , e.g. Brown et al 2010), there exists a population of single low-mass WDs with masses ⋆ E-mail: mzorotovic@dfa.uv.cl (MZ) 0.25M ⊙ < M WD < 0.50M ⊙ which makes up < ∼ 20 − 30 per cent of all low-mass WDs (Brown et al 2011). Combined with the fraction of low-mass WDs in the solar neighbourhood of ∼ 10 per cent (Kepler et al 2007), we estimate that < ∼ 2 − 3 per cent of all WDs are single low-mass WDs.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The origin of single low-mass WDs: another problem that consequential angular momentum loss in CVs might solve

Zorotovic¹,

Schreiber²

2016

Monthly Notices of the Royal Astronomical Society: Letters

View full text Add to dashboard Cite

Low-mass helium-core white-dwarfs (WDs) with masses below 0.5M ⊙ are known to be formed in binary star systems but unexpectedly a significant fraction of them seem to be single. On the other hand, in Cataclysmic Variables (CVs) a large number of low-mass WD primary stars is predicted but not observed. We recently showed that the latter problem can be solved if consequential angular momentum loss causes especially CVs with low-mass WDs to merge and form single stars. Here we simulate the population of single WDs resulting from single star evolution and from binary star mergers taking into account these new merging CVs. We show that according to the revised model of CV evolution, merging CVs might be the dominant channel leading to the formation of low-mass single WDs and that the predicted relative numbers are consistent with observations. This can be interpreted as further evidence for the revised model of CV evolution we recently suggested. This model includes consequential angular momentum loss that increases with decreasing WD mass and might not only explain the absence of low-mass WD primaries in CVs but also the existence of single low-mass WDs.

show abstract

Section: Resultssupporting

confidence: 72%

Section: L2 Zorotovic and Schreibermentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The origin of single low-mass WDs: another problem that consequential angular momentum loss in CVs might solve

Zorotovic¹,

Schreiber²

2016

Monthly Notices of the Royal Astronomical Society: Letters

View full text Add to dashboard Cite

show abstract

“…We compiled a list of 48 non-SDSS PCEBs containing a white dwarf plus a main sequence star from Ritter & Kolb (2003, version v7.14) and Brown et al (2011). The orbital period distribution of non-SDSS PCEBs (Fig.…”

Section: Comparison With Non Sdss Pcebsmentioning

confidence: 99%

Post common envelope binaries from SDSS

Gómez‐Morán

Gänsicke

Schreiber

et al. 2011

A&A

130

113

View full text Add to dashboard Cite

Context. The complexity of the common-envelope phase and of magnetic stellar wind braking currently limits our understanding of close binary evolution. Because of their intrinsically simple structure, observational population studies of white dwarf plus main sequence (WDMS) binaries can potentially test theoretical models and constrain their parameters. Aims. The Sloan Digital Sky Survey (SDSS) has provided a large and homogeneously selected sample of WDMS binaries, which we characterise in terms of orbital and stellar parameters. Methods. We have obtained radial velocity information for 385 WDMS binaries from follow-up spectroscopy and for an additional 861 systems from the SDSS subspectra. Radial velocity variations identify 191 of these WDMS binaries as post common-envelope binaries (PCEBs). Orbital periods of 58 PCEBs were subsequently measured, predominantly from time-resolved spectroscopy, bringing the total number of SDSS PCEBs with orbital parameters to 79. Observational biases inherent to this PCEB sample were evaluated through extensive Monte Carlo simulations. Results. We find that 21-24% of all SDSS WDMS binaries have undergone common-envelope evolution, which is in good agreement with published binary population models and high-resolution HST imaging of WDMS binaries unresolved from the ground. The bias-corrected orbital period distribution of PCEBs ranges from 1.9 h to 4.3 d and approximately follows a normal distribution in log(P orb ), peaking at ∼10.3 h. There is no observational evidence for a significant population of PCEBs with periods in the range of days to weeks. Conclusions. The large and homogeneous sample of SDSS WDMS binaries provides the means to test fundamental predictions of binary population models, hence to observationally constrain the evolution of all close compact binaries.

show abstract

“…Many short-period systems go through one or two common-envelope phases and evolve into systems containing low-mass WDs. Indeed, radial velocity surveys of low-mass, He-core WDs (M < 0.45 M ) indicate that most form in binary systems (Marsh et al 1995;Brown et al 2011a). The lower mass WDs are predicted to be larger in radius than their more massive counterparts.…”

Section: Introductionmentioning

confidence: 99%

Two New Tidally Distorted White Dwarfs

Hermes

Kilic

Brown

et al. 2012

ApJ

Self Cite

View full text Add to dashboard Cite

We identify two new tidally distorted white dwarfs (WDs), SDSS J174140. 49+652638.7 and J211921.96−001825.8 (hereafter J1741 and J2119). Both stars are extremely low mass (ELM, 0.2 M ) WDs in short-period, detached binary systems. High-speed photometric observations obtained at the McDonald Observatory reveal ellipsoidal variations and Doppler beaming in both systems; J1741, with a minimum companion mass of 1.1 M , has one of the strongest Doppler beaming signals ever observed in a binary system (0.59% ± 0.06% amplitude). We use the observed ellipsoidal variations to constrain the radius of each WD. For J1741, the star's radius must exceed 0.074 R . For J2119, the radius exceeds 0.10 R . These indirect radius measurements are comparable to the radius measurements for the bloated WD companions to A-stars found by the Kepler spacecraft, and they constitute some of the largest radii inferred for any WD. Surprisingly, J1741 also appears to show a 0.23% ± 0.06% reflection effect, and we discuss possible sources for this excess heating. Both J1741 and J2119 are strong gravitational wave sources, and the time-of-minimum of the ellipsoidal variations can be used to detect the orbital period decay. This may be possible on a timescale of a decade or less.

show abstract

The Binary Fraction of Low-Mass White Dwarfs

Cited by 62 publications

References 35 publications

The origin of single low-mass WDs: another problem that consequential angular momentum loss in CVs might solve

The origin of single low-mass WDs: another problem that consequential angular momentum loss in CVs might solve

Post common envelope binaries from SDSS

Two New Tidally Distorted White Dwarfs

Contact Info

Product

Resources

About