Solution to the problem of the surface gravity distribution of cool DA white dwarfs from improved 3D model atmospheres

Tremblay, P. E.; Ludwig, H.‐G.; Steffen, M.; Bergeron, P.; Freytag, B.

doi:10.1051/0004-6361/201117310

Cited by 74 publications

(70 citation statements)

References 18 publications

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“…One of the few remaining avenues of research is the computation of full three-dimensional hydrodynamic models of convection as a replacement to the mixing-length theory that has always been used, but ultimately constitutes an approximation. The preliminary results from such computations, as presented by Tremblay et al (2011b), show that these models produce corrections to the values of log g that are of the correct magnitude and direction when compared to shifts deduced from the analysis of large samples of DA white dwarfs. Hence, it seems that the solution to the highlog g problem has finally been nailed down.…”

Section: Mass Distributionmentioning

confidence: 89%

A Spectroscopic Survey and Analysis of Bright, Hydrogen-Rich White Dwarfs

Gianninas¹,

Bergeron²,

Ruíz³

2011

ApJ

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350

477

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We have conducted a spectroscopic survey of over 1300 bright (V ≤ 17.5), hydrogen-rich white dwarfs based largely on the last published version of the McCook & Sion catalog. The complete results from our survey, including the spectroscopic analysis of over 1100 DA white dwarfs, are presented. High signal-to-noise ratio optical spectra were obtained for each star and were subsequently analyzed using our standard spectroscopic technique where the observed Balmer line profiles are compared to synthetic spectra computed from the latest generation of model atmospheres appropriate for these stars. First, we present the spectroscopic content of our sample, which includes many misclassifications as well as several DAB, DAZ, and magnetic white dwarfs. Next, we look at how the new Stark broadening profiles affect the determination of the atmospheric parameters. When necessary, specific models and analysis techniques are used to derive the most accurate atmospheric parameters possible. In particular, we employ M dwarf templates to obtain better estimates of the atmospheric parameters for those white dwarfs that are in DA+dM binary systems. Certain unique white dwarfs and doubledegenerate binary systems are also analyzed in greater detail. We then examine the global properties of our sample including the mass distribution and their distribution as a function of temperature. We then proceed to test the accuracy and robustness of our method by comparing our results to those of other surveys such as SPY and Sloan Digital Sky Survey. Finally, we revisit the ZZ Ceti instability strip and examine how the determination of its empirical boundaries is affected by the latest line profile calculations.

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Section: Mass Distributionmentioning

confidence: 89%

A Spectroscopic Survey and Analysis of Bright, Hydrogen-Rich White Dwarfs

Gianninas¹,

Bergeron²,

Ruíz³

2011

ApJ

Self Cite

350

477

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“…The derived atmospheric parameters place the WD in a regime where convective atmospheric effects are known to produce systematic errors in one-dimensional (1D) model atmospheres (Tremblay et al 2011). Using the numerical estimates of Tremblay et al (2013Tremblay et al ( , 2015, we find that the "true" atmospheric parameters are =  T 8600 190 eff K and =  g log 6.97 0.22 dex.…”

Section: Atmospheric Parametersmentioning

confidence: 92%

An Eccentric Binary Millisecond Pulsar With a Helium White Dwarf Companion in the Galactic Field

Antoniadis

Kaplan

Stovall

et al. 2016

ApJ

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Low-mass white dwarfs (LMWDs) are believed to be exclusive products of binary evolution, as the universe is not old enough to produce them from single stars. Because of the strong tidal forces operating during the binary interaction phase, the remnant systems observed today are expected to have negligible eccentricities. Here, we report on the first unambiguous identification of an LMWD in an eccentric (e=0.13) orbit around the millisecond pulsar PSR J2234+0511, which directly contradicts this picture. We use our spectra and radio-timing solution (derived elsewhere) to infer the WD temperature ( =  T 8600 190 eff K), and peculiar systemic velocity relative to the local standard of rest (31 km s −1). We also place model-independent constraints on the WD radius . The WD and kinematic properties are consistent with the expectations for low-mass X-ray binary evolution and disfavor a dynamic three-body formation channel. In the case of the high eccentricity being the result of a spontaneous phase transition, we infer a mass of ∼1.60 M e for the pulsar progenitor, which is too low for the quark-nova mechanism proposed by Jiang et al., and too high for the scenario of Freire & Tauris, in which a WD collapses into a neutron star via a rotationally delayed accretion-induced collapse. We find that eccentricity pumping via interaction with a circumbinary disk is consistent with our inferred parameters. Finally, we report tentative evidence for pulsations that, if confirmed, would transform the star into an unprecedented laboratory for WD physics.

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“…Given that 1D white dwarf model spectra such as those used in this work yield overestimated surface gravity values for white dwarfs of effective temperatures below ∼12 000 K (e.g. Koester et al 2009;Tremblay et al 2011), we apply the 3D corrections of Tremblay et al (2013) to our effective temperature and surface gravity determinations (we apply the 3D corrections to all SDSS WDMS binaries we identified in previous works too, as these corrections were not available at that time). We then interpolate these values in the updated cooling sequences of Bergeron, Wesemael & Beauchamp (1995) and derive white dwarf masses.…”

Section: S T E L L a R Pa R A M E T E R Smentioning

confidence: 99%

The SDSS spectroscopic catalogue of white dwarf-main-sequence binaries: new identifications from DR 9–12

Rebassa‐Mansergas

Ren

Parsons

et al. 2016

Mon. Not. R. Astron. Soc.

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We present an updated version of the spectroscopic catalogue of white dwarf-main-sequence (WDMS) binaries from the Sloan Digital Sky Survey (SDSS). We identify 938 WDMS binaries within the data releases (DR) 9-12 of SDSS plus 40 objects from DR 1-8 that we missed in our previous works, 646 of which are new. The total number of spectroscopic SDSS WDMS binaries increases to 3294. This is by far the largest and most homogeneous sample of compact binaries currently available. We use a decomposition/fitting routine to derive the stellar parameters of all systems identified here (white dwarf effective temperatures, surface gravities and masses, and secondary star spectral types). The analysis of the corresponding stellar parameter distributions shows that the SDSS WDMS binary population is seriously affected by selection effects. We also measure the Na I λλ 8183.27, 8194.81 absorption doublet and H α emission radial velocities (RV) from all SDSS WDMS binary spectra identified in this work. 98 objects are found to display RV variations, 62 of which are new. The RV data are sufficient enough to estimate the orbital periods of three close binaries.Key words: binaries: close -binaries: spectroscopic -stars: low-mass -white dwarfs. I N T RO D U C T I O NA large fraction of main-sequence stars are found in binary systems (Duquennoy & Mayor 1991;Raghavan et al. 2010;Yuan et al. 2015b). It is expected that ∼25 per cent of all main-sequence binaries are close enough to begin mass transfer interactions when the more massive star becomes a red giant or an asymptotic giant star (Willems & Kolb 2004). This has been observationally verified e.g. by Farihi, Hoard & Wachter (2010) and by Nebot . Because the mass transfer rate generally exceeds the Eddington limit, the secondary star is not able to accrete the transferred material and the system evolves through a common envelope phase. That is, the core of the giant and the main-sequence companion orbit within a common envelope formed by the outer layers of the giant star. Drag forces between the two stars and the envelope lead to the shrinkage of the orbit and therefore to the release E-mail: alberto.rebassa@upc.edu of orbital energy. The orbital energy is deposited into the envelope and is eventually used to eject it (Webbink 2008). The outcome of common envelope evolution is hence a close binary formed by the core of the giant star (which later becomes a white dwarf) and a main-sequence companion, i.e. a close white dwarf-main-sequence (WDMS) binary. These are commonly referred to as post-common envelope binaries (PCEBs). The remaining ∼75 per cent of mainsequence binaries are wide enough to avoid mass transfer interactions. In these cases the more massive stars evolve like single stars until they eventually become white dwarfs. The orbital separations of such WDMS binaries are similar to those of the main-sequence binaries from which they descend.During the last years we have mined the Sloan Digital Sky Survey (SDSS; York et al. 2000) spectroscopic data base to build up th...

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Solution to the problem of the surface gravity distribution of cool DA white dwarfs from improved 3D model atmospheres

Cited by 74 publications

References 18 publications

A Spectroscopic Survey and Analysis of Bright, Hydrogen-Rich White Dwarfs

A Spectroscopic Survey and Analysis of Bright, Hydrogen-Rich White Dwarfs

An Eccentric Binary Millisecond Pulsar With a Helium White Dwarf Companion in the Galactic Field

The SDSS spectroscopic catalogue of white dwarf-main-sequence binaries: new identifications from DR 9–12

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