Eccentricity-pumping in post-AGB stars with circumbinary discs

Dermine, T.; Izzard, Robert G.; Jorissen, A.; Winckel, H. Van

doi:10.1051/0004-6361/201219430

Cited by 90 publications

(113 citation statements)

References 66 publications

Supporting

Mentioning

112

Contrasting

Order By: Relevance

“…In the case of MSPs with the WD companions,it was proposed by Antoniadis (2014) that the disk would form from the material escaping the WD progenitor as it undergoes hydrogen shell flashes prior to entering the WD cooling phase. Dermine et al (2013) and Antoniadis (2014) calculated eccentricity growth driven by tidal coupling of the binary to a non-evolving circumbinary disk with mass~--…”

Section: Introductionmentioning

confidence: 99%

On the Eccentricity Excitation in Post-Main-Sequence Binaries

Rafikov

2016

ApJ

View full text Add to dashboard Cite

Several classes of stellar binaries with post-main-sequence (post-MS) components-millisecond pulsars with the white dwarf companions (MSP+WD) and periods ofP 30 b days, binaries hosting post-asymptotic giant branch stars, or barium stars withP b several years-feature high eccentricities (up to 0.4) despite the expectation of their efficient tidal circularization during their post-MS evolution. It was suggested that the eccentricities of these binaries can be naturally excited by their tidal coupling to the circumbinary disk, formed by the material ejected from the binary. Here we critically reassess this idea using simple arguments rooted in the global angular momentum conservation of the disk+binary system. Compared to previous studies, we (1) fully account for the viscous spreading of the circumbinary disk, (2) consider the possibility of reaccretion from the disk onto the binary (in agreement with simulations and empirical evidence), and (3) allow for the reduced viscosity after the disk expands, cools, and forms dust. These ingredients conspire to significantly lower the efficiency of eccentricity excitation by the disk tides. We find that explaining eccentricities of the post-MS binaries is difficult and requires massive ( - M 10 2 ), long-lived (10 5 years) circumbinary disks that do not reaccrete. While disk tides may account for the eccentricities of the MSP+WD binaries, we show reaccretion to also be detrimental for these systems. Reduced efficiency of the disk-driven excitation motivates thestudy of alternative mechanisms for producing the peculiar eccentricities of the post-MS binaries.

show abstract

Section: Introductionmentioning

confidence: 99%

On the Eccentricity Excitation in Post-Main-Sequence Binaries

Rafikov

2016

ApJ

View full text Add to dashboard Cite

show abstract

“…Post-asymptotic giant branch (post-AGB) stars also represent a challenge to modellers, as their evolution is thought to involve circumbinary disc-orbit interactions (e.g. Dermine et al 2013).…”

Section: Introductionmentioning

confidence: 99%

BINSTAR: a new binary stellar evolution code

Siess

Izzard

Davis

et al. 2013

A&A

Self Cite

View full text Add to dashboard Cite

We provide a detailed description of a new stellar evolution code, BINSTAR, which has been developed to study interacting binaries. Based on the stellar evolution code STAREVOL, it is specifically designed to study low-and intermediate-mass binaries. We describe the state-of-the-art input physics, which includes treatments of tidal interactions, mass transfer and angular momentum exchange within the system. A generalised Henyey method is used to solve simultaneously the stellar structure equations of each component as well as the separation and eccentricity of the orbit. Test simulations for cases A and B mass transfer are presented and compared with available models. The results of the evolution of Algol systems are in remarkable agreement with the calculations of the Vrije Universiteit Brussel (VUB) group, thus validating our code. We also computed a large grid of models for various masses (2 ≤ M/M ≤ 20) and seven metallicities (Z = 0.0001, 0.001, 0.004, 0.008, 0.01, 0.02, 0.03) to provide a useful analytical parameterisation of the tidal torque constant E 2 , which allows the determination of the circularisation and synchronisation timescales for stars with a radiative envelope and convective core. The evolution of E 2 during the main sequence shows noticeable differences compared to available models. In particular, our new calculations indicate that the circularisation timescale is constant during core hydrogen burning. We also show that E 2 weakly depends on core overshooting but is substantially increased when the metallicity becomes lower.

show abstract

“…Barium stars are binaries where a red giant bears signs of contamination by the nuclear-synthetic products (such as barium) by the former AGB companion (now a WD). By adopting the formalism of Lubow & Artymowicz (1996), Dermine et al (2012) explored the binary-disk interaction regime relevant to barium stars and showed that circumbinary disks may play an important role in pumping the eccentricities of barium stars to the observed values.…”

Section: Introductionmentioning

confidence: 99%

Time-resolved spectroscopy of BD+46°442: Gas streams and jet creation in a newly discovered evolved binary with a disk

Gorlova

Winckel

Gielen

et al. 2012

A&A

Self Cite

View full text Add to dashboard Cite

Context. Previous studies have shown that many post-asymptotic giant branch (AGB) stars with dusty disks are associated with single-lined binary stars. The inferred orbital separations are too small to accommodate a fully grown AGB star, hence these systems represent a new evolutionary channel that bypasses a full AGB evolution. Aims. We wish to verify the binarity hypothesis for a larger sample establish the nature of the companions, and probe the disk structure and eventually the disk formation mechanisms in binary stars. To achieve these aims, we started a high-resolution spectral monitoring of ∼40 field giants whose binarity had been suspected based on either a light curve, an infrared excess, or a peculiar chemical composition. Methods. Starting from the spring of 2009, we monitored the programme stars with the fibre echelle spectrometer HERMES. We measure their radial velocities (RVs) with a precision of ∼0.2 km s −1 , perform detailed photospheric abundance analyses, and analyse the time-resolved high-resolution spectra to search for line-profile variability.Results. Here we report on the discovery of periodic RV variations in BD+46 • 442, a high Galactic latitude F giant with a disk. We infer that the variations are caused by the motion around a faint companion, and deduce the orbital parameters P orb = 140.77 ± 0.02 d , e = 0.083± 0.002, and a sin i = 0.31 AU. We find that it is a moderately metal-poor star ([M/H] = −0.7) without a strong depletion pattern in its photospheric abundances. Interestingly, many lines indeed show periodic changes with the orbital phase: Hα switches between a double-peak emission line and a P Cyg-like profile, while strong metal lines appear to be split at the maximum redshift. Similar effects are likely visible in the spectra of other post-AGB binaries, but their regularity is not always apparent owing to sporadic observations. We propose that these features result from an ongoing mass transfer from the evolved giant to the companion. In particular, the blueshifted absorption in Hα, which occurs only at superior conjunction, may result from a jet originating in the accretion disk around the companion and that is seen in absorption towards the luminous primary.

show abstract

Eccentricity-pumping in post-AGB stars with circumbinary discs

Cited by 90 publications

References 66 publications

On the Eccentricity Excitation in Post-Main-Sequence Binaries

On the Eccentricity Excitation in Post-Main-Sequence Binaries

BINSTAR: a new binary stellar evolution code

Time-resolved spectroscopy of BD+46°442: Gas streams and jet creation in a newly discovered evolved binary with a disk

Contact Info

Product

Resources

About