Revealing the Nature of Algol Disks through Optical and UV Spectroscopy, Synthetic Spectra, and Tomography of TT Hydrae

Budaj, J.; Richards, Mercedes T.; Koubský, P.; Peters, Geraldine J.

doi:10.1086/510476

Cited by 33 publications

(56 citation statements)

References 36 publications

(84 reference statements)

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“…The mass transfer rate of ≥2 × 10 −10 M yr −1 as found by Miller et al (2007) is, however, five orders of magnitude too low to obtain such a high hot spot temperature. The quoted value of the mass transfer rate would yield a hot spot with a temperature of 1000 K at most: only a little bit higher than the temperature at the edge of the accretion disk.…”

Section: A3 Systems Removed From the Samplementioning

confidence: 72%

Mass loss out of close binaries

Rensbergen

Greve

Mennekens

et al. 2011

A&A

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Context. Several authors have previously introduced liberal evolution of interacting binaries, with the purpose of meeting various observed binary characteristics better than with conservative evolution. Since Algols are eclipsing binaries, the distribution of their orbital periods is known precisely. The distribution of their mass ratios contains, however, more uncertainties. We try to reproduce these two distributions theoretically using a liberal scenario in which the gainer star can lose mass into interstellar space as a consequence of its rapid rotation and the energy of a hot spot. Aims. In a recent paper we calculated the liberal evolution of binaries with a B-type primary at birth where mass transfer starts during core hydrogen burning of the donor. In this paper we include the cases where mass transfer starts during shell hydrogen burning, and it is our aim to reproduce the observed distributions of the system parameters of Algol-type semidetached systems. Methods. Our calculations reveal the amount of time that an Algol binary lives with a well-defined value of mass ratio and orbital period. We used these data to simulate the distribution of mass ratios and orbital periods of Algols. Results. Binaries with a late B-type initial primary hardly lose any mass, whereas those with an early B primary evolve in a nonconservative way. Conservative binary evolution predicts only ∼12% of Algols with a mass ratio q above 0.4. This value is raised up to ∼17% using our scenario of liberal evolution, which is still far below the ∼45% that is observed. Conclusions. Observed orbital periods of Algol binaries longer than one day are faithfully reproduced by our liberal scenario. Mass ratios are reproduced better than with conservative evolution, but the resemblance is still poor.

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Section: A3 Systems Removed From the Samplementioning

confidence: 72%

Mass loss out of close binaries

Rensbergen

Greve

Mennekens

et al. 2011

A&A

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“…The simulations of Miller et al (2007) show that the dominant source of Hα emission in Algols is the disk, while the stream provides a much smaller contribution. A similar situation may be occurring in BD+46 • 442, with the exception that the accreting companion is much fainter than the giant (Fig.…”

Section: Hα Variability In Interacting Binariesmentioning

confidence: 98%

“…The P Cyg-like profile, on the other hand, is a signature of an outflow. It is very rare to find such a broad absorption feature (with velocities up to −300 km s −1 ) in Algols, and it may not be observed in every cycle (Peters 1989;Miller et al 2007). Algols usually display classical and inverse P Cyg-like profiles at a smaller range of velocities just before and after the giant's inferior conjunction, which is explained by the disk eclipse.…”

Section: Hα Variability In Interacting Binariesmentioning

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

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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.

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“…The outer edge temperature of AU Mon is from Djurasevic et al (2010). Other characteristic disk temperatures are from Miller et al (2007) for TT Hya, from Harmanec (2002) and Ak et al (2007) for β Lyr and from Wilson & Caldwell (1978) …”

Section: Observationsmentioning

confidence: 99%

Accretion disks in Algols: Progenitors and evolution

Greve

2016

A&A

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Context. There are only a few Algols with measured accretion disk parameters. These measurements provide additional constraints for tracing the origin of individual systems, narrowing down the initial parameter space. Aims. We investigate the origin and evolution of six Algol systems with accretion disks to find the initial parameters and evolutionary constraints for them. Methods. With a modified binary evolution code, series of close binary evolution are calculated to obtain the best match for observed individual systems. Results. Initial parameters for six Algol systems with accretion disks were determined matching both the present system parameters and the observed disk characteristics. Conclusions. When Roche lobe overflow (RLOF) starts during core hydrogen burning of the donor, the disk lifetime was found to be short. The disk luminosity is comparable to the luminosity of the gainer during a large fraction of the disk lifetime.

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Revealing the Nature of Algol Disks through Optical and UV Spectroscopy, Synthetic Spectra, and Tomography of TT Hydrae

Cited by 33 publications

References 36 publications

Mass loss out of close binaries

Mass loss out of close binaries

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

Accretion disks in Algols: Progenitors and evolution

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