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Mass transfer in eccentric binaries: the new oil-on-water smoothed particle hydrodynamics technique

Church, Ross P.; Dischler, Johann LU ; Davies, Melvyn B LU ; Tout, Christopher A.; Adams, Tim and Beer, Martin E. (2009) In Monthly Notices of the Royal Astronomical Society 395(2). p.1127-1134
Abstract
To measure the onset of mass transfer in eccentric binaries, we have developed a two-phase smoothed particle hydrodynamics (SPH) technique. Mass transfer is important in the evolution of close binaries, and a key issue is to determine the separation at which mass transfer begins. The circular case is well understood and can be treated through the use of the Roche formalism. To treat the eccentric case, we use a newly developed two-phase system. The body of the donor star is made up from high-mass water particles, whilst the atmosphere is modelled with low-mass oil particles. Both sets of particles take part fully in SPH interactions. To test the technique, we model circular mass-transfer binaries containing a 0.6 M-circle dot donor star... (More)
To measure the onset of mass transfer in eccentric binaries, we have developed a two-phase smoothed particle hydrodynamics (SPH) technique. Mass transfer is important in the evolution of close binaries, and a key issue is to determine the separation at which mass transfer begins. The circular case is well understood and can be treated through the use of the Roche formalism. To treat the eccentric case, we use a newly developed two-phase system. The body of the donor star is made up from high-mass water particles, whilst the atmosphere is modelled with low-mass oil particles. Both sets of particles take part fully in SPH interactions. To test the technique, we model circular mass-transfer binaries containing a 0.6 M-circle dot donor star and a 1 M-circle dot white dwarf; such binaries are thought to form cataclysmic variable ( CV) systems. We find that we can reproduce a reasonable CV mass-transfer rate, and that our extended atmosphere gives a separation that is too large by approximately 16 per cent, although its pressure scale height is considerably exaggerated. We use the technique to measure the semimajor axis required for the onset of mass transfer in binaries with a mass ratio of q = 0.6 and a range of eccentricities. Comparing to the value obtained by considering the instantaneous Roche lobe at pericentre, we find that the radius of the star required for mass transfer to begin decreases systematically with increasing eccentricity. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
methods: numerical, hydrodynamics, binaries: close, stars: mass-loss, stars: evolution, X-rays: binaries
in
Monthly Notices of the Royal Astronomical Society
volume
395
issue
2
pages
1127 - 1134
publisher
Wiley-Blackwell
external identifiers
  • wos:000265509500045
  • scopus:65349123532
ISSN
1365-2966
DOI
10.1111/j.1365-2966.2009.14619.x
language
English
LU publication?
yes
id
ba19983b-4d1c-401b-9470-fa71595d7076 (old id 1427872)
date added to LUP
2009-06-25 14:06:11
date last changed
2017-01-01 05:01:37
@article{ba19983b-4d1c-401b-9470-fa71595d7076,
  abstract     = {To measure the onset of mass transfer in eccentric binaries, we have developed a two-phase smoothed particle hydrodynamics (SPH) technique. Mass transfer is important in the evolution of close binaries, and a key issue is to determine the separation at which mass transfer begins. The circular case is well understood and can be treated through the use of the Roche formalism. To treat the eccentric case, we use a newly developed two-phase system. The body of the donor star is made up from high-mass water particles, whilst the atmosphere is modelled with low-mass oil particles. Both sets of particles take part fully in SPH interactions. To test the technique, we model circular mass-transfer binaries containing a 0.6 M-circle dot donor star and a 1 M-circle dot white dwarf; such binaries are thought to form cataclysmic variable ( CV) systems. We find that we can reproduce a reasonable CV mass-transfer rate, and that our extended atmosphere gives a separation that is too large by approximately 16 per cent, although its pressure scale height is considerably exaggerated. We use the technique to measure the semimajor axis required for the onset of mass transfer in binaries with a mass ratio of q = 0.6 and a range of eccentricities. Comparing to the value obtained by considering the instantaneous Roche lobe at pericentre, we find that the radius of the star required for mass transfer to begin decreases systematically with increasing eccentricity.},
  author       = {Church, Ross P. and Dischler, Johann and Davies, Melvyn B and Tout, Christopher A. and Adams, Tim and Beer, Martin E.},
  issn         = {1365-2966},
  keyword      = {methods: numerical,hydrodynamics,binaries: close,stars: mass-loss,stars: evolution,X-rays: binaries},
  language     = {eng},
  number       = {2},
  pages        = {1127--1134},
  publisher    = {Wiley-Blackwell},
  series       = {Monthly Notices of the Royal Astronomical Society},
  title        = {Mass transfer in eccentric binaries: the new oil-on-water smoothed particle hydrodynamics technique},
  url          = {http://dx.doi.org/10.1111/j.1365-2966.2009.14619.x},
  volume       = {395},
  year         = {2009},
}