Mass transfer in white dwarf-neutron star binaries
(2017) In Monthly Notices of the Royal Astronomical Society 467(3). p.3556-3575- Abstract
- We perform hydrodynamic simulations of mass transfer in binaries that contain a white dwarf and a neutron star (WD-NS binaries), and measure the specific angular momentum of material lost from the binary in disc winds. By incorporating our results within a long-term evolution model, we measure the long-term stability of mass transfer in these binaries. We find that only binaries containing helium white dwarfs (WDs) with masses less than a critical mass of M-WD, (crit) = 0.2 M-circle dot undergo stable mass transfer and evolve into ultracompact X-ray binaries. Systems with higher mass WDs experience unstable mass transfer, which leads to tidal disruption of the WD. Our low critical mass compared to the standard jet-only model of mass-loss... (More)
- We perform hydrodynamic simulations of mass transfer in binaries that contain a white dwarf and a neutron star (WD-NS binaries), and measure the specific angular momentum of material lost from the binary in disc winds. By incorporating our results within a long-term evolution model, we measure the long-term stability of mass transfer in these binaries. We find that only binaries containing helium white dwarfs (WDs) with masses less than a critical mass of M-WD, (crit) = 0.2 M-circle dot undergo stable mass transfer and evolve into ultracompact X-ray binaries. Systems with higher mass WDs experience unstable mass transfer, which leads to tidal disruption of the WD. Our low critical mass compared to the standard jet-only model of mass-loss arises from the efficient removal of angular momentum in the mechanical disc winds, which develop at highly super-Eddington mass-transfer rates. We find that the eccentricities expected for WD-NS binaries when they come into contact do not affect the loss of angular momentum, and can only affect the long-term evolution if they change on shorter time-scales than the mass-transfer rate. Our results are broadly consistent with the observed numbers of both ultracompact X-ray binaries and radio pulsars with WD companions. The observed calcium-rich gap transients are consistent with the merger rate of unstable systems with higher mass WDs. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/9f4d026e-425e-41e7-8dfa-8f8b2abfccff
- author
- Bobrick, Alexey
LU
; Davies, Melvyn B. LU and Church, Ross P. LU
- organization
- publishing date
- 2017-06-01
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- hydrodynamics, methods: numerical, binaries: close, stars: neutron, white dwarfs
- in
- Monthly Notices of the Royal Astronomical Society
- volume
- 467
- issue
- 3
- pages
- 20 pages
- publisher
- Oxford University Press
- external identifiers
-
- scopus:85039170078
- ISSN
- 0035-8711
- DOI
- 10.1093/mnras/stx312
- project
- Interacting Giants and Compact Stars
- language
- English
- LU publication?
- yes
- id
- 9f4d026e-425e-41e7-8dfa-8f8b2abfccff
- date added to LUP
- 2018-09-27 19:58:52
- date last changed
- 2024-04-15 12:15:07
@article{9f4d026e-425e-41e7-8dfa-8f8b2abfccff, abstract = {{We perform hydrodynamic simulations of mass transfer in binaries that contain a white dwarf and a neutron star (WD-NS binaries), and measure the specific angular momentum of material lost from the binary in disc winds. By incorporating our results within a long-term evolution model, we measure the long-term stability of mass transfer in these binaries. We find that only binaries containing helium white dwarfs (WDs) with masses less than a critical mass of M-WD, (crit) = 0.2 M-circle dot undergo stable mass transfer and evolve into ultracompact X-ray binaries. Systems with higher mass WDs experience unstable mass transfer, which leads to tidal disruption of the WD. Our low critical mass compared to the standard jet-only model of mass-loss arises from the efficient removal of angular momentum in the mechanical disc winds, which develop at highly super-Eddington mass-transfer rates. We find that the eccentricities expected for WD-NS binaries when they come into contact do not affect the loss of angular momentum, and can only affect the long-term evolution if they change on shorter time-scales than the mass-transfer rate. Our results are broadly consistent with the observed numbers of both ultracompact X-ray binaries and radio pulsars with WD companions. The observed calcium-rich gap transients are consistent with the merger rate of unstable systems with higher mass WDs.}}, author = {{Bobrick, Alexey and Davies, Melvyn B. and Church, Ross P.}}, issn = {{0035-8711}}, keywords = {{hydrodynamics; methods: numerical; binaries: close; stars: neutron; white dwarfs}}, language = {{eng}}, month = {{06}}, number = {{3}}, pages = {{3556--3575}}, publisher = {{Oxford University Press}}, series = {{Monthly Notices of the Royal Astronomical Society}}, title = {{Mass transfer in white dwarf-neutron star binaries}}, url = {{http://dx.doi.org/10.1093/mnras/stx312}}, doi = {{10.1093/mnras/stx312}}, volume = {{467}}, year = {{2017}}, }