Parsons, S.G. orcid.org/0000-0002-2695-2654, Gänsicke, B.T., Schreiber, M.R. et al. (5 more authors) (2021) Magnetic white dwarfs in post-common-envelope binaries. Monthly Notices of the Royal Astronomical Society, 502 (3). pp. 4305-4327. ISSN 0035-8711
Abstract
Magnitude-limited samples have shown that 20-25 per cent of cataclysmic variables contain white dwarfs with magnetic fields of Mega Gauss strength, in stark contrast to the approximately 5 per cent of single white dwarfs with similar magnetic field strengths. Moreover, the lack of identifiable progenitor systems for magnetic cataclysmic variables leads to considerable challenges when trying to understand how these systems form and evolve. Here we present a sample of six magnetic white dwarfs in detached binaries with low-mass stellar companions where we have constrained the stellar and binary parameters including, for the first time, reliable mass estimates for these magnetic white dwarfs. We find that they are systematically more massive than non-magnetic white dwarfs in detached binaries. These magnetic white dwarfs generally have cooling ages of more than 1 Gyr and reside in systems that are very close to Roche-lobe filling. Our findings are more consistent with these systems being temporarily detached cataclysmic variables, rather than pre-cataclysmic binaries, but we cannot rule out the latter possibility. We find that these systems can display unusual asymmetric light curves that may offer a way to identify them in larger numbers in future. Seven new candidate magnetic white dwarf systems are also presented, three of which have asymmetric light curves. Finally, we note that several newly identified magnetic systems have archival spectra where there is no clear evidence of magnetism, meaning that these binaries have been previously missed. Nevertheless, there remains a clear lack of younger detached magnetic white dwarf systems.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2021 The Authors. This is an author-produced version of a paper subsequently published in Monthly Notices of the Royal Astronomical Society. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | binaries: close; stars: white dwarfs; stars: late-type; stars: magnetic fields; stars: novae, cataclysmic variables |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > Department of Physics and Astronomy (Sheffield) |
Funding Information: | Funder Grant number Science and Technology Facilities Council ST/R003424/1 |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 15 Feb 2021 07:24 |
Last Modified: | 16 Feb 2022 17:14 |
Status: | Published |
Publisher: | Oxford University Press (OUP) |
Refereed: | Yes |
Identification Number: | 10.1093/mnras/stab284 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:170969 |