TY - GEN
T1 - The origin of high magnetic fields in white dwarfs
AU - Tout, Christopher A.
AU - Wickramasinghe, Dayal T.
AU - Liebert, James
AU - Ferrario, Lilia
AU - Pringle, James E.
PY - 2010
Y1 - 2010
N2 - The lack of evidence for Zeeman splitting of the hydrogen lines in the spectra of the 1,253 close but detached binary systems consisting of a white dwarf and a nondegenerate star, a sample that includes the pre-Cataclysmic Variables, identified in the Sloan Digital Sky Survey indicates that there are no identifiable progenitors for the Magnetic Cataclysmic Variables (MCVs), even though these comprise some 25per cent of all Cataclysmic Variables (CVs). Indeed, all high-field white dwarfs appear to be either single stars or components of AM Her systems. This suggests that all such white dwarfs have a binary origin. We resolve this dilemma by postulating that the 10 6-108G magnetic fields that are observed in the white dwarfs in the MCVs are generated in the common envelope phase of pre-CV evolution in systems which almost merge. Systems that merge in the common envelope phase yield a population of isolated magnetic white dwarfs with fields of 106-109G that make up the entire single magnetic white dwarf population.
AB - The lack of evidence for Zeeman splitting of the hydrogen lines in the spectra of the 1,253 close but detached binary systems consisting of a white dwarf and a nondegenerate star, a sample that includes the pre-Cataclysmic Variables, identified in the Sloan Digital Sky Survey indicates that there are no identifiable progenitors for the Magnetic Cataclysmic Variables (MCVs), even though these comprise some 25per cent of all Cataclysmic Variables (CVs). Indeed, all high-field white dwarfs appear to be either single stars or components of AM Her systems. This suggests that all such white dwarfs have a binary origin. We resolve this dilemma by postulating that the 10 6-108G magnetic fields that are observed in the white dwarfs in the MCVs are generated in the common envelope phase of pre-CV evolution in systems which almost merge. Systems that merge in the common envelope phase yield a population of isolated magnetic white dwarfs with fields of 106-109G that make up the entire single magnetic white dwarf population.
KW - binaries: close
KW - stars: magnetic fields
KW - white dwarfs
UR - http://www.scopus.com/inward/record.url?scp=78751501282&partnerID=8YFLogxK
U2 - 10.1063/1.3536364
DO - 10.1063/1.3536364
M3 - Conference contribution
AN - SCOPUS:78751501282
SN - 9780735408692
T3 - AIP Conference Proceedings
SP - 190
EP - 195
BT - International Conference on Binaries - In Celebration of Ron Webbink's 65th Birthday
T2 - International Conference on Binaries: In Celebration of Ron Webbink's 65th Birthday
Y2 - 22 June 2010 through 25 June 2010
ER -