On the incidence of weak magnetic fields in DA white dwarfs

@article{Landstreet2012OnTI,
  title={On the incidence of weak magnetic fields in DA white dwarfs},
  author={John D Landstreet and S Bagnulo and G. Valyavin and Luca Fossati and Stefan Jordan and Dmitry Monin and Gregg A. Wade},
  journal={Astronomy and Astrophysics},
  year={2012},
  volume={545}
}
Context. About 10 % of white dwarfs have magnetic fields with strength i n the range between about 10 5 and 5 10 8 G. It is not known whether the remaining white dwarfs are not magnetic, or if they have magnetic fields too weak to be detected with the techni ques adopted in the large surveys. Information is particularly l acking for the cooler (and generally fainter) white dwarfs. Aims. We describe the results of the first survey specifically devis ed to clarify the detection frequency of kG… Expand

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References

SHOWING 1-10 OF 24 REFERENCES
The Fraction of DA White Dwarfs with Kilo-Gauss Magnetic Fields
Context. Weak magnetic fields have been searched for on only a small number of white dwarfs. Current estimates find that about 10% of all white dwarfs have fields in excess of 1 MG; according toExpand
A search for kilogauss magnetic fields in white dwarfs and hot subdwarf stars
We present new results of a survey for weak magnetic fields among DA white dwarfs, including some brighter hot subdwarf stars. We have detected variable circular polarization in the Hα line of theExpand
Discovery of kilogauss magnetic fields in three DA white dwarfs
We have detected longitudinal magnetic fields between 2 and 4 kG in three (WD 0446−790, WD 1105−048, WD 2359−434) out of a sample of 12 normal DA white dwarfs by using optical spectropolarimetry doneExpand
A study of high proper-motion white dwarfs – I. Spectropolarimetry of a cool hydrogen-rich sample†
We conducted a spectropolarimetic survey of 58 high proper-motion white dwarfs which achieved uncertainties of >rsim 2 kG in the Hα line and >rsim 5 kG in the upper Balmer line series. The surveyExpand
Analysis of hydrogen-rich magnetic white dwarfs detected in the Sloan Digital Sky Survey
Context A large number of magnetic white dwarfs discovered in the SDSS have so far only been analyzed by visual comparison of the observations with relatively simple models of the radiationExpand
Magnetic fields and rotation of the white dwarfs 40 Eri B and WD 0009+501
We describe the results of our magnetometric monitoring of two white dwarfs: 40 Eri B and WD 0009+501. We found periodic variations in the longitudinal magnetic field of 40 Eri B. The fieldExpand
Spectropolarimetric Survey of Hydrogen‐rich White Dwarf Stars
We have conducted a survey of 61 southern white dwarfs searching for magnetic fields using Zeeman spectropolarimetry. Our objective is to obtain a magnetic field distribution for these objects and,Expand
Weak magnetic fields in Ap/Bp stars - Evidence for a dipole field lower limit and a tentative interp
Aims. We investigated a sample of 28 well-known spectroscopically-identified magnetic Ap/Bp stars, with weak, poorly-determined or previously undetected magnetic fields. The aim of this study is toExpand
The Peculiar Magnetic Field Morphology of the White Dwarf WD 1953–011: Evidence for a Large-Scale Magnetic Flux Tube?
We present and interpret new spectropolarimetric observations of the magnetic white dwarf WD 1953–011. Circular polarization and intensity spectra of the Hα spectral line demonstrate the presence ofExpand
SEARCHES FOR MAGNETIC FIELDS IN WHITE DWARFS SINCE BABCOCK
Discoveries of magnetic fields in 26 white dwarfs since 1970 do not negate the basic inference from the work of Babcock - that most of the over 1000 known white dwarfs do not have strong magneticExpand
...
1
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3
...