The True Incidence of Magnetism Among Field White Dwarfs

@article{Liebert2003TheTI,
  title={The True Incidence of Magnetism Among Field White Dwarfs},
  author={James William Liebert and Pierre Bergeron and Jay B. Holberg},
  journal={The Astronomical Journal},
  year={2003},
  volume={125},
  pages={348-353}
}
We study the incidence of magnetism in white dwarfs from three large and well-observed samples of hot, cool, and nearby white dwarfs in order to test whether the fraction of magnetic degenerates is biased and whether it varies with effective temperature, cooling age, or distance. The magnetic fraction is considerably higher for the cool sample of Bergeron, Ruiz, & Leggett and the Holberg, Oswalt, & Sion sample of local white dwarfs than it is for the generally hotter white dwarfs of the Palomar… Expand

Tables from this paper

The incidence of magnetic fields in cool DZ white dwarfs
Little is known about the incidence of magnetic fields among the coolest white dwarfs. Their spectra usually do not exhibit any absorption lines as the bound-bound opacities of hydrogen and heliumExpand
The origin of the magnetic fields in white dwarfs
Magnetic white dwarfs with fields in excess of ∼10 6 G (the high field magnetic white dwarfs; HFMWDs) constitute about ∼10 per cent of all white dwarfs and show a mass distribution with a mean massExpand
Magnetic White Dwarfs
In this paper we review the current status of research on the observational and theoretical characteristics of isolated and binary magnetic white dwarfs (MWDs).Magnetic fields of isolated MWDs areExpand
New insight into the magnetism of degenerate stars from the analysis of a volume-limited sample of white dwarfs
Many stars evolve into magnetic white dwarfs (MWDs), and observations may help to understand when the magnetic field appears at the stellar surface, if and how it evolves during the cooling phase,Expand
Suppression of cooling by strong magnetic fields in white dwarf stars
TLDR
It is found that strong fields are sufficient to suppress convection over the entire surface in cool magnetic white dwarf, which inhibits their cooling evolution relative to weakly magnetic and non-magnetic white dwarfs, making them appear younger than they truly are. Expand
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
Where Are the Magnetic White Dwarfs with Detached, Nondegenerate Companions?
The Sloan Digital Sky Survey has already more than doubled the sample of white dwarfs with spectral classifications, the subset with detached M dwarf companions, and the subset of magnetic whiteExpand
Searching for the weakest detectable magnetic fields in white dwarfs. Highly-sensitive measurements from first VLT and WHT surveys
Our knowledge of the magnetism in white dwarfs is based on an observational dataset that is biased in favour of stars with very strong magnetic fields. Most of the field measurements available in theExpand
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
Measuring the rotational periods of isolated magnetic white dwarfs
We present time-series photometry of 30 isolated magnetic white dwarfs, surveyed with the Jacobus Kapteyn Telescope between 2002 August and 2003 May. We find that 9 were untestable due to varyingExpand
...
1
2
3
4
5
...

References

SHOWING 1-10 OF 34 REFERENCES
The incidence of magnetism among white dwarfs: The first stars below 100 kilogauss
A survey for magnetic fields among a magnitude-limited sample of DA white dwarfs has identified two stars with weak circular polarization features across the profiles of H(alpha) and H(beta) WDExpand
Studies of magnetic and suspected-magnetic southern white dwarfs
ABSTRACT Optical spectrophotometry and circular spectropolarimetry are presented for sev-eral candidate magnetic white dwarfs that were identified during the Hamburg/ESOsurvey for bright QSOs. TwoExpand
The Chemical Evolution of Cool White Dwarfs and the Age of the Local Galactic Disk
Photometric and spectroscopic observations of 110 cool white dwarf stars are presented and analyzed with state-of-the-art model atmosphere calculations appropriate for cool white dwarfs with pureExpand
Magnetism in Isolated and Binary White Dwarfs
Since the discovery of the first isolated magnetic white dwarf (MWD) Grw +70°8047 nearly 60 years ago, the number of stars belonging to this class has grown steadily. There are now some 65 isolatedExpand
Photometric and Spectroscopic Analysis of Cool White Dwarfs with Trigonometric Parallax Measurements
A detailed photometric and spectroscopic analysis of cool (Teff 12,000 K) white dwarf stars is presented. The sample has been drawn from the Yale Parallax Catalog and from a proper motion survey inExpand
LB 8827: A Variable, Magnetic DBA White Dwarf
We present accurate CCD spectropolarimetry and spectra that show that the hot DB star LB 8827 (PG 0853+164) is a weakly magnetic, variable DBA white dwarf. We confirm Putney's detection of circularExpand
A determination of the local density of white dwarf stars
The most recent version of the Catalog of Spectroscopically Identified White Dwarfs lists 2249 white dwarf stars. Among these stars are 109 white dwarfs that have either reliable trigonometricExpand
An EUV-selected sample of DA white dwarfs from the ROSAT All-Sky Survey — I. Optically derived stellar parameters
One of the most important results of the ROSAT All-Sky X-ray and EUY Surveys has been the detection of a large number of white dwarfs, allowing a detailed study of the general properties of DA whiteExpand
Properties of Hot White Dwarfs in Extreme-Ultraviolet/Soft X-Ray Surveys*
Intermediate-dispersion spectroscopy (Δ ~ 6 A) of 38 ultrasoft X-ray sources (ROSAT PSPC/WFC and EUVE)—27 H-rich white dwarfs (DA), one magnetic white dwarf (DAp), eight active galactic nuclei, a newExpand
On the nature of spectral features in peculiar DQ white dwarfs
Spectropolarimetric measurements are presented for the DQ white dwarfs ESO 439-162, LHS 1126, and G225-68, whose spectroscopic features in the optical have been interpreted in the past asExpand
...
1
2
3
4
...