The nearby magnetic cool DZ white dwarf PM J08186-3110

Abstract

We present an analysis of photometric, spectroscopic and spectropolarimetric data of the nearby, cool, magnetic DZ white dwarf PM J08186-3110. High dispersion spectra show the presence of Zeeman splitted spectral lines due to the presence of a surface average magnetic field of 92 kG. The strong magnesium and calcium lines show extended wings shaped by interactions with neutral helium in a dense, cool helium-rich atmosphere. We found that the abundance of heavy elements varied between spectra taken ten years apart but we could not establish a time-scale for these variations; such variations may be linked to surface abundance variations in the magnetized atmosphere. Finally, we show that volume limited samples reveal that about 40% of DZ white dwarfs with effective temperatures below 7000 K are magnetic.

arXiv commentAccepted for publication in MNRAS

References in corpus (45)

• Gaia Data Release 2. Summary of the contents and survey properties
• The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
• The Transiting Exoplanet Survey Satellite
• Local Kinematics and the Local Standard of Rest
• galpy: A Python Library for Galactic Dynamics
• X-shooter, the new wide band intermediate resolution spectrograph at the ESO Very Large Telescope
• Molecfit: A general tool for telluric absorption correction II. Quantitative evaluation on ESO-VLT X-Shooter spectra
• Vertical distribution of Galactic disk stars I - Kinematics and metallicity
• SkyMapper Southern Survey: Second Data Release (DR2)
• Know Your Neighborhood: A Detailed Model Atmosphere Analysis of Nearby White Dwarfs
• Evidence for Water in the Rocky Debris of a Disrupted Extrasolar Minor Planet
• The Chemical Homogeneity of Sun-like Stars in the Solar Neighborhood
• Cool DZ white dwarfs II: Compositions and evolution of old remnant planetary systems
• 3D kinematics of white dwarfs from the SPY project II
• Analysis of Helium-Rich White Dwarfs Polluted by Heavy Elements in the Gaia Era
• Grids of white dwarf evolutionary models with masses from M= 0.1 to 1.2 Ms
• The nucleosynthetic history of elements in the Galactic disk: [X/Fe] - age relations from high-precision spectroscopy
• Measurements of Physical Parameters of White Dwarfs: A Test of the Mass-Radius Relation
• SkyMapper Filter Set: Design and Fabrication of Large Scale Optical Filters
• On The Evolution of Magnetic White Dwarfs
• The K2-HERMES Survey: Age and Metallicity of the Thick Disc
• $\text{Gaia}$ white dwarfs within 40 pc I: spectroscopic observations of new candidates
• On the incidence of weak magnetic fields in DA white dwarfs
• Trace hydrogen in helium atmosphere white dwarfs as a possible signature of water accretion
• The Magnetic and Metallic Degenerate G77-50
• The Solar Neighborhood. XXXIX. Parallax Results from the CTIOPI and NOFS Programs: 50 New Members of the 25 Parsec White Dwarf Sample
• The age-metallicity dependence for white dwarfs
• The incidence of magnetic fields in cool DZ white dwarfs
• Evolutionary sequences for hydrogen-deficient white dwarfs
• The polluted atmospheres of cool white dwarfs and the magnetic field connection
• The Solar Neighborhood XV: Discovery of New High Proper Motion Stars with mu >= 0.4"/yr between Declinations -47 degrees and 00 degrees
• The Solar Neighborhood. XX. Discovery and Characterization of 21 New Nearby White Dwarf Systems
• New High Proper Motion Stars from the Digitized Sky Survey. III. Stars with proper motions 0.45<mu<2.0''/yr south of Decl.=-30
• Discovery of six new strongly magnetic white dwarfs in the 20 pc local population
• Evidence of enhanced magnetism in cool, polluted white dwarfs
• Can magnetic fields suppress convection in the atmosphere of cool white dwarfs? A case study on WD2105-820
• Variability in Hot Carbon-Dominated Atmosphere (hot DQ) White Dwarfs: Rapid Rotation?
• The cool magnetic DAZ white dwarf NLTT 10480
• Diffusion coefficients in the envelopes of white dwarfs
• Discovery of weak magnetic fields in four DZ white dwarfs in the local 20pc volume. Implications for the frequency of magnetic fields with cooling age
• Spin and Magnetism of White Dwarfs
• An ancient double degenerate merger in the Milky Way halo
• Line Profiles of the Calcium I Resonance Line in Cool Metal-polluted White Dwarfs
• A Magnetic White Dwarf with Five H$\alpha$ Components
• Line shapes of the magnesium resonance lines in cool DZ white dwarf atmospheres

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