On the Interpretation of High Velocity White Dwarfs as Members of the Galactic Halo

Abstract

A detailed analysis of 32 of the 38 halo white dwarf candidates identified by Oppenheimer et al. is presented, based on model atmosphere fits to observed energy distributions built from optical BVRI and infrared JHK CCD photometry. Effective temperatures and atmospheric compositions are determined for all objects, as well as masses and cooling ages when trigonometric parallax measurements are available. This sample is combined with that of other halo white dwarf candidates and disk white dwarfs to study the nature of these objects in terms of reduced proper motion diagrams, tangential velocities, and stellar ages. We reaffirm the conclusions of an earlier analysis based on photographic magnitudes of the same sample that total stellar ages must be derived in order to associate a white dwarf with the old halo population, and that this can only be accomplished through precise mass and distance determinations.

arXiv comment31 pages, 8 figures, accepted for publication in the Astrophysical Journal

References in corpus (20)

• The Formation Rate, Mass and Luminosity Functions of DA White Dwarfs from the Palomar Green Survey
• Photometric and Spectroscopic Analysis of Cool White Dwarfs with Trigonometric Parallax Measurements
• JHK Standard Stars for Large Telescopes: the UKIRT Fundamental and Extended Lists
• Direct Detection of Galactic Halo Dark Matter
• HST Observations of the White Dwarf Cooling Sequence of M4
• A Survey for Cool White Dwarfs and the age of the Galactic Disc
• An Initial Survey of White Dwarfs in the Sloan Digital Sky Survey
• High-velocity white dwarfs: thick disk, not dark matter
• High proper motion white dwarfs and halo dark matter
• Element abundances in cool white dwarfs. II. Ultraviolet observations of DZ white dwarfs
• Discovery of a Cool, Massive, and Metal-Rich DAZ White Dwarf
• Model Atmosphere Analysis of Two Very Cool White Dwarfs
• Discovery of New Ultracool White Dwarfs in the Sloan Digital Sky Survey
• Observations of Ultracool White Dwarfs
• Halo White Dwarfs, Thick Disks and a Sanity Check
• Cool White Dwarfs Revisited -- New Spectroscopy and Photometry
• Type Ia Supernovae and High Velocity White Dwarfs
• Radiative transfer in the refractive atmospheres of very cool white dwarfs
• A Critical Examination of Halo White Dwarf Candidates
• Analysis of a Very Massive DA White Dwarf via the Trigonometric Parallax and Spectroscopic Methods

Cited by in corpus (39)

• The UKIRT Infrared Deep Sky Survey ZYJHK Photometric System: Passbands and Synthetic Colours
• Found: The missing blue opacity in atmosphere models of cool hydrogen white dwarfs
• Know Your Neighborhood: A Detailed Model Atmosphere Analysis of Nearby White Dwarfs
• The White Dwarf Luminosity Function from SDSS Imaging Data
• On type Ia supernovae and the formation of single low-mass white dwarfs
• A New Generation of Cool White Dwarf Atmosphere Models. I. Theoretical Framework and Applications to DZ Stars
• The Solar Neighborhood. XXI. Parallax Results from the CTIOPI 0.9m Program: 20 New Members of the 25 Parsec White Dwarf Sample
• A New Generation of Cool White Dwarf Atmosphere Models. IV. Revisiting the Spectral Evolution of Cool White Dwarfs
• First Results from Pan-STARRS1: Faint, High Proper Motion White Dwarfs in the Medium-Deep Fields
• The Solar Neighborhood. XXXIX. Parallax Results from the CTIOPI and NOFS Programs: 50 New Members of the 25 Parsec White Dwarf Sample
• A Detailed Model Atmosphere Analysis of Cool White Dwarfs in the Sloan Digital Sky Survey
• A study of high proper-motion white dwarfs I. Spectropolarimetry of a cool hydrogen-rich sample
• Discovery of a T dwarf + white dwarf binary system
• The Age of the Galactic Stellar Halo from Gaia White Dwarfs
• Random Forest identification of the thin disk, thick disk and halo Gaia-DR2 white dwarf population
• A New Generation of Cool White Dwarf Atmosphere Models. II. A DZ Star with Collision-Induced Absorption
• The Gaia DR2 halo white dwarf population: the luminosity function, mass distribution and its star formation history
• LP 400-22, A very low-mass and high-velocity white dwarf
• Spitzer Observations of the Oldest White Dwarfs in the Solar Neighborhood
• On the Dissociation Equilibrium of H2 in Very Cool, Helium-Rich White Dwarf Atmospheres
• Visitors from the Halo: 11 Gyr old White Dwarfs in the Solar Neighborhood
• A statistical view on stable and unstable Roche lobe overflow of a tertiary star onto the inner binary in triple systems
• A Nearby Old Halo White Dwarf Candidate from the Sloan Digital Sky Survey
• 11-12 Gyr old White Dwarfs 30 parsecs Away
• A New Generation of Cool White Dwarf Atmosphere Models. III. WD J2356$-$209: Accretion of a Planetesimal with an Unusual Composition
• Distant White Dwarfs in the US Naval Observatory Flagstaff Station Parallax Sample
• Ages of White Dwarf-Red Subdwarf Systems
• Trigonometric parallaxes of high velocity halo white dwarf candidates
• Discovery of a nearby halo white dwarf with proper motion mu=2.55 arcsec/yr
• Faint Blue Objects in the Hubble Deep Field South Revealed: White Dwarfs, Subdwarfs, and Quasars
• Cool White Dwarfs Found in the UKIRT Infrared Deep Sky Survey
• A hyper-runaway white dwarf in Gaia DR2 as a Type Iax supernova primary remnant candidate
• The Mass and Age Distribution of Halo White Dwarfs in the Canada-France Imaging Survey
• New Halo White Dwarf Candidates in the Sloan Digital Sky Survey
• Discovery of a Possible Cool White Dwarf Companion from the AllWISE Motion Survey
• Cool White Dwarfs Identified in the Second Data Release of the UKIRT Infrared Deep Sky Survey
• The Next Generation Virgo Cluster Survey. XXVIII. Characterization of the Galactic White Dwarf Population
• A Catalog of 531 White Dwarf Candidates in the Local Galactic Halo from Gaia Data Release 2
• Moving Objects in the Hubble Ultra Deep Field