The 100 pc White Dwarf Sample in the SDSS Footprint

Abstract

We present follow-up spectroscopy of 711 white dwarfs within 100 pc, and present a detailed model atmosphere analysis of the 100 pc white dwarf sample in the SDSS footprint. Our spectroscopic follow-up is complete for 83% of the white dwarfs hotter than 6000 K, where the atmospheric composition can be constrained reliably. We identify 1508 DA white dwarfs with pure hydrogen atmospheres. The DA mass distribution has an extremely narrow peak at $0.59M_{\odot }$, and reveals a shoulder from relatively massive white dwarfs with $M=0.7$-$0.9M_{\odot }$. Comparing this distribution with binary population synthesis models, we find that the contribution from single stars that form through mergers cannot explain the over-abundance of massive white dwarfs. In addition, the mass distribution of cool DAs shows a near absence of $M>1M_{\odot }$ white dwarfs. The pile-up of 0.7-$0.9M_{\odot }$ and the disappearance of $M>1M_{\odot }$ white dwarfs is consistent with the effects of core crystallization. Even though the evolutionary models predict the location of the pile-up correctly, the delay from the latent heat of crystallization by itself is insufficient to create a significant pile-up, and additional cooling delays from related effects like phase separation are necessary. We also discuss the population of infrared-faint (ultracool) white dwarfs, and demonstrate for the first time the existence of a well defined sequence in color and magnitude. Curiously, this sequence is connected to a region in the color-magnitude diagrams where the number of helium-dominated atmosphere white dwarfs is low. This suggests that the infrared-faint white dwarfs likely have mixed H/He atmospheres.

ApJ, in press

References in corpus (11)

• The UKIRT Infrared Deep Sky Survey (UKIDSS)
• The Chemical Composition of an Extrasolar Minor Planet
• Found: The missing blue opacity in atmosphere models of cool hydrogen white dwarfs
• On the Measurement of Fundamental Parameters of White Dwarfs in the Gaia Era
• White dwarf and subdwarf stars in the Sloan Digital Sky Survey Data Release 14
• The ELM Survey. VIII. 98 Double White Dwarf Binaries
• A New Generation of Cool White Dwarf Atmosphere Models. IV. Revisiting the Spectral Evolution of Cool White Dwarfs
• Merging Binary Stars and the magnetic white dwarfs
• Ultracool white dwarfs and the age of the Galactic disc
• The evolution of carbon-polluted white dwarfs at low effective temperatures
• Two new Double-lined Spectroscopic Binary White Dwarfs

Cited by in corpus (46)

• A catalogue of white dwarfs in Gaia EDR3
• Current challenges in the physics of white dwarf stars
• A highly magnetised and rapidly rotating white dwarf as small as the Moon
• The 40 pc sample of white dwarfs from Gaia
• ${}^{22}$Ne Phase Separation As A Solution To The Ultramassive White Dwarf Cooling Anomaly
• New Conductive Opacities for White Dwarf Envelopes
• Spectral classification of the 100 pc white dwarf population from Gaia-DR3 and the Virtual Observatory
• White dwarf-main sequence binaries from Gaia EDR3: the unresolved 100pc volume-limited sample
• Toward Precision Cosmochronology: A New C/O Phase Diagram for White Dwarfs
• Alkali metals in white dwarf atmospheres as tracers of ancient planetary crusts
• The Most Massive White Dwarfs in the Solar Neighborhood
• Discovery of 74 new bright ZZ Ceti stars in the first three years of TESS
• The Merger Fraction of Ultramassive White Dwarfs
• On the Spectral Evolution of Hot White Dwarf Stars. III. The PG 1159$-$DO$-$DB$-$DQ Evolutionary Channel Revisited
• Lithium pollution of a white dwarf records the accretion of an extrasolar planetesimal
• The spectral evolution of white dwarfs: where do we stand?
• White dwarfs as Physics laboratories: lights and shadows
• A population synthesis fitting of the $Gaia$ resolved white dwarf binary population within 100 pc
• A New Method for Finding Nearby White Dwarf Exoplanets and Detecting Biosignatures
• White dwarf Random Forest classification through Gaia spectral coefficients
• Carbon dredge-up required to explain the Gaia white dwarf colour-magnitude bifurcation
• Asynchronous accretion can mimic diverse white dwarf pollutants I: core and mantle fragments
• Computational Tools for the Spectroscopic Analysis of White Dwarfs
• Structure and evolution of ultra-massive white dwarfs in general relativity
• White dwarf spectral type-temperature distribution from Gaia-DR3 and the Virtual Observatory
• Phase Separation in Ultramassive White Dwarfs
• WD J004917.14$-$252556.81, the Most Massive Pulsating White Dwarf
• Asynchronous accretion can mimic diverse white dwarf pollutants II: water content
• The Rapid Rotation of the Strongly Magnetic Ultramassive White Dwarf EGGR 156
• The White Dwarfs of the Old, Solar Metallicity Open Star Cluster Messier 67: Properties and Progenitors
• The ubiquity of carbon dredge-up in hydrogen-deficient white dwarfs as revealed by GALEX
• Spectrophotometric analysis of magnetic white dwarf II: Helium-rich compositions
• Disk or Companion: Characterizing Excess Infrared Flux in Seven White Dwarf Systems with Near-Infrared Spectroscopy
• A White Dwarf-Main Sequence Binary Unveiled by Time-Domain Observations from LAMOST and TESS
• The velocity distribution of white dwarfs in Gaia EDR3
• Type Ia Supernova Magnitude Step from the local Dark Matter Environment
• A GALEX view of the DA White Dwarf Population
• Post-main sequence thermal evolution of planetesimals
• Astrometric and photometric verification of faint blue white dwarfs in the Gaia catalogue of nearby stars
• The pulsational properties of ultra-massive DB white dwarfs with carbon-oxygen cores coming from single-star evolution
• General relativistic pulsations of ultra-massive ZZ Ceti stars
• PHL 5038AB: Is the brown dwarf causing pollution of its white dwarf host star?
• Effects of modified gravity on microscopic properties and cooling timescale of white dwarfs
• Search of nearby resolved neutron stars among optical sources
• Revisiting constraints on asymmetric dark matter from collapse in white dwarf stars
• Hot Degenerates in the MCT Survey. III. A Sample of White Dwarf Stars in the Southern Hemisphere