Recent Submissions

  • An Update on Pulsations in Accreting White Dwarfs 

    Szkody, Paula; Mukadam, Anjum (2018-07)
    Since the last white dwarf workshop, there is continuing evidence that long (hrs to days) periodicities are being found in white dwarfs that are undergoing accretion in close binary systems. Pulsation modes remain a ...
  • Numerical simulations of the convective dilution process in helium-rich white dwarfs 

    Rolland, B.; Bergeron, P.; Fontaine, G. (2018-07)
    DB and DBA white dwarfs are generally believed to be the result of a process by which a thin radiative hydrogen atmosphere floating in diffusive equilibrium on top of a helium envelope is eventually completely diluted ...
  • Magnetic Torques Imply Fewer Double Detonations 

    Neunteufel, P.; Yoon, S.C.; Langer, N. (2018-07)
    Binary systems composed of one helium-rich nondegenerate star and one carbon-oxygen white dwarf (He+CO) have long been considered a promising progenitor candidate for a number of astrophysical transients like archetypical ...
  • The gravitational redshift of Sirius B 

    Joyce, S.R.G.; Barstow, M.A.; Holberg, J.B.; Bond, H.E.; Casewell, S.L.; Burleigh, M.R. (2018-07)
    Previous measurements of the gravitational redshift of Sirius B have resulted in a mass estimate which is significantly larger than the mass measured from the binary orbit. We have obtained new HST observations of ...
  • White dwarf collisions and the meteoritic Ne-E anomaly 

    Isern, J.; Bravo, E. (2018-07)
    The analysis of noble gases in primitive meteorites has shown the existence of anomalous isotopic abundances when compared with the average Solar System values. In particular it has been found that some graphite grains ...
  • A New Look at Magnetic White Dwarfs 

    Hardy, F.; Dufour, P.; Jordan, S. (2018-07)
    We present a homogeneous photometric analysis of a large sample of magnetic DA white dwarfs as well as selected results from a spectrophotometric analysis of magnetic carbon-dominated atmosphere white dwarfs. We find ...
  • A Precise Radial Velocity Search for Giant Planets orbiting polluted White Dwarfs 

    Endl, M.; Williams, K.A. (2018-07)
    We present a feasibility study for extending the well-known radial velocity technique to search for planetary companions around white dwarfs. Typically, the spectra of white dwarfs contain only a few pressure-broadened ...
  • Dusty Exoplanetary Debris Disks in the Single-Temperature Blackbody Plane 

    Dennihy, E.; Clemens, J.C.; Dunlap, B.H. (2018-07)
    We present a bulk sample analysis of the metal polluted white dwarfs which also host infrared bright dusty debris disks, known to be direct signatures of an active exoplanetary accretion source. We explore the relative ...
  • Evolutionary and pulsational properties of ultra-massive white dwarfs. The role of oxygen-neon phase separation. 

    De Gerónimo, F.C.; Camisassa, M.E.; Córsico, A.H.; Althaus, L.G. (2018-07)
    Ultra-massive hydrogen-rich white dwarfs (WDs) are expected to harbor oxygen/neon cores resulting from semi-degenerate carbon burning when the progenitor star evolves through the super asymptotic giant branch (SAGB) ...
  • Improved and Tested: A New Generation of Cool White Dwarf Atmosphere Models 

    Blouin, S.; Dufour, P.; Allard, N.F.; Kilic, M. (2018-07)
    The photosphere of cool, helium-rich white dwarfs is notoriously tricky to model due to its fluid-like density. Using modern ab initio calculations, we have developed a new generation of atmosphere models that include ...
  • Luminosity and cooling suppression in magnetized white dwarfs 

    Bhattacharya, M.; Mukhopadhyay, B.; Mukerjee, S. (2018-07)
    We investigate the luminosity and cooling of highly magnetized white dwarfs where cooling occurs by the diffusion of photons. We solve the magnetostatic equilibrium and photon diffusion equations to obtain the temperature ...
  • Constraining the Milky Way potential with Double White Dwarfs 

    Korol, V.; Rossi, E.M.; Barausse, E. (2018-07)
    The upcoming LISA mission is the only experiment that will allow us to study the Milky Way’s structure using gravitational wave signals from Galactic double white dwarfs (DWDs). The total number of expected detections ...
  • Revisiting the White Dwarf Luminosity Function from the Palomar-Green Survey 

    Bédard, A.; Bergeron, P.; Fontaine, G. (2018-07)
    We present updated atmospheric parameters for all DA, DB, and DO white dwarfs in the complete sample of the Palomar-Green survey. In particular, we perform a spectroscopic analysis of the DO stars using our new set of ...
  • 25 years of using the spectroscopic method: where do we stand? 

    Bergeron, P.; Genest-Beaulieu, C.; Coutu, S.; Blouin, S.; Bédard, A.; Cloutier, S. (2018-07)
    The spectroscopic technique, which consists in fitting high signal-to-noise optical spectra with the predictions of state-of-the-art model atmospheres, has routinely been used for over 25 years to measure the ...
  • An Analysis of the Circumstellar Absorption of WD 1145+017 

    Fortin-Archambault, M.; Dufour, P.; Xu, S. (2018-07)
    WD 1145+017 is a white dwarf that has an actively disintegrating object in orbit and also uniquely displays circumstellar gas absorption. We present a preliminary analysis of the circumstellar absorption features present ...
  • Mg line profiles for cool WD and their application in the UV 

    Gadéa, F.X.; Leininger, T.; Guillon, G.; Allard, N.F.; Blouin, S.; Dufour, P. (2018-07)
    Since last decade there have been great advances and extremely exciting results in the search and interpretation for cool DZ white dwarfs. In the formation of their spectra, the far wings of alkaline earth metals like ...
  • The difficulty of finding double-degenerate progenitors of type Ia supernovae 

    Rebassa-Manserga, A.; Toonen, S.; Korol, V.; Torres, S. (2018-07)
    The double-degenerate progenitors of type Ia supernovae (SNIa) are double white dwarf binaries with a total mass near the Chandrasekhar limit and with merger timescales smaller than the Hubble time. The fact that we ...
  • Temperatures and Chemical Abundances of Accreting White Dwarfs in Cataclysmic Binaries 

    Sion, E.M.; Godon, P. (2018-07)
    We present new results on surface temperatures, and chemical abundances of accreting white dwarfs (WD) in cataclysmic and symbiotic binaries. The S-Type symbiotic system RW Hydrae contains an accreting WD with a surface ...
  • The Gaia white dwarf population within 100 pc of the Sun 

    Torres, S.; Rebassa-Mansergas, A.; Jiménez-Esteban, F.M.; Cantero, C.; Canals, P.; Skorobogatov, G.; Solano, E. (2018-07)
    The recent Gaia Data Release 2 has provided an unprecedented sample of the local white dwarf population. The high astrometric resolution and the photometry provided by Gaia allows to build a clean magnitude-color diagram ...