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Related papers: Precise Diffusion Coefficients for White Dwarf Ast…

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We present 4.5$\mu$m and 8$\mu$m photometric observations of 18 cool white dwarfs obtained with the Spitzer Space Telescope. Our observations demonstrate that four white dwarfs with T_eff< 6000 K show slightly depressed mid-infrared fluxes…

Measurements of the luminosity of type Ia supernovae vs. redshift provided the original evidence for the accelerating expansion of the Universe and the existence of dark energy. Despite substantial improvements in survey methodology,…

Instrumentation and Methods for Astrophysics · Physics 2016-01-18 Christopher W. Stubbs , Yorke J. Brown

We present detailed theoretical mass-radius relations for massive white dwarf stars with oxygen-neon cores. This work is motivated by recent observational evidence about the existence of white dwarf stars with very high surface gravities.…

Astrophysics · Physics 2016-08-16 L. G. Althaus , E. García--Berro , J. Isern , A. H. Córsico

Millisecond pulsars with white dwarf companions have typical eccentricities $e\sim 10^{-6}-10^{-3}$. The eccentricities of helium white dwarfs are explained well by applying the fluctuation-dissipation theorem to convective eddies in their…

Solar and Stellar Astrophysics · Physics 2024-09-23 Yair Cohen , Sivan Ginzburg , Maya Levy , Tal Bar Shalom , Yoav Siman Tov

Translational diffusion coefficients are routinely estimated from molecular dynamics simulations. Linear fits to mean squared displacement (MSD) curves have become the de facto standard, from simple liquids to complex biomacromolecules.…

Computational Physics · Physics 2020-11-20 Jakob Tómas Bullerjahn , Sören von Bülow , Gerhard Hummer

Recent determinations of the white dwarf luminosity function (WDLF) from very large surveys have extended our knowledge of the WDLF to very high luminosities. It has been shown that the shape of the luminosity function of white dwarfs…

High Energy Physics - Phenomenology · Physics 2014-10-08 Marcelo M. Miller Bertolami , Brenda E. Melendez , Leandro G. Althaus , Jordi Isern

New calculations of the thermal and electrical electron conductivities are performed for a broad range of physical parameters typical for envelopes of neutron stars and cores of white dwarfs. We consider stellar matter composed of…

Astrophysics · Physics 2011-05-23 A. Y. Potekhin , D. A. Baiko , P. Haensel , D. G. Yakovlev

Accurately measuring the masses of white dwarf stars is crucial in many astrophysical contexts (e.g., asteroseismology and cosmochronology). These masses are most commonly determined by fitting a model atmosphere to an observed spectrum;…

Solar and Stellar Astrophysics · Physics 2016-10-10 T. A. Gomez , M. H. Montgomery , T. Nagayama , D. P. Kilcrease , D. E. Winget

Nowadays, the calculation of the Galactic Cosmic Rays diffusion coefficient with direct microscopic numerical simulations is a widespread approach. In this work, we investigated the numerical limits for such calculations and demonstrated…

Instrumentation and Methods for Astrophysics · Physics 2026-05-14 Vladimir Yurovsky , Ilya Kudryashov

We present the first grid of 3D simulations for the pure-helium atmospheres of DB white dwarfs. The simulations were computed with the CO5BOLD radiation-hydrodynamics code and cover effective temperatures and surface gravities between 12000…

Solar and Stellar Astrophysics · Physics 2018-09-05 E. Cukanovaite , P. -E. Tremblay , B. Freytag , H. -G. Ludwig , P. Bergeron

We consider the evolution of white dwarfs with compact object companions (specifically black holes with masses up to 10^6 solar masses, neutron stars, and other white dwarfs). We suppose that the orbits are initially quite elliptical and…

Astrophysics · Physics 2009-11-10 Yasser Rathore , Roger D. Blandford , Avery E. Broderick

We present new numerical method to compute structures of differentially rotating white dwarfs with thermal stratification. Our models have cores composed of ions and completely degenerate electrons and have isentropic envelopes composed of…

High Energy Astrophysical Phenomena · Physics 2019-04-24 Shin'ichirou Yoshida

We discuss the Gaia Data Release 1 (September 2016) and preliminary work on maximising the benefit for cool white dwarf (WD) science in advance of the full parallax catalogue which will appear around one year later in DR2. The Tycho…

Solar and Stellar Astrophysics · Physics 2017-02-09 Nigel Hambly , Nick Rowell , Marco Lam

The trajectory of the center of light of an unresolved binary is different from that of its center of mass. Binary-induced stellar centroid wobbling can therefore be detected as an excess in the goodness-of-fit of the single-star…

Solar and Stellar Astrophysics · Physics 2022-06-29 Valeriya Korol , Vasily Belokurov , Silvia Toonen

Spectrophotometric observations at high signal-to-noise ratio were obtained of a complete sample of 347 DA white dwarfs from the Palomar Green (PG) Survey. Fits of observed Balmer lines to synthetic spectra calculated from pure-hydrogen…

Astrophysics · Physics 2009-09-17 J. Liebert , P. Bergeron , J. B Holberg

The coefficients of different mass formulae derived from the liquid drop model and including or not the curvature energy, the diffuseness correction to the Coulomb energy, the charge exchange correction term, different forms of the Wigner…

Nuclear Experiment · Physics 2008-12-18 G. Royer

We have investigated the relationship between the kinematics and mass of young (<3x10^8 years) white dwarfs using proper motions. Our sample is taken from the colour selected catalogues of SDSS (Eisenstein et al. 2006) and the Palomar-Green…

Astrophysics of Galaxies · Physics 2015-06-05 Christopher Wegg , E. Sterl Phinney

We suggest the diffuse approach to the relaxation processes within the kinetic theory for the Wigner distribution function. The diffusion and drift coefficients are evaluated taking into consideration the interparticle collisions on the…

Nuclear Theory · Physics 2015-04-02 V. M. Kolomietz , S. V. Lukyanov

We present a study of the hypothesis that white dwarfs undergo a spectral change from hydrogen- to helium-dominated atmospheres using a volume-limited photometric sample drawn from the $Gaia$ DR2 catalogue, the Sloan Digital Sky Survey…

Solar and Stellar Astrophysics · Physics 2020-01-22 Tim Cunningham , Pier-Emmanuel Tremblay , Nicola Pietro Gentile Fusillo , Mark Hollands , Elena Cukanovaite

We present a set of ultramassive white dwarf models, focused on masses above $1.3\,M_\odot$. Given the uncertainties about the formation and compositions of such objects, we construct parameterized model sequences, guided by evolutionary…

Solar and Stellar Astrophysics · Physics 2021-08-18 Josiah Schwab
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