English
Related papers

Related papers: Precise Diffusion Coefficients for White Dwarf Ast…

200 papers

White dwarfs are stellar embers depleted of nuclear energy sources that cool over billions of years. These stars, which are supported by electron degeneracy pressure, reach densities of 1e7 grams per cubic centimetre in their cores. It has…

We present a prescription for parametrizing the chemical profile in the core of white dwarfs in the light of the recent discovery that pulsation modes may sometimes be deeply confined in some cool pulsating white dwarfs. Such modes may be…

Solar and Stellar Astrophysics · Physics 2017-01-18 N. Giammichele , S. Charpinet , G. Fontaine , P. Brassard

Over the last decade {\it ab initio} modeling of material properties has become widespread in diverse fields of research. It has proved to be a powerful tool for predicting various properties of matter under extreme conditions. We apply…

Solar and Stellar Astrophysics · Physics 2015-05-20 Piotr M. Kowalski , Mukremin Kilic

Cooling ages of white dwarfs are routinely determined by mapping effective temperatures and masses to ages using evolutionary models. Typically, the reported uncertainties on cooling ages only consider the error propagation of the…

Solar and Stellar Astrophysics · Physics 2025-03-12 Praneet Pathak , Simon Blouin , Falk Herwig

In this work we study white dwarfs where $30\,000\,\text{K} {>} \mathrm{T}_{\rm{eff}} {>} 5\,000\,\text{K}$ to compare the differences in the cooling of DAs and non-DAs and their formation channels. Our final sample is composed by nearly…

Solar and Stellar Astrophysics · Physics 2018-10-24 G. Ourique , A. D. Romero , S. O. Kepler , D. Koester , L. A. Amaral

Diffusion coefficients for crystallized Coulomb plasmas are essential microphysics input for modeling white dwarf cores and neutron star crusts but are poorly understood. In this work we present a model for diffusion in Coulomb crystals. We…

Plasma Physics · Physics 2024-09-13 M. E. Caplan , D. Yaacoub

Recent studies of the atmospheres of carbon-rich (DQ) white dwarfs have demonstrated the existence of two different populations that are distinguished by the temperature range, but more importantly, by the extremely high masses of the…

Solar and Stellar Astrophysics · Physics 2020-03-25 D. Koester , S. O. Kepler , A. W. Irwin

We review the state of the art regarding the computation of the resistance coefficients in conditions typical of the stellar plasma, and compare the various results studying their effect on the solar model. We introduce and discuss for the…

Astrophysics · Physics 2007-05-23 H. Schlattl , M. Salaris

We report on a comparison of spectroscopic analyses for hydrogen (DA) and helium atmosphere (DB) white dwarfs with Gaia Data Release 2 (DR2) parallaxes and photometry. We assume a reddening law and a mass-radius relation to connect the…

Solar and Stellar Astrophysics · Physics 2018-11-28 P. -E. Tremblay , E. Cukanovaite , N. P. Gentile Fusillo , T. Cunningham , M. Hollands

White dwarfs are almost completely degenerate objects that cannot obtain energy from thermonuclear sources, so their evolution is just a gravothermal cooling process. Recent improvements in the accuracy and precision of the luminosity…

Solar and Stellar Astrophysics · Physics 2012-04-17 J. Isern , L. Althaus , S. Catalan , A. Corsico , E. Garcia-Berro , M. Salaris , S. Torres

We present a detailed calculation of model atmospheres for DA white dwarfs. Our atmosphere code solves the atmosphere structure in local thermodynamic equilibrium with a standard partial linearization technique, which takes into account the…

Astrophysics · Physics 2015-06-24 R. D. Rohrmann

We revisit the properties and astrophysical implications of the field white dwarf mass distribution in preparation of Gaia applications. Our study is based on the two samples with the best established completeness and most precise…

Solar and Stellar Astrophysics · Physics 2016-07-27 P. -E. Tremblay , J. Cummings , J. S. Kalirai , B. T. Gaensicke , N. Gentile-Fusillo , R. Raddi

A photometric and spectroscopic analysis of 152 cool white dwarf stars is presented. The discovery of 7 new DA white dwarfs, 2 new DQ white dwarfs, 1 new magnetic white dwarf, and 3 weak magnetic white dwarf candidates, is reported, as well…

Astrophysics · Physics 2009-10-31 P. Bergeron , S. K. Leggett , Maria Teresa Ruiz

White dwarf and pre-white dwarf atmospheres are one of the best examples for the application of Stark broadening research results in astrophysics, due to plasma conditions very favorable for this line broadening mechanism. For example in…

Solar and Stellar Astrophysics · Physics 2018-03-14 Milan S. Dimitrijevic , Andjelka Kovacevic , Zoran Simic , Sylvie Sahal-Brechot

A recent study by Yoon & Langer (2004a) indicated that the inner cores of rapidly accreting (Mdot > 10^{-7} M_sun/yr) CO white dwarfs may rotate differentially, with a shear rate near the threshold value for the onset of the dynamical shear…

Astrophysics · Physics 2008-11-26 Sung-Chul Yoon , Norbert Langer

In this paper we compute detailed evolutionary models providing chemical profiles for white dwarfs having progenitors in the mass range from 1.0 to $7 M_{\sun}$ and we examine the influence of such profiles in the cooling process. The…

Astrophysics · Physics 2016-08-30 M. Salaris , I. Dominguez , E. Garcia-Berro , M. Hernanz , J. Isern , R. Mochkovitch

We calculate interdiffusion coefficients in a two-component, weakly or strongly coupled ion plasma (gas or liquid, composed of two ion species immersed into a neutralizing electron background). We use an effective potential method proposed…

Solar and Stellar Astrophysics · Physics 2015-06-22 M. V. Beznogov , D. G. Yakovlev

We explore the effects of element diffusion due to gravitational settling and thermal and chemical diffusion on the pulsational properties of DA white dwarfs. To this end, we employ an updated evolutionary code coupled with a pulsational,…

Astrophysics · Physics 2009-11-07 A. H. Corsico , O. G. Benvenuto , L. G. Althaus , A. M. Serenelli

We use a suite of high-resolution cosmological dwarf galaxy simulations to test the accuracy of commonly-used mass estimators from Walker et al.(2009) and Wolf et al.(2010), both of which depend on the observed line-of-sight velocity…

We present a theoretical description of macroscopic diffusion caused by convective overshoot in pure-hydrogen DA white dwarfs using three-dimensional (3D), closed-bottom, radiation hydrodynamics CO$^5$BOLD simulations. We rely on a new grid…

Solar and Stellar Astrophysics · Physics 2019-07-10 Tim Cunningham , Pier-Emmanuel Tremblay , Bernd Freytag , Hans-Günther Ludwig , Detlev Koester