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Related papers: Precise Diffusion Coefficients for White Dwarf Ast…

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The evolution of white dwarfs is a cooling process that depends on the energy stored in the core and on the way in which it is transferred through the envelope. In this paper we show that despite some (erroneous) claims, the redistribution…

Astrophysics · Physics 2009-10-31 J. Isern , E. Garcia-Berro , M. Hernanz , G. Chabrier

We investigate the evolution of cooling helium atmosphere white dwarfs using a full evolutionary code, specifically developed for following the effects of element diffusion and gravitational settling on white dwarf cooling. The major…

Astrophysics · Physics 2016-08-16 James MacDonald , Margarita Hernanz , Jordi José

The white dwarf luminosity function, which provides information about their cooling, has been measured with high precision in the past few years. Simulations that include well known Standard Model physics give a good fit to the data. This…

High Energy Physics - Phenomenology · Physics 2015-06-15 Herbert K. Dreiner , Jean-François Fortin , Jordi Isern , Lorenzo Ubaldi

Cosmic ray nuclei fluxes are expected to be measured with high precision in the near future. For instance, high quality data on the antiproton component could give important clues about the nature of the astronomical dark matter. A very…

Astrophysics · Physics 2008-11-26 D. Maurin , F. Donato , R. Taillet , P. Salati

We present new cooling models for carbon-oxygen white dwarfs with both H- and He-atmospheres, covering the whole relevant mass range, to extend our updated BaSTI (a Bag of Stellar Tracks and Isochrones) stellar evolution archive. They have…

Solar and Stellar Astrophysics · Physics 2021-12-22 Maurizio Salaris , Santi Cassisi , Adriano Pietrinferni , Sebastian Hidalgo

Given the importance of white dwarfs (WDs) in many fields of modern astrophysics, the precise knowledge of the actual degree of accuracy of the associated theoretical predictions is a primary task. In the first paper of a series dedicated…

Astrophysics · Physics 2009-11-13 P. G. Prada Moroni , O. Straniero

We present a set of full evolutionary sequences for white dwarfs with hydrogen-deficient atmospheres. We take into account the evolutionary history of the progenitor stars, all the relevant energy sources involved in the cooling, element…

White dwarfs with metal-polluted atmospheres have been studied widely in the context of the accretion of rocky debris from evolved planetary systems. One open question is the geometry of accretion and how material arrives and mixes in the…

The continuous cooling of a white dwarf is punctuated by events that affect its cooling rate. Probably the most significant of those is the crystallization of its core, a phase transition that occurs once the C/O interior has cooled down…

Solar and Stellar Astrophysics · Physics 2020-08-12 Simon Blouin , Jérôme Daligault , Didier Saumon , Antoine Bédard , Pierre Brassard

For many years, astronomers have promised that the study of pulsating white dwarfs would ultimately lead to useful information about the physics of matter under extreme conditions of temperature and pressure. In this paper we finally make…

Astrophysics · Physics 2009-10-08 T. S. Metcalfe , D. E. Winget , P. Charbonneau

We analysed the cooling of white dwarfs in the globular cluster 47 Tucanae using deep observations from the Hubble Space Telescope that resolve the white dwarf cooling sequence to late enough cooling times that the white dwarf core has…

Solar and Stellar Astrophysics · Physics 2025-07-30 Leesa Fleury , Harvey Richer , Jeremy Heyl

We discuss the potentials of several experimental configurations dedicated to direct measurements of charged cosmic ray (CR) nuclei at energies $\gsim$ 100 GeV/n. Within a two-zone propagation model for stable CRs, we calculate light…

Astrophysics · Physics 2009-11-10 A. Castellina , F. Donato

We present an accurate analytic approximation for the energy of a quantum one-component Coulomb liquid of ions in a uniform electron background which has been recently calculated from first principles (Baiko 2019). The approximation enables…

Solar and Stellar Astrophysics · Physics 2019-11-19 D. A. Baiko , D. G. Yakovlev

White dwarf asteroseismology offers the opportunity to probe the structure and composition of stellar objects governed by relatively simple physical principles. The observational requirements of asteroseismology have been addressed by the…

Astrophysics · Physics 2009-11-06 Travis S. Metcalfe

Element diffusion is a key physical process that substantially impacts the superficial abundances, internal structure, pulsation properties, and evolution of white dwarfs. We study the effect of Coulomb separation of ions in the cooling…

Solar and Stellar Astrophysics · Physics 2021-01-04 Leandro G. Althaus , Alejandro H. Córsico , Francisco De Gerónimo

We present a detailed analysis of 108 helium-line (DB) white dwarfs based on model atmosphere fits to high signal-to-noise optical spectroscopy. We derive a mean mass of 0.67 Mo for our sample, with a dispersion of only 0.09 Mo. White…

The precise astrometric measurements of the Gaia Data Release 2 have opened the door to detailed tests of the predictions of white dwarf cooling models. Significant discrepancies between theory and observations have been identified, the…

Solar and Stellar Astrophysics · Physics 2021-04-21 Simon Blouin , Jerome Daligault , Didier Saumon

We present improved atmospheric parameters of nearby white dwarfs lying within 20 pc of the Sun. The aim of the current study is to obtain the best statistical model of the least-biased sample of the white dwarf population. A homogeneous…

Solar and Stellar Astrophysics · Physics 2015-06-04 Noemi Giammichele , Pierre Bergeron , Patrick Dufour

The standard diffusion processes are known to be obtained as the limits of appropriate random walks. These prelimiting random walks can be quite different however. The diffusion coefficient can be made responsible for the size of jumps or…

Probability · Mathematics 2022-03-10 Vassili N. Kolokoltsov

A sequence of pure-hydrogen CO5BOLD 3D model atmospheres of DA white dwarfs is presented for a surface gravity of log g = 8 and effective temperatures from 6000 to 13,000 K. We show that convective properties, such as flow velocities,…

Solar and Stellar Astrophysics · Physics 2015-06-15 P. -E. Tremblay , H. -G. Ludwig , M. Steffen , B. Freytag