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Related papers: Precise Diffusion Coefficients for White Dwarf Ast…

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We present Hubble Space Telescope observations of the upper part (T_eff> 10 000 K) of the white dwarf cooling sequence in the globular cluster 47 Tucanae and measure a luminosity function of hot white dwarfs. Comparison with previous…

Solar and Stellar Astrophysics · Physics 2015-08-26 Bradley Hansen , Harvey Richer , Jason Kalirai , Ryan Goldsbury , Shane Frewen , Jeremy Heyl

We present a critical review of the determination of fundamental parameters of white dwarfs discovered by the Gaia mission. We first reinterpret color-magnitude and color-color diagrams using photometric and spectroscopic information…

Solar and Stellar Astrophysics · Physics 2019-05-15 P. Bergeron , P. Dufour , G. Fontaine , S. Coutu , S. Blouin , C. Genest-Beaulieu , A. Bédard , B. Rolland

In our galaxy, white dwarfs inevitably undergo scattering and capture processes with the interstellar diffuse dark matter. The captured dark matter forms a dark halo that eventually evaporates or annihilates. Theoretical pulsation modes and…

High Energy Astrophysical Phenomena · Physics 2025-04-10 Bo Zhang , Cui-Bai Luo , Lei Feng

The equation of state of the electron degenerate gas in a white dwarf is usually treated by employing the ideal dispersion relation. However, the effect of quantum gravity is expected to be inevitably present and when this effect is…

General Relativity and Quantum Cosmology · Physics 2019-01-08 Arun Mathew , Malay Kumar Nandy

We investigate the dissociation equilibrium of $\rm H_2$ in very cool, helium-rich white dwarf atmospheres. We present the solution of the non-ideal chemical equilibrium for the dissociation of molecular hydrogen in a medium of dense…

Astrophysics · Physics 2009-11-13 Piotr M. Kowalski

We examine the claim by Oppenheimer et al. (2001) that the local halo density of white dwarfs is an order of magnitude higher than previously thought. As it stands, the observational data support the presence of a kinematically distinct…

Astrophysics · Physics 2017-08-23 L. V. E. Koopmans , R. D. Blandford

White Dwarfs (WDs), the final evolutionary stage of most stars, are frequently modeled considering only a dense plasma matter. However, their potential interaction with dark matter (DM), especially in galactic halos where DM is expected to…

Solar and Stellar Astrophysics · Physics 2025-11-07 Sílvia P. Nunes , José D. V. Arbañil , Juan M. Z. Pretel , Sérgio B. Duarte

We analyse diffusion at low temperature by bringing the fluctuation-dissipation theorem (FDT) to bear on a physically natural, viscous response-function R(t). The resulting diffusion-law exhibits several distinct regimes of time and…

Statistical Mechanics · Physics 2018-05-03 Urbashi Satpathi , Supurna Sinha , Rafael D. Sorkin

We present a Monte Carlo simulation designed to predict the vertical velocity dispersion of brown dwarfs in the Milky Way. We show that since these stars are constantly cooling, the velocity dispersion has a noticeable trend with spectral…

Real data are constrained to finite sampling rates, which calls for a suitable mathematical description of the corrections to the finite-time estimations of the dynamic equations. Often in the literature, lower order discrete time…

Data Analysis, Statistics and Probability · Physics 2015-05-13 C. Anteneodo , R. Riera

Recently, the power of Gaia data has revealed an enhancement of high-mass white dwarfs (WDs) on the Hertzsprung--Russell diagram, called the Q branch. This branch is located at the high-mass end of the recently identified crystallization…

Solar and Stellar Astrophysics · Physics 2019-12-12 Sihao Cheng , Jeffrey D. Cummings , Brice Ménard

We propose a joint experimental and theoretical approach to measure the self-diffusion in a laser-cooled trapped ion cloud where part of the ions are shelved in a long-lived dark state. The role of the self-diffusion coefficient in the…

In the vast expanse of our galaxy, white dwarfs (WDs) are natural sentinels, capturing the enigmatic dark matter (DM) particles that incessantly traverse their interiors. These celestial bodies provide a unique vantage point for probing…

High Energy Physics - Phenomenology · Physics 2024-06-06 Jia-Shu Niu

Ultra-massive white dwarfs are powerful tools to study various physical processes in the Asymptotic Giant Branch (AGB), type Ia supernova explosions and the theory of crystallization through white dwarf asteroseismology. Despite the…

Dwarf galaxies are thought of as the building blocks of large galaxies such as our Milky Way. This paper presents new high-resolution hydrodynamical simulations of dwarf galaxies and their intergalactic medium with the \texttt{GIZMO} code.…

Astrophysics of Galaxies · Physics 2025-06-06 Pei-Cheng Tung , Ke-Jung Chen

White dwarf cooling sequences provides a useful indicator of the evolutionary time scales involved in the chronometry and star formation history of the galactic disk and, for this reason, the luminosity function of white dwarfs has become a…

Astrophysics · Physics 2007-05-23 Rene A. Mendez , Maria T. Ruiz

We present a synopsis of the project to establish thirty-two new faint ($ 16.5 \leq V \leq 19.8 $) DA white dwarfs as spectrophotometric standards distributed over the whole sky. Our results validate the use of fully radiative pure hydrogen…

Cooling white dwarfs (WDs) can yield accurate ages when theoretical cooling models fully account for the physics of the dense plasma of WD interiors. We use MESA to investigate cooling models for a set of massive and ultra-massive WDs…

Solar and Stellar Astrophysics · Physics 2020-10-21 Evan B. Bauer , Josiah Schwab , Lars Bildsten , Sihao Cheng

We investigate crystallization-driven convection in carbon-oxygen white dwarfs. We present a version of the mixing length theory (MLT) that self-consistently includes the effects of thermal diffusion and composition gradients, and provides…

Solar and Stellar Astrophysics · Physics 2024-07-01 Matias Castro-Tapia , Andrew Cumming , J. R. Fuentes

We present improved calculations for the Stark broadening of hydrogen lines in dense plasmas typical of white dwarf atmospheres. Our new model is based on the unified theory of Stark broadening from Vidal, Cooper, & Smith. For the first…

Solar and Stellar Astrophysics · Physics 2011-02-11 P. -E. Tremblay , P. Bergeron