Related papers: White dwarfs as physics laboratories: the case of …
By introducing a simplified transport model of outer layers of white dwarfs we derive an analytical semi-empirical relation which constrains effective temperature-mass-radius for white dwarfs. This relation is used to classify recent data…
Due to the short settling times of metals in DA white dwarf atmospheres, any white dwarfs with photospheric metals must be actively accreting. It is therefore natural to expect that the metals may not be deposited uniformly on the surface…
White dwarfs are a class of stars with unique physical properties. They present many challenging problems whose solution requires the application of advanced theories of dense matter, state-of-the-art experimental techniques, and extensive…
The purpose of this work is to explore the evolution of helium-core white dwarf stars in a self-consistent way with the predictions of detailed non-gray model atmospheres and element diffusion. To this end, we consider helium-core white…
We consider the effects of rotation and temperature on the structure of white dwarfs in order to compare them with the estimated data from observations.
Many magnetic white dwarfs exhibit a polarised spectrum that periodically varies as the star rotates because the magnetic field is not symmetric about the rotation axis. In this work, we report the discovery that while weakly magnetic white…
We present a novel candidate for cold dark matter consisting of condensed Cooper pairs in a theory of interacting fermions with broken chiral symmetry. Establishing the thermal history from the early radiation era to the present, the…
We examine the emergent fluxes from helium-core white dwarfs following their evolution from the end of pre-white dwarf stages down to advanced cooling stages. For this purpose, we include a detailed treatment of the physics of the…
Polarization measurements of thermal radiation from magnetic white dwarf (MWD) stars have been proposed as a probe of axion-photon mixing. The radiation leaving the surface of the MWD is unpolarized, but if low-mass axions exist then…
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…
We revisit the properties of white dwarfs accreting hydrogen-rich matter by constructing steady-state models, in which hydrogen shell burning consumes hydrogen at the same rate as the white dwarf accretes it. We obtain such steady-state…
We study ultralight scalar fields with quadratic couplings to Standard-Model fermions and derive strong constraints from white-dwarf mass-radius data. Such couplings source scalar profiles inside compact stars, shift fermion masses, and can…
A large fraction of white dwarfs are accreting or have recently accreted rocky material from their planetary systems, thereby polluting their atmospheres with elements heavier than helium. In recent years, the quest for mechanisms that can…
We present a new set of cooling models and isochrones for both H- and He-atmosphere white dwarfs, incorporating accurate boundary conditions from detailed model atmosphere calculations, and carbon-oxygen chemical abundance profiles based on…
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…
We discuss the recent claim that the thermohaline ("fingering") instability is important in accreting white dwarfs, increasing the derived accretion fluxes potentially by orders of magnitude. We present an alternative view and conclude that…
Stars have been recognized as optimal laboratories to probe axion properties. In the last decades there have been significant advances in this field due to a better modelling of stellar systems and accurate observational data. In this work…
Low mass axion-like particles could be produced in abundance within the cores of hot, compact magnetic white dwarf (MWD) stars from electron bremsstrahlung and converted to detectable X-rays in the strong magnetic fields surrounding these…
We present a novel candidate for cold dark matter consisting of condensed Cooper pairs in a theory of interacting fermions with broken chiral symmetry. Establishing the thermal history from the early radiation era to the present, the…
Convective overshooting in super asymptotic giant branch stars has been suggested to lead to the formation of hybrid white dwarfs with carbon-oxygen cores and oxygen-neon mantles. As the white dwarf cools, this core-mantle configuration…