Related papers: White dwarfs with a surface electrical charge dist…
We present the first analysis of an EUV selected sample of hot DA white dwarfs using a new type of atmospheric models. These models take into account the interplay between gravitational settling and radiative acceleration to predict the…
White Dwarf luminosities are powerful age indicators, whose calibration should be based on reliable models. We discuss the uncertainty of some chemical and physical parameters and their influence on the age estimated by means of white dwarf…
White dwarf photospheric parameters are usually obtained by means of spectroscopic or photometric analysis. These results are not always consistent with each other, with the published values often including just the statistical…
A significant fraction of white dwarfs harbour a magnetic field with strengths ranging from a few kG up to about 1000 MG. The fraction appears to depend on the specific class of white dwarfs being investigated and may hold some clues to the…
The observational signature of core crystallization of white dwarfs has recently been discovered. However, the magnitude of the crystallization-powered cooling delay required to match observed white dwarfs is larger than predicted by…
Long predicted more than fifty years ago, strong evidence for the existence of crystalline cores inside white dwarfs has recently been obtained by the Gaia space telescope. It is thus important to investigate how a crystalline core may…
We compare the mass distribution of central stars of planetary nebulae (CSPN) with those of their progeny, white dwarfs (WD). We use a dynamical method to measure masses with an uncertainty of 0.02 M$_\odot$. The CSPN mass distribution is…
We revisit in this work the problem of the maximum masses of magnetized White Dwarfs (WD). The impact of a strong magnetic field onto the structure equations is addressed. The pressures become anisotropic due to the presence of the magnetic…
We report on an undergraduate student project initiated in the summer semester of 2004 with the aim to establish equations of state for white dwarfs and neutron stars for computing mass-radius relations as well as corresponding maximum…
We use the Sloan Digital Sky Survey Data Release 12, which is the largest available white dwarf catalog to date, to study the evolution of the kinematical properties of the population of white dwarfs in the Galactic disc. We derive masses,…
Star clusters and dwarf galaxies gradually dissolve as they move in the potential of their host galaxy. Once their density falls below a certain critical density (which is comparable with the background density of the galaxy) it is often…
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…
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…
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…
We study the effect of having a finite temperature on the equation of state and structure of a white dwarf. In order to keep the treatment as general as possible we carry on our discussion for ideal quantum gases obeying to both the…
We determine the distribution of cooling ages of massive Gaia EDR3 white dwarfs identified with over 90% probability within 200 pc and with mass in the range 0.95-1.25 $M_\odot$. Using three sets of publicly available models, we consider…
The masses and radii of strongly magnetized anisotropic deformed white dwarf stars are investigated using the stellar structure equations in the parameterized $\gamma$-metric formalism. The Equation of State (EoS) of a completely degenerate…
The mass function of hydrogen-rich atmosphere white dwarfs has been frequently found to reveal a distinctive high-mass excess near 1Msun. However, a significant excess of massive white dwarfs has not been detected in the mass function of…
Optical spectroscopic observations of white dwarf stars selected from catalogs based on the Gaia DR2 database reveal nine new gaseous debris disks that orbit single white dwarf stars, about a factor of two increase over the previously known…
We present a population synthesis model which addresses the different mass distributions of the metal-polluted and non-metal-polluted hydrogen-atmosphere white dwarfs identified in volume-limited samples. Specifically, metal-pollution has…