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Related papers: Cool white dwarfs : cooling theory and Galactic im…

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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 carried out a spectroscopic investigation of single lined white dwarfs (WDs) in double degenerate (DD) systems and discuss their binary evolution. Simulated spectra of the Halpha region are used to derive upper limits on the temperature…

Solar and Stellar Astrophysics · Physics 2009-07-22 S. Weston , R. Napiwotzki

Reliable modeling of the atmospheres of cool white dwarfs is crucial for understanding the atmospheric evolution of these stars and for accurate white dwarfs cosmochronology. Over the last decade {\it ab initio} modeling entered many…

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

A simple cooling model of white dwarf stars is re-analyzed in Palatini $f(R)$ gravity. Modified gravity affects the white dwarf structures and consequently their ages. We find that the resulting super-Chandrasekhar white dwarfs need more…

General Relativity and Quantum Cosmology · Physics 2022-12-06 Surajit Kalita , Lupamudra Sarmah , Aneta Wojnar

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

We examine the recent results of the MACHO collaboration towards the Large Magellanic Cloud (Alcock et al. 1996) in terms of a halo brown dwarf or white dwarf population. The possibility for most of the microlensing events to be due to…

Astrophysics · Physics 2009-10-28 Gilles Chabrier , Laurent Segretain , Dominique Méra

White dwarf evolution is essentially a gravothermal cooling process, which,for cool white dwarfs, sensitively depends on the treatment of the outer boundary conditions. We provide detailed outer boundary conditions appropriate for computing…

Solar and Stellar Astrophysics · Physics 2015-06-11 R. D. Rohrmann , L. G. Althaus , E. García-Berro , A. H. Córsico , M. M. Miller Bertolami

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…

Solar and Stellar Astrophysics · Physics 2017-11-20 Riccardo Fantoni

White Dwarfs (WDs) are the final evolutionary product of the vast majority of stars in the Universe. They are electron-degenerate structures characterized by no stable thermonuclear activity, and their evolution is generally described as a…

Astrophysics of Galaxies · Physics 2021-09-07 J. Chen , F. R. Ferraro , M. Cadelano , M. Salaris , B. Lanzoni , C. Pallanca , L. G. Althaus , E. Dalessandro , -

Motivated by recent measurements which suggest that roughly half the mass of the galactic halo may be in the form of white dwarfs, we study the implications of such a halo. We first use current limits on the infrared background light and…

Astrophysics · Physics 2009-10-28 Fred C. Adams , Greg Laughlin

The evolution of white dwarfs is essentially a gravothermal process of cooling in which the basic ingredients for predicting their evolution are well identified, although not always well understood. There are two independent ways to test…

High Energy Astrophysical Phenomena · Physics 2022-02-07 Jordi Isern , Santiago Torres , Alberto Rebassa-Mansergas

We investigate the luminosity and cooling of highly magnetized white dwarfs with electron-degenerate cores and non-degenerate surface layers where cooling occurs by diffusion of photons. We find the temperature and density profiles in the…

Solar and Stellar Astrophysics · Physics 2018-05-14 Mukul Bhattacharya , Banibrata Mukhopadhyay , Subroto Mukerjee

We calculate the expected white dwarf luminosity functions and discovery functions in photometric passbands, if these stellar remnants provide a substantial fraction of the sought Galactic dark matter, as suggested on various observational…

Astrophysics · Physics 2009-10-31 Gilles Chabrier

We analyze the effects of modified gravity on specific heats of electrons and ions, Debye temperature, crystallization process, and cooling mechanism in white dwarfs. We derive the Lane-Emden-Chandrasekhar equation and relate it to the…

General Relativity and Quantum Cosmology · Physics 2023-03-07 Surajit Kalita , Lupamudra Sarmah , Aneta Wojnar

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…

Cool white dwarfs are reliable and independent stellar chronometers. The most common white dwarfs have carbon-oxygen dense cores. Consequently, the cooling ages of very cool white dwarfs sensitively depend on the adopted phase diagram of…

Solar and Stellar Astrophysics · Physics 2015-05-30 Leandro G. Althaus , Enrique García-Berro , Jordi Isern , Alejandro H. Córsico , Marcelo M. Miller Bertolami

White dwarfs carry information on the structure and evolution of the Galaxy, especially through their luminosity function and initial-to-final mass relation. Very cool white dwarfs provide insight into the early ages of each population.…

Sufficiently old white dwarfs cool down through a convective envelope that directly couples their degenerate cores to the surface. Magnetic fields may inhibit this convection by stiffening the criterion for convective instability. We…

Solar and Stellar Astrophysics · Physics 2024-09-13 Sivan Ginzburg

Recent Hubble Space Telescope observations have unveiled the white dwarf cooling sequence of the Galactic bulge. Although the degenerate sequence can be well fitted employing the most up-to-date theoretical cooling sequences, observations…

Astrophysics of Galaxies · Physics 2018-02-21 S. Torres , E. García-Berro , R. Cojocaru , A. Calamida

It was predicted more than 40 years ago that the cores of the coolest white dwarf stars should eventually crystallize. This effect is one of the largest sources of uncertainty in white dwarf cooling models, which are now routinely used to…

Astrophysics · Physics 2009-11-10 T. S. Metcalfe , M. H. Montgomery , A. Kanaan