English
Related papers

Related papers: Mass-Radius Relation for Magnetic White Dwarfs

200 papers

In this work, we study the properties of magnetized white dwarfs taking into account possible instabilities due to electron capture and pycnonuclear fusion reactions in the cores of such objects. The structure of white dwarfs is obtained by…

Solar and Stellar Astrophysics · Physics 2017-03-31 Edson Otoniel , Bruno Franzon , Manuel Malheiro , Stefan Schramm , Fridolin Weber

In this work we compute models for relativistic white dwarfs in the presence of strong magnetic fields. These models possibly contribute to super-luminous SNIa. With an assumed axi-symmetric and poloidal magnetic field, we study the…

Solar and Stellar Astrophysics · Physics 2015-10-21 Bruno Franzon , Stefan Schramm

The equilibrium configuration and the radial stability of white dwarfs composed of charged perfect fluid are investigated. These cases are analyzed through the results obtained from the solution of the hydrostatic equilibrium equation. We…

Solar and Stellar Astrophysics · Physics 2018-05-21 G. A. Carvalho , José D. V. Arbañil , R. M. Marinho , M. Malheiro

Many stars evolve into magnetic white dwarfs, and observations may help to understand when the magnetic field appears at the stellar surface, if and how it evolves during the cooling phase, and what are the mechanisms that generate it.…

Solar and Stellar Astrophysics · Physics 2021-10-04 S. Bagnulo , J. D. Landstreet

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…

Solar and Stellar Astrophysics · Physics 2018-01-18 A. Kawka

Massive, highly magnetized white dwarfs with fields up to $10^9$ G have been observed and theoretically used for the description of a variety of astrophysical phenomena. Ultramagnetized white dwarfs with uniform interior fields up to…

Solar and Stellar Astrophysics · Physics 2014-09-29 J. G. Coelho , R. M. Marinho , M. Malheiro , R. Negreiros , D. L. Cáceres , J. A. Rueda , R. Ruffini

Recently, some over-luminous Ia supernovaes are found, suggesting that their progenitors are white dwarfs more massive than the Chandrasekhar limit, which perhaps result from ultra-strong magnetic field inside the white dwarfs. We present…

High Energy Astrophysical Phenomena · Physics 2015-05-06 Qi-Xiang Zou , Xin-He Meng

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

The magnetic white dwarfs (MWDs) are found either isolated or in interacting binaries. They divide into two groups: a high field group (0.1-1,000MegaGauss) comprising some 13% of all white dwarfs (WDs), and a low field group (B<0.1MG) whose…

Solar and Stellar Astrophysics · Physics 2020-01-29 Lilia Ferrario , D. T. Wickramasinghe , Adela Kawka

We produce the simple formula for the radius R of a cold body of mass M, (4 pi rho/3)^{1/3} R = I.M^{1/3} / [1+ (M/Mp)^{2/3}], where I is one for white dwarfs with non-relativistic electrons, but depends on the ratio of the total mass to…

Astrophysics · Physics 2007-05-23 D. Lynden-Bell , J. P. O'Dwyer

We investigate the luminosity suppression and its effect on the mass-radius relation as well as cooling evolution of highly magnetised white dwarfs. Based on the effect of magnetic field relative to gravitational energy, we suitably modify…

Solar and Stellar Astrophysics · Physics 2022-04-06 Mukul Bhattacharya , Alexander J. Hackett , Abhay Gupta , Christopher A. Tout , Banibrata Mukhopadhyay

In this work, we investigate the equilibrium configurations of massive white dwarfs (MWD) in the context of modified gravity, namely $f(R,L_m)$ gravity, where $R$ stands for the Ricci scalar and $L_m$ is the Lagrangian matter density. We…

General Relativity and Quantum Cosmology · Physics 2022-06-22 R. V. Lobato , G. A. Carvalho , N. G. Kelkar , M. Nowakowski

Our ongoing spectroscopic survey of high proper motion stars is a rich source of new magnetic white dwarfs. We present a few examples among cool white dwarfs showing the effect of field strength and geometry on the observed optical…

Solar and Stellar Astrophysics · Physics 2018-01-18 S. Vennes , A. Kawka , L. Ferrario , E. Paunzen

The presence of a strong magnetic field is a feature common to a significant fraction of degenerate stars, yet little is understood about field origin and evolution. New observational constraints from volume-limited surveys point to a more…

Solar and Stellar Astrophysics · Physics 2022-08-24 Stefano Bagnulo , John D. Landstreet

When a star exhausts its nuclear fuel, it either explodes as a supernova or more quiescently becomes a white dwarf, an object about half the mass of our Sun with a radius of about that of the Earth. About one fifth of white dwarfs exhibit…

We clarify important physics issues related to the recently established new mass limit for magnetized white dwarfs which is significantly super-Chandrasekhar. The issues include, justification of high magnetic field and the corresponding…

Solar and Stellar Astrophysics · Physics 2014-06-05 Upasana Das , Banibrata Mukhopadhyay

Around 10% of white dwarfs exhibit global magnetic structures with fields ranging from 1 kG to hundreds of MG. Recently, the first radiation magnetohydrodynamics simulations of the atmosphere of white dwarfs showed that convection should be…

The presence of a white dwarf in a resolved binary system, such as Sirius, provides an opportunity to combine dynamical information about the masses, from astrometry and spectroscopy, with a gravitational red-shift measurement and…

Solar and Stellar Astrophysics · Physics 2015-05-14 M. A. Barstow , H. E. Bond , M. R. Burleigh , S. L. Casewell , J. Farihi , J. B. Holberg , I. Hubeny

Weak magnetic field has been searched for on only a small number of white dwarfs. Current estimates for white dwarfs with fields in excess of 1MG are about 10%; according to previous studies this number increases up to about 25% in the kG…

Astrophysics · Physics 2007-05-23 S. Jordan , R. Aznar Cuadrado , R. Napiwotzki , H. M. Schmid , S. K. Solanki

The mass-radius relations for white dwarf stars are investigated by solving the Newtonian as well as Tolman-Oppenheimer-Volkoff (TOV) equations for hydrostatic equilibrium assuming the electron gas to be non-interacting. We find that the…

Solar and Stellar Astrophysics · Physics 2017-11-07 Arun Mathew , Malay K. Nandy