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Title: Dynamical instability of white dwarfs and breaking of spherical symmetry under the presence of extreme magnetic fields

Massive, highly magnetized white dwarfs with fields up to 10{sup 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 10{sup 18} G have been recently purported to obey a new maximum mass limit, M {sub max} ≈ 2.58 M {sub ☉}, which largely overcomes the traditional Chandrasekhar value, M {sub Ch} ≈ 1.44 M {sub ☉}. Such a larger limit would make these astrophysical objects viable candidates for the explanation of the superluminous population of Type Ia supernovae. We show that several macro and micro physical aspects such as gravitational, dynamical stability, breaking of spherical symmetry, general relativity, inverse β decay, and pycnonuclear fusion reactions are of most relevance for the self-consistent description of the structure and assessment of stability of these objects. It is shown in this work that the first family of magnetized white dwarfs indeed satisfy all the criteria of stability, while the ultramagnetized white dwarfs are very unlikely to exist in nature since they violate minimal requests of stability. Therefore, the canonical Chandrasekhar mass limit of white dwarfs still has to be applied.
Authors:
; ; ;  [1] ; ;  [2] ;  [3]
  1. Dipartimento di Fisica and ICRA, Sapienza Università di Roma, P.le Aldo Moro 5, I-00185 Rome (Italy)
  2. Departamento de Física, Instituto Tecnológico de Aeronáutica, ITA, São José dos Campos, 12228-900 SP (Brazil)
  3. Instituto de Física, Universidade Federal Fluminense, UFF, Niterói, 24210-346 RJ (Brazil)
Publication Date:
OSTI Identifier:
22370443
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 794; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ASTROPHYSICS; GENERAL RELATIVITY THEORY; HEAVY ION FUSION REACTIONS; INSTABILITY; MAGNETIC FIELDS; MASS; SPHERICAL CONFIGURATION; STABILITY; SUPERNOVAE; SYMMETRY; THERMONUCLEAR REACTIONS; WHITE DWARF STARS