Hypernuclear matter in strong magnetic field
Abstract
Compact stars with strong magnetic fields (magnetars) have been observationally determined to have surface magnetic fields of order of 10^{14}10^{15} G, the implied internal field strength being several orders larger. We study the equation of state and composition of dense hypernuclear matter in strong magnetic fields in a range expected in the interiors of magnetars. Within the nonlinear BogutaBodmerWalecka model we find that the magnetic field has sizable influence on the properties of matter for central magnetic field B⩾10^{17} G, in particular the matter properties become anisotropic. Moreover, for the central fields B⩾10^{18} G, the magnetized hypernuclear matter shows instability, which is signalled by the negative sign of the derivative of the pressure parallel to the field with respect to the density, and leads to vanishing parallel pressure at the critical value B_{cr}≃10^{19} G. This limits the range of admissible homogeneously distributed fields in magnetars to fields below the critical value B_{cr}.
 Publication:

Nuclear Physics A
 Pub Date:
 January 2013
 DOI:
 10.1016/j.nuclphysa.2012.12.076
 arXiv:
 arXiv:1005.4995
 Bibcode:
 2013NuPhA.898...43S
 Keywords:

 Neutron stars;
 Nuclear matter;
 Strong magnetic fields;
 Astrophysics  High Energy Astrophysical Phenomena;
 Astrophysics  Astrophysics of Galaxies;
 Astrophysics  Solar and Stellar Astrophysics
 EPrint:
 Revised substantially with new title