Fallback accretion onto magnetized neutron stars and the hidden magnetic field model

Spanish Relativity Meeting: almost 100 years after Einstein's revolution

Torres, A.^1 ; Cerdá-Durán, P.^1 ; Font, J.A.^1,2

Departamento de Astronomía y Astrofísica, Universitat de València, Dr. Moliner 50, Burjassot (València)

46100, Spain^1

Observatori Astronòmic, Universitat de València, C/ Catedrático José Beltrán 2, Paterna (València)

46980, Spain^2

关键词: General Relativity;    Low magnetic fields;    Magnetic field modeling;    Magnetized neutron stars;    Polytropic model;    Supernova remnants;    Surface magnetic field;    Thermodynamical;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/600/1/012057/pdf
DOI  :  10.1088/1742-6596/600/1/012057

来源: IOP

【 摘 要 】

The observation of several neutron stars with relatively low values of the surface magnetic field found in supernova remnants has led in recent years to controversial interpretations. A possible explanation is the slow rotation of the proto-neutron star at birth which is unable to amplify its magnetic field to typical pulsar levels. An alternative possibility, the hidden magnetic field scenario, seems to be favoured over the previous one due to the observation of three low magnetic field magnetars. This scenario considers the accretion of the fallback of the supernova debris onto the neutron star as the responsible for the observed low magnetic field. In this work, we have studied under which conditions the magnetic field of a neutron star can be buried into the crust due to an accreting fluid. We have considered a simplified toy model in general relativity to estimate the balance between the incoming accretion flow an the magnetosphere. We conclude that the burial is possible for values of the surface magnetic field below 1013G. The preliminary results reported in this paper for simplified polytropic models should be confirmed using a more realistic thermodynamical setup.