Title of article :
Dierent Magnetic Field Distributions in Deformed Neutron Stars
Author/Authors :
Zamani, Mina Department of Physics - University of Zanjan, Zanjan, Iran , Bigdeli, Mohsen Department of Physics - University of Zanjan, Zanjan, Iran
Abstract :
In this work, we review the formalism which would allow us to model
magnetically deformed neutron stars. We study the eect of dierent magnetic eld
congurations on the equation of state (EoS) and the structure of such stars. For
this aim, the EoS of magnetars is acquired by using the lowest order constraint varia-
tional (LOCV) method and employing the AV18 potential. We show how the magnetic
eld varies from the surface to the center of neutron star by using various exponential
and polynomial proles and compare their results. In addition, global properties of
neutron stars are obtained within two formalisms. The rst formalism is described
by considering the pressure into two directions and the deformation of neutron stars
is governed by anisotropies in the equation of state. The second formalism for in-
vestigating macroscopic properties of magnetars is gained by treating the nonuniform
pressure as a perturbation to the total pressure and expanding metric and pressure up
to the quadrupole term in spherical harmonics. Afterwards, we include three nucleon
interactions (TNI) to the EoS and apply this model to represent our results for both
exponential and polynomial magnetic eld proles. The maximum gravitational mass
is obtained in the range of (1.71-1.80) M and (2.13-2.19) M for the EoS without and
with TNI contribution, respectively.
Keywords :
deformed neutron stars , magnetic field profiles , magnetars