The origin of magnetars - The role of anisotropic neutron superfluid of neutron stars

We estimate the strength of the induced magnetic field due to the Pauli paramagnetic moment of the P-3(2) Cooper pairs for the anisotropic (P-3(2)) neutron superfluid under the applied magnetic field (B-o) in neutron stars. The induced magnetic field of the anisotropic (P-3(2)) neutron superfluid is as follows. B-(in) approximate to 1.9/T-7 eta B-0 (T-7 denotes the interior temperature of the neutron star in unit of 10(7) K), eta = m(P-3(2))/0.1 M-circle dot R-NS,6(-3). The induced magnetic field will gradually increase with the temperature of the neutron star decreasing in their late evolutionary stage. A magnetar may appear in a condition when T-7 << eta. The upper limit of the magnetic field for the magnetars is B-max((in)) (P-3(2)) approximate to 2.02 x 10(14) eta.