Time dependent London approach, dissipation due to out-of-core normal excitations by moving vortices

The dissipative currents due to normal excitations are included in the London description. The resulting time dependent London equations are solved for a moving vortex and a moving vortex lattice. It is shown that the field distribution of a moving vortex looses it cylindrical symmetry, it experiences contraction which is stronger in the direction of the motion, than in the direction normal to the velocity $\bm v$. The London contribution of normal currents to dissipation is small relative to the Bardeen-Stephen core dissipation at small velocities, but approaches the latter at high velocities, where this contribution is no longer proportional to $v^2$. To minimize the London contribution to dissipation, the vortex lattice orients as to have one of the unit cell vectors along the velocity, the effect seen in experiments and predicted within the time-dependent Ginzburg-Landau theory.Comment: 6 pages, 5 figure

Origin of GRB Afterglows in the Model of Galactic Neutron Stars

The launch of the Beppo-Sax satellite gave a unique opportunity to investigate gamma ray bursts (GRB) in different spectral regions. The large diversity of the afterglow behavior creates additional problems for the cosmological model with a fireball. Formation of the afterglow giving the observed diversity of properties is suggested in the Galactic neutron star model of GRBs. It is based on the transient accretion disc formation around the neutron star with a low-mass brown companion irradiated by the neutron star.Comment: Talk at the Workshop "Gamma-Ray Bursts in the Afterglow Era", Rome, November 3-6. To appear in A&A Supp

High Velocity Neutron Stars as a Result of Asymmetric Neutrino Emission

Formation of a neutron star is accompanied by neutrino emission carring about 10% of the rest energy of the star. Toroidal field produced by twisting of a dipole field in differentially rotating star is antisymmetric. Its summation with antisymmetric toroidal field results in braking of mirror symmetry of the magnetic field . For large magnetic field the neutron decay rate depends on its strength. Neutrino is emitted more in one direction leading to flux asymmetry and recoil of the neutron star. Estimations show that the neutron star can reach velocities $\sim 1000$ km/s for 3% asymmetry of the neutrino flux.Comment: Latex, no figures, 5 page