THE INFLUENCE OF A STRONG MAGNETIC-FIELD ON ELECTRON-CAPTURE IN AN ACCRETING NEUTRON-STAR

By considering the quantum effect of electrons in a strong magnetic field (SMF), the formulas of electron-capture (EC) rate and neutrino energy loss rate in the outer crust of an accreting neutron star in the presence of a SMF are derived and compared with the circumstance in the absence of a magnetic field (MF). As an example, the EC reactions of helium-3 in a SMF are investigated. We draw the following conclusions: (1) for a sufficiently SMF and a low density (only the lowest Landau level), the SMF slows down the reactions at constant density; (2) for a relatively weak MF and a high density, the MF has only a minor effect on the reactions.