Iron group nuclei electron capture in super-Chandrasekhar superstrong magnetic white dwarfs

Abstract

Abstract Using the theory of relativistic mean-field effective interactions, the influences of superstrong magnetic fields (SMFs) on electron Fermi energy, binding energy per nucleus and single-particle level structure are discussed in super-Chandrasekhar magnetic white dwarfs. Based on the relativistical SMFs theory model of Potekhin et al., the electron chemical potential is corrected in SMFs, and the electron capture (EC) of iron group nuclei is investigated by using the Shell-Model Monte Carlo method and Random Phase Approximation theory. The EC rates can increase by more than three orders of magnitude due to the increase of the electron Fermi energy and the change of single-particle level structure by SMFs. However, the EC rates can decrease by more than four orders of magnitude due to increase of the nuclei binding energy by SMFs. We compare our results with those of FFNs (Fuller et al.), AUFDs (Aufderheide et al.) and Nabi (Nabi et al.). Our rates are higher by about four orders of magnitude than those of FFN, AUFD and Nabi due to SMFs. Our study may have important reference value for subsequent studies of the instability, mass radius relationship, and thermal and magnetic evolution of super-Chandrasekhar magnetic white dwarfs.