The neutrino emissivity and the cooling energy resources by magnetic monopole in white dwarfs

Abstract

Some typical low mass and high mass white dwarfs (WDs) are selected and the neutrino emissivity and the cooling energy resources problems are discussed. We present three models (I, II, III) to investigate the number of magnetic monopole (MM) captured, the luminosity, and the neutrino emissivity based on the MM catalytic nuclear decay. Model (I) mainly considers the effect of compression factor on thermonuclear cross section and ignores the effect of mass radius relationship on luminosity and neutrino emissivity. Model (II) only considers the effect of mass radius relationship at zero temperature on the number of MMs captured, the luminosities and the neutrino emissivity. Model (III) discusses the equation of state of the plasma and considers the effect of the number of MMs captured on the mass radius relationship, then investigates the number of MMs captured, the luminosities and the neutrino emissivity. Firstly, we find that the maximum of the number of captured MMs and the luminosities of these WDs can be 1.313×1029, and 2.083×1036ergss−1, respectively. Secondly, the luminosities due to MM catalytic nuclear decay for models (I, III) are agreed well with the observations, but the luminosities for model (II) are higher than the observations. Finally, the maximum of the neutrino emission rates of these WDs can be 1.626×1038s−1. The neutrino emission may not influence the structure and the evolution of the WDs. However, the monopole-catalyzed nucleon decay process may be regarded as a mechanism for keeping WDs hot.