Long-period thermal oscillations in superfluid millisecond pulsars

摘要: Context. In previous papers, we have shown that, as the rotation of a neutron star slows down, it will be internally heated consequence progressively changing mix particles (rotochemical heating). previously studied cases (non-superfluid stars or superfluid with only modified Urca reactions), this leads to quasi-steady state in which radiates thermal photons for long time, possibly accounting ultraviolet radiation observed from millisecond pulsar J0437-4715. Aims. For first explore phenomenology rotochemical heating direct reactions and uniform isotropic energy gaps different sizes. Methods. We do exploratory work by integrating chemical evolution equations numerically gaps, uncovers rich stable unstable solutions. To understand these, perform stability analysis around state, identifying characteristic times growing, decaying, oscillating Results. small is similar cases, sense that solutions quickly converge state. large (>0.05 MeV), these become unstable, leading limit-cycle behavior periodicity ∼10 6−7 yr, hot (Ts > 10 5 K) fraction cycle (∼5–20%), cold longer time.