Impact Of Rotation-driven Changes Of Neutrino Radiation Rate On The Thermal Evolution Of Neutron Stars

The inner core of neutron stars is composed of dense matter,the density of which is several times nuclear saturation density or in higher density range.As for the lack of the accurate description for multibody theory of strong interaction particle in nuclear physics and impossible representing the progress in the laboratory on earth,it is difficult to study the core of neutron stars directly.However,with the continuous enrichment of neutron stars thermal radiation datas in recent years,comparing the thermal evolution theory and observational datas may be a good way to exlpore the inner matter in neutron stars.Recent observational datas indicate that the temperature of some neutron stars reduced suddenly as they were spinning down,for example one in Case A and massive neutron star PSR J1614-2230.The amplitude of this process was tremendous.Some neutron stars even cooled down to remarkably low temperatures of T≤106K.The aim of this thesis is to build a self-consistent model to explain the phenomenon of neutron stars temperature reducing tremendously.It provides a possible theory of neutron star thermal evolution for the future observational datas.This model is divided into two parts.The first part is the impact of rotation-driven changes of the stars structure (neutrino radiation rate). We all know that neutrino radiation rate is an integration of a function from the inner core to the outer shell R. Parameters of the function are particle number density、energy density and pressure in r(r≤R).The constitution and state of inner matter would change as the stars spin down.In other words,all the parameters of the function also would change during the same process.Our model would take this impact into consider and revise all the parameters by small perturbation. The second part is the influence of second-order r-mode to speed up the start of Direct Urca process. The second-order r-mode is more effective than magnetic dipole braking.So angular velocity could reach the critical velocity (proton abundance ratio reaches11%)earlier.The result is the temperature of neutron star decreasing suddenly.In our model,we analyse the thermal evolution curve mainly in two sides.As we take the heating effect of second-order r-mode into consider,the first result we can get is that the thermal evolution of the object we choose having structure.It can be divided into seven parts,and two of them are the temperature reducing tremendously for the start of Direct Urca process. We can not observe the first one because of heating relaxation in early time.However,the time and thermal evolution of second one are within observing rage well.The second result:as the heating effect of second-order r-mode is opposite to the temperature reducing of rotation-driven start of Direct Urca process,the relative order of them and the energy they release respectively are crucial to thermal evolution of neutron stars.The effect would change as we choose different K.