年轻脉冲星周期-磁场分类及演化

年轻脉冲星多处于超新星遗迹(Supernova Remnant, SNR)中, 其分为转动供能脉冲星(Rotation-powered SNR-PSR)、磁星(Magnetar)和中心致密天体(Central Compact Object, CCO), 这3类年轻脉冲星有着不同的自旋周期及磁场强度分布. % 其中, 遗迹磁星(SNR-Magnetar)的平均自旋周期比转动供能遗迹脉冲星大近一个量级, 平均磁场强度高近两个量级. % 同时, 中心致密天体比转动供能遗迹脉冲星的平均磁场强度低近两个量级. % 这3类年轻脉冲星不同的物理性质, 可能源于其不同的前身星或不同的超新星爆发过程, 也可能源于其中子星诞生后的不同演化过程. % 此外, 转动供能遗迹脉冲星比年轻的转动供能非遗迹脉冲星具有更快的平均自旋周期、更大的平均磁场强度和更短的平均特征年龄. % 这暗示新诞生的中子星经时间约为$10^5$--$10^6$yr的演化过程, 其自旋速度将减小近一半, 同时其磁场强度也将衰减近一半.

Period-magnetic Field Classification and Evolution of the Young Pulsars

The young pulsars mostly locate in the supernova remnants, which can be classified as the rotation-powered pulsars, magnetars and central compact objects, and these three types of young pulsars share the different distributions of the spin periods and magnetic field strengths. % The remnant magnetars share the average spin period larger than the rotation-powered remnant pulsars by nearly one order of magnitude, while their average magnetic field strength is higher than that of the rotation-powered remnant pulsars by about two orders of magnitude. % Meanwhile, the central compact objects share the average magnetic field strength lower than the rotation-powered remnant pulsars by about two orders of magnitude. % The different physical properties of these three types of young pulsars may originate from their different predecessors, or their different supernova processes, and may also originate from their different evolutional processes after the neutron stars were born. % Furthermore, the rotation-powered remnant pulsars exhibit the faster average spin period, the higher average magnetic field strength, and the shorter average characteristic age than the young rotation-powered non-remnant pulsars. % This implies that when the new born neutron star undergos the evolution process with the timescale of $\tau\sim10^5-10^6$yr, its spin velocity will decrease by about a half, and its magnetic field strength will also decrease by about a half simultaneously. %