More than 50 years after the discovery of pulsars¹ and confirmation of their association with supernova explosions^2,3,4, the origin of the initial spin and velocity of pulsars remains largely a mystery. The typical space velocities of several hundred km s⁻¹ have been attributed to ‘kicks’ resulting from asymmetries either in the supernova ejecta or in the neutrino emission^5,6,7. Observations have shown a strong tendency for alignment between the pulsar space velocity and the spin axis in young pulsars, but until now these comparisons have been restricted to two dimensions. Here, we report evidence for three-dimensional alignment between the spin and velocity vectors, largely based on observations made with the Five-hundred-meter Aperture Spherical Radio Telescope (FAST) of the pulsar PSR J0538+2817 and its associated supernova remnant S147. Analysis of these and related observations has enabled us to determine the location of the pulsar within the supernova remnant and hence its radial velocity. Current simulations of supernova explosions have difficulty producing such three-dimensional alignment^7,8,9. Our results, which depend on the unprecedented sensitivity of the observations, add another dimension to the intriguing correlation between pulsar spin-axis and birth-kick directions, thereby deepening the mysteries surrounding the birth of neutron stars.

^{在发现脉冲星1}并确认它们与超新星爆炸^2,3,4的关联50 多年后，脉冲星的初始自旋和速度的起源在很大程度上仍然是一个谜。数百 km s ^-1的典型空间速度归因于超新星喷出物或中微子发射中的不对称性导致的“踢” ^5,6,7. 观测表明，年轻脉冲星的脉冲星空间速度和自旋轴之间存在强烈的对齐趋势，但到目前为止，这些比较仅限于二维。在这里，我们报告了自旋和速度矢量之间的三维对齐的证据，主要基于对脉冲星 PSR J0538+2817 及其相关超新星遗迹 S147 的 500 米孔径球面射电望远镜 (FAST) 的观测。对这些和相关观测的分析使我们能够确定脉冲星在超新星遗迹内的位置，从而确定它的径向速度。当前对超新星爆炸的模拟很难产生这样的三维排列^7,8,9. 我们的结果依赖于前所未有的观测灵敏度，为脉冲星自旋轴和出生踢方向之间有趣的相关性增加了另一个维度，从而加深了围绕中子星诞生的谜团。