发表机构
California Institute of Technology; University of California, Los Angeles; Mani L. Bhaumik Institute for Theoretical Physics（加州理工学院; 加州大学洛杉矶分校; 马尼·L·巴乌米克理论物理研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究构建中子星出生踢的协调模型，结合Gaia和Be+NS双星及孤立脉冲星数据，发现双峰分布可统一解释各群体，并预测低速踢仅占10%但主导双星形成，且约束了前身星及三星系统存活率。
AI 中文摘要
中子星（NS）在超新星爆发期间获得出生时的踢速度，这影响它们在双星系统中的存活以及它们在银河系中的运动。整个中子星种群中这些踢速度的全局分布仍不确定。在此，我们结合Gaia中子星和Be+NS双星的轨道特性与诞生率，以及年轻孤立脉冲星的速度约束，构建了一个中子星出生踢的协调模型。我们发现，这三个种群可以共同由一个共享的双峰踢分布来描述。低速分量遵循对数正态分布，参数为$\mu_{\ln v}=1.87^{+0.65}_{-0.53}$和$\sigma_{\ln v}=0.55^{+0.85}_{-0.44}$，对应的中位速度为$6.5^{+5.9}_{-2.7}~{\rm km~s^{-1}}$。高速分量与从年轻脉冲星推断出的分布一致，该分布峰值接近$200~{\rm km~s^{-1}}$。低速分量仅贡献了所有中子星诞生的约$10\\%$，但产生了大多数Gaia中子星双星和约一半的Be+NS双星。同一模型预测的系统性反冲速度与观测到的Gaia中子星、Be+NS双星以及中子星低质量X射线双星的运动学一致。对于形成历史仍未知的Gaia中子星，我们利用该踢分布来约束其前身星。我们倾向于前身超新星双星系统包含中等质量剥离恒星，其伴星质量约为$1~{\rm M_\odot}$，轨道尺度为au级，并预测银河系中目前约有300个这样的双星系统，大麦哲伦星云中约有40个，小麦哲伦星云中约有30个。最后，我们考虑了这些踢对层次三星系统中子星的影响。我们发现，2-10$\\%$的Gaia中子星三星系统和3-23$\\%$的Be+NS三星系统在超新星爆发后保留了其第三星。总的来说，我们的结果表明，一个共享的出生踢定律可以解释孤立脉冲星和存活的中子星双星系统，其中大多数中子星获得大踢速度，而低速踢在存活的双星系统中很常见。
英文摘要
Neutron stars (NSs) receive natal kicks during supernovae that affect their survival in binaries and motion through the Galaxy. The global distribution of these kick velocities across the NS population remains uncertain. Here, we combine the orbital properties and birth rates of Gaia NS and Be+NS binaries with velocity constraints from young isolated pulsars to construct a concordance model of NS natal kicks. We find that all three populations can be jointly described by a shared bimodal kick distribution. The low-velocity component follows a lognormal distribution with $μ_{\ln v}=1.87^{+0.65}_{-0.53}$ and $σ_{\ln v}=0.55^{+0.85}_{-0.44}$, corresponding to a median speed of $6.5^{+5.9}_{-2.7}~{\rm km~s^{-1}}$. The high-velocity component is consistent with the distribution inferred from young pulsars, which peaks near $200~{\rm km~s^{-1}}$. The low-velocity component contributes only $\sim10\%$ of all NS births, but produces most Gaia NS binaries and roughly half of Be+NS binaries. The same model predicts systemic recoil velocities consistent with the observed kinematics of Gaia NSs, Be+NS binaries, and NS low-mass X-ray binaries. For Gaia NSs, whose formation history remains unknown, we use this kick distribution to constrain their progenitors. We favor pre-supernova binaries containing intermediate-mass stripped stars with $\sim1~{\rm M_\odot}$ companions in au-scale orbits, and predict $\sim300$ such binaries in the Milky Way today, $\sim40$ in the LMC, and $\sim30$ in the SMC. Finally, we consider the implications of these kicks for NSs in hierarchical triples. We find that 2-10$\%$ of Gaia NS triples and 3-23$\%$ of Be+NS triples retain their tertiary after the supernova. Overall, our results suggest that a shared natal kick law can account for isolated pulsars and surviving NS binaries, where most NSs receive large kicks and low kicks are common among surviving binaries.
Comments37 pages, 17 figures, 5 tables. Submitted to PASP; comments are welcome. A simple Python function to sample the kick velocity distribution is available at https://github.com/cheyanneshariat/ns-kick-sampler
