发表机构
National Astronomical Observatories, Chinese Academy of Sciences; School of Astronomy and Space Science, University of Chinese Academy of Sciences（中国科学院国家天文台; 中国科学院大学天文学与空间科学学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
利用FAST发现双中子星系统PSR J1856--0039，测量其相对论效应，证实广义相对论预测，该系统总质量最低，并合后可能形成稳定中子星或黑洞。
AI 中文摘要
紧凑双中子星（DNS）系统是检验引力理论和研究中子星合并的独特实验室。在此，我们报告了在五百米口径球面射电望远镜（FAST）中发现的一个新DNS系统PSR J1856--0039的性质。该脉冲星为轻度再循环脉冲星，周期为23.4毫秒，处于一个紧凑偏心轨道（$e=0.106$）中，轨道周期为2.36小时。通过FAST后续观测，我们测量了相对论效应，包括轨道周期导数$\dot{P}_{\rm orb}=-1.284\pm0.019\times10^{-12}$ s s$^{-1}$、近星点进动$\dot\omega=17.5859\pm0.0007$ deg yr$^{-1}$以及爱因斯坦延迟$\gamma=0.445\pm0.011$ ms。该DNS系统具有较低的轨道倾角$i=133^\circ.2\pm1^\circ.1$，并且是所有已知DNS中总质量最低的，$M_{\rm tot}=2.48841\pm0.00015 M_\odot$，其中确定的脉冲星质量为$1.304\pm0.022 M_\odot$，伴星质量为$1.185\pm0.022 M_\odot$，属于最低的中子星质量之一。观测到的由引力波辐射引起的轨道衰减$\dot{P}^{\rm GW}_{\rm orb,obs}$与广义相对论预测的轨道衰减$\dot{P}^{\rm GW}_{\rm orb,pred}$在$\dot{P}^{\rm GW}_{\rm orb,obs}/\dot{P}^{\rm GW}_{\rm orb,pred}=1.009(14)$（68%置信度）水平上一致。该DNS将在82 Myr后并合，并可能在自转减慢后形成稳定的中子星或坍缩为黑洞。长期监测可能探测到Lense-Thirring进动。
英文摘要
Compact double neutron star (DNS) systems are unique laboratories for testing gravitational theories and studying DNS mergers. Here we report the properties of a new DNS system, PSR J1856--0039, discovered in the Five-hundred-meter Aperture Spherical radio Telescope (FAST). The pulsar is mildly recycled with a period of 23.4~ms in a compact eccentric orbit ($e=0.106$) with an orbital period of 2.36 hours. By following up FAST observations, we measured the relativistic effects, including the orbital period derivative $\dot{P}_{\rm orb}=-1.284\pm0.019\times10^{-12}$ s s$^{-1}$, periastron advance $\dotω=17.5859\pm0.0007$ deg yr$^{-1}$, and Einstein delay $γ=0.445\pm0.011$ ms. This DNS system has a low orbital inclination of $i=133^\circ.2\pm1^\circ.1$ and the lowest total mass of any known DNS, $M_{\rm tot}=2.48841\pm0.00015 M\odot$, with a determined pulsar mass of $1.304\pm0.022 M_\odot$ and a companion mass of $1.185\pm0.022 M_\odot$, one of the lowest neutron-star masses. The observed orbital decay due to gravitational-wave emission $\dot{P}^{\rm GW}_{\rm orb,obs}$ and the orbital decay predicted by general relativity $\dot{P}^{\rm GW}_{\rm orb,pred}$ are consistent at a level of $\dot{P}^{\rm GW}_{\rm orb,obs}/\dot{P}^{\rm GW}_{\rm orb,pred}=$1.009(14) (68% confidence). This DNS will merge after 82 Myr and may form a stable neutron star or collapse into a black hole after spin-down. Long-term monitoring could potentially probe the Lense-Thirring precession.
Comments9 pages, 4 figures, Published by Phys. Rev. Lett
Journal refYang et al., Phys. Rev. Lett., 2026, 137, 121401
