标题： 无星核心 L 1512 的磁场 显示英文标题

标题： Magnetic fields of the starless core L 1512

摘要： 我们展示了JCMT POL-2 850微米尘埃极化观测和Mimir H波段恒星偏振观测针对星less核心L1512的结果。 我们检测到了POL-2数据所追踪的高度有序的核心尺度磁场，该磁场的方向与由Planck数据追踪的解析尺度磁场方向一致，表明从低密度区域到致密核心区域的大尺度磁场贯穿其中。 由Mimir数据追踪的周围磁场显示出场向更宽的变化，表明在包层尺度上可能存在磁场形态的转变。 先前的一项研究通过时变化学分析提出L1512可能超过1.4 Myr，暗示磁场可能足够强以减缓L1512的塌缩。 在这项研究中，我们使用Davis-Chandrasekhar-Fermi方法得出了天空平面上的磁场强度（$B_{pos}$）为18$\pm$7 μG和观测到的质量通量比（$\lambda_{obs}$）为3.5$\pm$2.4，表明L1512在磁性上是超临界的。 然而，没有显著的吸积运动和存在振荡包层与磁性超临界条件不一致。 通过Virial分析，我们建议存在一个迄今隐藏的视线磁场强度约为27 μG且质量通量比（$\lambda_{tot}$）约为1.6，在这种情况下，磁场压力和动能压力都是支持L1512核心的重要因素。 另一方面，L1512可能刚刚达到超临界状态并且随时会塌缩。 显示英文摘要

摘要： We present JCMT POL-2 850 um dust polarization observations and Mimir H band stellar polarization observations toward the starless core L1512. We detect the highly-ordered core-scale magnetic field traced by the POL-2 data, of which the field orientation is consistent with the parsec-scale magnetic fields traced by Planck data, suggesting the large-scale fields thread from the low-density region to the dense core region in this cloud. The surrounding magnetic field traced by the Mimir data shows a wider variation in the field orientation, suggesting there could be a transition of magnetic field morphology at the envelope scale. L1512 was suggested to be presumably older than 1.4 Myr in a previous study via time-dependent chemical analysis, hinting that the magnetic field could be strong enough to slow the collapse of L1512. In this study, we use the Davis-Chandrasekhar-Fermi method to derive a plane-of-sky magnetic field strength ($B_{pos}$) of 18$\pm$7 uG and an observed mass-to-flux ratio ($\lambda_{obs}$) of 3.5$\pm$2.4, suggesting that L1512 is magnetically supercritical. However, the absence of significant infall motion and the presence of an oscillating envelope are inconsistent with the magnetically supercritical condition. Using a Virial analysis, we suggest the presence of a hitherto hidden line-of-sight magnetic field strength of ~27 uG with a mass-to-flux ratio ($\lambda_{tot}$) of ~1.6, in which case both magnetic and kinetic pressures are important in supporting the L1512 core. On the other hand, L1512 may have just reached supercriticality and will collapse at any time.