标题： 磁场和流出物在大Bok球状体CB 54中 显示英文标题

标题： Magnetic fields and outflows in the large Bok globule CB 54

摘要： 我们使用詹姆斯·克拉克·麦克斯韦望远镜（JCMT）上的POL-2偏振计，在850$\mu$米偏振光下观测了大布克球状体CB 54。 我们发现，球状体边缘的磁场相对于球状体中心的平均磁场方向表现出显著的有序偏离。 这种偏离似乎与从球状体中心的0类源发出的延伸但相对较弱的$^{12}$CO外流相对应。 能量分析表明，如果外流正在重塑球状体边缘的磁场，那么我们可以将球状体边缘的磁场强度上限定为$<27\,\mu$G。 与档案中的普朗克和CARMA测量结果比较显示，球状体中心的磁场在多个数量级的尺寸尺度上是一致的，并且在投影上与该区域的密度结构平行。 因此，我们假设虽然该区域的非热运动可能是亚阿尔芬的，但在广泛的尺寸尺度上，磁场对重力来说是次主导的。 我们的结果表明，即使是一个相对较弱的外流，也能够在$> 0.1$pc尺度上显著重塑恒星形成区域的磁场。 显示英文摘要

摘要： We have observed the large Bok globule CB 54 in 850$\mu$m polarised light using the POL-2 polarimeter on the James Clerk Maxwell Telescope (JCMT). We find that the magnetic field in the periphery of the globule shows significant, ordered deviation from the mean field direction in the globule centre. This deviation appears to correspond with the extended but relatively weak $^{12}$CO outflow emanating from the Class 0 sources at the centre of the globule. Energetics analysis suggests that if the outflow is reshaping the magnetic field in the globule's periphery, then we can place an upper limit of $<27\,\mu$G on the magnetic field strength in the globule's periphery. Comparison with archival Planck and CARMA measurements shows that the field in the centre of the globule is consistent over several orders of magnitude in size scale, and oriented parallel to the density structure in the region in projection. We thus hypothesise that while non-thermal motions in the region may be sub-Alfv\'enic, the magnetic field is subdominant to gravity over a wide range of size scales. Our results suggest that even a relatively weak outflow may be able to significantly reshape magnetic fields in star-forming regions on scales $> 0.1$ pc.