Magnetic fields and outflows in the large Bok globule CB 54
Magnetic fields and outflows in the large Bok globule CB 54
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大博克小球 CB 54 中的磁场和流出
DOI：
10.1093/mnras/stac1356
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发表时间：
2022
影响因子：
4.8
通讯作者：
Zielinski Niko
中科院分区：
文献类型：
--
作者：
Pattle Kate;Lai Shih-Ping;Sadavoy Sarah;Coude Simon;Wolf Sebastian;Furuya Ray;Kwon Woojin;Lee Chang Won;Zielinski Niko
我们用詹姆斯·克拉克麦克斯韦望远镜（JCMT）上的POL-2偏振计在850-m偏振光下观测了大博克球状体CB 54。我们发现，在小球的外围磁场显示出显着的，有序的偏离平均场方向的小球中心。这种偏差似乎对应于扩展，但相对较弱的12 CO流出所产生的0级源在中心的球。能量学分析表明，如果外流正在重塑球体外围的磁场，那么我们可以将球体外围磁场强度的上限设为G。与普朗克和CARMA测量结果的比较表明，球中心的场在几个数量级的尺度上是一致的，并且在投影中与该区域的密度结构平行。因此，我们假设，虽然在该地区的非热运动可能是次阿尔夫文尼克，磁场是次主导的重力在很大范围内的大小尺度。我们的研究结果表明，即使是相对较弱的外流，也可能在大于0.1 pc的尺度上显著重塑恒星形成区域的磁场。
We have observed the large Bok globule CB 54 in 850-m polarized 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 a significant, ordered deviation from the mean-field direction in the globule centre. This deviation appears to correspond with the extended but relatively weak12CO 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 ofG on the magnetic field strength in the globule’s periphery. Comparison with archivalPlanckand 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 hypothesize that while non-thermal motions in the region may be sub-Alfvénic, 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.