Magnetic Field Uniformity Across the GF 9-2 YSO, L1082C Dense Core, and GF 9 Filamentary Dark Cloud
Magnetic Field Uniformity Across the GF 9-2 YSO, L1082C Dense Core, and GF 9 Filamentary Dark Cloud
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DOI：
10.3847/1538-4357/aae2af
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发表时间：
2018-09
期刊：
影响因子：
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通讯作者：
D. Clemens;A. M. El-Batal;C. Cerny;S. Kressy;G. Schroeder;T. Pillai
中科院分区：
文献类型：
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作者：
D. Clemens;A. M. El-Batal;C. Cerny;S. Kressy;G. Schroeder;T. Pillai
丝状暗云 GF 9 中磁场（B 场）的方向从云的外围追踪到包含低质量、低光度 0 级年轻恒星物体 (YSO) GF 9-2 (IRAS 20503+6006) 的 L1082C 致密核心。这是使用 216 μm 处的 SOFIA HAWC+ 尘埃热发射偏振测定法 (TEP) 结合在 H 波段 (1.6 μm) 和 K 波段 (2.2 μm) 中进行的 Mimir 近红外背景星光偏振测定法 (BSP) 完成的。这些观察结果通过已发表的 I 波段 (0.77 μm) BSP 和 Planck 850 μm TEP 得到增强，以探测 B 场方向，与 YSO 的偏移范围在 6000 au 到 3 pc 之间。没有发现随着偏移量而发生强烈的 B 场方向变化，这表明从云边缘到 YSO 周围的 B 场具有显着的均匀性。这一发现与云核和 YSO 形成的弱场模型不一致。 TEP 和 BSP 探测器推断的 B 场方向的连续性有力地证明了两者都在采样均匀穿过云、核心和 YSO 区域的公共 B 场。对与 Mimir BSP 恒星匹配的 Gaia DR2 恒星进行贝叶斯分析，发现与 GF 9 的距离为 270 ± 10 pc。与之前的说法相反，没有发现 B 场取向角对波长有很强的依赖性。
The orientation of the magnetic field (B field) in the filamentary dark cloud GF 9 was traced from the periphery of the cloud into the L1082C dense core that contains the low-mass, low-luminosity Class 0 young stellar object (YSO) GF 9-2 (IRAS 20503+6006). This was done using SOFIA HAWC+ dust thermal emission polarimetry (TEP) at 216 μm in combination with Mimir near-infrared background starlight polarimetry (BSP) conducted in the H band (1.6 μm) and K band (2.2 μm). These observations were augmented with published I-band (0.77 μm) BSP and Planck 850 μm TEP to probe B-field orientations with offset from the YSO in a range spanning 6000 au to 3 pc. No strong B-field orientation change with offset was found, indicating remarkable uniformity of the B-field from the cloud edge to the YSO environs. This finding disagrees with weak-field models of cloud core and YSO formation. The continuity of inferred B-field orientations for both TEP and BSP probes is strong evidence that both are sampling a common B field that uniformly threads the cloud, core, and YSO region. Bayesian analysis of Gaia DR2 stars matched to the Mimir BSP stars finds a distance to GF 9 of 270 ± 10 pc. No strong wavelength dependence of B-field orientation angle was found, contrary to previous claims.