Magnetic Fields in Giant Filaments Probed by the Velocity Gradient Technique: Regular Magnetic Field Interrupted by Magnetization Gaps
Magnetic Fields in Giant Filaments Probed by the Velocity Gradient Technique: Regular Magnetic Field Interrupted by Magnetization Gaps
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DOI：
10.3847/1538-4357/ad09df
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发表时间：
2023-11
期刊：
影响因子：
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通讯作者：
Meng-Ke Zhao;Guangxing Li;Jianjun Zhou;Xindi Tang;J. Esimbek;Yuxin He;Da-lei Li;W. Ji;Z. Chang;K. Tursun
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文献类型：
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作者：
Meng-Ke Zhao;Guangxing Li;Jianjun Zhou;Xindi Tang;J. Esimbek;Yuxin He;Da-lei Li;W. Ji;Z. Chang;K. Tursun
本文利用速度梯度技术（VGT）对GRS、FUGIN和SEDIGSM巡天的13CO光谱数据进行了分析，研究了与银河系旋臂有关的六个巨暗条的磁场结构。与尘埃偏振发射不同，VGT允许我们使用速度信息分离前景和背景，从中可以可靠地确定磁场的方向。我们发现，在大多数情况下，磁场保持与丝体，这是平行于磁盘中平面对齐。其中，G29、G47和G51表现出平滑的磁场，而G24、G339和G349表现出不连续性。事实上，大多数暗条的磁场都与银河圆盘中平面保持一致，这表明银河剪切可能是形成暗条的原因。磁场可以在我们分析的分辨率（10 pc）下保持规则，其中湍流穿越时间与剪切时间相比很短，这一事实表明湍流运动不能有效地破坏磁场的规则取向。在某些暗条中发现的不连续性可能是由暗条重组、引力坍缩和恒星反馈等过程造成的。
We study the magnetic field structures in six giant filaments associated with the spiral arms of the Milky Way by applying the velocity gradient technique (VGT) to the 13CO spectroscopic data from the GRS, FUGIN, and SEDIGSM surveys. Unlike dust-polarized emission, the VGT allows us to separate the foreground and background using the velocity information, from which the orientation of the magnetic field can be reliably determined. We find that in most cases the magnetic fields stay aligned with the filament bodies, which are parallel to the disk midplane. Among these, G29, G47, and G51 exhibit smooth magnetic fields, and G24, G339, and G349 exhibit discontinuities. The fact that most filaments have magnetic fields that stay aligned with the Galactic disk midplane suggests that Galactic shear may be responsible for shaping the filaments. The fact that the magnetic field can stay regular at the resolution of our analysis (≲10 pc), where the turbulence crossing time is short compared to the shear time, suggests that turbulent motion cannot effectively disrupt the regular orientation of the magnetic field. The discontinuities found in some filaments can be caused by processes including filament reassembly, gravitational collapse, and stellar feedback.