arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2407.19635astro-ph.GA
收藏

猎户座中的原恒星：表征其磁化包层的性质

The protostars in Orion: Characterizing the properties of their magnetized envelopes

B. Huang, J. M. Girart, I. W. Stephens, M. Fernandez-Lopez, J. J. Tobin, P. Cortes, N. M. Murillo, P. C. Myers, S. Sadavoy, Q. Zhang, H. G. Arce, J. M. Carpente… 展开作者

B. Huang, J. M. Girart, I. W. Stephens, M. Fernandez-Lopez, J. J. Tobin, P. Cortes, N. M. Murillo, P. C. Myers, S. Sadavoy, Q. Zhang, H. G. Arce, J. M. Carpenter, W. Kwon, V. J. M. Le Gouellec, Z. -Y. Li, L. W. Looney, T. Megeath, E. G. Cox, N. Karnath, D. Segura-Cox

备注：
25 pages, 6 figures, accepted in ApJ
阅读 PDF
arXiv 页面 ↗HTML 原文 ↗

AI总结：

该研究利用ALMA等观测数据探究猎户座原恒星包层性质与磁场形态的关联，发现磁场形态影响包层碎裂与盘大小，标准沙漏形磁场磁制动更强，磁场与外流轴不对准则会削弱制动形成更大盘。

摘要：

我们开展了一项将原恒星包层物理性质与包层尺度磁场形态相关联的研究。我们利用来自B场猎户座原恒星巡天（B-field Orion Protostellar Survey）的61颗年轻原恒星在0.87毫米、~400-3000 au尺度下的ALMA偏振观测结果，推断包层尺度的磁场，并利用尘埃发射在相近尺度上测量包层性质。我们发现，呈现标准沙漏场形态的原恒星，其包层往往质量更大、速度弥散更低，而具有螺旋场形态的系统则速度弥散更高。结合猎户座VLA/ALMA新生盘与多性巡天（Orion VLA/ALMA Nascent Disk and Multiplicity survey）得到的盘性质，我们将包层性质与碎裂过程关联起来。结果表明，碎裂水平与磁场的角度弥散呈正相关，说明包层碎裂倾向于被磁场抑制。我们还发现，与其他磁场位形（尤其是旋转沙漏形，以及螺旋形等其他形态）相比，呈现标准沙漏磁场结构的原恒星往往盘更小、磁场角度弥散更低，表明标准沙漏形磁场的磁制动效应更显著。不过，磁场与外流轴之间的显著不对准往往会削弱磁制动，从而导致更大的盘形成。

英文摘要：

We present a study connecting the physical properties of protostellar envelopes to the morphology of the envelope-scale magnetic field. We used the ALMA polarization observations of 61 young prtostars at 0.87 mm on $\sim400-3000$ au scales from the {\em B}-field Orion Protostellar Survey to infer the envelope-scale magnetic field, and used the dust emission to measure the envelope properties on comparable scales. We find that protostars showing standard-hourglass-field morphology tend to have larger masses and lower velocity dispersions in their envelopes, whereas systems with spiral-field morphologies have higher velocity dispersion. Combining with the disk properties taken from the Orion VLA/ALMA Nascent Disk and Multiplicity survey, we connect envelope properties to fragmentation. Our results show that the fragmentation level is positively correlated with the angle dispersion of the magnetic field, suggesting that the envelope fragmentation tends to be suppressed by the magnetic field. We also find that protostars exhibiting standard hourglass magnetic field structure tend to have a smaller disk and smaller angle dispersion of the magnetic field than other field configurations, specially the rotated hourglass, but also the spiral and others, suggesting a more effective magnetic braking in the standard hourglass morphology of magnetic fields. Nevertheless, significant misalignment between the magnetic field and outflow axes tends to reduce magnetic braking, leading to the formation of larger disks.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

↑