发表机构
National Astronomical Observatory of Japan; Institute of Science Tokyo; Niigata University; Shanghai Jiao Tong University; RIKEN Pioneering Research Institute; Institut de Ciències de l’Espai (ICE-CSIC)（日本国立天文台; 东京科学大学; 新潟大学; 上海交通大学; 理化学研究所先锋研究本部; 空间科学研究所在（加泰罗尼亚高等科学研究院））
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
利用ALMA高分辨率观测麦哲伦云中三个大质量年轻恒星天体，揭示不同程度的分裂、外流及化学特征，表明大质量恒星形成过程具有跨环境普遍性。
AI 中文摘要
麦哲伦云为研究超出典型银河系环境的大质量恒星形成提供了极好的实验室。利用ALMA band 7长基线观测，我们呈现了迄今为止麦哲伦云中三个大质量年轻恒星天体（MYSOs）的最高分辨率（约0.03角秒，1500天文单位）视图，即LMC中的Lh03和Lh09，以及SMC中的S07。0.87毫米连续谱，灵敏度约为30微央斯基每束，揭示了不同程度的分裂，从单个致密源（S07）、少数（Lh03）到致密源团簇（Lh09）。在Lh09中，我们识别出17个核候选体，其最低测量质量为2.6太阳质量，其去投影间距峰值约为6000天文单位。所有三个目标均表现出高速CO(3--2)外流，包括检测到由Lh09中一个核驱动的准直双极喷流。在所有源中均检测到来自HCO+、SO和SO2的光谱线。我们观测到可能示踪旋转环面（Lh03）或更复杂运动（Lh09、S07）的速度梯度。综合来看，这些在约1500天文单位尺度上观测到的现象与银河系MYSOs中观测到的现象定性相似，表明在不同环境中大质量恒星形成的基本过程具有一定程度的普遍性。然而，连续谱形态和致密气体运动学中显著的源间多样性促使进行更大规模的高分辨率巡天，以确定这些性质如何随源特征和环境变化。
英文摘要
The Magellanic Clouds provide an excellent laboratory to study massive star formation beyond typical Galactic environments. Using ALMA band 7 long-baseline observations, we present the highest resolution (approximately 0.03", $1500{\rm\:au}$) view to date of three massive young stellar objects (MYSOs) in the Magellanic Clouds, i.e., Lh03 and Lh09 in the LMC, and S07 in the SMC. The 0.87 mm continuum, with a sensitivity of $\sim30\:μ$Jy beam$^{-1}$, reveals varying levels of fragmentation, from a single compact source (S07), a few (Lh03), to a cluster of compact sources (Lh09). In Lh09, we identified 17 core candidates with lowest measured mass of 2.6 Msun, and their de-projected separations peak around 6000~au. All three targets exhibit high velocity CO(3--2) outflows, including detection of a collimated bipolar jet driven by a core in Lh09. Spectral lines from HCO$^+$, SO, and SO$_2$ are detected in all sources. We observe velocity gradients that likely trace rotating toroids (Lh03) or more complex motions (Lh09, S07). Taken together, these phenomena observed on $\sim1500$~au scales are qualitatively similar to those seen in Galactic MYSOs, suggesting a degree of universality in the basic processes of massive star formation across different environments. Nevertheless, the substantial source-to-source diversity in continuum morphology and dense-gas kinematics motivates larger high-resolution surveys to determine how these properties vary with source characteristics and environment.
Comments22 pages, 10 figures, accepted by ApJ
