论文标题

原始群集中的巨大质子 - G35.20-0.74N的多尺度Alma视图

Massive Protostars in a Protocluster -- A Multi-Scale ALMA View of G35.20-0.74N

论文作者

Zhang, Yichen, Tanaka, Kei E. I., Tan, Jonathan C., Yang, Yao-Lun, Greco, Eva, Beltrán, Maria T., Sakai, Nami, De Buizer, James M., Rosero, Viviana, Fedriani, Rubén, Garay, Guido

论文摘要

我们提出了一项详细的研究,该研究对ALMA 1.3 mm多配置观测值进行了巨大的恒星形成区G35.2-0.74N。在0.2“(440 au)的分辨率下,连续发射揭示了沿丝状结构的几个致密核,与先前的ALMA 0.85 mm观测一致。在0.03“(66 au)分辨率下,我们检测到22个紧凑型源,其中大多数与丝状相关。其中四个来源与紧凑的厘米连续发射有关,其中两个与H30α重组线发射有关。 H30α线运动学显示离子气体的有序运动与磁盘旋转和/或流出扩展一致。我们构建了光电离区域的模型,以同时拟合多波长的无效通量和H30α总通量。衍生特性表明至少存在三个具有新生超紧张HII区域的大型年轻恒星。这些电离区域中的两个被一个大的旋转结构包围,该结构供应两个单独的磁盘,这些磁盘由密集的气体示踪剂(例如SO2,H2CO和CH3OH)揭示。特别是,SO2发射突出了其中一个磁盘中的两个螺旋结构,并探测了更快的旋转内部磁盘。来自一般区域的12CO发射揭示了一个复杂的流出结构,至少确定了四个外流。预计其余的18个紧凑型源将与大型恒星附近形成的低质量原恒星有关。我们发现由于该原始群集内部区域的动态相互作用而导致磁盘破坏的潜在证据。来源的空间分布表明没有亚集群的平稳整体径向密度梯度,但具有原始质量分离的暂定证据。

We present a detailed study of the massive star-forming region G35.2-0.74N with ALMA 1.3 mm multi-configuration observations. At 0.2" (440 au) resolution, the continuum emission reveals several dense cores along a filamentary structure, consistent with previous ALMA 0.85 mm observations. At 0.03" (66 au) resolution, we detect 22 compact sources, most of which are associated with the filament. Four of the sources are associated with compact centimeter continuum emission, and two of these are associated with H30α recombination line emission. The H30α line kinematics show ordered motion of the ionized gas, consistent with disk rotation and/or outflow expansion. We construct models of photoionized regions to simultaneously fit the multi-wavelength free-free fluxes and the H30α total fluxes. The derived properties suggest the presence of at least three massive young stars with nascent hypercompact Hii regions. Two of these ionized regions are surrounded by a large rotating structure that feeds two individual disks, revealed by dense gas tracers, such as SO2, H2CO, and CH3OH. In particular, the SO2 emission highlights two spiral structures in one of the disks and probes the faster-rotating inner disks. The 12CO emission from the general region reveals a complex outflow structure, with at least four outflows identified. The remaining 18 compact sources are expected to be associated with lower-mass protostars forming in the vicinity of the massive stars. We find potential evidence for disk disruption due to dynamical interactions in the inner region of this protocluster. The spatial distribution of the sources suggests a smooth overall radial density gradient without subclustering, but with tentative evidence of primordial mass segregation.

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