A Detailed View of the Circumstellar Environment and Disk of the Forming O-star AFGL 4176
A Detailed View of the Circumstellar Environment and Disk of the Forming O-star AFGL 4176
复制标题
DOI：
10.3847/1538-4357/ab8adc
复制
发表时间：
2020-04
期刊：
影响因子：
--
通讯作者：
K. Johnston;M. Hoare;H. Beuther;H. Linz;P. Boley;R. Kuiper;N. Kee;T. Robitaille
中科院分区：
文献类型：
--
作者：
K. Johnston;M. Hoare;H. Beuther;H. Linz;P. Boley;R. Kuiper;N. Kee;T. Robitaille
我们提出了一个详细的分析的磁盘和星周环境的形成O型星星AFGL 4176毫米1，放置从阿塔卡马大型毫米/亚毫米阵列（阿尔马）的结果到上下文与多波长数据。利用阿尔马，我们探测到了17个1.2 mm连续谱源，其距离AFGL 4176 mm-1为5“（21，000 Au）。我们发现mm 1在阿尔马波段的光谱指数为3.4 ± 0.2，其1.2 mm连续谱发射的87%以上来自尘埃。从mm 1投影4200 Au的源mm 2可能是喷流中的伴流或蓝移结。我们还探讨了用阿尔马检测的分子系之间的形态差异，从25个分子中发现了203个系，我们将其分为几种形态类型。我们的研究结果表明，AFGL 4176 mm 1提供了一个形成O星的例子，它具有一个大的化学复杂的磁盘，主要是由含氮分子跟踪。在蓝移一侧的磁盘上显示出强烈的发射线主要是含氧的，我们认为这是跟踪磁盘吸积冲击。分子C34 S，H2 CS和CH 3CCN跟踪一个缓慢的广角风或密集的结构在流出腔壁。利用澳大利亚望远镜紧凑阵列（ATCA），我们探测到一个紧凑的连续源（96%来自电离气体）。ATCA NH3（1，1）和（2，2）的发射追踪到一个大尺度（r = 0.5 pc）旋转环，圆盘源mm 1位于该结构的蓝移部分，向西北偏置。
We present a detailed analysis of the disk and circumstellar environment of the forming O-type star AFGL 4176 mm1, placing results from the Atacama Large Millimeter/submillimeter Array (ALMA) into context with multiwavelength data. With ALMA, we detect seventeen 1.2 mm continuum sources within 5″ (21,000 au) of AFGL 4176 mm1. We find that mm1 has a spectral index of 3.4 ± 0.2 across the ALMA band, with >87% of its 1.2 mm continuum emission from dust. The source mm2, projected 4200 au from mm1, may be a companion or a blueshifted knot in a jet. We also explore the morphological differences between the molecular lines detected with ALMA, finding 203 lines from 25 molecules, which we categorize into several morphological types. Our results show that AFGL 4176 mm1 provides an example of a forming O-star with a large and chemically complex disk, which is mainly traced by nitrogen-bearing molecules. Lines that show strong emission on the blueshifted side of the disk are predominantly oxygen-bearing, which we suggest are tracing a disk accretion shock. The molecules C34S, H2CS, and CH3CCN trace a slow wide-angle wind or dense structures in the outflow cavity walls. With the Australia Telescope Compact Array (ATCA), we detect a compact continuum source (96% is from ionized gas. The ATCA NH3(1, 1) and (2, 2) emission traces a large-scale (r ∼ 0.5 pc) rotating toroid with the disk source mm1 in the blueshifted part of this structure offset to the northwest.