A Detailed View of the Circumstellar Environment and Disk of the Forming O-star AFGL 4176 - Online Data

These data accompany the ApJ paper Johnston et al. (2020), "A Detailed View of the Circumstellar Environment and Disk of the Forming O-star AFGL 4176" ArXiv link: https://arxiv.org/abs/2004.13739 Abstract: 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 C^{34}S, 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 (<2000 x 760 au) at 1.2 cm, associated with mm1, of which >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. A list and short description of the files in this Zenodo dataset are given in the file README_Johnstonetal2020.txt.本数据集配套发表于《天体物理学杂志》(Astrophysical Journal，ApJ)的Johnston等人(2020)论文《形成中的O型星AFGL 4176的星周环境与原行星盘精细观测》，预印本链接：https://arxiv.org/abs/2004.13739。 摘要：我们对形成中的O型星AFGL 4176 mm1的原行星盘与星周环境开展精细分析，将阿塔卡马大型毫米/亚毫米波阵列(Atacama Large Millimeter/submillimeter Array，ALMA)的观测结果与多波段数据结合展开阐释。利用ALMA，我们在AFGL 4176 mm1周围5角秒（对应21000天文单位，au）范围内探测到17个1.2毫米连续辐射源。我们发现mm1在ALMA各波段的谱指数为3.4±0.2，其1.2毫米连续辐射中超过87%来自尘埃辐射。投影距离mm1为4200 au的源mm2，可能是一颗伴星或是喷流中的蓝移结团。我们还分析了ALMA探测到的分子谱线的形态差异，共识别出25种分子的203条谱线，并将其划分为多种形态类型。 我们的研究结果表明，AFGL 4176 mm1是一颗形成中的O型星，其拥有大尺度且化学组成复杂的原行星盘，该盘主要由含氮分子示踪。蓝移侧发射较强的谱线则以含氧分子为主，我们认为这类谱线示踪了盘吸积激波。分子C³⁴S、H₂CS与CH₃CCN示踪了外流腔壁处的慢速广角风或致密结构。 利用澳大利亚紧凑型望远镜阵列(Australia Telescope Compact Array，ATCA)，我们在1.2厘米波段探测到一个与mm1相关的致密连续辐射源（尺寸小于2000×760 au），其中超过96%的辐射来自电离气体。ATCA观测到的NH₃(1,1)与(2,2)发射示踪了一个尺度约0.5秒差距（pc）的大尺度旋转环面，盘源mm1位于该结构的蓝移区域，并向西北方向存在偏移。 本Zenodo数据集包含的文件清单与简要说明详见README_Johnstonetal2020.txt文件。