arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 1010.3606astro-ph.GA
收藏

红外暗云G48的光谱[ CI ]制图. 65 -0.29

Spectroscopic [CI] mapping of the infrared dark cloud G48.65-0.29

Volker Ossenkopf, Chris W. Ormel, Robert Simon, Kefeng Sun, Jürgen Stutzki

摘要:

本文首次报道了红外暗云(IRDC)中碳原子谱线的光谱图。通过观察IRDC中[CI]发射的空间分布,将其与13 CO发射和已知的内部热源分布进行比较,我们可以量化内部和外部UV照射在原子碳产生中的作用。我们使用位于戈尔内格拉特的KOSMA天文台的2x 4像素SMART接收器来绘制IRDC G48.65-0.29中的[CI] 3 P1 - 3 P0线,并将所得光谱与BU-FCRAO 13 CO 1-0银河系环巡天的数据进行比较。[Cl]/13 CO有效束温度比下降到约0.3,局部偏差小于2倍。在[CI]中也检测到13 CO中观察到的所有速度分量。然而,我们发现,在两个示踪剂中看到的最亮区域的形态有显着差异。虽然13 CO基本上遵循来自近红外(NIR)消光和亚毫米连续谱的柱密度分布,但[CI]发射峰值位于两个已知NIR点源的位置。我们发现CI/CO丰度比在0.07和0.13之间,与先前在恒星形成区测量的范围的低端相匹配。评估嵌入源和银河系星际紫外场照射的相对重要性,我们发现在G48.65-0.29中,大多数[CI]发射可以归因于外部照明表面。嵌入源有显着的影响,原子碳的总体丰度分布,只要他们被发现在一个明显的近红外通量的演变状态。

英文摘要:

We report the first spectroscopic mapping of an atomic carbon line in an infrared dark cloud (IRDC). By observing the spatial distribution of the [CI] emission in an IRDC, comparing it with the 13CO emission and the known distribution of internal heating sources, we can quantify the role of internal and external UV irradiation in the production of atomic carbon. We used the 2x4 pixel SMART receiver of the KOSMA observatory on Gornergrat to map the [CI] 3P1 - 3P0 line in the IRDC G48.65-0.29 and compared the resulting spectra with data from the BU-FCRAO 13CO 1-0 Galactic Ring Survey. The [CI]/13CO effective beam temperature ratio falls at about 0.3 with local deviations by less than a factor two. All velocity components seen in 13CO are also detected in[CI]. We find, however, significant differences in the morphology of the brightest regions seen in the two tracers. While 13CO basically follows the column density distribution derived from the near-infrared (NIR) extinction and the submm continuum, the [CI] emission peaks at the locations of the two known NIR point sources. We find CI/CO abundance ratios between 0.07 and 0.13, matching the lower end of the range previously measured in star-forming regions. Evaluating the relative importance of the irradiation by embedded sources and by the Galactic interstellar UV field, we find that in G48.65-0.29 most [CI] emission can be attributed to externally illuminated surfaces. Embedded sources have a significant impact on the overall abundance distribution of atomic carbon as soon as they are found in an evolved state with noticeable NIR flux.

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。

↑