DENSE CLUMPS AND CANDIDATES FOR MOLECULAR OUTFLOWS IN W40
DENSE CLUMPS AND CANDIDATES FOR MOLECULAR OUTFLOWS IN W40
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DOI：
10.1088/0004-637x/806/2/201
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发表时间：
2015-05
期刊：
影响因子：
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通讯作者：
T. Shimoikura;K. Dobashi;F. Nakamura;C. Hara;Tomohiro Tanaka;Y. Shimajiri;Kouji Sugitani;R. Kawabe
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文献类型：
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作者：
T. Shimoikura;K. Dobashi;F. Nakamura;C. Hara;Tomohiro Tanaka;Y. Shimajiri;Kouji Sugitani;R. Kawabe
我们报道了用阿塔卡马亚毫米望远镜实验(ASTE)10米望远镜(HPBW−22“)对W40HⅡ区的12Co(J=3−2)和Hco+(J=4≃3)的观测结果，以寻找分子外流和致密团块。我们发现该地区的速度场非常复杂，在VLSR≃3、5、7和10 KM S−1处至少有4个不同的速度分量。∼7 KM S−1分量代表了整个区域周围冷气体的系统速度，并在6≲VLSR≲9 KM S−1速度范围内引起了12CO谱的强吸收。∼5和∼10 KM S−1分量具有很高的12CO温度(≳40K)，主要分布在H II区附近，这表明这些分量可能是追踪与H II区周围膨胀壳层相互作用的致密气体。基于12co数据，我们确定了13个高速气体区域，我们将其解释为候选的流出叶。利用HCO+数据，我们还识别了六个团块，并估计了它们的物理参数。基于2MASS的ASTE数据和近红外图像，我们提出了一个更新的该区域的三维模型。为了研究W40的分子外流，用野山射电天文台的45m望远镜也观测到了SiO(J=1−0，v=0)发射线和其他一些40 GHz的发射线，但在目前的灵敏度下没有探测到它们。
We report the results of the 12CO (J = 3−2) and HCO+ (J = 4−3) observations of the W40 H ii region with the Atacama Submillimeter Telescope Experiment (ASTE) 10 m telescope (HPBW ≃ 22″) to search for molecular outflows and dense clumps. We found that the velocity field in the region is highly complex, consisting of at least four distinct velocity components at VLSR ≃ 3, 5, 7, and 10 km s−1. The ∼7 km s−1 component represents the systemic velocity of cold gas surrounding the entire region, and causes heavy absorption in the 12CO spectra over the velocity range 6 ≲ VLSR ≲ 9 km s−1. The ∼5 and ∼10 km s−1 components exhibit high 12CO temperature (≳40 K) and are found mostly around the H ii region, suggesting that these components are likely to be tracing dense gas interacting with the expanding shell around the H ii region. Based on the 12CO data, we identified 13 regions of high velocity gas, which we interpret as candidate outflow lobes. Using the HCO+ data, we also identified six clumps and estimated their physical parameters. On the basis of the ASTE data and near-infrared images from 2MASS, we present an updated three-dimensional model of this region. In order to investigate molecular outflows in W40, the SiO (J = 1−0, v = 0) emission line and some other emission lines at 40 GHz were also observed with the 45 m telescope at the Nobeyama Radio Observatory, but they were not detected at the present sensitivity.