Herschel and SCUBA-2 observations of dust emission in a sample of Planck cold clumps-猫眼课题宝

DOI：

10.1051/0004-6361/201731921

发表时间：

2017-11

期刊：

Astronomy and Astrophysics

影响因子：

6.5

通讯作者：

中科院分区：

物理与天体物理2区

文献类型：

作者：

M. Juvela;Jinhua He;K. Pattle;Tie Liu;G. Bendo;D. Eden;O. Fehér;M. Fich;G. Fuller;N. Hirano;Kee-Tae Kim;Di Li;Sheng-Yuan Liu;J. Malinen;D. Marshall;D. Paradis;H. Parsons;V. Pelkonen;M. Rawlings;I. Ristorcelli;Manash R. Samal;K. Tatematsu;M. Thompson;A. Traficante;Ke Wang;D. Ward-Thompson;Yue-fang Wu;Hee-Weon Yi;H. Yoo

上下文对全天普朗克亚毫米观测和IRAS 100 μm数据的分析导致了对银河系冷团群的探测。这些团块可用于研究银河系广泛环境中的星星形成和尘埃特性。目标。我们的目标是测量尘埃光谱能量分布（SED）的变化作为空间尺度和波长的函数。方法.我们使用IRAS，普朗克和赫歇尔数据在大尺度上研究了SED。在较小的尺度上，我们将JCMT/SCUBA-2 850 μm地图与使用SCUBA-2管道过滤的Herschel数据进行了比较。使用Fellwalker方法提取团块，并将其光谱建模为修改后的黑体函数。结果根据IRAS和Planck资料，大部分地区的尘埃色温TC约为14-18 K，不透明度光谱指数β值为1.5-1.9。在SCUBA-2图上识别的团块和核心具有T ~ 13 K和相似的β值。有迹象表明，尘埃发射光谱在波长超过500微米时变得平坦。在涉及普朗克数据的拟合中，其意义受到CO线污染修正的不确定性的限制。SPIRE数据的拟合给出了略高于1.8的中位β值。在联合SPIRE和SCUBA-2 850 μm拟合中，该值降低到β ~ 1.6。大多数观测到的T-β ε关系可以用噪声来解释。结论.冷团的典型亚毫米不透明度光谱指数β约为1.7。这高于漫射云的值，但低于以前对密集云的一些研究。只有初步的证据表明T-β π关系和β在毫米波长处减小。

Context. Analysis of all-sky Planck submillimetre observations and the IRAS 100 μm data has led to the detection of a population of Galactic cold clumps. The clumps can be used to study star formation and dust properties in a wide range of Galactic environments. Aims. Our aim is to measure dust spectral energy distribution (SED) variations as a function of the spatial scale and the wavelength. Methods. We examined the SEDs at large scales using IRAS, Planck, and Herschel data. At smaller scales, we compared JCMT/SCUBA-2 850 μm maps with Herschel data that were filtered using the SCUBA-2 pipeline. Clumps were extracted using the Fellwalker method, and their spectra were modelled as modified blackbody functions. Results. According to IRAS and Planck data, most fields have dust colour temperatures TC ~ 14–18 K and opacity spectral index values of β = 1.5–1.9. The clumps and cores identified in SCUBA-2 maps have T ~ 13 K and similar β values. There are some indications of the dust emission spectrum becoming flatter at wavelengths longer than 500 μm. In fits involving Planck data, the significance is limited by the uncertainty of the corrections for CO line contamination. The fits to the SPIRE data give a median β value that is slightly above 1.8. In the joint SPIRE and SCUBA-2 850 μm fits, the value decreases to β ~ 1.6. Most of the observed T-β anticorrelation can be explained by noise. Conclusions. The typical submillimetre opacity spectral index β of cold clumps is found to be ~1.7. This is above the values of diffuse clouds, but lower than in some previous studies of dense clumps. There is only tentative evidence of a T-β anticorrelation and β decreasing at millimetre wavelengths.

Herschel and SCUBA-2 observations of dust emission in a sample of Planck cold clumps

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