Characterizing filaments in regions of high-mass star formation: High-resolution submilimeter imaging of the massive star-forming complex NGC 6334 with ArTeMiS
Characterizing filaments in regions of high-mass star formation: High-resolution submilimeter imaging of the massive star-forming complex NGC 6334 with ArTeMiS
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DOI：
10.1051/0004-6361/201628378
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发表时间：
2016-05
影响因子：
6.5
通讯作者：
P. Andr'e;V. Rev'eret;V. Konyves;D.Arzoumanian;J. Tig'e;P. Gallais;H. Roussel;J. Pennec
中科院分区：
文献类型：
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作者：
P. Andr'e;V. Rev'eret;V. Konyves;D.Arzoumanian;J. Tig'e;P. Gallais;H. Roussel;J. Pennec
赫歇尔对附近分子云的观测表明，星际细丝和星前核心代表了星星形成过程中的两个基本步骤。观测结果支持了低质量星星形成的图像，根据该图像，约0.1 pc宽的细丝首先在冷的星际介质中形成，可能是由于超音速湍流对星际物质的大规模压缩，然后星前核心由重力破碎的致密细丝产生。这种情况是否也适用于大质量星星形成的区域是一个悬而未决的问题，部分原因是赫歇尔数据无法解决最近的大质量星星形成区域中细丝的内部宽度。我们使用APEX望远镜上的测辐射热计相机ArTeMiS来绘制NGC 6334复合体的中心部分，其分辨率比Herschel的350微米高出3倍。将ArTeMiS数据与Herschel数据相结合，使我们能够在d ~ 1.7kpc的分辨率为8”或<0.07pc的条件下研究复合体的主细丝结构。我们的研究证实，这种灯丝是一种非常致密的大质量线性结构，其线质量范围从~ 500 Msun/pc到~ 2000 Msun/pc，超过近10 pc。它还表明，它的内部宽度保持为W ~ 0.15 +-0.05 pc的窄沿沿着所有的长丝长度，在一个系数< 2的特征值0.1 pc的赫歇尔发现的低质量的长丝在古尔德带。虽然目前还不完全清楚NGC 6334的暗条是否会在未来形成大质量恒星，但它的密度比古尔德带云中观察到的大多数暗条高出两到三个数量级，而且内部宽度非常相似。这指出了一个共同的物理机制来设定灯丝的宽度，并表明附近云的一些重要结构特性也适用于高质量星星形成区域。
Herschel observations of nearby molecular clouds suggest that interstellar filaments and prestellar cores represent two fundamental steps in the star formation process. The observations support a picture of low-mass star formation according to which ~ 0.1 pc-wide filaments form first in the cold interstellar medium, probably as a result of large-scale compression of interstellar matter by supersonic turbulent flows, and then prestellar cores arise from gravitational fragmentation of the densest filaments. Whether this scenario also applies to regions of high-mass star formation is an open question, in part because Herschel data cannot resolve the inner width of filaments in the nearest regions of massive star formation. We used the bolometer camera ArTeMiS on the APEX telescope to map the central part of the NGC6334 complex at a factor of > 3 higher resolution than Herschel at 350 microns. Combining ArTeMiS data with Herschel data allowed us to study the structure of the main filament of the complex with a resolution of 8" or < 0.07 pc at d ~ 1.7 kpc. Our study confirms that this filament is a very dense, massive linear structure with a line mass ranging from ~ 500 Msun/pc to ~ 2000 Msun/pc over nearly 10 pc. It also demonstrates that its inner width remains as narrow as W ~ 0.15 +- 0.05 pc all along the filament length, within a factor of < 2 of the characteristic 0.1 pc value found with Herschel for lower-mass filaments in the Gould Belt. While it is not completely clear whether the NGC 6334 filament will form massive stars or not in the future, it is two to three orders of magnitude denser than the majority of filaments observed in Gould Belt clouds, and yet has a very similar inner width. This points to a common physical mechanism for setting the filament width and suggests that some important structural properties of nearby clouds also hold in high-mass star forming regions.