论文标题
分子云中两个微米的所有天空调查团的旋转
Rotation of Two Micron All Sky Survey Clumps in Molecular Clouds
论文作者
论文摘要
我们已经使用$^{13} $ CO（1--0）和C $^{18} $ O（1--0）五个大学无线电天文学天文台13.7 m射电望远镜的$^{18} $ O（1--0）地图分析了12个团块的旋转属性。位于分子云内的团块在0.06-0.27 \，PC的范围内具有半径（$ r $）。团块伸长的方向与速度梯度的方向无关。我们测量了基于$^{13} $ co图像的特定角动量（J/m）在0.0022至0.025 pc \，km \，km \，s $^{ - 1} $之间，以及基于C $^{18} $ o的0.0025和0.0025和0.0025和0.0021 pc \，kmm \，km \，s $^{ - 1} $。 $ j/m $的一致性基于不同的示踪剂，表明$^{13} $ CO和C $^{18} $ o在密集的团块中的痕迹基本相同的材料基本上是相同的材料。我们还发现，$ j/m $单调增加，这是$ r $ power-law表单的函数，$ j/m〜 \ propto〜r^{1.58〜 \ pm〜0.11} $。旋转能量与重力能之间的比率为$β$，范围为0.0012至0.018。 $β$的小值表明，仅旋转不足以支持重力崩溃的团块。
We have analyzed the rotational properties of 12 clumps using $^{13}$CO (1--0) and C$^{18}$O (1--0) maps of the Five College Radio Astronomy Observatory 13.7 m radio telescope. The clumps, located within molecular clouds, have radii ($R$) in the range of 0.06 -- 0.27\,pc. The direction of clump elongation is not correlated with the direction of the velocity gradient. We measured the specific angular momentum (J/M) to be between 0.0022 and 0.025 pc\,km\,s$^{-1}$ based on $^{13}$CO images, and between 0.0025 and 0.021 pc\,km\,s$^{-1}$ based on C$^{18}$O images. The consistency of $J/M$ based on different tracers indicates the $^{13}$CO and C$^{18}$O in dense clumps trace essentially the same material despite significantly different opacities. We also found that $J/M$ increases monotonically as a function of $R$ in power--law form, $J/M~\propto~R^{1.58~\pm~0.11}$. The ratio between rotation energy and gravitational energy, $β$, ranges from 0.0012 to 0.018. The small values of $β$ imply that rotation alone is not sufficient to support the clump against gravitational collapse.
