论文标题
重新审视分子云中结构的质量大小关系
Revisiting The Mass-Size Relation Of Structures In Molecular Clouds
论文作者
论文摘要
我们基于Cygnus-X分子云配合物的柱密度图的分子云结构的质量大小关系。我们在Cygnus-X中提取135柱密度峰，并分析这些峰周围的柱密度分布。在所有峰周围的平均柱密度概要文件$ n（r）$都可以很好地安装在损坏的幂律上，由内部幂律索引$ n $，外部幂律索引$ m $和半径$ r _ {\ rm tp} $和列密度$ n _ {\ n _ {\ rm n _ {\ rm n _ {\ rm n _ {\ rm n _ {\ rm n _ {然后，我们通过更改$ n（r）$参数和列密度阈值$ n_0 $的$ n（r）$参数来探索具有不同云结构样本的$ m-r $关系，该关系决定了云结构的边界。我们发现，只有当$ n_0 $具有广泛的值时，$ m-r $的关系才能在很大程度上探测密度分布，而$ M-R $关系的合适幂律指数与$ n（r）$的幂律指数有关。相反，$ m -r $关系与密度分布没有直接连接；在这种情况下，$ m -r $关系的合适幂律指数等于2（当$ n_0 \ ge n _ {\ rm tp} $和$ n $具有狭窄的值），大于2（当$ n_0 \ ge n_0 \ ge n _ {\ rm tp} $和$ n $ she $ nest $ n时或少于$ n $ 2（ TP} $）。
We revisit the mass-size relation of molecular cloud structures based on the column density map of the Cygnus-X molecular cloud complex. We extract 135 column density peaks in Cygnus-X and analyze the column density distributions around these peaks. The averaged column density profiles, $N(R)$, around all the peaks can be well fitted with broken power-laws, which are described by an inner power-law index $n$, outer power-law index $m$, and the radius $R_{\rm TP}$ and column density $N_{\rm TP}$ at the transition point. We then explore the $M-R$ relation with different samples of cloud structures by varying the $N(R)$ parameters and the column density threshold, $N_0$, which determines the boundary of a cloud structure. We find that only when $N_0$ has a wide range of values, the $M - R$ relation may largely probe the density distribution, and the fitted power-law index of the $M-R$ relation is related to the power-law index of $N(R)$. On the contrary, with a constant $N_0$, the $M - R$ relation has no direct connection with the density distribution; in this case, the fitted power-law index of the $M - R$ relation is equal to 2 (when $N_0\ge N_{\rm TP}$ and $n$ has a narrow range of values), larger than 2 (when $N_0\ge N_{\rm TP}$ and $n$ has a wide range of values), or slightly less than 2 (when $N_0< N_{\rm TP}$).
