论文标题
隐藏在sombrero星系中的分子气圈
A Molecular Gas Ring Hidden in the Sombrero Galaxy
论文作者
论文摘要
我们介绍了Herschel，Alma和Muse观察到Messier 104的分子环，也称为Sombrero Galaxy。这些以前未发表的档案数据为M104的星际介质的含量提供了新的启示。特别是，通过CO发射和通过远红外光测得的粉尘测得的分子氢沿环均匀分布。 H $α$揭示的电离气体和[CII]发射沿环的结中分布。尽管被归类为SAA星系，但M104仍显示早期类型星系的特征。因此，我们将其[CII]和粉尘排放与用Herschel和Sofia观察到的早期型星系样本进行了比较。 M104的[CII]/FIR比远低于典型的星形星系，而与早期型星系的相似性更为相似。通过使用光发射线诊断的区域进行分类，我们还发现，分类为HII的区域比[CII]/FIR图中的星形星系靠近，而不是分类为低离子化发射区的区域。 [CII]和H $α$发射之间的良好匹配与CO发射和恒星形成之间缺乏相关性的结合表明，沿环的活性星形成非常有限，并且大多数[CII]发射来自电离和中性原子气体，而不是分子气体而不是分子气体。从CO线的总强度来看，我们估计分子氢质量为0.9 $ \ times10^9 $ m $ _ {\ odot} $，这是早期类型星系和我们星系分子环的含量之间的值中间。
We present Herschel, ALMA, and MUSE observations of the molecular ring of Messier 104, also known as the Sombrero galaxy. These previously unpublished archival data shed new light on the content of the interstellar medium of M104. In particular, molecular hydrogen measured by CO emission and dust measured by far-infrared light are uniformly distributed along the ring. The ionized gas revealed by H$α$ and [CII] emission is distributed in knots along the ring. Despite being classified as an SAa galaxy, M104 displays features typical of early-type galaxies. We therefore compared its [CII] and dust emission to a sample of early-type galaxies observed with Herschel and SOFIA. The [CII]/FIR ratio of M104 is much lower than that of typical star-forming galaxies and is instead much more similar to that of early-type galaxies. By classifying regions using optical emission line diagnostics we also find that regions classified as HII lie closer to star-forming galaxies in the [CII]/FIR diagram than those classified as low-ionization emission regions. The good match between [CII] and H$α$ emission in conjunction with the lack of correlation between CO emission and star formation suggest that there is very limited active star formation along the ring and that most of the [CII] emission is from ionized and neutral atomic gas rather than molecular gas. From the total intensity of the CO line we estimate a molecular hydrogen mass of 0.9$\times10^9$M$_{\odot}$, a value intermediate between those of early type galaxies and the content of the molecular ring of our galaxy.
