论文标题
集中浓缩的H I分布增强星系中的恒星形成
Centrally Concentrated H I Distribution Enhances Star Formation in Galaxies
论文作者
论文摘要
我们使用来自苜蓿和SDSS光谱调查的13,511个附近星系的样本来研究H I 21 cm发射率（SFR）的H I 21 cm发射率（SFR）之间的关系。我们引入了一个新的非参数$ K $，该$ K $从生产线的增长曲线中测量，以描述集成的H I配置文件的形状。 $ K $的值从双角增加到单峰轮廓，具体取决于投影效应以及气体的空间和速度分布。使用精心选择的样品来控制影响综合线路轮廓的竞争因素，我们认为可以对气体的空间分布进行有用的推论。我们发现，在固定条件下，具有$ K $的高值的星系往往在星系的光磁盘中具有更高的集中浓度的H I分布，并且较大的$ K $的值与较高的总SFR和中央SFR相关。结果表明，H I的全球浓度在促进中性原子氢向分子氢气的转化方面起着重要作用，这反过来影响整个光磁盘的恒星形成活性。我们的样本与静态星系有偏差，因此结论可能无法对较低的SFR或低H I含量的星系得出。
We use a sample of 13,511 nearby galaxies from the ALFALFA and SDSS spectroscopic surveys to study the relation between the spatial distribution of H I 21 cm emission and star formation rate (SFR). We introduce a new non-parametric quantity $K$, measured from the curve-of-growth of the line, to describe the shape of the integrated H I profile. The value of $K$ increases from double-horned to single-peaked profiles, depending on projection effects and the spatial and velocity distribution of the gas. Using carefully chosen samples to control for the competing factors that influence the integrated line profile, we argue that useful inferences can be made on the spatial distribution of the gas. We find that galaxies with a high value of $K$ tend to have more centrally concentrated H I distribution within the optical disk of the galaxy at fixed conditions, and that larger values of $K$ are associated with higher levels of total and central SFR. The results suggest that the global concentration of H I plays an important role in facilitating the conversion of neutral atomic hydrogen to molecular hydrogen gas, which, in turn, affects the star formation activity throughout the optical disk. Our sample is biased against quiescent galaxies, and thus the conclusions may not hold for galaxies with low SFR or low H I content.
