论文标题
星系通过超调分析的全局HI特性
Global HI Properties of Galaxies via Super-profile Analysis
论文作者
论文摘要
我们提出了一种新方法，该方法构建了基于剖面分解分析的星系的HI超调。 HI数据立方体的分解速度曲线具有最佳数量的高斯组件，在相对于其质心速度以速度对齐后，共同添加了速度。将此与以前的方法进行比较，该方法没有对堆叠的速度曲线进行先前的分解分解。 S/N改进的超构件可用于得出星系的全局HI特性，例如速度分散和质量，这些质量和观测值无法为银河系提供足够的表面亮度灵敏度。作为一个实际测试，我们将新方法应用于当地宇宙中附近星系的64个高分辨率HI数据立方体，这些数据是从事物和小事物中获取的。此外，我们还使用对称和所有速度剖面构建了两个样品星系的HI Super-Profiles，它们的质心速度分别从Hermite $ H_3 $多项式拟合确定。我们发现，使用新方法构建的HI超封面具有比其他两个超级底座更狭窄的内核和更宽的翅膀。这主要是由于先前方法中不对称速度曲线的中央速度偏置的影响，或者在先前方法中除去不对称速度曲线对所得的HI超构矿的影响。我们讨论形状如何（$σ_ {\ rm {n}}/σ_ {\ rm {b}} $，$ a _ _ {\ rm {n}}/a _ _ {\ rm {bm {bm {b}}} $ $A_{\rm{n}}/A_{\rm{tot}}$) of the new HI super-profiles which are measured from a double Gaussian fit are correlated with star formation rates of the sample galaxies and are compared with those of the other two super-profiles.
We present a new method which constructs an HI super-profile of a galaxy which is based on profile decomposition analysis. The decomposed velocity profiles of an HI data cube with an optimal number of Gaussian components are co-added after being aligned in velocity with respect to their centroid velocities. This is compared to the previous approach where no prior profile decomposition is made for the velocity profiles being stacked. The S/N improved super-profile is useful for deriving the galaxy's global HI properties like velocity dispersion and mass from observations which do not provide sufficient surface brightness sensitivity for the galaxy. As a practical test, we apply our new method to 64 high-resolution HI data cubes of nearby galaxies in the local Universe which are taken from THINGS and LITTLE THINGS. In addition, we also construct two additional HI super-profiles of the sample galaxies using symmetric and all velocity profiles of the cubes whose centroid velocities are determined from Hermite $h_3$ polynomial fitting, respectively. We find that the HI super-profiles constructed using the new method have narrower cores and broader wings in shape than the other two super-profiles. This is mainly due to the effect of either asymmetric velocity profiles' central velocity bias or the removal of asymmetric velocity profiles in the previous methods on the resulting HI super-profiles. We discuss how the shapes ($σ_{\rm{n}}/σ_{\rm{b}}$, $A_{\rm{n}}/A_{\rm{b}}$, and $A_{\rm{n}}/A_{\rm{tot}}$) of the new HI super-profiles which are measured from a double Gaussian fit are correlated with star formation rates of the sample galaxies and are compared with those of the other two super-profiles.
