论文标题
附近星系中的体积星形成法
The volumetric star formation law in nearby galaxies
论文作者
论文摘要
星形的恒星形成定律是星系中冷气（HI+H $ _2 $）之间的经验关系，其恒星形成率（SFR）对于任何星系形成和进化模型都至关重要。此类法律的一个众所周知的例子是基于预计的表面密度的Schmidt-Kennicutt法律。但是，尚不清楚固有量密度之间是否存在更基本的关系。通过假设垂直静水平衡，我们在23个局部星系样品中推断出气态圆盘厚度的径向轮廓，并使用这些测量值将观测到的气体和SFR的表面密度转化为脱落体积密度。我们发现将这些数量链接起来的紧密相关性，我们称之为体积星形成法。这种关系及其特性对我们对恒星形成物理的理解具有至关重要的影响。
Star formation laws are empirical relations between the cold gas (HI+H$_2$) content of a galaxy and its star formation rate (SFR), being crucial for any model of galaxy formation and evolution. A well known example of such laws is the Schmidt-Kennicutt law, which is based on the projected surface densities. However, it has been long unclear whether a more fundamental relation exists between the intrinsic volume densities. By assuming the vertical hydrostatic equilibrium, we infer radial profiles for the thickness of gaseous discs in a sample of 23 local galaxies, and use these measurements to convert the observed surface densities of the gas and the SFR into the de-projected volume densities. We find a tight correlation linking these quantities, that we call the volumetric star formation law. This relation and its properties have crucial implications for our understanding of the physics of star formation.
