论文标题
密度指数分析：由重力驱动的星形区域的密度分布的陡峭陡峭
Density Exponent Analysis: Gravity-driven steepening of the density profiles of star-forming regions
论文作者
论文摘要
分子星际云的演变是一个复杂的多尺度过程。幂律密度指数描述了密度曲线的陡度，并且已用于表征云的密度结构，但其使用通常仅限于球形对称系统。导入级别的方法，我们开发了一种新的形式主义，该形式主义在每个位置都会在每个位置生成广义密度指数$k_ρ$的可靠地图，以实现复杂的密度分布。通过将其应用于高保真度，使用来自Herschel和Planck卫星的数据构建的Perseus Molecular Cloud的高动力学范围图，我们发现密度指数显示出令人惊讶的变化范围（$ -3.5 \ 3.5 \ lyssimk_ρ\ lyssim -lesssim -0.5 $）。重力崩溃后期的区域与较高的密度曲线有关。在一个区域内，位于致密结构的泡沫中的气体具有非常陡峭的密度曲线，$k_ρ\约-3 $，由于耗尽而形成。该密度指数分析揭示了各种密度结构，形成了连贯的图像，即引力塌陷导致密度曲线的持续陡峭。我们希望我们的方法有效研究其他类似幂律的密度结构，包括颗粒状材料和宇宙的大规模结构。
The evolution of molecular interstellar clouds is a complex, multi-scale process. The power-law density exponent describes the steepness of density profiles, and it has been used to characterize the density structures of the clouds yet its usage is usually limited to spherically symmetric systems. Importing the Level-Set Method, we develop a new formalism that generates robust maps of a generalized density exponent $k_ρ$ at every location for complex density distributions. By applying it to high fidelity, high dynamical range map of the Perseus molecular cloud constructed using data from the Herschel and Planck satellites, we find that the density exponent exhibits a surprisingly wide range of variation ($-3.5 \lesssim k_ρ \lesssim -0.5$). Regions at later stages of gravitational collapse are associated with steeper density profiles. Inside a region, gas located in the vicinities of dense structures has very steep density profiles with $k_ρ \approx -3$, which forms because of depletion. This density exponent analysis reveals diverse density structures, forming a coherent picture that gravitational collapse leads to a continued steepening of the density profile. We expect our method to be effective in studying other power-law-like density structures, including granular materials and the Large-Scale Structure of the Universe.
