论文标题
矮星系中的缩放高度
HI scale height in dwarf galaxies
论文作者
论文摘要
假设在重型盘中有垂直的静水平衡，则在小象征调查中建立了关节泊松式布尔茨曼方程并在附近的23个附近矮星系中进行数值求解。这是迄今为止对进行详细的静液压建模的最大样本。 Poisson's-Boltzmann方程的溶液提供了这些星系中原子氢（HI）的完整三维分布。使用这些溶液，我们估计HI的垂直尺度高度（定义为最大值的一半宽度（HWHM）的一半宽度）是半径的函数。我们发现，样品星系中的比例高度在中心几百个parsec之间与边缘的几公斤。这些值明显高于螺旋星系中观察到的值。我们进一步估计轴向比率研究矮星系中HI圆盘的厚度。对于我们的样品星系，我们发现中位轴向比为0.40，比以银河系观察到的相同的轴向比率高得多。这表明垂直静水平衡会导致矮星系中较厚的HI圆盘。
Assuming a vertical hydrostatic equilibrium in the baryonic discs, joint Poisson's-Boltzmann equation was set up and solved numerically in a sample of 23 nearby dwarf galaxies from the LITTLE-THINGS survey. This is the largest sample to date for which detailed hydrostatic modeling is performed. The solutions of the Poisson's-Boltzmann equation provide a complete three-dimensional distribution of the atomic hydrogen (HI) in these galaxies. Using these solutions, we estimate the vertical scale height (defined as the Half Width at Half Maxima (HWHM) of the density distribution) of the HI as a function of radius. We find that the scale height in our sample galaxies varies between a few hundred parsecs at the center to a few kiloparsecs at the edge. These values are significantly higher than what is observed in spiral galaxies. We further estimate the axial ratios to investigate the thickness of the HI discs in dwarf galaxies. For our sample galaxies, we find a median axial ratio to be 0.40, which is much higher than the same observed in the Milky Way. This indicates that the vertical hydrostatic equilibrium results in thicker HI discs in dwarf galaxies naturally.
