Dense Gas in Galactic Nuclei

杰克逊9318849 尽管进行了广泛的研究，但人们对外部星系核中分子气体的性质知之甚少。 以往星系中的分子ISM都是用CO辐射来研究的，它提供了分子气体的分布和质量。 不幸的是，CO不能直接探测致密的分子气体。 致密气体特别重要，因为它活跃地形成恒星，并追踪环核环境。 首席研究员将通过观察HCN等分子开发一套新的工具，这些分子需要高密度的激发。 这项技术现在已经到位，可以以50 pc的分辨率绘制附近星系中的这些物种。 通过观察几条线，他将详细绘制星系核中致密分子气体的密度、温度、成分和运动。 他将对一些星系进行HCN调查，以描述其致密气体的特性。

9318849 Jackson Despite extensive study, the properties of molecular gas in the nuclei of external galaxies are poorly understood. Previously the molecular ISM in galaxies has been studied with CO emission, which provides the distribution and mass of molecular gas. Unfortunately, CO does not directly probe the dense molecular gas. Dense gas is particularly important because it actively forms stars and also traces the circumnuclear environment. The Principal Investigator will develop a new set of tools by observing molecules such as HCN, which require high densities for excitation. The technology is now in place to map these species in nearby galaxies at 50 pc resolution. By observing several lines he will map in detail the density, temperature, composition, and motion of the dense molecular gas in galactic nuclei. He will perform HCN surveys of a number of galaxies in order to characterize their dense gas properties.