标题： 星形成和活动核对超亮红外星系中星际介质的影响 显示英文标题

标题： The Impact of Star Formation and Active Nuclei on the Interstellar Medium in Ultraluminous Infrared Galaxies

摘要： ULIRGs（超光度红外星系）中输入到星际介质的能量非常巨大，无论能量来源的性质如何。我将讨论这些星系中星际介质结构和能量的一些主要结果。观测上，ULIRGs核区的柱密度已知非常高，这使得区分星暴和活动星系核（AGN）变得非常困难。能量和动量注入的水平意味着星际介质中的压力必须极高，至少比本地星际介质或典型的巨大分子云高3-4个数量级。这也意味着ULIRGs中的巨分子云（GMCs）的光度必须非常高，因为它们在其寿命内必须辐射出许多倍于其结合能的能量。我简要回顾了X射线辐射对AGN驱动的ULIRGs中星际介质可能产生的影响。最后，我展示了ULIRGs中多环芳烃（PAH）特征的存在并不意味着它们必须由星暴主导，因为在ULIRGs星际介质典型的柱密度和压力下，即使距离AGN有数十秒差距的距离，PAHs也能存活。 显示英文摘要

摘要： The energy input into the interstellar medium in Ultraluminous Infrared Galaxies (ULIRGs) is enormous, regardless of the nature of the power source. I discuss some of the major consequences for the structure and energetics of the ISM in these galaxies. Observationally, the column densities in the nuclear regions of ULIRGs are known to be very high, which makes distinguishing starbursts from AGN quite difficult. The level of energy and momentum injection means that the pressure in the ISM must be extremely high, at least 3-4 orders of magnitude larger than in the local ISM or typical giant molecular clouds. It also means that the luminosity of GMCs in ULIRGs must be very high, as they must radiate many times their binding energy over their lifetimes. I briefly review the influence which X-ray irradiation can have on the ISM in AGN-powered ULIRGs. Finally, I show that the presence of PAH features in ULIRGs does not imply that they must be starburst-dominated, since at the column densities and pressures typical of the ISM in ULIRGs PAHs can survive even at tens of parsec distances from the AGN.