The evolution of the warm-hot intergalactic medium in a hierarchically evolving Universe

利用类星体吸收线光谱和数值模拟，我们希望继续我们的研究的性质的温暖，热星系际介质（WHIM）和它的演化从高红移到低。最近的研究表明，这种星系际介质（IGM）的高温气相包含了本地宇宙中总重子预算的约30%，并且可能进一步代表了在高红移星系中产生的金属的储存库。在这个项目中，我们正在研究从z=3到z=0的WHIM中重子和金属的分布，并分析宇宙不同时期的温暖-热星系际气体与星系结构的关系。我们希望继续我们正在进行的分析HI和高离子吸收系统在高分辨率的光学和紫外光谱和合成光谱的数值模拟。使用观测和模拟的光谱数据，我们要表征WHIM吸收系统的物理和统计特性，并确定各种过程，有助于发生在IGM的热气体，如银河风和崩溃的大规模的灯丝。WHIM的模拟数据和观测数据的结合分析是解决宇宙中“丢失的金属”和“丢失的重子”问题的有力手段。因此，我们的项目将导致更好地了解星系际介质的演变在一个层次不断演变的宇宙的背景下。

Using quasar absorption-line spectroscopy and numerical simulations we want to continue our studies on the properties of the warm-hot intergalactic medium (WHIM) and its evolution from high to low redshifts. Recent studies indicate that this high-temperature gas phase of the intergalactic medium (IGM) contains about 30 percent of the total baryon budget in the local Universe and further may represent a reservoir of the metals produced in galaxies at high redshift. In this project we are studying the distribution of baryons and metals in the WHIM from z=3 to z=0 and analyze the relation between warm-hot intergalactic gas and galactic structures at different epochs of the Universe. We want to continue our on-going analysis of HI and high-ion absorption systems in high-resolution optical and ultraviolet spectra and in synthetic spectra from numerical simulations. Using both observational and simulated spectral data we want to characterize the physical and statistical properties of WHIM absorption systems and identify the various processes that contribute to the occurrence of hot gas in the IGM, such as galactic winds and collapsing large-scale filaments. The combined analysis of simulated and observational data of the WHIM is a powerful method to tackle the problem of the “missing metals” and “missing baryons” in the Universe. Our project thus will lead to a better understanding of the evolution of the intergalactic medium in the context of a hierarchically evolving Universe.