Galaxy formation and its feedback effect on the intergalactic medium

星系是宇宙的基石。我们所在的银河系只是宇宙中数十亿个星系中的一个。星系之间的空间并不是空的，而是充满了氢、氦和更重元素的扩散混合物，称为星际介质。人们认为，星系起源于星际介质中的微小密度波动，这些波动在引力的影响下生长。星系形成过程的细节还没有被很好地理解。挑战是设计一个星系形成模型，能够解释星系的许多可观察到的属性。虽然星系间介质的性质最终将决定星系的物理性质，但星系反过来也会影响星系间介质的演化，这一过程被称为反馈。星系产生风：超新星爆炸将热气吹出星系。这种气体将热量储存到星际介质中，并改变其化学成分。这最终将影响后续世代星系的形成。拟议的研究计划的目标是研究星系形成和演化的过程，星系间介质的演化，以及这些过程如何相互作用。

Galaxies are the building blocks of the universe. Our own galaxy, the Milky-Way, is only one of billions of galaxies in the universe. The space between galaxies is not empty, but filled with a diffuse mixture of hydrogen, helium, and heavier elements, called the Intergalactic Medium. It is believed that galaxies originate form small density fluctuations in the Intergalactic Medium, which grow under the effect of gravity. The details of the galaxy formation process are not well understood. The challange is to design a galaxy formation model that can account for the numerous observable properties of galaxies. While the properties of the Intergalactic Medium will ultimately determine the physical properties of galaxies, galaxies in turn can affect the evolution of the Intergalactic Medium, a processus called feedback. Galaxies produce winds: hot gas blown out of galaxies by supernova explosions. This gas deposits heat into the Intergalactic Medium, and modifies its chemical composition. This will eventually affect the formation of subsequents generations of galaxies. The goal of the proposed research program is to study the processes of galaxy formation and evolution, the evolution of the Intergalactic Medium, and how these processes interact with one another.