Galaxy formation and its feedback effect on the intergalactic medium

星系是宇宙的基石。我们自己的星系，银河系，只是宇宙中数十亿个星系中的一个。星系之间的空间不是空的，而是充满了氢、氦和更重的元素的弥散混合物，称为星系间介质。据信，星系起源于星系间介质中的小密度波动，这些波动在重力的作用下增长。星系形成过程的细节尚不清楚。挑战在于设计一个能够解释星系众多可观测属性的星系形成模型。虽然星系际介质的特性最终将决定星系的物理特性，但星系反过来又会影响星系际介质的演化，这一过程被称为反馈。星系产生风：超新星爆炸从星系中吹出的热气。这种气体将热量沉积到星系际介质中，并改变其化学成分。这将最终影响下一代星系的形成。提出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.