The role of galaxy-galaxy interactions in Galaxy evolution

附近的宇宙包含了星系相互作用的惊人例子。 这个过程会使一个或两个星系受到引力的干扰，并可能导致合并。 与此同时，这些近距离接触既可以触发新一代恒星的形成，也可以（后来）抑制这些星系中星星的形成。 近年来，对相互作用星系的研究极大地提高了我们对这些过程的理解，尽管还有很多东西有待了解。 一个关键的挑战是将这些相互作用的星系的观测与更典型的（孤立的）星系联系起来，这些星系可能经历了相对较新的相互作用，深刻地改变了它们的演化历史。 拟议的研究计划将建立在我们最近在这一领域的贡献，并将采用一套非凡的数据和环境分类，我们已经为此目的组装。 我们已经使用这个数据库来识别大量的星系在密切的对和紧凑的群体，这提供了理想的，但不同的环境，在其中检测正在进行的，最近的和即将发生的相互作用。 我们将解决我们的科学目标，通过测量广泛的属性对星系和紧凑的群体，通过比较这些属性的星系在定义良好的控制样本，通过相关的密切对宽对，并通过相关的紧凑的群体星系在他们的周围。 随着度量，如大小-光度关系，质量-金属丰度关系，颜色-颜色图，和星星形成的历史，我们准备大大提高我们的相互作用在星系演化中的作用的理解。 我们现有的星系对和致密星系群的样本在星系数量、测量指数的质量和广度、使用复杂的控制样本以及将相互作用的星系与目前没有相互作用的星系直接联系起来的能力方面都是无与伦比的。 此外，我们有专业知识，在未来的许多年里利用这些资源，并继续参与博士后，研究生和本科生在这个令人兴奋的合作努力。

The nearby universe contains striking examples of galaxies which are interacting with one another. This process gravitationally disrupts one or both galaxies, and may result in a merger. At the same time, these close encounters can both trigger the formation of new generations of stars and (later) quench star formation in these galaxies. The study of interacting galaxies has greatly improved our understanding of these processes in recent years, though much remains to be learned. A crucial challenge is to relate the observations of these interacting galaxies to more typical (isolated) galaxies, which may nevertheless have undergone relatively recent interactions that have profoundly altered their evolutionary histories. The proposed research program will build on our recent contributions in this field, and will employ an extraordinary set of data and environmental classifications that we have assembled for this purpose. We have used this database to identify large numbers of galaxies in close pairs and compact groups, which provide ideal but distinct environments within which to detect ongoing, recent and imminent interactions. We will address our science goals by measuring a wide range of properties for galaxies in pairs and compact groups, by comparing these properties to galaxies in well defined control samples, by relating close pairs to wide pairs, and by relating compact group galaxies to those in their surroundings. With metrics such as the size-luminosity relation, the mass-metallicity relation, the colour-colour diagram, and star formation histories, we are poised to greatly improve our understanding of the role of interactions in galaxy evolution. Our existing samples of galaxy pairs and compact groups are unparalleled in terms of the number of galaxies, the quality and breadth of indices measured, the use of sophisticated control samples, and the ability to directly relate interacting galaxies to those which are not currently undergoing interactions. Moreover, we have the expertise in place to exploit these resources for many years to come, and to continue to involve postdocs, graduate students, and undergraduate students in this exciting collaborative endeavour.