当前对星团性质的新见解及其它们深远的影响- - 我们通常认为的单族恒星观念被终结了吗？

Until about a decade ago, star clusters were considered 'simple' stellar populations: it was generally agreed that all member stars in a given cluster formed at approximately the same time from the same progenitor gas cloud. All stars in a cluster were therefore thought to have similar ages and the same metallicity, while the stellar masses covered a range defined by the stellar initial mass function. This situation has changed dramatically, implying that the stellar populations making up star clusters can no longer be considered simple. Yet, at the same time, they are among the brightest stellar population components and, as such, they are visible out to much greater distances than individual stars, so that understanding the complexities of star cluster composition and their evolution is imperative for understanding stellar populations and the evolution of galaxies as a whole. Here I propose to focus on five research questions of significant current interest, using cutting-edge observations at optical and infrared wavelengths. I will combine our newly gained observational insights with the latest advances in computational astrophysics to produce high-impact scientific results on realistic timescales. Specifically, I will address (i) the evolution of primordial and evolved binary populations in clusters covering a large range in age; (ii) the origin of the multiple stellar populations commonly observed in old Galactic globular clusters; (iii) the formation mechanisms of blue straggler stars in star clusters; (iv) the impact of stochastically sampled stellar mass functions and their effects on the determination of fundamental star cluster properties based on integrated photometry; (v) the evolutionary timescale(s) of massive star cluster populations in the dense environments of galactic circumnuclear and polar rings; while I also aim at (vi) contributing significantly to our improved understanding of the Milky Way bulge's 3D structure using a combination of variable stars and open star clusters.

约十年前，星团还认为只有单族恒星：星团中恒星都同时形成于一片气体云，因而它们都拥有相似的年龄和金属丰度，而恒星在某范围的质量由初始质量函数确定。这个观点已经深刻改变了，星团的恒星不再认为是单族。而星团总是最明亮的恒星成分，当看不到遥远的单个恒星时，却能容易地看到这个距离的星团。所以了解错综复杂的星团组成和演化对理解整个星系的星族演化至关重要。利用最先进的光学及红外观测，我们将把最近的观测与计算天体物理的最新进展结合起来，在计划内作出高度重要的科研结果。我们将致力于此领域最重要的五部分：1、不同年龄星团中原初和演化的双星星族；2、银河系年老球状星团中多星族的来源；3、星团中蓝离散星的形成机制；4、基于累积测光的随机抽样恒星质量函数，和它们对确定星团基本性质的影响；5、致密的绕心星系环上大质量星团的演化时标；我们同时也致力于：6、结合疏散星团和变星的数据，使人们更好的了解银河系核球的三维结构。

约十年前，星团还认为只有单族恒星：星团中恒星都同时形成于一片气体云，因而它们都拥有相似的年龄和金属丰度，而恒星在某范围的质量由初始质量函数确定。这个观点已经深刻改变了，星团的恒星不再认为是单族。而星团总是最明亮的恒星成分，当看不到遥远的单个恒星时，却能容易地看到这个距离的星团。所以了解错综复杂的星团组成和演化对理解整个星系的星族演化至关重要。利用最先进的光学及红外观测，我们将把最近的观测与计算天体物理的最新进展结合起来，在计划内作出高度重要的科研结果。我们将致力于此领域最重要的五部分：1、不同年龄星团中原初和演化的双星星族；2、银河系年老球状星团中多星族的来源；3、星团中蓝离散星的形成机制；4、基于累积测光的随机抽样恒星质量函数，和它们对确定星团基本性质的影响；5、致密的绕心星系环上大质量星团的演化时标；我们同时也致力于：6、结合疏散星团和变星的数据，使人们更好的了解银河系核球的三维结构。