Star Clusters and Stellar Populations in Nearby Galaxies

对M33星系中星团的研究提供了许多关于星团系统本身、盘的化学演化和一些运动学方面的信息。利用夏威夷莫纳克亚山的观测条件，这项调查将扩展到更深的范围。星团的深度光度函数将作为M33中星团形成和解散过程的线索。波长范围将扩展到紫外线（UV）波段和近红外（IR）波长，使用阵列来获得更大样本簇的改进变红，年龄和金属丰度估计。我们将探测星团中最亮的疏散星团所在的区域。将使用高空间分辨率相机，以地面设施提供的最佳质量对野外进行分辨。光谱学将用于研究星团系统的运动学和校准金属丰度估计。M33的恒星成分也将被检查，使用与调查星团相同的数据。将研究星盘中恒星群在不同位置的变化。结合HII区域和星系团在M33中追踪到的金属丰度梯度，整个磁盘的年龄金属丰度和人口变化将被揭示。与M31和银河系的研究相比，M33的接近度和倾角允许对参数进行最佳采样，这些参数为星系结构和演化理论提供了约束，而M31和银河系的研究则受到灭绝的严重限制。M33的样本将与小麦哲伦云（SMC）和大麦哲伦云（LMC）的数据进行比较，以了解恒星和星团的演化有多少是由母星系决定的。继续对M33的研究，从地面上可以获得更暗的星等，这样就可以从目前发表的“更亮”的调查（V=14-20）顺利过渡到哈勃太空望远镜（HST）选择的领域。地面研究将用于选择“最有利可图”的空间观测领域。在其他星系中，只对最亮的部分进行采样，将使用现有数据进行测量。将得到蓝色、紫色、紫外线、红色和红外分光光度法。本星系群中恒星成分的特性表征，因为它们在每个星系和星系之间都是不同的，将被用来理解更遥远系统的综合特性。

The study of stellar clusters in the galaxy M33 has provided much information concerning the stellar cluster system itself, chemical evolution of the disk and some kinematics. This survey will be extended to deeper limits taking advantage of the quality of observing conditions on Mauna Kea, Hawaii. Deep luminosity functions of clusters will be obtained as clues to the formation and cluster dissolution processes occurring in M33. The wavelength range will be extended to the Ultraviolet (UV) band and to the near infrared (IR) wavelength using arrays to obtain improved reddening, age and metallicity estimates for a larger sample of clusters. The region of the brightest open clusters in the disk will be probed. High spatial resolution cameras will be used to resolve the fields at the best quality offered at ground-based facilities. Spectroscopy will be used to study the kinematics of the cluster system and to calibrate the metallicity estimates. The stellar content of M33 will be examined as well, using the same data taken to survey the clusters. The variation of the stellar population from place to place in the disk will be investigated. Coupled with the metallicity gradient seen in M33 traced by HII regions and the clusters, the age-metallicity and population variations across the disk will be unveiled. The proximity and inclination of M33 allows optimal sampling of parameters that provide constraints for galactic structure and evolution theories, in contrast to studies of M31 and the Galaxy which are severely restricted by extinction. The M33 samples will be compared to data for the Small Magellanic Cloud (SMC) and Large Magellanic Cloud (LMC) to understand how much of stellar and cluster evolution is determined by the parent galaxy. Continuing the M33 study to fainter magnitudes achievable from the ground permits a smooth transition from the "brighter" surveys (V=14-20) currently published to fields selected for Hubble Space Telescope (HST). The ground based studies will be used to choose the "most profitable" fields for space observations. Stars in other galaxies, sampled at only the brightest fraction of the population, will be measured using existing data. Blue, violet, ultraviolet, red and infrared protometry will be obtained. Characterization of the properties of the stellar content of Local Group galaxies, as they vary within each galaxy and from galaxy to galaxy, will be used to understand the integrated properties of more distant systems.