The stellar and sub-stellar content of the Trapezium Cluster

梯形星系团是研究恒星、原行星盘和亚恒星天体形成和演化的主要目标之一。除了距离较近之外，正是由于高质量和低质量恒星的大量和数密度，恒星质量的广泛范围，以及它的极端年轻，使这个星系团成为研究恒星和行星形成的各个方面的理想选择。然而，尽管进行了大量调查，仍然没有对梯形星系团进行全面的红外研究--即在空间覆盖(和分辨率)以及敏感度方面完整和统一。在VLT，我们最近对这个重要的星系团进行了最广泛的IR研究，覆盖了21‘x 28’的区域，由36个单独的帧组成。观测可以在极佳的能见度(~0.5“)条件下进行，产生了前所未有的极限震级，分别为J=24、H=20和K=18。博士生需要整理和分析这些庞大的数据，并研究以下问题：-从50M⊙到亚恒星质量的真正初始质量谱的详细形状。-被认为经历了恒星形成的区域的表观年龄扩散。-恒星形成的时间序列作为恒星质量的函数。-红外线过剩和直接成像所证明的盘状物的大小。-所有这些方面的趋势与星团半径。结合现有的光学和MIR光度学、光谱学和X射线数据，该项目将提供对恒星天体物理学中最重要的星系团之一的完整概述。当前项目的科学相关性已经得到了ESO计划委员会的认可。

The Trapezium Cluster is one of the prime targets to study the formation and evolution of stars, proto-planetary disks and sub-stellar objects. Apart from its proximity it is the large number and number density of high- and low-mass stars, the wide range in stellar mass, and its extreme youth that make this cluster ideal to investigate all aspects of star and planet formation. Nevertheless, despite numerous investigations, a comprehensive IR study of the Trapezium cluster - i.e. complete and uniform in terms of spatial coverage (and resolution) as well as in terms of sensitivity - is still missing. At the VLT we have recently performed the most extensive IR study on this important cluster, covering an area of 21’ x 28’ and consisting of 36 individual frames. The observations could be done in superb seeing conditions (~ 0.5”) resulting in unprecedented limiting magnitudes of J = 24, H = 20 and K = 18, respectively. A PhD student is required to reduce and analyze this huge amount of data and to study the following issues:- The detailed shape of a truly initial mass spectrum from 50 M⊙ to sub-stellar masses.- The apparent age spread in a region thought to have undergone triggered star formation.- The time sequence of star formation as a function of stellar mass.- The size of the disk population as witnessed by IR excesses and direct imaging.- Trends of all these aspects with cluster radius.In combination with existing optical and MIR photometry, spectroscopy, and X-ray data this project will provide a complete overview of one of the most important clusters in stellar astrophysics. The scientific relevance of the current project has been acknowledged by the ESO program committee.