Intermediate and Low-mass Young Stellar Populations in the Magellanic Clouds

大麦哲伦云和小麦哲伦云（MCs）是在金属贫乏条件下详细研究恒星形成的最接近的模板。这些星系反映了典型的星系在其组合的早期阶段的条件，为理解高红移恒星形成提供了一个垫脚石，在高红移恒星形成的过程不能直接观察到。这项博士研究将使用Vista麦哲伦星云（VMC）巡天的近红外光度测量技术与SMASH巡天的光学光度测量技术相结合，以限制和表征MCs中的年轻恒星群。这个项目的重点是天空中两个1.2平方度的区域，每个星系中都有一个，它们包含了超过20个时代观测到的200多万个光源。该学生将使用财团成员开发的工具对这些地区的VMC图像进行PSF光度测定，预计将进行中等时间的工作访问。这些点源代表着不同的恒星群，它们需要被解开，这样年轻的恒星才能被识别和表征。学生将使用包括监督机器学习在内的统计方法来识别年轻恒星，在整个恒星形成复合体中构建初始质量函数，绘制和量化这些区域的真实范围以及与气体和尘埃的相互作用。该项目还可以利用VMC调查的多历元数据来描述大质量年轻恒星在MCs中的变化，以限制对银河系环境的任何环境依赖。需要分析可用的光曲线来识别和描述变量，其中最极端的是年轻的恒星。

The Large and Small Magellanic Clouds (MCs) are the nearest templates for the detailed study of star formation under metal-poor conditions. These galaxies mirror the conditions typical of galaxies during the early phases of their assembly, providing a stepping stone to understand star formation at high redshift where such processes cannot be directly observed. This PhD research will use near-IR photometry from the Vista Magellanic Cloud (VMC) Survey combined with optical photometry from the SMASH survey to constrains and characterise young stellar populations in the MCs. This project focuses on two 1.2 degree squared regions in the sky, one in each galaxy, that contain well over two million sources observed over 20 epochs. The student will perform PSF photometry on the VMC images of these regions, using tools developed by consortium members, for which at medium length work visit is envisaged. The point sources represent different stellar populations, that need to be disentangled so that the young stars can be identified and characterised. The student will use statistical methods including supervised machine learning to identify young stars, construct the Initial Mass Function across whole star formation complexes, map and quantify the true extent of these regions and the interplay with the gas and dust. This project can also make use of the VMC survey multi-epoch data to characterise massive young stellar variability across the MCs, to constrain any environmental dependence on the galactic environment. The available light curves need to be analysed to identify and characterise variables, the most extreme of which are the young stars.