Star formation and magnetic fields in the interstellar medium

恒星形成过程是现代天体物理学中最重要的悬而未决的问题之一。了解新星质量分布的起源(初始质量函数)，以及这些恒星形成效率极低的原因，对于星系如何演化，以及像我们自己的太阳系是如何诞生等各种问题至关重要。恒星形成过程中的一个关键未知数是星际磁场在调节恒星形成区引力坍塌中的作用和动力学重要性。在阿塔卡马大毫米阵列(ALMA)、詹姆斯·克莱克·麦克斯韦望远镜(JCMT)和普朗克卫星等仪器的推动下，我们推断这些星际磁场特性的能力正处于一场革命的开始，这些仪器能够测量从银河系旋臂到年轻恒星周围圆盘的大小范围内的极化尘埃排放。该项目将使用远红外和亚毫米偏振仪器，主要是JCMT和ALMA，来观察银河系内各种恒星形成区域的尘埃偏振和磁场特性。这些观测将被用来研究恒星形成的不同弱场和强场模式的存在与否，以及磁场在决定恒星形成效率和新星质量分布方面的作用。

The process of star formation is one of the most important unsolved problems in modern astrophysics. Understanding the origin of the mass distribution of new stars (the Initial Mass Function), and the cause of the very low efficiency with which these stars form, is crucial to questions as diverse as how galaxies evolve, and how solar systems such as our own are born. One of the key unknowns in the star formation process is the role and dynamic importance of interstellar magnetic fields in mediating the gravitational collapse of star-forming regions. We are at the beginning of a revolution in our ability to deduce the properties of these interstellar magnetic fields, driven by instrumentation such as the Atacama Large Millimeter Array (ALMA), the James Clerk Maxwell Telescope (JCMT) and the Planck satellite, which are capable of measuring polarised dust emission on size scales ranging from the spiral arms of the Milky Way through to the discs around young stars. This project will use far-infrared and submillimetre polarimetric instrumentation, primarily the JCMT and ALMA, to observe dust polarisation, and so magnetic field properties, in a variety of star-forming regions within the Milky Way. These observations will be used to investigate the existence or otherwise of distinct weak- and strong-field modes of star formation, and so the role of magnetic fields in determining star formation efficiency and the mass distribution of new stars.