An Unbiased View of the Physical Drivers of Star Formation over Cosmic Time

星系演化研究最基本的测量方法是宇宙恒星形成速率密度随宇宙时间的演化，以及恒星形成速率密度在每个时期在星系群中的分布。目前对高红移恒星形成的研究几乎普遍基于紫外连续辐射；然而，这受到尘埃消失的严重影响，需要大量和不确定的修正。这个项目的重点是使用替代的、独立于尘埃的技术，以一种可靠的方式进行这些关键的测量，使用大量的、无偏的恒星形成星系的样本，直到最高的红移。h α选择的恒星形成星系的样本将从JWST窄带成像中提取，以探测低光度恒星形成的最高红移。此外，来自为期5年的LOFAR大型项目的无线电观测将用于在研究得最好的河外区域获得最深的广域无线电调查，并通过使用新的WEAVE光谱仪对所有（~240k）探测到的射电源进行专用光学光谱的增强。这将确定恒星形成的分布，作为星系质量、环境和红移的独立函数，直到恒星形成活动的峰值时代在z~2，并使恒星形成速率密度的全球测量回到再电离时代。

The most fundamental measurements for galaxy evolution studies are the evolution of the cosmic star-formation rate density as a function of cosmic time and the distribution of the star-formation rate density amongst the galaxy population at each epoch. Current studies of star formation at high redshifts are almost ubiquitously based on the ultraviolet continuum emission; however, this is heavily affected by dust extinction, requiring large and uncertain corrections. This project is focussed on using alternative, dust independent, techniques to make these critical measurements in a robust manner, using large and unbiased samples of star-forming galaxies out to the highest redshifts. Samples of H-alpha-selected star-forming galaxies will be drawn from JWST narrow-band imaging to probe lower-luminosity star formation back to the highest redshifts. In addition, radio observations from a 5-yr large programme with LOFAR will be used to obtain the deepest, wide-area radio survey in the best-studied extragalactic fields, augmented by dedicated optical spectroscopy of all (~240k) detected radio sources using the new WEAVE spectrograph. This will determine the distribution of star-formation as independent functions of galaxy mass, environment and redshift, out to the peak epoch of star formation activity at z~2, and enable a global measure of the star formation rate density back to the Epoch of Reionisation.