Ultraviolet deep imaging surveys

The ultraviolet band is an important part of the spectral energy distribution of galaxies; this wavelength region is rich in resonance lines of common elements in their neutral and ionized states. The ultraviolet continuum is also related to several key processes in astrophysics, providing essential constraints for theoretical studies. In extragalactic studies, ultraviolet radiation can be used to trace massive stars, providing an important tool to measure the cosmic star formation history. It can also be used to trace the accretion disks of massive black holes, which is necessary for understanding the accretion process. The key scientific issues in ultraviolet astronomy include the lack of knowledge on the star formation history and galaxy evolution at cosmic noon, the missing baryon problem, the source of reionization, and feedback of galaxy accretion and outflow. We herein review the status of various ultraviolet deep-field observations and the scientific possibilities of these data in extragalactic astronomy. We present the instrument parameters, scientific goals, data products, and the main discoveries of ultraviolet deep-field surveys. We also outline future ultraviolet projects and the science to be carried out in this field.