星系紫外深场巡天观测进展

Ultraviolet deep imaging surveys

紫外波段是星系能谱分布中的重要部分.其包含大量原子、离子和分子的共振线以及研究重要物理过程的连续辐射,提供了理论研究重要的观测限制.在星系研究中,紫外辐射追踪大质量恒星,是测量和理解宇宙中恒星形成历史的重要工具.紫外辐射也可追踪大质量黑洞吸积盘,是理解吸积物理过程的重要手段.其涉及的关键科学问题包括宇宙正午时期的恒星形成历史与星系演化、宇宙重子物质缺失、宇宙再电离能量来源以及星系吸积和外流反馈等.本文重点阐述了紫外深场巡天观测的发展现状及其在星系科学研究中发挥的作用.主要介绍了深场仪器的基本参数、深场观测的目的和任务,以及数据及科学产出,并对国内外正在计划中的未来紫外观测进行了总结和展望.

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.