标题： 用本地体积中HWO紫外光谱探测星系内和星系间星际尘埃丰度和特性的变化 显示英文标题

标题： Probing the variations of interstellar dust abundance and properties within and between galaxies with HWO UV spectroscopy in the Local Volume

摘要： 金属在中性星际介质（ISM）的气体相和尘埃相之间的循环是星系中重子循环的重要组成部分。 这种星际尘埃丰度和性质的变化对我们在宇宙时间尺度上准确追踪宇宙化学富集的程度具有重要意义。 使用HWO进行多目标紫外光谱观测可以提供大量所需的丰度和尘埃耗竭测量数据，以理解星际尘埃的丰度和性质在星系内部和星系之间的变化，从而从观测上解决关于化学富集和星系演化的关键问题。 在本地体积星系（D < 10 Mpc）中的大质量恒星全紫外波段（950-3150 A）中进行中等分辨率（R~50,000）的光谱观测将能够测量关键元素（如Fe、Si、Mg、S、Zn）的气体相和尘埃相的丰度。 这些测量将提供一个估计，说明尘埃丰度如何随环境变化，特别是金属丰度和气体密度。 然而，由于这些元素的非饱和紫外跃迁极其微弱，测量尘埃中的碳和氧含量需要非常高的分辨率（R > 100,000）和高信噪比（S/N > 100）。 由于中性ISM中的碳和氧为尘埃提供了最大的金属质量库，因此HWO设计中必须包含类似于哈勃空间望远镜STIS H光栅的光栅，以提供非常高的分辨率，以及能够达到非常高的S/N的FUV和NUV探测器。 显示英文摘要

摘要： The cycle of metals between the gas and the dust phases in the neutral interstellar medium (ISM) is an integral part of the baryon cycle in galaxies. The resulting variations in the abundance and properties of interstellar dust have important implications for how accurately we can trace the chemical enrichment of the universe over cosmic time. Multi-object UV spectroscopy with HWO can provide the large samples of abundance and dust depletion measurements needed to understand how the abundance and properties of interstellar dust vary within and between galaxies, thereby observationally addressing important questions about chemical enrichment and galaxy evolution. Medium-resolution (R~50,000) spectroscopy in the full UV range (950-3150 A) toward massive stars in Local Volume galaxies (D < 10 Mpc) will enable gas- and dust-phase abundance measurements of key elements, such as Fe, Si, Mg, S, Zn. These measurements will provide an estimate of how the dust abundance varies with environment, in particular metallicity and gas density. However, measuring the carbon and oxygen contents of dust requires very high resolution (R > 100,000) and high signal-to-noise (S/N > 100) owing to the non-saturated UV transitions for those elements being extremely weak. Since carbon and oxygen in the neutral ISM contribute the largest metal mass reservoir for dust, it is critical that the HWO design include a grating similar to the HST STIS H gratings providing very high resolution, as well as FUV and NUV detectors capable of reaching very high S/N.