标题： 用宜居世界观测站解析邻近大星系中的单个恒星 显示英文标题

标题： Resolving Individual Stars in Nearby Large Galaxies with the Habitable Worlds Observatory

摘要： 星系多样化和动态的演化历史导致了我们在现今宇宙中观察到的它们属性的惊人多样性。哈勃太空望远镜（HST），现在还有詹姆斯·韦布太空望远镜（JWST），率先研究了银河系和其他本地星系群成员中的分辨个体恒星，揭示了其形态、恒星形成和化学演化的驱动因素。HWO将构成范式转变：引入将本地体积内的每个星系主体分解为其组成恒星的全波段分辨能力。在这个科学案例中，我们总结了HWO将在通过分辨恒星种群研究星系演化领域取得的突破性进展。HWO将在三个距离范围内改变我们对星系的理解：(1) 在最近的星系（$\sim$5 Mpc）中，它将分辨低于最古老主序星转折点的恒星，使精确的恒星天体物理学和恒星形成历史（SFH）推断能够追溯到最早的宇宙时间；(2) 在更大的本地体积（$\sim$20 Mpc）中，它将分辨低于红团簇的恒星，为数百个星系提供准确的SFH，涵盖整个哈勃序列；以及(3) 到宇宙学体积（$\sim$50+ Mpc），提供对数千个星系中的明亮恒星种群的访问，使我们能够以前所未有的视角观察它们的形态、恒星丰度和尘埃含量。这个科学案例提出的主要技术要求是一种分辨率为$\leqslant$0.015'' 的相机，该相机是衍射极限的，并且是奈奎斯特采样（每像素0.01''），至少达到550 nm$-$，与LUVOIR概念中的高清成像仪相当。 显示英文摘要

摘要： The varied and dynamic evolutionary histories of galaxies give rise to the stunning diversity in their properties that we observe in the present-day universe. HST, and now JWST, have pioneered the study of resolved individual stars in the Milky Way and other members of the Local Group, uncovering the drivers of their morphological, star formation, and chemical evolution. HWO will constitute a paradigm shift: introducing the ability to panchromatically resolve the main bodies of every galaxy in the Local Volume into their constituent stars. In this science case, we summarize the breakthrough progress that HWO will advance in the field of galaxy evolution through resolved stellar populations. HWO will transform our understanding of galaxies in three distance regimes: (1) in the nearest galaxies ($\sim$5 Mpc), where it will resolve stars below the oldest Main Sequence Turnoff, enabling precision stellar astrophysics and star formation history (SFH) inferences to the earliest cosmic times; (2) in the greater Local Volume ($\sim$20 Mpc), where it will resolve stars below the Red Clump, providing access to accurate SFHs for hundreds of galaxies, spanning the entire Hubble Sequence; and (3) out to cosmological volumes ($\sim$50+ Mpc), providing access to the luminous stellar populations in thousands of galaxies, enabling unprecedented views of their morphology, stellar abundances, and dust content. The principal technological requirement advanced by this science case is a camera with a resolution of $\leqslant$0.015'' that is diffraction-limited, and Nyquist-sampled (0.01'' per pixel), to at least 550 nm $-$ comparable to the High Definition Imager from the LUVOIR concept.