发表机构
Instituto de Astrofísica de Canarias; Universidad de La Laguna; INAF-Osservatorio Astronomico di Capodimonte; Swinburne University; Observatoire de Paris, LERMA, PSL University; Université Paris-Cité（加那利天体物理研究所; 拉古纳大学; 意大利国家天体物理研究所卡波迪蒙特天文台; 斯威本科技大学; 巴黎天文台，LERMA，PSL大学; 巴黎西岱大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究提出以半分辨恒星群光谱推导星系距离的新方法，对M 31核球的应用结果与现有测量一致，无需次级校准，为距离测量提供了互补途径。
AI 中文摘要
星系距离是我们理解宇宙的核心。尽管现有方法已取得成功，独立且互补的方法对于检验系统效应和扩展不同距离标尺的适用范围仍具重要价值。本文证明，单个半分辨恒星群的光谱编码了其距离的直接信息，原则上可通过结合多个独立测量值获得有价值的距离约束。将该方法应用于仙女座星系（M 31）核球的光学光谱时，我们推导得出基于恒星群的距离为756±57千秒差距（μ₀=24.39±0.15），与当前最先进的测量结果一致。关键在于，半分辨恒星群距离无需次级校准，尽管其绝对尺度仍取决于所采用的恒星群模型。我们的研究首次评估了从简单恒星群模型推导基于恒星群的距离估计的可行性，为进一步检验该方法更广泛的适用性和精度提供了依据。
英文摘要
Galaxy distances are central to our understanding of the Universe. Despite the success of existing approaches, independent and complementary methods remain valuable for testing systematic effects and extending the applicability range of different distance metrics. Here we demonstrate that the spectrum of an individual semi-resolved stellar population encodes direct information about its distance and that valuable distance constraints can, in principle, be obtained by combining multiple independent measurements. When applied to optical spectra of bulge of the Andromeda galaxy (M\,31), we derive a stellar population-based distance of 756$\pm$57 kpc ($μ_0 = 24.39 \pm 0.15$), in agreement with state-of-the-art measurements. Crucially, semi-resolved stellar population distances does not require secondary calibrations, although its absolute scale remains conditional on the adopted stellar population models. Our findings provide a first assessment of the feasibility of deriving stellar population-based distance estimates from simple stellar population models, motivating further tests of the broader applicability and precision of the method.
Comments5 pages, 4 figures. Accepted for publication in ApJL
