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arXiv 2601.22232astro-ph.CO
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LBT Y_p 项目I：原始氦丰度的改进测定——项目描述、样本选择、观测与方法论

The LBT $Y_{\rm p}$ Project I: An Improved Determination of the Primordial Helium Abundance -- Project Description, Sample Selection, Observations, and Methodology

University of Minnesota（明尼苏达大学）；The Ohio State University（俄亥俄州立大学）；Gonzaga University（贡萨加大学）；Northwestern University（西北大学）；University of Texas at Austin（德克萨斯大学奥斯汀分校）
Evan D. Skillman, Richard W. Pogge, Erik Aver, Noah S. J. Rogers, Miqaela K. Weller, Keith A. Olive, Danielle A. Berg, John J. Salzer, John H. Miller, Jayde Spi… 展开作者

Evan D. Skillman, Richard W. Pogge, Erik Aver, Noah S. J. Rogers, Miqaela K. Weller, Keith A. Olive, Danielle A. Berg, John J. Salzer, John H. Miller, Jayde Spiegel, Tsung-Han Yeh, Brian D. Fields

备注：
17 pages, 2 Figures, 1 Table, submitted to AAS journals
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AI总结：

LBT Y_p项目通过改进观测与分析方法，提高原始氦丰度测定精度，为中微子家族数提供独立约束。

摘要：

极低金属度的HII区域已被观测，目的是确定原始氦丰度（Y_p）。Y_p结合标准大爆炸核合成和中子半衰期，可提供中微子家族数的直接测量，但Y_p必须非常精确地测量才能对超出标准模型的物理提供有意义的约束。本文描述了一个程序，旨在将新的LBT观测与新的分析方法相结合，显著提高Y_p的测定。LBT配备MODS和LUCI仪器，能够产生光谱，结合新的分析方法，可为单个HII区域提供氦丰度，其不确定性约为2%或更低。存档的LBT/MODS标准星光谱在四年期间内，使能确定MODS光谱响应的波长依赖性不确定性，从而改进相对发射线不确定性。经过优化的低金属度星系样本已选定，目标是通过约0.5%的精度确定Y_p，足以提供中微子家族有效数约3%的独立约束。

英文摘要：

Extremely low metallicity HII regions have been observed with the goal of determining the primordial helium abundance ($Y_{\rm p}$). $Y_{\rm p}$, combined with standard big bang nucleosynthesis and the half-life of the neutron, provides a direct measurement of the number of neutrino families, but $Y_{\rm p}$ must be measured very precisely to provide meaningful constraints on physics beyond the Standard Model. Here we describe a program to combine new Large Binocular Telescope (LBT) observations with a new analysis methodology to significantly improve the determination of $Y_{\rm p}$. The LBT, with its MODS and LUCI instruments, produces spectra, which, when combined with our new analysis methodology, are capable of delivering He abundances in individual HII regions with uncertainties of approximately 2% or less. Archival LBT/MODS spectra of standard stars over a four-year period enable the determination of a wavelength-dependent uncertainty in the MODS spectral response, resulting in improved relative emission line uncertainties. An optimized sample of low-metallicity galaxies has been selected with the goal of producing a determination of $Y_{\rm p}$ with a precision of $\sim$ 0.5%, sufficient to provide an independent constraint on the effective number of neutrino families of $\sim$ 3%.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

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