标题： 关于旋转对经典造父变星群体的影响 I. 太阳金属丰度下的预测 显示英文标题

标题： On the effect of rotation on populations of classical Cepheids I. Predictions at solar metallicity

摘要： [简写版] 我们旨在从演化的角度增进对造父变星的理解，并确立旋转在造父变星范式中的作用。 特别是，我们关注旋转对造父变星质量问题的贡献，并探讨可以与观测结果相对照的可测试预测量。 详细研究了包含均匀且自洽旋转处理的演化模型，这些模型在经典不稳定带（IS）的穿越过程中被分析。 研究了几种参数对初始旋转的依赖性，这些参数包括质量、光度、温度、寿命、赤道速度、表面丰度以及周期变化率。 得到了几个关键结果：i) 质量-光度（M-L）关系依赖于旋转，特别是在蓝环阶段；ii) 不稳定带穿越之间的光度会增加。 因此，固定初始旋转速率下的造父变星M-L关系取决于穿越次数（更快的旋转会导致更大的光度差异）；iii) 当考虑旋转和穿越次数时，造父变星的质量差异问题消失，无需高核心过度混合值或增强的质量损失；iv) 旋转会在固定质量和金属丰度下预测的平均参数周围产生分散。 这对周光关系尤为重要，因为旋转是固有分散的一个来源；v) 增强的表面丰度并不能明确区分占据赫茨普龙间隙的造父变星与蓝环上的造父变星（吸积后），因为旋转混合可能导致显著增强的主序（MS）丰度；vi) 由于主序寿命更长，旋转模型预测的造父变星年龄大于非旋转模型。 旋转对经典造父变星具有显著的演化影响，不应再被忽略。 显示英文摘要

摘要： [Abridged] We aim to improve the understanding of Cepheids from an evolutionary perspective and establish the role of rotation in the Cepheid paradigm. In particular, we are interested in the contribution of rotation to the problem of Cepheid masses, and explore testable predictions of quantities that can be confronted with observations. Evolutionary models including a homogeneous and self-consistent treatment of rotation are studied in detail during the crossings of the classical instability strip (IS). The dependence of several parameters on initial rotation is studied. These parameters include mass, luminosity, temperature, lifetimes, equatorial velocity, surface abundances, and rates of period change. Several key results are obtained: i) mass-luminosity (M-L) relations depend on rotation, particularly during the blue loop phase; ii) luminosity increases between crossings of the IS. Hence, Cepheid M-L relations at fixed initial rotation rate depend on crossing number (faster rotation yields greater luminosity difference between crossings); iii) the Cepheid mass discrepancy problem vanishes when rotation and crossing number are taken into account, without a need for high core overshooting values or enhanced mass loss; iv) rotation creates dispersion around average parameters predicted at fixed mass and metallicity. This is of particular importance for the period-luminosity-relation, for which rotation is a source of intrinsic dispersion; v) enhanced surface abundances do not unambiguously distinguish Cepheids occupying the Hertzsprung gap from ones on blue loops (after dredge-up), since rotational mixing can lead to significantly enhanced Main Sequence (MS) abundances; vi) rotating models predict greater Cepheid ages than non-rotating models due to longer MS lifetimes. Rotation has a significant evolutionary impact on classical Cepheids and should no longer be neglected in their study.