论文标题
放大镜下的头孢虫 - 毕竟不是那么简单！
Cepheids under the magnifying glass -- not so simple, after all!
论文作者
论文摘要
经典的头孢虫是蓝色循环恒星，被称为“恒星进化的放大镜”，已经研究了很长时间了。随着越来越精确的头孢虫观察到不断增长的颞碱基，我们对管理这些关键恒星的物理学的无知变得越来越清楚。因此，现在是时候加大放大倍率并研究我们对经典脉动器的理解的局限性。当然，由于Leavitt Law允许测量附近宇宙的距离，因此经典的头孢虫也是标准蜡烛。如今，头孢虫是精确校准的距离梯子的骨干，该梯子允许测量哈勃的常数（H0）高于2％，从而为精确宇宙学提供了重要的约束。在晚期宇宙中测得的H0值和从对早期宇宙的观察中推断出的H0值之间的不一致需要在估计系统不确定性方面的最大努力，以增强结果的重要性。在本演讲中，我重点介绍了最近与Cepheid相关研究的两个主要方面。首先，我介绍了日内瓦头射径向速度调查（GE-CERTS），以及根据8年监测的4 D Cepheid QZ Normae所展示的调制光谱变异性的更新。然后，我讨论了针对理解不一致H0值的宇宙学含义所需的1％H0测量的一些努力。最后，我认为现在是利用恒星物理学与观察宇宙学之间的协同作用的特别时机。
Classical Cepheids are blue loop stars that have famously been dubbed "magnifying glasses of stellar evolution" and have been studied for a long time. As more and more precise observations of Cepheids are secured over ever-increasing temporal baselines, our ignorance of the physics governing these crucial stars is becoming increasingly clear. Thus, it is time to turn up the magnification and investigate the limitations of our understanding of classical pulsators. Of course, classical Cepheids are also standard candles thanks to the Leavitt law that allows to measure distances in the nearby Universe. Nowadays, Cepheids serve as the backbone of a precisely calibrated distance ladder that allows to measure Hubble's constant (H0) to better than 2%, thus providing crucial constraints for precision cosmology. The recently established discord among H0 values measured in the late-time Universe and inferred from observations of the early Universe requires utmost diligence in estimating systematic uncertainties in order to strengthen the significance of the results. In this presentation I focus on two main aspects of recent Cepheid-related research. First, I present the Geneva Cepheid Radial Velocity survey (GE-CeRVS) and an update on the modulated spectroscopic variability exhibited by the 4 d Cepheid QZ Normae based on 8 years of monitoring. Then, I discuss some efforts directed towards a 1% H0 measurement needed for understanding the cosmological implications of discordant H0 values. Finally, I argue that now is a particularly opportune time to leverage the synergies between stellar physics and observational cosmology.
