距离阶梯与哈勃常数危机  

Distance ladders and the Hubble constant crisis

作　　者：陈孝钿 王舒 CHEN XiaoDian;WANG Shu(National Astronomical Observatories,Chinese Academy of Sciences,Beijing 100101,China;Institute for Frontiers in Astronomy and Astrophysics,Beijing Normal University,Beijing 102206,China;School of Astronomy and Space Science,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院国家天文台,北京100101 [2]北京师范大学天文与天体物理前沿所,北京102206 [3]中国科学院大学天文与空间科学学院,北京100049

出　　处：《中国科学：物理学、力学、天文学》2024年第11期44-54,共11页Scientia Sinica Physica,Mechanica & Astronomica

基　　金：国家自然科学基金(编号:12322306,12173047);国家重点基础研究发展计划(编号:2022YFF0503404)资助项目。

摘　　要：哈勃常数是天文学中的一个重要参数.当前最前沿的两项观测证据在哈勃常数上出现了5倍标准差的差异,即“哈勃常数危机”.本文总结了基于距离阶梯测量哈勃常数方法中的几种常用量天尺,包括几何距离、造父变星、红巨星顶点恒星和Ia型超新星;分析了它们的优缺点、潜在问题以及未来的优化预期.同时,介绍了几种潜在的量天尺.它们能帮助检查常用量天尺并独立测量哈勃常数.未来五年内,随着Gaia DR4的释放和视差零点的优化、詹姆斯韦伯望远镜的数据累积、中国空间站巡天望远镜的发射和观测及数据释放,天文学家将有望给出当前“哈勃常数危机”的答案.The Hubble constant is an important parameter in astronomy,and recent observational evidences reveal a 5σdiscrepancy in its measurements,known as the“Hubble constant crisis”.In this review,we summarize several commonly used distance ladder methods for measuring the Hubble constant,including geometric distances,classical Cepheid distances,tip of red giant branch star(TRGB)distances,and type Ia supernova distances.We introduce and discuss their strengths,weaknesses,potential problems,and expectations for future optimization.The most accurate geometric distances include the Gaia parallax,the eclipsing binary distance measurement of the Large Magellanic Cloud,and the water maser distance measurement of NGC 4258,with the Gaia parallax showing the most promising for further optimization.By combining these three geometric distances,the distance errors based on Cepheids and TRGBs are 0.7%and 1.1%,respectively,and they are used to calibrate type Ia supernovae in the nearby galaxies.Cepheids were used to calibrate the absolute magnitude of 42 nearby type Ia supernovae with an error of 0.9%,while TRGBs were used to calibrate the absolute magnitude of 18 nearby type Ia supernovae with an error of 1.3%.The Hubble constant can be measured using the apparent magnitudes and redshifts of more distant type Ia supernovae.The Hubble constant based on Cepheids+type Ia supernovae is 73 km s−1 Mpc−1 with an error of 1.4%,while that based on TRGB+type Ia supernovae are 70 km s−1 Mpc−1 with an error of 1.7%.Additionally,we introduce several potential methods for distance measurement that can help verify commonly used distance ladders or measure the Hubble constant independently.In the next five years,with the optimization of the Gaia parallax,the accumulation of data from the James Webb Telescope,and the launch of the Chinese Space Station Telescope,astronomers are expected to resovle the current“Hubble Constant Crisis”.

关 键 词：哈勃常数 经典造父变星 红巨星顶点恒星 IA型超新星 几何距离 

分 类 号：P159[天文地球—天文学]