论文标题
红色巨型分支（TRGB）的尖端的校准
Calibration of the Tip of the Red Giant Branch (TRGB)
论文作者
论文摘要
红色巨人（TRGB）方法的尖端提供了测量附近星系距离的最准确和精确的手段之一。在这里，我们基于大麦芽云（LMC）中TRGB恒星的观察结果对TRGB进行了VIJHK绝对校准，该观察结果基于脱落的二进制二进制文件（DEBS）。本文介绍了Freedman等人首次提出的方法的更详细的描述。 （2019年）用于测量视线灭绝的校正和对LMC的变红。在这种方法中，我们使用LMC中红色巨型种群的差异比较，首先与当地集团Galaxy，IC 1613中的红色巨人，然后与小麦哲伦云中的红色巨头进行比较。作为一致性检查，我们单独使用SMC来得出TRGB序列的独立校准，并调用其几何距离也通过DEB校准。额外的一致性检查来自银河球状簇的近红外观察，涵盖了广泛的金属度。在所有情况下，我们都在零点校准中都发现了极好的一致性。然后，我们研究了Yuan等人的最新主张。 （2019年），证明，在SMC的情况下，他们仅纠正了灭绝，同时忽略了重新磨损的基本校正。在IC 1613的情况下，我们表明它们的分析包含对金属性（过度校正）的不正确处理。使用我们修订的LMC TRGB灭绝（直接）测量，我们发现HO的值= 69.6 +/- 0.8（+/- 1.1％STAT）+/- 1.7（+/- 2.4％SYS）km/s/s/mpc。
The Tip of the Red Giant (TRGB) method provides one of the most accurate and precise means of measuring the distances to nearby galaxies. Here we present a VIJHK absolute calibration of the TRGB based on observations of TRGB stars in the Large Magellanic Cloud (LMC),grounded on detached eclipsing binaries (DEBs). This paper presents a more detailed description of the method first presented in Freedman et al. (2019) for measuring corrections for the total line-of-sight extinction and reddening to the LMC. In this method, we use a differential comparison of the red giant population in the LMC, first with red giants in the Local Group galaxy, IC 1613, and then with those in the Small Magellanic Cloud. As a consistency check, we derive an independent calibration of the TRGB sequence using the SMC alone, invoking its geometric distance also calibrated by DEBs. An additional consistency check comes from near-infrared observations of Galactic globular clusters covering a wide range of metallicities. In all cases we find excellent agreement in the zero-point calibration. We then examine the recent claims by Yuan et al. (2019), demonstrating that, in the case of the SMC, they corrected for extinction alone while neglecting the essential correction for reddening as well. In the case of IC 1613, we show that their analysis contains an incorrect treatment of (over-correction for) metallicity. Using our revised (and direct) measurement of the LMC TRGB extinction, we find a value of Ho = 69.6 +/-0.8 (+/-1.1% stat) +/- 1.7 (+/-2.4% sys) km/s/Mpc.
