The Megamaser Cosmology Project. XIII. Combined Hubble Constant Constraints
The Megamaser Cosmology Project. XIII. Combined Hubble Constant Constraints
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DOI：
10.3847/2041-8213/ab75f0
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发表时间：
2020-03-01
影响因子：
7.9
通讯作者：
Lo, K. Y.
中科院分区：
文献类型：
--
作者：
Pesce, D. W.;Braatz, J. A.;Lo, K. Y.
我们提出了一个测量的哈勃常数使用几何距离测量巨脉泽托管星系。我们已经应用了一种改进的方法来拟合脉泽数据，并获得了更好的距离估计的四个星系先前公布的巨脉泽宇宙学计划：UGC 3789，NGC 6264，NGC 6323，和NGC 5765 b。将这些更新的距离测量结果与脉泽星系CGCG 074-064和NGC 4258的距离测量结果相结合，并假设与特殊运动相关的固定速度不确定度为250 km·s（-1），我们将哈勃常数限制为H-0 = 73.9 +/-3.0 km·s（-1）Mpc（-1），与距离阶梯和宇宙微波背景无关。这个最佳值仅依赖于基于脉泽的距离和速度测量，并且它不使用任何特殊的速度校正。不同的修正特殊速度的方法不会使H-0的修正超过+/- 1 sigma，最佳拟合的哈勃常数范围为71.8-76.9 km s（-1）Mpc（-1）。我们证实了先前的迹象表明，当地的H-0值超过早期宇宙的值，不同的治疗的特殊速度的置信水平从95%到99%不等。
We present a measurement of the Hubble constant made using geometric distance measurements to megamaser-hosting galaxies. We have applied an improved approach for fitting maser data and obtained better distance estimates for four galaxies previously published by the Megamaser Cosmology Project: UGC 3789, NGC 6264, NGC 6323, and NGC 5765b. Combining these updated distance measurements with those for the maser galaxies CGCG 074-064 and NGC 4258, and assuming a fixed velocity uncertainty of 250 km s(-1) associated with peculiar motions, we constrain the Hubble constant to be H-0 = 73.9 +/- 3.0 km s(-1) Mpc(-1) independent of distance ladders and the cosmic microwave background. This best value relies solely on maser-based distance and velocity measurements, and it does not use any peculiar velocity corrections. Different approaches for correcting peculiar velocities do not modify H-0 by more than +/- 1 sigma, with the full range of best-fit Hubble constant values spanning 71.8-76.9 km s(-1) Mpc(-1). We corroborate prior indications that the local value of H-0 exceeds the early-universe value, with a confidence level varying from 95% to 99% for different treatments of the peculiar velocities.