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 $H_0 = 73.9 \pm 3.0$ 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 ${\pm}1σ$, 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 95-99% for different treatments of the peculiar velocities.
Water megamasers at 22 GHz with a gas disk configuration in galaxies provide the most precise measurements of supermassive black hole masses, as well as independent constraints on the Hubble constant in the nearby universe. The existence of other maser types, such as jet or outflow masers, represents another tracer for AGN science. However, the detection rate of water megamasers in galaxies is extremely low. Over 40 years, only $\sim$ 160 galaxies are found to harbour maser emission, and $\sim$ 30\% of them show features in their maser emission that indicate a disk-like geometry. Therefore, in…
The tip of the red giant branch has been used to measure distances to 500 nearby galaxies with the Hubble Space Telescope (HST) which are available in the Color-Magnitude Diagrams and Tip of the Red Giant Branch (CMDs/TRGB) catalog on the Extragalactic Distance Database (EDD). Our established methods are employed to perform an independent reduction of the targets presented by the Carnegie-Chicago Hubble Program (CCHP) in the series of papers culminating in Freedman (2021). Our distinct methodology involves modeling the observed luminosity function of red giant branch and asymptotic giant branc…
The mm-Wave Interferometric Survey of Dark Object Masses (WISDOM) is probing supermassive black holes (SMBHs) in galaxies across the Hubble sequence via molecular gas dynamics. We present the first WISDOM study of a luminous infrared galaxy with an active galactic nuclei (AGN): Fairall 49. We use new ALMA observations of the CO(2-1) line with a spatial resolution of about 80 pc together with ancillary HST imaging. We reach the following results: (1) The CO kinematics are well described by a regularly rotating gas disk with a radial inflow motion, suggesting weak feedback on the cold gas from b…
We present a measurement of the Hubble constant ($H_{0}$) and other cosmological parameters from a joint analysis of six gravitationally lensed quasars with measured time delays. All lenses except the first are analyzed blindly with respect to the cosmological parameters. In a flat $Λ$CDM cosmology, we find $H_{0} = 73.3_{-1.8}^{+1.7}$, a 2.4% precision measurement, in agreement with local measurements of $H_{0}$ from type Ia supernovae calibrated by the distance ladder, but in $3.1σ$ tension with $Planck$ observations of the cosmic microwave background (CMB). This method is completely indepen…
Cosmological redshift of a Schwarzschild-de Sitter black hole: Towards estimating the Hubble constant
Instituto de Física, Benemérita Universidad Autónoma de Puebla（普埃布拉自治大学物理研究所）；Facultad de Ciencias Físico-Matemáticas, Universidad Michoacana de San Nicolás de Hidalgo（圣尼古拉斯德伊达尔戈米乔阿坎大学理学院）
We present year-long, near-infrared Hubble Space Telescope WFC3 observations used to search for Mira variables in NGC 1559, the host galaxy of the Type Ia supernova (SN Ia) 2005df. This is the first dedicated search for Miras, highly-evolved low-mass stars, in a SN Ia host and subsequently the first calibration of the SN Ia luminosity using Miras in a role historically played by Cepheids. We identify a sample of 115 O-rich Miras with P < 400 days based on their light curve properties. We find that the scatter in the Mira Period-Luminosity Relation (PLR) is comparable to Cepheid PLRs seen in SN…
Redshift-binned constraints on the Hubble constant under $Λ$CDM, CPL, and Padé cosmography
Institute for Frontiers in Astronomy and Astrophysics, Beijing Normal University（北京师范大学前沿天文与天体物理研究所）；School of Physics and Astronomy, Beijing Normal University（北京师范大学物理与天文学院）；Institute for Astrophysics, School of Physics, Zhengzhou University（郑州大学物理学院天体物理研究所）
We present the lens mass model of the quadruply-imaged gravitationally lensed quasar WFI2033-4723, and perform a blind cosmographical analysis based on this system. Our analysis combines (1) time-delay measurements from 14 years of data obtained by the COSmological MOnitoring of GRAvItational Lenses (COSMOGRAIL) collaboration, (2) high-resolution $\textit{Hubble Space Telescope}$ imaging, (3) a measurement of the velocity dispersion of the lens galaxy based on ESO-MUSE data, and (4) multi-band, wide-field imaging and spectroscopy characterizing the lens environment. We account for all known so…
Planck intermediate results. XIII. Constraints on peculiar velocities
利用\Planck \资料，结合X射线探测星系团Meta星表（MCXC），我们通过寻找动力学Sunyaev-Zeldovich效应（kSZ）的证据来研究星系团的特殊运动.通过实施各种过滤器，旨在提取kSZ产生的集群的位置，我们得到一致的约束径向特有的速度平均值，均方根（rms），和当地的整体流量振幅在不同的深度。对于平均红移为0.18的整个星系团样品，测量到的相对于该红移处的宇宙微波背景（CMB）辐射的平均径向特有速度，即，kSZ的平均值等于$72 \pm 60$ km s $^{-1}$。相对于我们的本地CMB框架，这构成了不到1%的相对哈勃速度的集群样本。虽然在$z=0.15$上对典型星团径向速度rms的线性$Λ$ CDM预测接近230 km s $^{-1}$，但\Planck \数据对星团子样本施加的上限在95%置信水平下对应于800 km s $^{-1}$，即，大约高出三倍。\Planck \数据还对以本地群为中心的体积中的本地整体流量设置了强约束。有没有检测到的整体流量测量在任何共动领域延伸到最大的红移所涵盖的集群样本。在这个样本中的大规模流动的盲搜索有一个上限为254公里秒$^{-1}$（95%的置信水平）占主导地位的CMB混乱和仪器噪声，表明宇宙在很大程度上是均匀的Gpc尺度。在这种背景下，结合超新星观测，\Planck \能够排除一大类非均匀空洞模型作为暗能量或…
