发表机构
University of Oxford; University of Portsmouth（牛津大学; 朴茨茅斯大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
针对哈勃张力，本文用贝叶斯正向模型联合分析五个MCP星系脉泽数据，并考虑本动速度重建，得到$H_0=71.6\pm3.7$ km/s/Mpc，另对NGC 4258单独建模得到其距离。
AI 中文摘要
哈勃张力促使人们对支撑本地距离阶梯的红移无关距离进行仔细审查。水兆脉泽通过吸积盘中的轨道动力学提供了纯几何距离。针对兆脉泽宇宙学项目（MCP）六个星系中的五个，我们提出了一种贝叶斯正向模型，该模型从甚长基线干涉测量的准观测量（即脉泽斑点位置、速度和加速度）联合推断角直径距离和翘曲的开普勒盘参数。然后，我们利用这些距离和宿主星系红移来约束$H_0$，其中包括一个物理距离先验，对星系样本选择进行建模，并测试线性和非线性本动速度重建。考虑非线性Manticore重建的本动速度后，我们推断出$H_0 = 71.6 \pm 3.7$ km/s/Mpc，其中不确定性为统计性的。相对于忽略本动速度，线性和非线性重建分别使$H_0$降低$0.8$--$1.4$和$1.6$--$2.1$ km/s/Mpc，而改变选择变量则使其变化小于$1$ km/s/Mpc。我们单独分析了第六个星系NGC 4258。将其盘建模为偏心且二次翘曲的盘，我们推断出其角直径距离为$7.558 \pm 0.073$（统计）Mpc，与已发表的脉泽距离相差$0.13\sigma$。
英文摘要
The Hubble tension motivates careful scrutiny of the redshift-independent distances underpinning the local distance ladder. Water megamasers afford a purely geometric distance from orbital dynamics in an accretion disc. For five of the six Megamaser Cosmology Project (MCP) galaxies, we present a Bayesian forward model that infers the angular-diameter distance and warped Keplerian disc parameters jointly from the very long baseline interferometry quasi-observables: maser spot positions, velocities, and accelerations. We then constrain $H_0$ from these distances and the host redshifts, including a physical distance prior, modelling the galaxy sample selection and testing a linear and a non-linear peculiar-velocity reconstruction. Accounting for peculiar velocities with the non-linear Manticore reconstruction, we infer $H_0 = 71.6 \pm 3.7$ km/s/Mpc, where the uncertainty is statistical. Relative to ignoring peculiar velocities, the linear and non-linear reconstructions lower $H_0$ by $0.8$--$1.4$ and $1.6$--$2.1$ km/s/Mpc, respectively, whereas changing the selection variable alters it by less than $1$ km/s/Mpc. We analyse the sixth galaxy, NGC 4258, separately. Modelling its disc as eccentric and quadratically warped, we infer an angular-diameter distance of $7.558 \pm 0.073$ (stat.) Mpc, within $0.13σ$ of the published maser distance.
Comments19 pages, 5 figures. Submitted to OJA
