2021-01-15 11:00  P5A-1

The Megamaser Cosmology Project: The final outcome and its implication for the Hubble tension problem

Cheng-Yu Kuo

In this talk, I will first discuss the science goals and methodology of the Megamaser Cosmology project and present our final measurement of the Hubble constant made using geometric distance measurements to six megamaser-hosting galaxies. This Hubble constant will then be compared the values obtained with the Type 1a supernovae (the SH0ES project), strong gravitational lensing systems (the H0LiCOW project) as well as observations of cosmic microwave background conducted by the Planck collaboration. This comparison will be followed by a discussion of possible causes of the current tension between the early and late universe Hubble constant measurements. In the end of the talk, I will explain how we could resolve the Hubble tension problem by making a 1% Hubble constant measurement using the megamaser technique and discuss the role of the next generation Very Large Array (ngVLA) in our efforts to achieve this goal.