Events

Masers and Cosmology

Astrophysical water masers residing in the parsec-scale accretion disks around supermassive black holes in active galactic nuclei have proven to be remarkable tools that uniquely probe the geometry and kinematics of nuclear molecular gas, provide gold-standard masses of supermassive black holes, and allow us to determine geometric distances to galaxies in the Hubble flow.  These distance measurements are independent of standard candles, distance ladders, or the cosmic microwave background, and can thus be used to place independent constraints on the Hubble constant — i.e., the local expansion rate of the Universe.  In this talk, I will give an overview of the history of AGN disk maser observations and modeling, describe the role that they play in shaping our modern cosmological picture, and pose some thoughts about future prospects using high-frequency masers and next-generation radio facilities.

Monday, May 19, 2025 11:00 AM