Mega-maser Cosmology Project and NRAO

Colloquium: Astronomy Colloquia | February 7 | 4-5 p.m. | 1 LeConte Hall

Speaker/Performer: Fred Lo, NRAO

Sponsor: Department of Astronomy

Better measurements of Ho - the current expansion rate of the Universe, provide critical independent constraints on dark energy, spatial curvature of the Universe, neutrino physics, and validity of general relativity. The Mega-maser Cosmology Project (MCP) aims to determine the Hubble Constant at high accuracy by measuring the angular-diameter distance to galaxies in the Hubble Flow. A geometric measurement of the distance to a galaxy at 140 Mpc in one step, via micro-arc-second astrometry of its circum-nuclear mega-maser disk, has been demonstrated. The current status and future prospects of the MCP will be described. The MCP also enables accurate determination of the central black-hole mass in mega-maser galaxies. The large intrinsic scatter of BH masses in a narrow range of the velocity dispersion in the mega-maser galaxy bulges raise questions about the validity of the well-known M-sigma relation of BH mass and the spherical component of galaxies. Other key science projects at the NRAO, and Jansky VLA and ALMA early science results on high z galaxies and proto-planetary disks, will also be presented.

Event Contact: rhelgens@astro.berkeley.edu, 510-642-5275