Wednesday, November 07, 2012
4:00 PM -
5:00 PM
Cahill, Hameetman Auditorium
Astronomy Colloquium
Series: Astronomy Colloquium Series
The Mega-maser Cosmology Project
Fred Lo,
NRAO,
The Mega-maser Cosmology Project (MCP) aims to determine the Hubble Constant, Ho, to ~3 percent accuracy by measuring the angular diameter distance to "mega-maser galaxies" that harbor circum-nuclear Keplerian disks exhibiting powerful water maser emission. Under the MCP, mega-maser search using the GBT and mapping using the VLBA and GBT have now identified 10 mega-maser galaxies with distances ranging from 30 Mpc to 140 Mpc, well in the Hubble flow. A 10% angular diameter distance determination to NGC6264 at 150 Mpc has been demonstrated. A by-product of the MCP is precise mass determination of the supermassive black-holes (BH) in the mega-maser galaxies. The mega-maser BH mass results appear to be inconsistent with the putative M-sigma relationship between black holes and galactic bulges. The status of the MCP will be described.
Event Sponsors:
For more information, please contact Gina Armas by phone at 4671 or by email at [email protected] or visit http://www.astro.caltech.edu/~gma/colloquia.html.